J/Ψ resonant formation and mass measurement in antiproton-proton annihilations

NASA Astrophysics Data System (ADS)

Baglin, C.; Bassompierre, G.; Brient, J. C.; Broll, C.; Bussiere, A.; Guillaud, J. P.; Morch, C.; Poulet, M.; Baird, S.; Khan-Aronsen, E.; Leistam, L.; Lundby, A.; Mouellic, B.; Poole, J.; Buzzo, A.; Ferroni, S.; Gracco, V.; Macri', M.; Mattera, L.; Pia, M. G.; Pozzo, A.; Santroni, A.; Tomasini, F.; Valbusa, U.; Burq, J. P.; Chemarin, M.; Chevallier, M.; Fay, J.; Ille, B.; Lambert, M.; Bugge, L.; Buran, T.; Kirsebom, K.; Skjevling, G.; Stapnes, S.; Stugu, B.; Petrillo, L.; Severi, M.; Brom, J. M.; Escoubes, B.; Biino, C.; Borreani, G.; Cester, R.; Marchetto, F.; Menichetti, E.; Pastrone, N.; Rinaudo, G.

Experiment R704, the last to be performed at the CERN-ISR, has successfully applied a new method to study ( overlinecc ) states formed directly in antiproton-proton annihilations. The novelty of the method rests on the capability to build a highly performing annihilation source by letting a cold

Antiprotons

DOE R&D Accomplishments Database

Chamberlain, Owen; Segre, Emilio; Wiegand, Clyde

1955-11-29

Since the development of Dirac's theory of the electron and the brilliant confirmation of one of its most startling predictions by the discovery of the positron by Anderson, it has been assumed most likely that the proton would also have its charge conjugate, the antiproton. The properties that define the antiproton are: (a) charge equal to the electron charge (also in sign); (b) mass equal to the proton mass; (c) stability against spontaneous decay; (d) ability to annihilate by interaction with a proton or neutron, probably generating pions and releasing in some manner the energy 2 mc{sup 2}; (e) generation in pairs with ordinary nucleons; (f) magnetic moment equal but opposite to that of the proton; (g) fermion of spin 1/2. Not all these properties are independent, but all might ultimately be subjected to experiment.

Observation of Antiprotons

DOE R&D Accomplishments Database

Chamberlain, Owen; Segre, Emilio; Wiegand, Clyde; Ypsilantis, Thomas

1955-10-19

One of the striking features of Dirac's theory of the electron was the appearance of solutions to his equations which required the existence of an antiparticle, later identified as the positron. The extension of the Dirac theory to the proton requires the existence of an antiproton, a particle which bears to the proton the same relationship as the positron to the electron. However, until experimental proof of the existence of the antiproton was obtained, it might be questioned whether a proton is a Dirac particle in the same sense as is the electron. For instance, the anomalous magnetic moment of the proton indicates that the simple Dirac equation does not give a complete description of the proton.

Antiproton-proton annihilation into light neutral meson pairs within an effective meson theory

NASA Astrophysics Data System (ADS)

Wang, Ying; Bystritskiy, Yury M.; Ahmadov, Azad I.; Tomasi-Gustafsson, Egle

2017-08-01

Antiproton-proton annihilation into light neutral mesons in the few GeV energy domain is investigated in view of a global description of the existing data and predictions for future work at the Antiproton Annihilation at Darmstadt (PANDA) experiment at the Facility for Antiproton and Ion Research (FAIR). An effective meson model earlier developed, with mesonic and baryonic degrees of freedom in s , t , and u channels, is applied here to π0π0 production. Form factors with logarithmic s and t (u ) dependencies are applied. A fair agreement with the existing angular distributions is obtained. Applying SU(3) symmetry, it is straightforward to recover the angular distributions for π0η and η η production in the same energy range. A good agreement is generally obtained with all existing data.

Comparison of hadron production models for π±, k±, protons and antiprotons production in proton-carbon interactions at 60 GeV/c

NASA Astrophysics Data System (ADS)

Ajaz, M.; Ullah, S.; Ali, Y.; Younis, H.

2018-02-01

In this research paper, the comprehensive results on the double differential yield of π± and k± mesons, protons and antiprotons as a function of laboratory momentum are reported. These hadrons are produced in proton-carbon interaction at 60 GeV/c. EPOS 1.99, EPOS-LHC and QGSJETII-04 models are used to perform simulations. Comparing the predictions of these models show that QGSJETII-04 model predicts higher yields of all the hadrons in most of the cases at the peak of the distribution. In this interval, the EPOS 1.99 and EPOS-LHC produce similar results. In most of the cases at higher momentum of the hadrons, all the three models are in good agreement. For protons, all models are in good agreement. EPOS-LHC gives high yield of antiprotons at high momentum values as compared to the other two models. EPOS-LHC gives higher prediction at the peak value for π+ mesons and protons at higher polar angle intervals of 100 < 𝜃 < 420 and 100 < 𝜃 < 360, respectively, and EPOS 1.99 gives higher prediction at the peak value for π- mesons for 140 < 𝜃 < 420. The model predictions, except for antiprotons, are compared with the data obtained by the NA61/SHINE experiment at 31 GeV/c proton-carbon collision, which clearly shows that the behavior of the distributions in models are similar to the ones from the data but the yield in data is low because of lower beam energy.

Charm Production in Interactions of Antiproton with Proton and Nuclei at \\bar{it{P}}it{ANDA} Energies

NASA Astrophysics Data System (ADS)

Shyam, R.; Tsushima, K.

2018-05-01

We study the production of charmed baryons in the antiproton-proton and antiproton-nucleus interactions within a fully covariant model that is based on an effective Lagrangian approach. The baryon production proceeds via the t-channel D^0 and D^{*0} meson-exchange diagrams. We have also explored the production of the charm-baryon hypernucleus ^{16}_{Λ_c^+}O in the antiproton-^{16}O collisions. For antiproton beam momenta of interest to the {\\bar{P}}ANDA experiment, the 0° differential cross sections for the formation of ^{16}_{Λ_c^+}O hypernuclear states with simple particle-hole configurations, have magnitudes in the range of a few μ b/sr.

Antiproton-proton annihilation into charged light meson pairs within effective meson theory

NASA Astrophysics Data System (ADS)

Wang, Ying; Bystritskiy, Yury M.; Tomasi-Gustafsson, Egle

2017-04-01

We revisit antiproton-proton annihilation into light mesons in the energy domain relevant to the antiproton annihilation at Darmstadt (PANDA) experiment at the GSI Facility for Antiproton and Ion Research (FAIR) [2.25 (1.5 ) ≤√{s }(pL) ≤5.47 (15 ) GeV (GeV /c ) where √{s }(pL) is the total energy (the beam momentum in the laboratory frame)]. An effective meson model is developed, with mesonic and baryonic degrees of freedom. Form factors are added to take into account the composite nature of the interacting hadrons. A comparison is made with the existing data for charged pion pair production and predictions for angular distributions and energy dependence in the range 3.362 (5 ) ≤√{s }(pL) ≤4.559 (10.1 ) GeV (GeV /c ). The model is applied to π±p elastic scattering, using crossing symmetry, and to charged kaon pair production, on the basis of SU(3) symmetry. In all cases the results illustrate a nice agreement with the data.

From the elastica compass to the elastica catapult: an essay on the mechanics of soft robot arm

PubMed Central

Armanini, C.; Dal Corso, F.; Misseroni, D.

2017-01-01

An elastic rod is clamped at one end and has a dead load attached to the other (free) end. The rod is then slowly rotated using the clamp. When the load is smaller than the buckling value, the rod describes a continuous set of quasi-static forms and its end traces a (smooth, convex and simple) closed curve, which would be a circle if the rod were rigid. The closed curve is analytically determined through the integration of the Euler’s elastica, so that for sufficiently small loads the mechanical system behaves as an ‘elastica compass’. For loads higher than that of buckling, the elastica reaches a configuration from which a snap-back instability occurs, realizing a sort of ‘elastica catapult’. The whole quasi-static evolution leading to the critical configuration for snapping is calculated through the elastica and the subsequent dynamic motion simulated using two numerical procedures, one ad hoc developed and another based on a finite-element scheme. The theoretical results are then validated on a specially designed and built apparatus. An obvious application of the present model would be in the development of soft robotic limbs, but the results are also of interest for the optimization analysis in pole vaulting. PMID:28293144

From the elastica compass to the elastica catapult: an essay on the mechanics of soft robot arm.

PubMed

Armanini, C; Dal Corso, F; Misseroni, D; Bigoni, D

2017-02-01

An elastic rod is clamped at one end and has a dead load attached to the other (free) end. The rod is then slowly rotated using the clamp. When the load is smaller than the buckling value, the rod describes a continuous set of quasi-static forms and its end traces a (smooth, convex and simple) closed curve, which would be a circle if the rod were rigid. The closed curve is analytically determined through the integration of the Euler's elastica, so that for sufficiently small loads the mechanical system behaves as an 'elastica compass'. For loads higher than that of buckling, the elastica reaches a configuration from which a snap-back instability occurs, realizing a sort of 'elastica catapult'. The whole quasi-static evolution leading to the critical configuration for snapping is calculated through the elastica and the subsequent dynamic motion simulated using two numerical procedures, one ad hoc developed and another based on a finite-element scheme. The theoretical results are then validated on a specially designed and built apparatus. An obvious application of the present model would be in the development of soft robotic limbs, but the results are also of interest for the optimization analysis in pole vaulting.

Secondary antiproton production in relativistic plasmas

NASA Technical Reports Server (NTRS)

Dermer, C. D.; Ramaty, R.

1985-01-01

The possibility is investigated that the reported excess low energy antiproton component of the cosmic radiation results from proton-proton (p-p) interactions in relativistic plasmas. Because of both target and projectile motion in such plasmas, the antiproton production threshold in the frame of the plasma is much lower than the threshold of antiproton production in cosmic ray interactions with ambient matter. The spectrum of the resultant antiprotons therefore extends to much lower energy than in the cosmic ray case. The antiproton spectrum is calculated for relativistic thermal plasmas and the spectrum is estimated for relativistic nonthermal plasmas. As possible production sites, matter accreting onto compact objects located in the galaxy is considered. Possible overproduction of gamma rays from associated neutral pion production can be avoided if the site is optically thick to the photons but not to the antiprotons. A possible scenario involves a sufficiently large photon density that the neutral pion gamma rays are absorbed by photon-photon pair production. Escape of the antiprotons to the interstellar medium can be mediated by antineutron production.

Towards Polarized Antiprotons at FAIR

NASA Astrophysics Data System (ADS)

Rathmann, Frank

2007-06-01

Understanding the interplay of the nuclear interaction with polarized protons and the electromagnetic interaction with polarized electrons in polarized atoms is crucial to progress towards the PAX goal to eventually produce stored polarized antiproton beams at FAIR. Presently, there exist two competing theoretical scenarios: one with substantial spin filtering of (anti)protons by atomic electrons, and a second one suggesting a self-cancellation of the electron contribution to spin filtering. After a brief review of the PAX physics case for polarized antiprotons at FAIR, a detailed discussion of future investigations, including spin-filtering experiments at COSY-Jülich and at the AD of CERN is presented.

Scaling Properties of Proton and Antiproton Production in (sNN)=200 GeV Au+Au Collisions

NASA Astrophysics Data System (ADS)

Adler, S. S.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Alexander, J.; Amirikas, R.; Aphecetche, L.; Aronson, S. H.; Averbeck, R.; Awes, T. C.; Azmoun, R.; Babintsev, V.; Baldisseri, A.; Barish, K. N.; Barnes, P. D.; Bassalleck, B.; Bathe, S.; Batsouli, S.; Baublis, V.; Bazilevsky, A.; Belikov, S.; Berdnikov, Y.; Bhagavatula, S.; Boissevain, J. G.; Borel, H.; Borenstein, S.; Brooks, M. L.; Brown, D. S.; Bruner, N.; Bucher, D.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Burward-Hoy, J. M.; Butsyk, S.; Camard, X.; Chai, J.-S.; Chand, P.; Chang, W. C.; Chernichenko, S.; Chi, C. Y.; Chiba, J.; Chiu, M.; Choi, I. J.; Choi, J.; Choudhury, R. K.; Chujo, T.; Cianciolo, V.; Cobigo, Y.; Cole, B. A.; Constantin, P.; D'Enterria, D. G.; David, G.; Delagrange, H.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dietzsch, O.; Drapier, O.; Drees, A.; Du Rietz, R.; Durum, A.; Dutta, D.; Efremenko, Y. V.; El Chenawi, K.; Enokizono, A.; En'yo, H.; Esumi, S.; Ewell, L.; Fields, D. E.; Fleuret, F.; Fokin, S. L.; Fox, B. D.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fung, S.-Y.; Garpman, S.; Ghosh, T. K.; Glenn, A.; Gogiberidze, G.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, G.; Guryn, W.; Gustafsson, H.-Å.; Hachiya, T.; Haggerty, J. S.; Hamagaki, H.; Hansen, A. G.; Hartouni, E. P.; Harvey, M.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Heuser, J. M.; Hibino, M.; Hill, J. C.; Holzmann, W.; Homma, K.; Hong, B.; Hoover, A.; Ichihara, T.; Ikonnikov, V. V.; Imai, K.; Isenhower, L. D.; Ishihara, M.; Issah, M.; Isupov, A.; Jacak, B. V.; Jang, W. Y.; Jeong, Y.; Jia, J.; Jinnouchi, O.; Johnson, B. M.; Johnson, S. C.; Joo, K. S.; Jouan, D.; Kametani, S.; Kamihara, N.; Kang, J. H.; Kapoor, S. S.; Katou, K.; Kelly, S.; Khachaturov, B.; Khanzadeev, A.; Kikuchi, J.; Kim, D. H.; Kim, D. J.; Kim, D. W.; Kim, E.; Kim, G.-B.; Kim, H. J.; Kistenev, E.; Kiyomichi, A.; Kiyoyama, K.; Klein-Boesing, C.; Kobayashi, H.; Kochenda, L.; Kochetkov, V.; Koehler, D.; Kohama, T.; Kopytine, M.; Kotchetkov, D.; Kozlov, A.; Kroon, P. J.; Kuberg, C. H.; Kurita, K.; Kuroki, Y.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Ladygin, V.; Lajoie, J. G.; Lebedev, A.; Leckey, S.; Lee, D. M.; Lee, S.; Leitch, M. J.; Li, X. H.; Lim, H.; Litvinenko, A.; Liu, M. X.; Liu, Y.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Manko, V. I.; Mao, Y.; Martinez, G.; Marx, M. D.; Masui, H.; Matathias, F.; Matsumoto, T.; McGaughey, P. L.; Melnikov, E.; Messer, F.; Miake, Y.; Milan, J.; Miller, T. E.; Milov, A.; Mioduszewski, S.; Mischke, R. E.; Mishra, G. C.; Mitchell, J. T.; Mohanty, A. K.; Morrison, D. P.; Moss, J. M.; Mühlbacher, F.; Mukhopadhyay, D.; Muniruzzaman, M.; Murata, J.; Nagamiya, S.; Nagle, J. L.; Nakamura, T.; Nandi, B. K.; Nara, M.; Newby, J.; Nilsson, P.; Nyanin, A. S.; Nystrand, J.; O'Brien, E.; Ogilvie, C. A.; Ohnishi, H.; Ojha, I. D.; Okada, K.; Ono, M.; Onuchin, V.; Oskarsson, A.; Otterlund, I.; Oyama, K.; Ozawa, K.; Pal, D.; Palounek, A. P.; Pantuev, V. S.; Papavassiliou, V.; Park, J.; Parmar, A.; Pate, S. F.; Peitzmann, T.; Peng, J.-C.; Peresedov, V.; Pinkenburg, C.; Pisani, R. P.; Plasil, F.; Purschke, M. L.; Purwar, A.; Rak, J.; Ravinovich, I.; Read, K. F.; Reuter, M.; Reygers, K.; Riabov, V.; Riabov, Y.; Roche, G.; Romana, A.; Rosati, M.; Rosnet, P.; Ryu, S. S.; Sadler, M. E.; Saito, N.; Sakaguchi, T.; Sakai, M.; Sakai, S.; Samsonov, V.; Sanfratello, L.; Santo, R.; Sato, H. D.; Sato, S.; Sawada, S.; Schutz, Y.; Semenov, V.; Seto, R.; Shaw, M. R.; Shea, T. K.; Shibata, T.-A.; Shigaki, K.; Shiina, T.; Silva, C. L.; Silvermyr, D.; Sim, K. S.; Singh, C. P.; Singh, V.; Sivertz, M.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Staley, F.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Sullivan, J. P.; Takagui, E. M.; Taketani, A.; Tamai, M.; Tanaka, K. H.; Tanaka, Y.; Tanida, K.; Tannenbaum, M. J.; Tarján, P.; Tepe, J. D.; Thomas, T. L.; Tojo, J.; Torii, H.; Towell, R. S.; Tserruya, I.; Tsuruoka, H.; Tuli, S. K.; Tydesjö, H.; Tyurin, N.; van Hecke, H. W.; Velkovska, J.; Velkovsky, M.; Villatte, L.; Vinogradov, A. A.; Volkov, M. A.; Vznuzdaev, E.; Wang, X. R.; Watanabe, Y.; White, S. N.; Wohn, F. K.; Woody, C. L.; Xie, W.; Yang, Y.; Yanovich, A.; Yokkaichi, S.; Young, G. R.; Yushmanov, I. E.; Zajc, W. A.; Zhang, C.; Zhou, S.; Zolin, L.

2003-10-01

We report on the yield of protons and antiprotons, as a function of centrality and transverse momentum, in Au+Au collisions at (sNN)=200 GeV measured at midrapidity by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider. In central collisions at intermediate transverse momenta (1.5protons and antiprotons. They show a centrality-scaling behavior different from that of pions. The p¯/π and p/π ratios are enhanced compared to peripheral Au+Au, p+p, and e+e- collisions. This enhancement is limited to pT<5 GeV/c as deduced from the ratio of charged hadrons to π0 measured in the range 1.5

Bottom quark anti-quark production and mixing in proton anti-proton collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Zhaoou

2003-03-01

The studies of bottom quark-antiquark production in proton-antiproton collisions play an important role in testing perturbative QCD. Measuring the mixing parameter of B mesons imposes constraints on the quark mixing (CKM) matrix and enhances the understanding of the Standard Model. Multi-GeV pmore » $$\\bar{p}$$ colliders produce a significant amount of b$$\\bar{b}$$ pairs and thus enable studies in both of these fields. This thesis presents results of the b$$\\bar{b}$$ production cross section from p$$\\bar{p}$$ collisions at √s = 1.8 TeV and the time-integrated average B$$\\bar{B}$$ mixing parameter ($$\\bar{χ}$$) using highmass dimuon d a ta collected by CDF during its Run IB.« less

High-precision comparison of the antiproton-to-proton charge-to-mass ratio.

PubMed

Ulmer, S; Smorra, C; Mooser, A; Franke, K; Nagahama, H; Schneider, G; Higuchi, T; Van Gorp, S; Blaum, K; Matsuda, Y; Quint, W; Walz, J; Yamazaki, Y

2015-08-13

Invariance under the charge, parity, time-reversal (CPT) transformation is one of the fundamental symmetries of the standard model of particle physics. This CPT invariance implies that the fundamental properties of antiparticles and their matter-conjugates are identical, apart from signs. There is a deep link between CPT invariance and Lorentz symmetry--that is, the laws of nature seem to be invariant under the symmetry transformation of spacetime--although it is model dependent. A number of high-precision CPT and Lorentz invariance tests--using a co-magnetometer, a torsion pendulum and a maser, among others--have been performed, but only a few direct high-precision CPT tests that compare the fundamental properties of matter and antimatter are available. Here we report high-precision cyclotron frequency comparisons of a single antiproton and a negatively charged hydrogen ion (H(-)) carried out in a Penning trap system. From 13,000 frequency measurements we compare the charge-to-mass ratio for the antiproton (q/m)p- to that for the proton (q/m)p and obtain (q/m)p-/(q/m)p − 1 =1(69) × 10(-12). The measurements were performed at cyclotron frequencies of 29.6 megahertz, so our result shows that the CPT theorem holds at the atto-electronvolt scale. Our precision of 69 parts per trillion exceeds the energy resolution of previous antiproton-to-proton mass comparisons as well as the respective figure of merit of the standard model extension by a factor of four. In addition, we give a limit on sidereal variations in the measured ratio of <720 parts per trillion. By following the arguments of ref. 11, our result can be interpreted as a stringent test of the weak equivalence principle of general relativity using baryonic antimatter, and it sets a new limit on the gravitational anomaly parameter of |α − 1| < 8.7 × 10(-7).

Experiments on Antiprotons: Antiproton-Nucleon Cross Sections

DOE R&D Accomplishments Database

Chamberlain, Owen; Keller, Donald V.; Mermond, Ronald; Segre, Emilio; Steiner, Herbert M.; Ypsilantis, Tom

1957-07-22

In this paper experiments are reported on annihilation and scattering of antiprotons in H{sub 2}O , D{sub 2}O, and O{sub 2}. From the data measured it is possible to obtain an antiproton-proton and an antiproton-deuteron cross section at 457 Mev (lab). Further analysis gives the p-p and p-n cross sections as 104 mb for the p-p reaction cross section and 113 mb for the p-n reaction cross section. The respective annihilation cross sections are 89 and 74 mb. The Glauber correction necessary in order to pass from the p-d to the p-n cross section by subtraction of the p-p cross section is unfortunately large and somewhat uncertain. The data are compared with the p-p and p-n cross sections and with other results on p-p collisions.

Hadron Physics with Antiprotons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiedner, Ulrich

2005-10-26

The new FAIR facility which comes into operation at GSI in the upcoming years has a dedicated program of utilizing antiprotons for hadron physics. In particular, the planned PANDA experiment belongs to the group of core experiments at the new FAIR facility in Darmstadt/Germany. PANDA will be a universal detector to study the strong interaction by utilizing the annihilation process of antiprotons with protons and nuclear matter. The current paper gives an introduction into the hadron physics with antiprotons and part of the planned physics program with PANDA.

Numerical simulations of an elastica pendulum

NASA Astrophysics Data System (ADS)

Sinclair, R.

Folklore would have it that a massless clamped-free elastica undergoing planar motion with a point end mass possesses periodic solutions corresponding to a single mode of oscillation. We present a battery of numerical simulations leading to the single conclusion that these supposed periodic solutions do not exist, due to a strong nonlinear coupling of two modes, the frequency of one of which is apparently inversely proportional to the magnitude of the force acting on the elastica.

Comparison of different hadron production models for the study of π±, K±, protons and antiprotons production in proton-carbon interactions at 90 GeV/c

NASA Astrophysics Data System (ADS)

Ajaz, M.; Ali, Y.; Ullah, S.; Ali, Q.; Tabassam, U.

2018-05-01

In this research paper, comprehensive results on the double differential yield of π± and K± mesons, protons and antiprotons as a function of laboratory momentum in several polar angle ranges from 0-420 mrad for pions, 0-360 mrad for kaons, proton and antiproton are reported. EPOS 1.99, EPOS-LHC and QGSJETII-04 models are used to perform simulations. The predictions of these models at 90 GeV/c are plotted for comparison, which shows that QGSJETII-04 model gives overall higher yield for π+ mesons in the polar angle interval of 0-40 mrad but for the π‑ the yield is higher only up to 20 mrad. For π+ mesons after 40 mrad, EPOS-LHC predicts higher yield as compared to EPOS 1.99 and QGSJETII-04 while EPOS-LHC and EPOS 1.99 give similar behavior in these two intervals. However, for π‑ mesons EPOS-LHC and EPOS 1.99 give similar behavior in these two intervals. For of K± mesons, QGSJETII-04 model gives higher predictions in all cases from 0-300 mrad, while EPOS 1.99 and EPOS-LHC show similar distributions. In case of protons, all models give similar distribution but this is not true for antiproton. All models are in good agreement for p > 20 GeV/c. EPOS 1.99 produce lower yield compared to the other two models from 60-360 mrad polar angle interval.

Evidence For The Production Of Slow Antiprotonic Hydrogen In Vacuum

NASA Astrophysics Data System (ADS)

Zurlo, N.; Amoretti, M.; Amsler, C.; Bonomi, G.; Carraro, C.; Cesar, C. L.; Charlton, M.; Doser, M.; Fontana, A.; Funakoshi, R.; Genova, P.; Hayano, R. S.; Jørgensen, L. V.; Kellerbauer, A.; Lagomarsino, V.; Landua, R.; Rizzini, E. Lodi; Macrì, M.; Madsen, N.; Manuzio, G.; Mitchard, D.; Montagna, P.; Posada, L. G.; Pruys, H.; Regenfus, C.; Rotondi, A.; Testera, G.; der Werf, D. P. Van; Variola, A.; Venturelli, L.; Yamazaki, Y.

2006-10-01

We present evidence showing how antiprotonic hydrogen, the quasistable antiproton (p¯)-proton bound system, has been synthesized following the interaction of antiprotons with the molecular ion H2+ in a nested Penning trap environment. From a careful analysis of the spatial distributions of antiproton annihilation events, evidence is presented for antiprotonic hydrogen production with sub-eV kinetic energies in states around n=70, and with low angular momenta. The slow antiprotonic hydrogen may be studied using laser spectroscopic techniques.

Rapidity dependence of antiproton-to-proton ratios in Au+Au collisions at square root of (sNN) = 130 GeV.

PubMed

Bearden, I G; Beavis, D; Besliu, C; Blyakhman, Y; Brzychczyk, J; Budick, B; Bøggild, H; Chasman, C; Christensen, C H; Christiansen, P; Cibor, J; Debbe, R; Gaardhøje, J J; Grotowski, K; Hagel, K; Hansen, O; Holm, A; Holme, A K; Ito, H; Jakobsen, E; Jipa, A; Jørdre, J I; Jundt, F; Jørgensen, C E; Keutgen, T; Kim, E J; Kozik, T; Larsen, T M; Lee, J H; Lee, Y K; Løvhøiden, G L; Majka, Z; Makeev, A; McBreen, B; Murray, M; Natowitz, J; Nielsen, B S; Olchanski, K; Olness, J; Ouerdane, D; Planeta, R; Rami, F; Röhrich, D; Samset, B H; Sanders, S J; Sheetz, R A; Sosin, Z; Staszel, P; Thorsteinsen, T F; Tveter, T S; Videbaek, F; Wada, R; Wieloch, A; Zgura, I S

2001-09-10

Measurements, with the BRAHMS detector, of the antiproton-to-proton ratio at midrapidities and forward rapidities, are presented for Au+Au reactions at square root of [s(NN)] = 130 GeV, and for three different collision centralities. For collisions in the 0%-40% centrality range, we find N(&pmacr;)/N(p) = 0.64+/-0.04((stat))+/-0.06((syst)) at y approximately 0, 0.66+/-0.03+/-0.06 at y approximately 0.7, and 0.41+/-0.04+/-0.06 at y approximately 2. The ratios are found to be nearly independent of collision centrality and transverse momentum. The antiproton and proton rapidity densities vary differently with rapidity, and indicate a significant degree of collision transparency, although a net-baryon free midrapidity plateau (Bjorken limit) is not yet reached.

Laser-driven ultrafast antiproton beam

NASA Astrophysics Data System (ADS)

Li, Shun; Pei, Zhikun; Shen, Baifei; Xu, Jiancai; Zhang, Lingang; Zhang, Xiaomei; Xu, Tongjun; Yu, Yong; Bu, Zhigang

2018-02-01

Antiproton beam generation is investigated based on the ultra-intense femtosecond laser pulse by using two-dimensional particle-in-cell and Geant4 simulations. A high-flux proton beam with an energy of tens of GeV is generated in sequential radiation pressure and bubble regime and then shoots into a high-Z target for producing antiprotons. Both yield and energy of the antiproton beam increase almost linearly with the laser intensity. The generated antiproton beam has a short pulse duration of about 5 ps and its flux reaches 2 × 10 20 s - 1 at the laser intensity of 2.14 × 10 23 W / cm 2 . Compared to conventional methods, this new method based on the ultra-intense laser pulse is able to provide a compact, tunable, and ultrafast antiproton source, which is potentially useful for quark-gluon plasma study, all-optical antihydrogen generation, and so on.

A comparison of proton, antiproton and meson distributions in final states of deep inelastic muon scattering

NASA Astrophysics Data System (ADS)

Aubert, J. J.; Bassompierre, G.; Becks, K. H.; Benchouk, C.; Best, C.; Böhm, E.; de Bouard, X.; Brasse, F. W.; Broll, C.; Brown, S.; Carr, J.; Clifft, R. W.; Cobb, J. H.; Coignet, G.; Combley, F.; Court, G. R.; D'Agostini, G.; Dau, W. D.; Davies, J. K.; Déclais, Y.; Dosselli, U.; Drees, J.; Edwards, A.; Edwards, M.; Favier, J.; Ferrero, M. I.; Flauger, W.; Forsbach, H.; Gabathuler, E.; Gamet, R.; Gayler, J.; Gerhardt, V.; Gössling, C.; Haas, J.; Hamacher, K.; Hayman, P.; Henckes, M.; Korbel, V.; Landgraf, U.; Leenen, M.; Maire, M.; Minssieux, H.; Mohr, W.; Montgomery, H. E.; Moser, K.; Mount, R. P.; Nagy, E.; Nassalski, J.; Norton, P. R.; McNicholas, J.; Osborne, A. M.; Payre, P.; Peroni, C.; Pessard, H.; Pietrzyk, U.; Rith, K.; Schneegans, M.; Sloan, T.; Stier, H. E.; Stockhausen, W.; Thenard, J. M.; Thompson, J. C.; Urban, L.; Villers, M.; Wahlen, H.; Whalley, M.; Williams, D.; Williams, W. S. C.; Williamson, J.; Wimpenny, S. J.; European Muon Collaboration

1984-02-01

New results on the forward produced protons and antiprotons in high energy muon-nucleon scattering are presented. Their W2, z and p2T dependences are compared with those of the other charged hadrons. Significant differences are observed which can be related to the flavour content of the target and to a difference between the baryon content of quark and gluon jets.

Cosmic ray antiprotons in closed galaxy model

NASA Technical Reports Server (NTRS)

Protheroe, R.

1981-01-01

The flux of secondary antiprotons expected for the leaky-box model was calculated as well as that for the closed galaxy model of Peters and Westergard (1977). The antiproton/proton ratio observed at several GeV is a factor of 4 higher than the prediction for the leaky-box model but is consistent with that predicted for the closed galaxy model. New low energy data is not consistent with either model. The possibility of a primary antiproton component is discussed.

Production of charmed pseudoscalar mesons in antiproton-proton annihilation

NASA Astrophysics Data System (ADS)

Haidenbauer, J.; Krein, G.

2014-06-01

We study the production of charmed mesons (D, Ds) in antiproton-proton (p ¯p) annihilation close to the reaction thresholds. The elementary charm production process is described by baryon exchange and in the constituent quark model. Effects of the interactions in the initial and final states are taken into account rigorously. The calculations are performed in close analogy to our earlier study on p ¯p→K ¯K by connecting the processes via SU(4) flavor symmetry. Our predictions for the DD ¯ production cross section are in the order of 10-2-10-1 μb. They turned out to be comparable to those obtained in other studies. The cross section for a Ds+Ds- pair is found to be of the same order of magnitude despite the fact that its production in p ¯p scattering requires a two-step process.

Formation of the χ1 and χ2 charmonium resonances in antiproton-proton annihilation and measurements of their masses and total widths

NASA Astrophysics Data System (ADS)

Baglin, C.; Baird, S.; Bassompierre, G.; Borreani, G.; Brient, J.-C.; Broll, C.; Brom, J.-M.; Bugge, L.; Buran, T.; Bruq, J.-P.; Bussière, A.; Buzzo, A.; Cester, R.; Chemarin, M.; Chevallier, M.; Escoubes, B.; Fay, J.; Ferroni, S.; Gracco, V.; Guillaud, J.-P.; Khan-Aronsen, E.; Kirsebom, K.; Kylling, A.; Ille, B.; Lambert, M.; Leistam, L.; Lundby, A.; Macri, M.; Marchetto, F.; Menichetti, E.; Mörch, Ch.; Mouellic, B.; Olsen, D.; Pastrone, N.; Petrillo, L.; Pia, M. G.; Poole, J.; Poulet, M.; Rinaudo, G.; Santroni, A.; Severi, M.; Skjevling, G.; Stugu, B.

1986-05-01

In an experiment performed at the CERN-ISR the direct formation is observed of the χ1 and χ2 charmonium states in proton-antiproton annihiliation. A novel technique provided excellent energy resolution together with small background and reduced systematics. The following values for the masses and total widths of the states were obtained: Λχ1 <3 MeV (95% CL); mχ1 = (3511.3+/-0.4+/-0.4) MeV; Λχ2=(2.6 +1.4-1.0) MeV; mξ2=(3556.9+/-0.4+/-0.5) MeV. First measurements of the partial widths to antiproton-proton are also reported: Λ(χ1-->pp)=57+13-11+/-11) and Λ(χ2-->pp)=(233 +51-45+/-48) eV.

Commissioning of the ECR ion source of the high intensity proton injector of the Facility for Antiproton and Ion Research (FAIR)

NASA Astrophysics Data System (ADS)

Tuske, O.; Chauvin, N.; Delferriere, O.; Fils, J.; Gauthier, Y.

2018-05-01

The CEA at Saclay is in charge of developing and building the ion source and the low energy line of the proton linac of the FAIR (Facility for Antiproton and Ion Research) accelerator complex located at GSI (Darmstadt) in Germany. The FAIR facility will deliver stable and rare isotope beams covering a huge range of intensities and beam energies for experiments in the fields of atomic physics, plasma physics, nuclear physics, hadron physics, nuclear matter physics, material physics, and biophysics. A significant part of the experimental program at FAIR is dedicated to antiproton physics that requires an ultimate number 7 × 1010 cooled pbar/h. The high-intensity proton beam that is necessary for antiproton production will be delivered by a dedicated 75 mA/70 MeV proton linac. A 2.45 GHz microwave ion source will deliver a 100 mA H+ beam pulsed at 4 Hz with an energy of 95 keV. A 2 solenoids low energy beam transport line allows the injection of the proton beam into the radio frequency quadrupole (RFQ) within an acceptance of 0.3π mm mrad (norm. rms). An electrostatic chopper system located between the second solenoid and the RFQ is used to cut the beam macro-pulse from the source to inject 36 μs long beam pulses into the RFQ. At present time, a Ladder-RFQ is under construction at the University of Frankfurt. This article reports the first beam measurements obtained since mid of 2016. Proton beams have been extracted from the ECR ion source and analyzed just after the extraction column on a dedicated diagnostic chamber. Emittance measurements as well as extracted current and species proportion analysis have been performed in different configurations of ion source parameters, such as magnetic field profile, radio frequency power, gas injection, and puller electrode voltage.

Balance de carbono en un bosque novedoso de Castilla elastica: resultados preliminares

Treesearch

Ariel E. Lugo; Jessica Fonseca da Silva; Alejandra María Sáez Uribe

2008-01-01

During June 17 and 18, 2008, a Castilla elastica forest located in El Tallonal, municipality of Arecibo, functioned as a carbon sink. The net photosynthetic rate ranged from 14.28 (native species) and 21.96 (C. elastica) g C m-1 day-1 and respiration of leaves, stems, and soil varied from 13.76 (native species) and 16.88 (C. elastica) g C m-1 day-1. The net...

Recent progress of laser spectroscopy experiments on antiprotonic helium

NASA Astrophysics Data System (ADS)

Hori, Masaki

2018-03-01

The Atomic Spectroscopy and Collisions Using Slow Antiprotons (ASACUSA) collaboration is currently carrying out laser spectroscopy experiments on antiprotonic helium ? atoms at CERN's Antiproton Decelerator facility. Two-photon spectroscopic techniques have been employed to reduce the Doppler width of the measured ? resonance lines, and determine the atomic transition frequencies to a fractional precision of 2.3-5 parts in 109. More recently, single-photon spectroscopy of buffer-gas cooled ? has reached a similar precision. By comparing the results with three-body quantum electrodynamics calculations, the antiproton-to-electron mass ratio was determined as ?, which agrees with the known proton-to-electron mass ratio with a precision of 8×10-10. The high-quality antiproton beam provided by the future Extra Low Energy Antiproton Ring (ELENA) facility should enable further improvements in the experimental precision. This article is part of the Theo Murphy meeting issue `Antiproton physics in the ELENA era'.

Antiproton acceleration in the Fermilab Main Ring and Tevatron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, P.; Dinkel, J.; Ducar, R.

1987-03-01

The operation of the Fermilab Main Ring and Tevatron rf systems for colliding beams physics is discussed. The changes in the rf feedback system required for the accelration of antiprotons, and the methods for achieving proper transfer of both protons and antiprotons are described. Data on acceleration and transfer efficiencies are presented.

RF Stabilization for Storage of Antiprotons

NASA Technical Reports Server (NTRS)

Pearson, J. Boise; Lewis, Raymond A.

2005-01-01

Portable storage of antimatter is an important step in the experimental exploration of antimatter in propulsion applications. The High Performance Antiproton Trap (HiPAT) at NASA Marshall Space Flight Center is a Penning-Malmberg ion trap being developed to trap and store low energy antiprotons for a period of weeks. The antiprotons can then be transported for use in experiments. HiPAT is being developed and evaluated using normal matter, before an attempt is made to store and transport antiprotons. Stortd ions have inherent instabilities that limit the storage lifetime. RF stabilization at cyclotron resonance frequencies is demonstrated over a period of 6 days for normal matter ion clouds. A variety of particles have been stored, including protons, C+ ions, and H2+ ions. Cyclotron resonance frequencies are defined and experimental evidence presented to demonstrate excitation of cyclotron waves in the plasma for all three species of ions.

Rapidity dependence of anti-proton production in relativistic heavy ion collisions at 14.6 GeV/c per nucleon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rothschild, P.J.

1993-04-01

Experiment E859 at Brookhaven National Laboratory is an extension of experiment E802, using additional tracking chambers and a new second-level trigger to provide on-line particle identification, thereby providing better event selection and allowing higher beam intensities to be used. The anti-proton measurements made by E802 have been extended to lower rapidities and the statistics in the y-pt regions already studied have been improved by approximately an order of magnitude. The authors present dn/dy distributions and cross-sections for antiproton production in the rapidity range 0.6 < y < 1.7, for 14.6 GeV/c Si beams on Al and Au targets. In addition,more » anti-lambda production will be discussed.« less

Multiplicity dependence of charged pion, kaon, and (anti)proton production at large transverse momentum in p-Pb collisions at √{sNN} = 5.02 TeV

NASA Astrophysics Data System (ADS)

Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, S.; Ahn, S. U.; Aiola, S.; Akindinov, A.; Alam, S. N.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Almaraz, J. R. M.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andronic, A.; Anguelov, V.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Arnaldi, R.; Arnold, O. W.; Arsene, I. C.; Arslandok, M.; Audurier, B.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Balasubramanian, S.; Baldisseri, A.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Barth, K.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bello Martinez, H.; Bellwied, R.; Belmont, R.; Belmont-Moreno, E.; Belyaev, V.; Benacek, P.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biro, G.; Biswas, R.; Biswas, S.; Bjelogrlic, S.; Blair, J. T.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Bossú, F.; Botta, E.; Bourjau, C.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Butt, J. B.; Buxton, J. T.; Caffarri, D.; Cai, X.; Caines, H.; Calero Diaz, L.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Carena, F.; Carena, W.; Carnesecchi, F.; Castillo Castellanos, J.; Castro, A. J.; Casula, E. A. R.; Ceballos Sanchez, C.; Cerello, P.; Cerkala, J.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chauvin, A.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Cho, S.; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa Del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortés Maldonado, I.; Cortese, P.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danisch, M. C.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; de, S.; de Caro, A.; de Cataldo, G.; de Conti, C.; de Cuveland, J.; de Falco, A.; de Gruttola, D.; De Marco, N.; de Pasquale, S.; Deisting, A.; Deloff, A.; Dénes, E.; Deplano, C.; Dhankher, P.; di Bari, D.; di Mauro, A.; di Nezza, P.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Drozhzhova, T.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Endress, E.; Engel, H.; Epple, E.; Erazmus, B.; Erdemir, I.; Erhardt, F.; Espagnon, B.; Estienne, M.; Esumi, S.; Eum, J.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabbietti, L.; Fabris, D.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Feuillard, V. J. G.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Fleck, M. G.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fronze, G. G.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Gasik, P.; Gauger, E. F.; Germain, M.; Gheata, A.; Gheata, M.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Gladysz-Dziadus, E.; Glässel, P.; Goméz Coral, D. M.; Gomez Ramirez, A.; Gonzalez, V.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Grachov, O. A.; Graczykowski, L. K.; Graham, K. L.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Gronefeld, J. M.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gunji, T.; Gupta, A.; Gupta, R.; Haake, R.; Haaland, Ø.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hamon, J. C.; Harris, J. W.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Hess, B. A.; Hetland, K. F.; Hillemanns, H.; Hippolyte, B.; Horak, D.; Hosokawa, R.; Hristov, P.; Huang, M.; Humanic, T. J.; Hussain, N.; Hussain, T.; Hutter, D.; Hwang, D. S.; Ilkaev, R.; Inaba, M.; Incani, E.; Ippolitov, M.; Irfan, M.; Ivanov, M.; Ivanov, V.; Izucheev, V.; Jacazio, N.; Jacobs, P. M.; Jadhav, M. B.; Jadlovska, S.; Jadlovsky, J.; Jahnke, C.; Jakubowska, M. J.; Jang, H. J.; Janik, M. A.; Jayarathna, P. H. S. Y.; Jena, C.; Jena, S.; Jimenez Bustamante, R. T.; Jones, P. G.; Jusko, A.; Kalinak, P.; Kalweit, A.; Kamin, J.; Kang, J. H.; Kaplin, V.; Kar, S.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karayan, L.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keijdener, D. L. D.; Keil, M.; Mohisin Khan, M.; Khan, P.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, D. W.; Kim, D. J.; Kim, D.; Kim, H.; Kim, J. S.; Kim, M.; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, C.; Klein, J.; Klein-Bösing, C.; Klewin, S.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobdaj, C.; Kofarago, M.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Kondratyuk, E.; Konevskikh, A.; Kopcik, M.; Kostarakis, P.; Kour, M.; Kouzinopoulos, C.; Kovalenko, O.; Kovalenko, V.; Kowalski, M.; Koyithatta Meethaleveedu, G.; Králik, I.; Kravčáková, A.; Kretz, M.; Krivda, M.; Krizek, F.; Kryshen, E.; Krzewicki, M.; Kubera, A. M.; Kučera, V.; Kuhn, C.; Kuijer, P. G.; Kumar, A.; Kumar, J.; Kumar, L.; Kumar, S.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kweon, M. J.; Kwon, Y.; La Pointe, S. L.; La Rocca, P.; Ladron de Guevara, P.; Lagana Fernandes, C.; Lakomov, I.; Langoy, R.; Lara, C.; Lardeux, A.; Lattuca, A.; Laudi, E.; Lea, R.; Leardini, L.; Lee, G. R.; Lee, S.; Lehas, F.; Lemmon, R. C.; Lenti, V.; Leogrande, E.; León Monzón, I.; León Vargas, H.; Leoncino, M.; Lévai, P.; Li, S.; Li, X.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Ljunggren, H. M.; Lodato, D. F.; Loenne, P. I.; Loginov, V.; Loizides, C.; Lopez, X.; López Torres, E.; Lowe, A.; Luettig, P.; Lunardon, M.; Luparello, G.; Lutz, T. H.; Maevskaya, A.; Mager, M.; Mahajan, S.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manko, V.; Manso, F.; Manzari, V.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Margutti, J.; Marín, A.; Markert, C.; Marquard, M.; Martin, N. A.; Martin Blanco, J.; Martinengo, P.; Martínez, M. I.; Martínez García, G.; Martinez Pedreira, M.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Massacrier, L.; Mastroserio, A.; Matyja, A.; Mayer, C.; Mazer, J.; Mazzoni, M. A.; McDonald, D.; Meddi, F.; Melikyan, Y.; Menchaca-Rocha, A.; Meninno, E.; Mercado Pérez, J.; Meres, M.; Miake, Y.; Mieskolainen, M. M.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Minervini, L. M.; Mischke, A.; Mishra, A. N.; Miśkowiec, D.; Mitra, J.; Mitu, C. M.; Mohammadi, N.; Mohanty, B.; Molnar, L.; Montaño Zetina, L.; Montes, E.; Moreira de Godoy, D. A.; Moreno, L. A. P.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Mühlheim, D.; Muhuri, S.; Mukherjee, M.; Mulligan, J. D.; Munhoz, M. G.; Munzer, R. H.; Murakami, H.; Murray, S.; Musa, L.; Musinsky, J.; Naik, B.; Nair, R.; Nandi, B. K.; Nania, R.; Nappi, E.; Naru, M. U.; Natal da Luz, H.; Nattrass, C.; Navarro, S. R.; Nayak, K.; Nayak, R.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Nellen, L.; Ng, F.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Noferini, F.; Nomokonov, P.; Nooren, G.; Noris, J. C. C.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Oh, S. K.; Ohlson, A.; Okatan, A.; Okubo, T.; Olah, L.; Oleniacz, J.; Oliveira da Silva, A. C.; Oliver, M. H.; Onderwaater, J.; Oppedisano, C.; Orava, R.; Ortiz Velasquez, A.; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Ozdemir, M.; Pachmayer, Y.; Pagano, P.; Paić, G.; Pal, S. K.; Pan, J.; Pandey, A. K.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, W. J.; Parmar, S.; Passfeld, A.; Paticchio, V.; Patra, R. N.; Paul, B.; Pei, H.; Peitzmann, T.; Pereira da Costa, H.; Peresunko, D.; Pérez Lara, C. E.; Perez Lezama, E.; Peskov, V.; Pestov, Y.; Petráček, V.; Petrov, V.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pimentel, L. O. D. L.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Płoskoń, M.; Planinic, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L. M.; Poghosyan, M. G.; Polichtchouk, B.; Poljak, N.; Poonsawat, W.; Pop, A.; Porteboeuf-Houssais, S.; Porter, J.; Pospisil, J.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Rami, F.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rascanu, B. T.; Rathee, D.; Read, K. F.; Redlich, K.; Reed, R. J.; Rehman, A.; Reichelt, P.; Reidt, F.; Ren, X.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Revol, J.-P.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Ristea, C.; Rocco, E.; Rodríguez Cahuantzi, M.; Rodriguez Manso, A.; Røed, K.; Rogochaya, E.; Rohr, D.; Röhrich, D.; Romita, R.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Rubio Montero, A. J.; Rui, R.; Russo, R.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Sadovsky, S.; Šafařík, K.; Sahlmuller, B.; Sahoo, P.; Sahoo, R.; Sahoo, S.; Sahu, P. K.; Saini, J.; Sakai, S.; Saleh, M. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Šándor, L.; Sandoval, A.; Sano, M.; Sarkar, D.; Sarma, P.; Scapparone, E.; Scarlassara, F.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schuchmann, S.; Schukraft, J.; Schulc, M.; Schuster, T.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Šefčík, M.; Seger, J. E.; Sekiguchi, Y.; Sekihata, D.; Selyuzhenkov, I.; Senosi, K.; Senyukov, S.; Serradilla, E.; Sevcenco, A.; Shabanov, A.; Shabetai, A.; Shadura, O.; Shahoyan, R.; Shahzad, M. I.; Shangaraev, A.; Sharma, A.; Sharma, M.; Sharma, M.; Sharma, N.; Shigaki, K.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Sielewicz, K. M.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Simonetti, G.; Singaraju, R.; Singh, R.; Singha, S.; Singhal, V.; Sinha, B. C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Slupecki, M.; Smirnov, N.; Snellings, R. J. M.; Snellman, T. W.; Søgaard, C.; Song, J.; Song, M.; Song, Z.; Soramel, F.; Sorensen, S.; de Souza, R. D.; Sozzi, F.; Spacek, M.; Spiriti, E.; Sputowska, I.; Spyropoulou-Stassinaki, M.; Stachel, J.; Stan, I.; Stankus, P.; Stefanek, G.; Stenlund, E.; Steyn, G.; Stiller, J. H.; Stocco, D.; Strmen, P.; Suaide, A. A. P.; Sugitate, T.; Suire, C.; Suleymanov, M.; Suljic, M.; Sultanov, R.; Šumbera, M.; Szabo, A.; Szanto de Toledo, A.; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Tabassam, U.; Takahashi, J.; Tambave, G. J.; Tanaka, N.; Tangaro, M. A.; Tarhini, M.; Tariq, M.; Tarzila, M. G.; Tauro, A.; Tejeda Muñoz, G.; Telesca, A.; Terasaki, K.; Terrevoli, C.; Teyssier, B.; Thäder, J.; Thomas, D.; Tieulent, R.; Timmins, A. R.; Toia, A.; Trogolo, S.; Trombetta, G.; Trubnikov, V.; Trzaska, W. H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ullaland, K.; Uras, A.; Usai, G. L.; Utrobicic, A.; Vajzer, M.; Vala, M.; Valencia Palomo, L.; Vallero, S.; van der Maarel, J.; van Hoorne, J. W.; van Leeuwen, M.; Vanat, T.; Vande Vyvre, P.; Varga, D.; Vargas, A.; Vargyas, M.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vauthier, A.; Vechernin, V.; Veen, A. M.; Veldhoen, M.; Velure, A.; Venaruzzo, M.; Vercellin, E.; Vergara Limón, S.; Vernet, R.; Verweij, M.; Vickovic, L.; Viesti, G.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Villatoro Tello, A.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Vislavicius, V.; Viyogi, Y. P.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; von Haller, B.; Vorobyev, I.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Wagner, B.; Wagner, J.; Wang, H.; Wang, M.; Watanabe, D.; Watanabe, Y.; Weber, M.; Weber, S. G.; Weiser, D. F.; Wessels, J. P.; Westerhoff, U.; Whitehead, A. M.; Wiechula, J.; Wikne, J.; Wilk, G.; Wilkinson, J.; Williams, M. C. S.; Windelband, B.; Winn, M.; Yang, H.; Yang, P.; Yano, S.; Yasin, Z.; Yin, Z.; Yokoyama, H.; Yoo, I.-K.; Yoon, J. H.; Yurchenko, V.; Yushmanov, I.; Zaborowska, A.; Zaccolo, V.; Zaman, A.; Zampolli, C.; Zanoli, H. J. C.; Zaporozhets, S.; Zardoshti, N.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zgura, I. S.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhang, C.; Zhang, Z.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, Y.; Zhou, Z.; Zhu, H.; Zhu, J.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zyzak, M.; Alice Collaboration

2016-09-01

The production of charged pions, kaons and (anti)protons has been measured at mid-rapidity (- 0.5 < y < 0) in p-Pb collisions at √{sNN} = 5.02 TeV using the ALICE detector at the LHC. Exploiting particle identification capabilities at high transverse momentum (pT), the previously published pT spectra have been extended to include measurements up to 20 GeV/c for seven event multiplicity classes. The pT spectra for pp collisions at √{ s} = 7 TeV, needed to interpolate a pp reference spectrum, have also been extended up to 20 GeV/c to measure the nuclear modification factor (RpPb) in non-single diffractive p-Pb collisions. At intermediate transverse momentum (2 proton-to-pion ratio increases with multiplicity in p-Pb collisions, a similar effect is not present in the kaon-to-pion ratio. The pT dependent structure of such increase is qualitatively similar to those observed in pp and heavy-ion collisions. At high pT (> 10 GeV / c), the particle ratios are consistent with those reported for pp and Pb-Pb collisions at the LHC energies. At intermediate pT the (anti)proton RpPb shows a Cronin-like enhancement, while pions and kaons show little or no nuclear modification. At high pT the charged pion, kaon and (anti)proton RpPb are consistent with unity within statistical and systematic uncertainties.

Precise Measurements of the Cosmic Ray Antiproton Spectrum with BESS Including the Effects of Solar Modulation

NASA Technical Reports Server (NTRS)

Mitchell, J. W.; Abe, K.; Anraku, K.; Asaoka, Y.; Fujikawa, M.; Fuke, H.; Haino, S.; Hams, T.; Ikeda, N.; Imori, M.

2002-01-01

The Balloon Borne Experiment with a Superconducting Spectrometer (BESS) has measured the energy spectrum of cosmic-ray antiprotons between 0.18 and 4.20 GeV in eight flights between 1993 and 2002. Above about 1 GeV, models in which antiprotons are secondary products of the interactions of primary cosmic rays with the interstellar gas agree with the BESS antiproton spectrum. Below 1 GeV, the data show a possible excess antiproton flux compared to secondary model predictions, suggesting the presence of an additional source of antiprotons. The antiproton/proton ratios measured between 1993 and 1999, during the Sun's positive-polarity phase, are consistent with simple models of solar modulation. However, results from the 2000 flight, following the solar magnetic field reversal, show a sudden increase in the antiproton/proton ratio and tend to favor a charge-sign-dependent drift model. To extend BESS measurements to lower energies, an evolutionary instrument, BESS-Polar, is under construction for polar flight in 2004.

Evidence for the Stochastic Acceleration of Secondary Antiprotons by Supernova Remnants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cholis, Ilias; Hooper, Dan; Linden, Tim

2017-01-16

The antiproton-to-proton ratio in the cosmic-ray spectrum is a sensitive probe of new physics. Using recent measurements of the cosmic-ray antiproton and proton fluxes in the energy range of 1-1000 GeV, we study the contribution to themore » $$\\bar{p}/p$$ ratio from secondary antiprotons that are produced and subsequently accelerated within individual supernova remnants. We consider several well-motivated models for cosmic-ray propagation in the interstellar medium and marginalize our results over the uncertainties related to the antiproton production cross section and the time-, charge-, and energy-dependent effects of solar modulation. We find that the increase in the $$\\bar{p}/p$$ ratio observed at rigidities above $$\\sim$$ 100 GV cannot be accounted for within the context of conventional cosmic-ray propagation models, but is consistent with scenarios in which cosmic-ray antiprotons are produced and subsequently accelerated by shocks within a given supernova remnant. In light of this, the acceleration of secondary cosmic rays in supernova remnants is predicted to substantially contribute to the cosmic-ray positron spectrum, accounting for a significant fraction of the observed positron excess.« less

Multiplicity dependence of charged pion, kaon, and (anti)proton production at large transverse momentum in p–Pb collisions at s NN = 5.02  TeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adam, J.; Adamová, D.; Aggarwal, M. M.

The production of charged pions, kaons and (anti)protons has been measured at mid-rapidity (-0.5 < y < 0) in p–Pb collisions at s NN =5.02 TeV using the ALICE detector at the LHC. Exploiting particle identification capabilities at high transverse momentum (p T ), the previously published p T spectra have been extended to include measurements up to 20 GeV/c for seven event multiplicity classes. The p T spectra for pp collisions at s=7 TeV, needed to interpolate a pp reference spectrum, have also been extended up to 20 GeV/c to measure the nuclear modification factor (R pPb ) in non-single diffractivemore » p–Pb collisions. At intermediate transverse momentum (2 < p T < 10 GeV/c) the proton-to-pion ratio increases with multiplicity in p–Pb collisions, a similar effect is not present in the kaon-to-pion ratio. The p T dependent structure of such increase is qualitatively similar to those observed in pp and heavy-ion collisions. At high p T ( > 10 GeV/c), the particle ratios are consistent with those reported for pp and Pb–Pb collisions at the LHC energies. At intermediate p T the (anti)proton R pPb shows a Cronin-like enhancement, while pions and kaons show little or no nuclear modification. At high p T the charged pion, kaon and (anti)proton R pPb are consistent with unity within statistical and systematic uncertainties.« less

Multiplicity dependence of charged pion, kaon, and (anti)proton production at large transverse momentum in p–Pb collisions at s NN = 5.02  TeV

DOE PAGES

Adam, J.; Adamová, D.; Aggarwal, M. M.; ...

2016-07-22

The production of charged pions, kaons and (anti)protons has been measured at mid-rapidity (-0.5 < y < 0) in p–Pb collisions at s NN =5.02 TeV using the ALICE detector at the LHC. Exploiting particle identification capabilities at high transverse momentum (p T ), the previously published p T spectra have been extended to include measurements up to 20 GeV/c for seven event multiplicity classes. The p T spectra for pp collisions at s=7 TeV, needed to interpolate a pp reference spectrum, have also been extended up to 20 GeV/c to measure the nuclear modification factor (R pPb ) in non-single diffractivemore » p–Pb collisions. At intermediate transverse momentum (2 < p T < 10 GeV/c) the proton-to-pion ratio increases with multiplicity in p–Pb collisions, a similar effect is not present in the kaon-to-pion ratio. The p T dependent structure of such increase is qualitatively similar to those observed in pp and heavy-ion collisions. At high p T ( > 10 GeV/c), the particle ratios are consistent with those reported for pp and Pb–Pb collisions at the LHC energies. At intermediate p T the (anti)proton R pPb shows a Cronin-like enhancement, while pions and kaons show little or no nuclear modification. At high p T the charged pion, kaon and (anti)proton R pPb are consistent with unity within statistical and systematic uncertainties.« less

Measurement of interaction between antiprotons

DOE PAGES

Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; ...

2015-11-04

In this paper, one of the primary goals of nuclear physics is to understand the force between nucleons, which is a necessary step for understanding the structure of nuclei and how nuclei interact with each other. Rutherford discovered the atomic nucleus in 1911, and the large body of knowledge about the nuclear force that has since been acquired was derived from studies made on nucleons or nuclei. Although antinuclei up to antihelium-4 have been discovered and their masses measured, little is known directly about the nuclear force between antinucleons. Here, we study antiproton pair correlations among data collected by themore » STAR experiment at the Relativistic Heavy Ion Collider (RHIC), where gold ions are collided with a centre-of-mass energy of 200 gigaelectronvolts per nucleon pair. Antiprotons are abundantly produced in such collisions, thus making it feasible to study details of the antiproton–antiproton interaction. By applying a technique similar to Hanbury Brown and Twiss intensity interferometry, we show that the force between two antiprotons is attractive. In addition, we report two key parameters that characterize the corresponding strong interaction: the scattering length and the effective range of the interaction. Our measured parameters are consistent within errors with the corresponding values for proton–proton interactions. Our results provide direct information on the interaction between two antiprotons, one of the simplest systems of antinucleons, and so are fundamental to understanding the structure of more-complex antinuclei and their properties.« less

Exclusive Central $$\\pi^{+}\\pi^{-}$$ Production in Proton Antiproton Collisions at the CDF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zurek, Maria

Exclusivemore » $$\\pi^{=}\\pi^{-}$$ production in proton-antiproton collisions at $$\\sqrt{s}$$ = 0.9 and 1.96 TeV in the Collider Detector at Fermilab has been measured. We select events with two particles with opposite charge in pseudorapidity region -1.3 < $$\\eta$$ < 1.3 with no other particles detected in -5.9 < $$\\eta$$ < 5.9. Particles are assumed to be pions. The $$\\pi^{+}\\pi^{-}$$system is required to have rapidity -1.0 < $y$ < 1.0. The data are expected to be dominated by the double pomeron exchange mechanism. Therefore, the quantum numbers of the central state are constrained. The data extend up to dipion mass M($$\\pi^{+}\\pi^{-}$$) = 5000 MeV/$c^2$. Resonance structures consistent with $$f_0$$ and $$f_2$$(1270) mesons are visible. The results are valuable for light hadron spectroscopy and for providing information about the nature of the pomeron in a region between non-perturbative and perturbative quantum chromodynamics« less

Feasibility study of single photon emission coupled tomography imaging technique based on prompt gamma ray during antiproton therapy using boron particle

NASA Astrophysics Data System (ADS)

Shin, Han-Back; Jung, Joo-Young; Kim, Moo-Sub; Kim, Sunmi; Choi, Yong; Yoon, Do-Kun; Suh, Tae Suk

2018-06-01

In this study, we proposed an absorbed-dose monitoring technique using prompt gamma rays emitted from the reaction between an antiproton and a boron particle, and demonstrated the greater physical effect of the antiproton boron fusion therapy in comparison with proton beam using Monte Carlo simulation. The physical effect of the treatment, which was 3.5 times greater, was confirmed from the antiproton beam irradiation compared to the proton beam irradiation. Moreover, the prompt gamma ray image is acquired successfully during antiproton irradiation to boron regions. The results show the application feasibility of absorbed dose monitoring technique proposed in our study.

Revisit of cosmic ray antiprotons from dark matter annihilation with updated constraints on the background model from AMS-02 and collider data

NASA Astrophysics Data System (ADS)

Cui, Ming-Yang; Pan, Xu; Yuan, Qiang; Fan, Yi-Zhong; Zong, Hong-Shi

2018-06-01

We study the cosmic ray antiprotons with updated constraints on the propagation, proton injection, and solar modulation parameters based on the newest AMS-02 data near the Earth and Voyager data in the local interstellar space, and on the cross section of antiproton production due to proton-proton collisions based on new collider data. We use a Bayesian approach to properly consider the uncertainties of the model predictions of both the background and the dark matter (DM) annihilation components of antiprotons. We find that including an extra component of antiprotons from the annihilation of DM particles into a pair of quarks can improve the fit to the AMS-02 antiproton data considerably. The favored mass of DM particles is about 60~100 GeV, and the annihilation cross section is just at the level of the thermal production of DM (langleσvrangle ~ O(10‑26) cm3 s‑1).

Chaotic non-planar vibrations of the thin elastica. Part I: Experimental observation of planar instability

NASA Astrophysics Data System (ADS)

Cusumano, J. P.; Moon, F. C.

1995-01-01

In this two-part paper, the results of an investigation into the non-linear dynamics of a flexible cantilevered rod (the elastica) with a thin rectangular cross-section are presented. An experimental examination of the dynamics of the elastica over a broad parameter range forms the core of Part I. In Part II, the experimental work is related to a theoretical study of the mechanics of the elastica, and the study of a two-degree-of-freedom model obtained by modal projection. The experimental system used in this investigation is a rod with clamped-free boundary conditions, forced by sinusoidally displacing the clamped end. Planar periodic motions of the driven elastica are shown to lose stability at distinct resonant wedges, and the resulting motions are shown in general to be non-planar, chaotic, bending-torsion oscillations. Non-planar motions in all resonances exhibit energy cascading and dynamic two-well phenomena, and a family of asymmetric, bending-torsion non-linear modes is discovered. Correlation dimension calculations are used to estimate the number of active degrees of freedom in the system.

RF Manipulation and Detection of Protons in the High Performance Antiproton Trap (HiPAT)

NASA Technical Reports Server (NTRS)

Martin, James J.; Lewis, Raymond A.; Pearson, J. Boise; Sims, W. Herb; Chakrabarti, Suman; Fant, Wallace E.; McDonald, Stan

2003-01-01

The significant energy density of matter-antimatter annihilation is attractive to the designers of future space propulsion systems, with the potential to offer a highly compact source of power. Many propulsion concepts exist that could take advantage of matter-antimatter reactions, and current antiproton production rates are sufficient to support basic proof-of-principle evaluation of technology associated with antimatter-derived propulsion. One enabling technology for such experiments is portable storage of low energy antiprotons, allowing antiprotons to be trapped, stored, and transported for use at an experimental facility.

Long-range multiplicity correlations in proton-proton collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bzdak, Adam

The forward-backward long-range multiplicity correlations in proton-proton collisions are investigated in the model with two independent sources of particles: one left- and one right-moving wounded nucleon. A good agreement with the UA5 Collaboration proton-antiproton data at the c.m. energy of 200 GeV is observed. For comparison the model with only one source of particles is also discussed.

Study of substructure of high transverse momentum jets produced in proton-antiproton collisions at √s=1.96 TeV

DOE PAGES

Aaltonen, T.; Alon, R.; Álvarez González, B.; ...

2012-05-03

A study of the substructure of jets with transverse momentum greater than 400 GeV/c produced in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron Collider and recorded by the CDF II detector is presented. The distributions of the jet mass, angularity, and planar flow are measured for the first time in a sample with an integrated luminosity of 5.95 fb⁻¹. The observed substructure for high mass jets is consistent with predictions from perturbative quantum chromodynamics.

The Cosmic-Ray Antiproton Flux between 3 and 49 GeV

NASA Astrophysics Data System (ADS)

Boezio, M.; Bonvicini, V.; Schiavon, P.; Vacchi, A.; Zampa, N.; Bergström, D.; Carlson, P.; Francke, T.; Grinstein, S.; Suffert, M.; Hof, M.; Kremer, J.; Menn, W.; Simon, M.; Stephens, S. A.; Ambriola, M.; Bellotti, R.; Cafagna, F.; Ciacio, F.; Circella, M.; De Marzo, C.; Finetti, N.; Papini, P.; Piccardi, S.; Spillantini, P.; Vannuccini, E.; Bartalucci, S.; Ricci, M.; Casolino, M.; De Pascale, M. P.; Morselli, A.; Picozza, P.; Sparvoli, R.; Mitchell, J. W.; Ormes, J. F.; Streitmatter, R. E.; Bravar, U.; Stochaj, S. J.

2001-11-01

We report on a new measurement of the cosmic ray antiproton spectrum. The data were collected by the balloon-borne experiment CAPRICE98, which was flown on 1998 May 28-29 from Fort Sumner, New Mexico. The experiment used the NMSU-WiZard/CAPRICE98 balloon-borne magnet spectrometer equipped with a gas Ring Imaging Cherenkov (RICH) detector, a time-of-flight system, a tracking device consisting of drift chambers and a superconducting magnet, and a silicon-tungsten calorimeter. The RICH detector was the first ever flown capable of mass-resolving charge-one particles at energies above 5 GeV. A total of 31 antiprotons with rigidities between 4 and 50 GV at the spectrometer were identified with small backgrounds from other particles. The absolute antiproton energy spectrum was determined in the kinetic energy region at the top of the atmosphere between 3.2 and 49.1 GeV. We found that the observed antiproton spectrum and the antiproton-to-proton ratio are consistent with a pure secondary origin. However, a primary component may not be excluded.

Measurement of the forward-backward asymmetry in low-mass bottom-quark pairs produced in proton-antiproton collisions

NASA Astrophysics Data System (ADS)

Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; D'Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; Donati, S.; D'Onofrio, M.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Erbacher, R.; Errede, S.; Esham, B.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Galloni, C.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grosso-Pilcher, C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. H.; Kim, S. B.; Kim, Y. J.; Kim, Y. K.; Kimura, N.; Kirby, M.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lucà, A.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Majersky, O.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Marchese, L.; Margaroli, F.; Marino, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Song, H.; Sorin, V.; St. Denis, R.; Stancari, M.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vázquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizán, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S. M.; Waters, D.; Wester, W. C.; Whiteson, D.; Wicklund, A. B.; Wilbur, S.; Williams, H. H.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W.-M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Zanetti, A. M.; Zeng, Y.; Zhou, C.; Zucchelli, S.; CDF Collaboration

2016-06-01

We report a measurement of the forward-backward asymmetry, AFB , in b b ¯ pairs produced in proton-antiproton collisions and identified by muons from semileptonic b -hadron decays. The event sample is collected at a center-of-mass energy of √{s }=1.96 TeV with the CDF II detector and corresponds to 6.9 fb-1 of integrated luminosity. We obtain an integrated asymmetry of AFB(b b ¯ ) =(1.2 ±0.7 )% at the particle level for b -quark pairs with invariant mass, mb b ¯ , down to 40 GeV /c2 and measure the dependence of AFB(b b ¯ ) on mb b ¯ . The results are compatible with expectations from the standard model.

The Antiproton-Nucleon Annihilation Process (Antiproton Collaboration Experiment)

DOE R&D Accomplishments Database

Barkas, W. H.; Birge, R. W.; Chupp, W. W.; Ekspong, A. G.; Goldhaber, G.; Goldhaber, S.; Heckman, H. H.; Perkins, D. H.; Sandweiss, J.; Segre, E.; Smith, F. M.; Stork, D. H.; Rossum, L. Van; Amaldi, E.; Baroni, G.; Castagnoli, C.; Franzinetti, C.; Manfredini, A.

1956-09-10

In the exposure to a 700-MeV/c negative particle beam, 35 antiproton stars have been found. Of these antiprotons, 21 annihilate in flight and three give large-angle scatters ({Theta} > 15 , T{sub P-} > 50 Mev), while 14 annihilate at rest. From the interactions in flight we obtain the total cross section for antiproton interaction.

Dark Matter Search in Space: Combined Analysis of Cosmic-Ray Antiproton-to-proton Flux Ratio and Positron Flux Measured by AMS-02

NASA Astrophysics Data System (ADS)

Feng, Jie; Zhang, Hong-Hao

2018-05-01

Dark matter searches in space have been carried out for many years. Measurements of cosmic-ray (CR) photons, charged antiparticles, and neutrinos are useful tools for dark matter indirect searches. The antiparticle energy spectra of CRs have several exciting features, such as the unexpected positron excess at E ∼ 10–500 GeV and the remarkably flattening antiproton/proton at E ∼ 60–450 GeV precisely measured by the AMS-02 experiment, which cannot be explained simultaneously by secondary production in the interstellar medium. In this work, we report a combined analysis of CR antiproton and positron spectra arising from dark matter on the top of a secondary production in a spatial-dependent propagation model. We discuss the systematic uncertainties from the antiproton production cross section using the two latest Monte Carlo generators, i.e., EPOS LHC and QGSJET-II-04m. We compare their results. In the case of EPOS LHC, we find that the dark matter pair annihilating into τ leptons channel with a 100% branching ratio and the p-wave annihilation cross section assumption is the only possible one-channel scenario to explain the data. On the other hand, there is not a single possible channel in the case of QGSJET-II-04m. We also propose possible two-channel scenarios based on these two Monte Carlo generators.

Fragmentation of an elastica

NASA Astrophysics Data System (ADS)

Vandenberghe, Nicolas; Villermaux, Emmanuel

2009-03-01

When a thin rod is submitted to an axial force greater than its critical buckling load it takes the shape of an elastica. As the load further increases, a rod made of a brittle material breaks suddenly. More than two fragments may be formed during this fragmentation. In this work we discuss the sequence of events that lead to the final broken state with two or more fragments. We show that the criterion for breaking is not trivial. In particular, we investigate the effect of the duration of the loading and we show that at a given load the waiting time before breaking is broadly distributed. We discuss the consequences of the time delayed breaking on the distributions of fragment sizes and fragment numbers.

The cosmic-ray antiproton spectrum from dark matter annihilation and its astrophysical implications - A new look

NASA Technical Reports Server (NTRS)

Stecker, F. W.; Tylka, A. J.

1989-01-01

The spectrum of antiprotons from dark matter annihilation are calculated using the Lund Monte Carlo program, and simple analytic expressions for the spectrum and low-energy antiproton/proton ratio are derived. Comparing the results with recent upper limits on low energy antiprotons, it is concluded that the reported 4-13 GeV antiproton flux cannot be accounted for by dark matter annihilation. The new upper limits do not provide useful constraints on dark matter particles. They restrict the annihilation rate and imply that annihilation gamma ray and e(+) fluxes would be far below the fluxes produced by cosmic-ray collisions. It may be possible to look for a dark matter halo annihilation signal at antiprotons energies below 0.5 GeV, where the flux from cosmic-ray collisions is expected to be negligible.

Measurement of the forward-backward asymmetry in low-mass bottom-quark pairs produced in proton-antiproton collisions

DOE PAGES

Aaltonen, T.; Amerio, S.; Amidei, D.; ...

2016-06-02

Here, we report a measurement of the forward-backward asymmetry, AFB, inmore » $$b\\bar{b}$$ pairs produced in proton-antiproton collisions and identified by muons from semileptonic b-hadron decays. The event sample is collected at a center-of-mass energy of √s = 1.96 TeV with the CDF II detector and corresponds to 6.9 fb –1 of integrated luminosity. We obtain an integrated asymmetry of A FB($$b\\bar{b}$$)=(1.2±0.7)% at the particle level for b-quark pairs with invariant mass, m $$b\\bar{b}$$, down to 40 GeV/c 2 and measure the dependence of A FB($$b\\bar{b}$$) on m $$b\\bar{b}$$. The results are compatible with expectations from the standard model.« less

Phenomenological study of exclusive binary light particle production from antiproton-proton annihilation at FAIR/PANDA

NASA Astrophysics Data System (ADS)

Ying, Wang

2016-08-01

Exclusive binary annihilation reactions induced by antiprotons of momentum from 1.5 to 15 GeV/c can be extensively investigated at FAIR/PANDA [1]. We are especially interested in the channel of charged pion pairs. Whereas this very probable channel constitutes the major background for other processes of interest in the PANDA experiment, it carries unique physical information on the quark content of proton, allowing to test different models (quark counting rules, statistical models,..). To study the binary reactions of light meson formation, we are developing an effective Lagrangian model based on Feynman diagrams which takes into account the virtuality of the exchanged particles. Regge factors [2] and form factors are introduced with parameters which may be adjusted on the existing data. We present preliminary results of our formalism for different reactions of light meson production leading to reliable predictions of cross sections, energy and angular dependencies in the PANDA kinematical range.

Vibration of a spatial elastica constrained inside a straight tube

NASA Astrophysics Data System (ADS)

Chen, Jen-San; Fang, Joyce

2014-04-01

In this paper we study the dynamic behavior of a clamped-clamped spatial elastica under edge thrust constrained inside a straight cylindrical tube. Attention is focused on the calculation of the natural frequencies and mode shapes of the planar and spatial one-point-contact deformations. The main issue in determining the natural frequencies of a constrained rod is the movement of the contact point during vibration. In order to capture the physical essence of the contact-point movement, an Eulerian description of the equations of motion based on director theory is formulated. After proper linearization of the equations of motion, boundary conditions, and contact conditions, the natural frequencies and mode shapes of the elastica can be obtained by solving a system of eighteen first-order differential equations with shooting method. It is concluded that the planar one-point-contact deformation becomes unstable and evolves to a spatial deformation at a bifurcation point in both displacement and force control procedures.

The bar{P}ANDA Experiment at FAIR — Subatomic Physics with Antiprotons

NASA Astrophysics Data System (ADS)

Messchendorp, Johan

The non-perturbative nature of the strong interaction leads to spectacular phenomena, such as the formation of hadronic matter, color confinement, and the generation of the mass of visible matter. To get deeper insight into the underlying mechanisms remains one of the most challenging tasks within the field of subatomic physics. The antiProton ANnihilations at DArmstadt (bar{P}ANDA) collaboration has the ambition to address key questions in this field by exploiting a cooled beam of antiprotons at the High Energy Storage Ring (HESR) at the future Facility for Antiproton and Ion Research (FAIR) combined with a state-of-the-art and versatile detector. This contribution will address some of the unique features of bar{P}ANDA that give rise to a promising physics program together with state-of-the-art technological developments.

A study of the energy dependence of the underlying event in proton-antiproton collisions

DOE PAGES

Aaltonen, T.

2015-11-23

We study charged particle production (p T > 0.5 GeV/c, |η| < 0.8) in proton-antiproton collisions at 300 GeV, 900 GeV, and 1.96 TeV. We use the direction of the charged particle with the largest transverse momentum in each event to define three regions of η-Φspace; “toward”, “away”, and “transverse”. Furthermore, the average number and the average scalar p T sum of charged particles in the transverse region are sensitive to the modeling of the “underlying event”. The transverse region is divided into a MAX and MIN transverse region, which helps separate the “hard component” (initial and final-state radiation) frommore » the “beam-beam remnant” and multiple parton interaction components of the scattering. We found that the center-of-mass energy dependence of the various components of the event are studied in detail. The data presented here can be used to constrain and improve QCD Monte Carlo models, resulting in more precise predictions at the LHC energies of 13 and 14 TeV.« less

The semi-Hooperon: Gamma-ray and anti-proton excesses in the Galactic Center

NASA Astrophysics Data System (ADS)

Arcadi, Giorgio; Queiroz, Farinaldo S.; Siqueira, Clarissa

2017-12-01

A puzzling excess in gamma-rays at GeV energies has been observed in the center of our galaxy using Fermi-LAT data. Its origin is still unknown, but it is well fitted by Weakly Interacting Massive Particles (WIMPs) annihilations into quarks with a cross section around 10-26 cm3s-1 with masses of 20-50 GeV, scenario which is promptly revisited. An excess favoring similar WIMP properties has also been seen in anti-protons with AMS-02 data potentially coming from the Galactic Center as well. In this work, we explore the possibility of fitting these excesses in terms of semi-annihilating dark matter, dubbed as semi-Hooperon, with the process WIMP WIMP → WIMP X being responsible for the gamma-ray excess, where X = h , Z. An interesting feature of semi-annihilations is the change in the relic density prediction compared to the standard case, and the possibility to alleviate stringent limits stemming from direct detection searches. Moreover, we discuss which models might give rise to a successful semi-Hooperon setup in the context of Z3,Z4 and extra "dark" gauge symmetries.

Dynamics of novel forests of Castilla elastica in Puerto Rico: from species to ecosystems.

PubMed

Fonseca da Silva, Jéssica

2015-08-01

Novel forests (NFs)-forests that contain a combination of introduced and native species-are a consequence of intense anthropogenic disturbances and the natural resilience of disturbed ecosystems. The extent to which NFs have similar forest function as comparable native secondary forests is a matter of debate in the scientific community. Little is known about the performance of individual species in those forests. This study focuses on the functional attributes of Castilla elastica NFs in Puerto Rico and on the differences between introduced and native species growing side by side in these forests. Rates of processes measured here were later compared with data from literature about NSFs. I hypothesize that juvenile plants of C. elastica in NFs have higher survival rate than those of native species and that C. elastica trees have faster biomass fluxes than native trees. To test the hypotheses, I measured survival rates of juvenile plants and tree growth and characterized the aboveground litter fluxes and storage. Although juvenile plants of native species displayed higher survival rates than those of C. elastica (53% vs. 28%), the latter was dominant in the understory (96%). Stand biomass growth rate was 2.0 ± 0.4 (average ± one standard deviation) Mg·ha(-1)·year(-1) for the whole forest, and Guarea guidonia, a native species, exhibited the highest tree growth. Total litter fall was 9.6 ± 0.5 Mg·ha(-1)·year(-1), and mean litter standing stock was 4.4 ± 0.1 Mg·ha(-1). Castilla elastica litter fall decomposed twice as fast as that of native species (5.8 ± 1.1 vs. 3.03 ± 1 k·year(-1)). Literature comparisons show that the present NFs differ in some rates of processes from NSFs. This study brings unique and detailed supporting data about the ecological dynamics under mature novel forest stands. Further comprehensive studies about NFs are important to strengthen the body of knowledge about the wide range of variation of emerging tropical ecosystems. Due to the

Practical Uses of Antiprotons

NASA Astrophysics Data System (ADS)

Jackson, Gerald P.

The production of commercial quantities of antiprotons has been a reality for many years now. The deceleration and trapping of antiprotons is a relatively new activity, but has been sufficiently proven to be translated into a business enterprise. Now that NASA has a portable Penning trap for transporting antiprotons, all the elements are in place to begin the commercial distribution of antiprotons. The list of potential customers for antiprotons is continuously growing, with detailed market analyses already performed on some medical and propulsion applications. In this paper these applications are reviewed, along with their appetite for antiprotons and the steps needed to bring them to market.

On the shape of things: From holography to elastica

NASA Astrophysics Data System (ADS)

Fonda, Piermarco; Jejjala, Vishnu; Veliz-Osorio, Alvaro

2017-10-01

We explore the question of which shape a manifold is compelled to take when immersed in another one, provided it must be the extremum of some functional. We consider a family of functionals which depend quadratically on the extrinsic curvatures and on projections of the ambient curvatures. These functionals capture a number of physical setups ranging from holography to the study of membranes and elastica. We present a detailed derivation of the equations of motion, known as the shape equations, placing particular emphasis on the issue of gauge freedom in the choice of normal frame. We apply these equations to the particular case of holographic entanglement entropy for higher curvature three dimensional gravity and find new classes of entangling curves. In particular, we discuss the case of New Massive Gravity where we show that non-geodesic entangling curves have always a smaller on-shell value of the entropy functional. Then we apply this formalism to the computation of the entanglement entropy for dual logarithmic CFTs. Nevertheless, the correct value for the entanglement entropy is provided by geodesics. Then, we discuss the importance of these equations in the context of classical elastica and comment on terms that break gauge invariance.

Shielding experiments by the JASMIN Collaboration at Fermilab (II) - radioactivity measurement induced by secondary particles from the anti-proton production target

DOE PAGES

Hiroshi, Yashima; Norihiro, Matsuda; Yoshimi, Kasugai; ...

2011-08-01

The JASMIN Collaboration has performed an experiment to conduct measurements of nuclear reaction rates around the anti-proton production (Pbar) target at the Fermi National Accelerator Laboratory (FNAL). At the Pbar target station, the target, consisting of an Inconel 600 cylinder, was irradiated by a 120 GeV/c proton beam from the FNAL Main Injector. The beam intensity was 3.6 x 10 12 protons per second. The samples of Al, Nb, Cu, and Au were placed near the target to investigate the spatial and energy distribution of secondary particles emitted from it. After irradiation, the induced activities of the samples were measuredmore » by studying their gamma ray spectra using HPGe detectors. The production rates of 30 nuclides induced in Al, Nb, Cu, Au samples were obtained. These rates increase for samples placed in a forward (small angle) position relative to the target. The angular dependence of these reaction rates becomes larger for increasing threshold energy. These experimental results are compared with Monte Carlo calculations. The calculated results generally agree with the experimental results to within a factor of 2 to 3.« less

Shielding experiments by the JASMIN collaboration at Fermilab (II) - Radioactivity measurement induced by secondary particles from the anti-proton production target

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yashima, Hiroshi; /Kyoto U., KURRI; Matsuda, Norihiro

2011-01-01

The JASMIN Collaboration has performed an experiment to conduct measurements of nuclear reaction rates around the anti-proton production (Pbar) target at the Fermi National Accelerator Laboratory (FNAL). At the Pbar target station, the target, consisting an Inconel 600 cylinder, was irradiated by a 120 GeV/c proton beam from the FNAL Main Injector. The beam intensity was 3.6 x 10{sub 12} protons per second. Samples of Al, Nb, Cu, and Au were placed near the target to investigate the spatial and energy distribution of secondary particles emitted from it. After irradiation, the induced activities of the samples were measured by studyingmore » their gamma ray spectra using HPGe detectors. The production rates of 30 nuclides induced in Al, Nb, Cu, Au samples were obtained. These rates increase for samples placed in a forward (small angle) position relative to the target. The angular dependence of these reaction rates becomes larger for increasing threshold energy. These experimental results are compared with Monte Carlo calculations. The calculated results generally agree with the experimental results to within a factor of 2 to 3.« less

Studies of high-transverse momentum jet substructure and top quarks produced in 1.96 TeV proton-antiproton collisions

NASA Astrophysics Data System (ADS)

Aaltonen, T.; Alon, R.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; D'Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; Donati, S.; D'Onofrio, M.; Dorigo, M.; Driutti, A.; Duchovni, E.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Galloni, C.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. H.; Kim, S. B.; Kim, Y. J.; Kim, Y. K.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lucà, A.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Marchese, L.; Margaroli, F.; Marino, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Perez, G.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sinervo, P.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Song, H.; Sorin, V.; St. Denis, R.; Stancari, M.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vázquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizán, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S. M.; Waters, D.; Wester, W. C.; Whiteson, D.; Wicklund, A. B.; Wilbur, S.; Williams, H. H.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W.-M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Zanetti, A. M.; Zeng, Y.; Zhou, C.; Zucchelli, S.; CDF Collaboration

2015-02-01

Results of a study of the substructure of the highest transverse momentum (pT) jets observed by the CDF Collaboration are presented. Events containing at least one jet with pT>400 GeV /c in a sample corresponding to an integrated luminosity of 5.95 fb-1 , collected in 1.96 TeV proton-antiproton collisions at the Fermilab Tevatron collider, are selected. A study of the jet mass, angularity, and planar-flow distributions is presented, and the measurements are compared with predictions of perturbative quantum chromodynamics. A search for boosted top-quark production is also described, leading to a 95% confidence level upper limit of 38 fb on the production cross section of top quarks with pT>400 GeV /c .

Measurements of the u valence quark distribution function in the proton and u quark fragmentation functions

NASA Astrophysics Data System (ADS)

Arneodo, M.; Arvidson, A.; Aubert, J. J.; Badelek, B.; Beaufays, J.; Bee, C. P.; Benchouk, C.; Berghoff, G.; Bird, I. G.; Blum, D.; Böhm, E.; De Bouard, X.; Brasse, F. W.; Braun, H.; Broll, C.; Brown, S. C.; Brück, H.; Calen, H.; Chima, J. S.; Ciborowski, J.; Clifft, R.; Coignet, G.; Combley, F.; Coughlan, J.; D'Agostini, G.; Dahlgren, S.; Dengler, F.; Derado, I.; Dreyer, T.; Drees, J.; Düren, M.; Eckardt, V.; Edwards, A.; Edwards, M.; Ernst, T.; Eszes, G.; Favier, J.; Ferrero, M. I.; Figiel, J.; Flauger, W.; Foster, J.; Gabathuler, E.; Gajewski, J.; Gamet, R.; Gayler, J.; Geddes, N.; Grafström, P.; Grard, F.; Haas, J.; Hagberg, E.; Hasert, F. J.; Hayman, P.; Heusse, P.; Jaffre, M.; Jacholkowska, A.; Janata, F.; Jancso, G.; Johnson, A. S.; Kabuss, E. M.; Kellner, G.; Korbel, V.; Krüger, A.; Krüger, J.; Kullander, S.; Landgraf, U.; Lanske, D.; Loken, J.; Long, K.; Maire, M.; Malecki, P.; Manz, A.; Maselli, S.; Mohr, W.; Montanet, F.; Montgomery, H. E.; Nagy, E.; Nassalski, J.; Norton, P. R.; Oakham, F. G.; Osborne, A. M.; Pascaud, C.; Pawlik, B.; Payre, P.; Peroni, C.; Peschel, H.; Pessard, H.; Pettingale, J.; Pietrzyk, B.; Poensgen, B.; Pötsch, M.; Renton, P.; Ribarics, P.; Rith, K.; Rondio, E.; Sandacz, A.; Scheer, M.; Schlagböhmer, A.; Schiemann, H.; Schmitz, N.; Schneegans, M.; Scholz, M.; Schouten, M.; Schröder, T.; Schultze, K.; Sloan, T.; Stier, H. E.; Studt, M.; Taylor, G. N.; Thenard, J. M.; Thompson, J. C.; De la Torre, A.; Toth, J.; Urban, L.; Urban, L.; Wallucks, W.; Whalley, M.; Wheeler, S.; Williams, W. S. C.; Wimpenny, S. J.; Windmolders, R.; Wolf, G.; European Muon Collaboration

1989-07-01

A new determination of the u valence quark distribution function in the proton is obtained from the analysis of identified charged pions, kaons, protons and antiprotons produced in muon-proton and muon-deuteron scattering. The comparison with results obtained in inclusive deep inelastic lepton-nucleon scattering provides a further test of the quark-parton model. The u quark fragmentation functions into positive and negative pions, kaons, protons and antiprotons are also measured.

Exploration of a High Luminosity 100 TeV Proton Antiproton Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oliveros, Sandra J.; Summers, Don; Cremaldi, Lucien

New physics is being explored with the Large Hadron Collider at CERN and with Intensity Frontier programs at Fermilab and KEK. The energy scale for new physics is known to be in the multi-TeV range, signaling the need for a future collider which well surpasses this energy scale. We explore a 10more » $$^{\\,34}$$ cm$$^{-2}$$ s$$^{-1}$$ luminosity, 100 TeV $$p\\bar{p}$$ collider with 7$$\\times$$ the energy of the LHC but only 2$$\\times$$ as much NbTi superconductor, motivating the choice of 4.5 T single bore dipoles. The cross section for many high mass states is 10 times higher in $$p\\bar{p}$$ than $pp$ collisions. Antiquarks for production can come directly from an antiproton rather than indirectly from gluon splitting. The higher cross sections reduce the synchrotron radiation in superconducting magnets and the number of events per beam crossing, because lower beam currents can produce the same rare event rates. Events are more centrally produced, allowing a more compact detector with less space between quadrupole triplets and a smaller $$\\beta^{*}$$ for higher luminosity. A Fermilab-like $$\\bar p$$ source would disperse the beam into 12 momentum channels to capture more antiprotons. Because stochastic cooling time scales as the number of particles, 12 cooling ring sets would be used. Each set would include phase rotation to lower momentum spreads, equalize all momentum channels, and stochastically cool. One electron cooling ring would follow the stochastic cooling rings. Finally antiprotons would be recycled during runs without leaving the collider ring by joining them to new bunches with synchrotron damping.« less

First Mass-resolved Measurement of High-Energy Cosmic-Ray Antiprotons

NASA Astrophysics Data System (ADS)

Bergström, D.; Boezio, M.; Carlson, P.; Francke, T.; Grinstein, S.; Khalchukov, F.; Suffert, M.; Hof, M.; Kremer, J.; Menn, W.; Simon, M.; Stephens, S. A.; Ambriola, M. L.; Bellotti, R.; Cafagna, F.; Ciacio, F.; Circella, M.; De Marzo, C.; Finetti, N.; Papini, P.; Piccardi, S.; Spillantini, P.; Bartalucci, S.; Ricci, M.; Casolino, M.; De Pascale, M. P.; Morselli, A.; Picozza, P.; Sparvoli, R.; Bonvicini, V.; Schiavon, P.; Vacchi, A.; Zampa, N.; Mitchell, J. W.; Ormes, J. F.; Streitmatter, R. E.; Bravar, U.; Stochaj, S. J.

2000-05-01

We report new results for the cosmic-ray antiproton-to-proton ratio from 3 to 50 GeV at the top of the atmosphere. These results represent the first measurements, on an event-by-event basis, of mass-resolved antiprotons above 18 GeV. The results were obtained with the NMSU-WIZARD/CAPRICE98 balloon-borne magnet spectrometer equipped with a gas-RICH (Ring-Imaging Cerenkov) counter and a silicon-tungsten imaging calorimeter. The RICH detector was the first ever flown that is capable of identifying charge-one particles at energies above 5 GeV. The spectrometer was flown on 1998 May 28-29 from Fort Sumner, New Mexico. The measured p/p ratio is in agreement with a pure secondary interstellar production.

A program to study antiprotons in the cosmic rays: Arizona collaboration

NASA Technical Reports Server (NTRS)

Bowen, Theodore

1987-01-01

The Low Energy AntiProton (LEAP) experiment was designed to measure the primary antiproton flux in the 200 MeV to 1 GeV kinetic energy range. A superconducting magnetic spectrometer, a time-of-flight (TOF) detector, and a Cherenkov counter are the main components of LEAP. An additional scintillation detector was designed and constructed to detect the passage of particles through the bottom of the Cherenkov counter. The LEAP package was launched on August 22, 1987, and enjoyed a 27 hour flight, with 23 hours of data at high altitude. Preliminary plans for data analysis include using the Micro-Vax at the University of Arizona for data reduction of the Cherenkov and S2 signals.

Deceleration of Antiprotons in Support of Antiproton Storage/Utilization Research

NASA Astrophysics Data System (ADS)

Howe, Steven D.; Jackson, Gerald P.; Pearson, J. Boise; Lewis, Raymond A.

2005-02-01

Antimatter has the highest energy density known to mankind. Many concepts have been studied that use antimatter for propulsion. All of these concepts require the development of high density storage. Hbar Technologies, under contract with the NASA Marshall Space Flight Center, has undertaken the first step toward development of high density storage. Demonstration of the ability to store antiprotons in a Penning Trap provides the technology to pursue research in alternative storage methods that may lead to eventually to high density concepts. Hbar Technologies has undertaken research activity on the detailed design and operations required to decelerate and redirect the Fermi National Accelerator Laboratory (FNAL) antiproton beam to lay the groundwork for a source of low energy antiprotons. We have performed a detailed assessment of an antiproton deceleration scheme using the FNAL Main Injector, outlining the requirements to significantly and efficiently lower the energy of antiprotons. This task shall require a combination of: theoretical/computation simulations, development of specialized accelerator controls programming, modification of specific Main Injector hardware, and experimental testing of the modified system. Testing shall be performed to characterize the system with a goal of reducing the beam momentum from 8.9 GeV/c to a level of 1 GeV/c or less. We have designed an antiproton degrader system that will integrate with the FNAL decelerated/transferred beam. The degrader shall be designed to maximize the number of low energy antiprotons with a beam spot sized for acceptance by the Mark I test hardware.

Some remarks about simulation of cosmic ray phenomena with use of nuclear interaction models based on the current SPS proton-antiproton data

NASA Technical Reports Server (NTRS)

Wrotniak, J. A.; Yodh, G. B.

1985-01-01

The x-y controversy is studied by introducing models with as many features (except for x and y distributions) in common, as possible, to avoid an extrapolation problem, only primary energies of 500 TeV are considered. To prove the point, Monte Carlo simulations are performed of EAS generated by 500 TeV vertical primary protons. Four different nuclear interaction models were used. Two of them are described elsewhere. Two are: (1) Model M-Y00 - with inclusive x and y distributions behaving in a scaling way; and (2) Model M-F00 - at and below ISR energies (1 TeV in Lab) exactly equivalent to the above, then gradually changing to provide the distributions in rapidity at 155 TeV as given by SPS proton-antiproton. This was achieved by gradual decrease in the scale unit in x distributions of produced secondaries, as interaction energy increases. Other modifications to the M-Y00 model were made.

Physics with thermal antiprotons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hynes, M.V.; Campbell, L.J.

1988-01-01

The same beam cooling techniques that have allowed for high luminosity antiproton experiments at high energy also provide the opportunity for experiments at ultra-low energy. Through a series of deceleration stages, antiprotons collected and cooled at the peak momentum for production can by made available at thermal or sub-thermal energies. In particular, the CERN, PS-200 collaboration is developing an RFO-plused ion trap beam line for the antiproton gravitational mass experiment at LEAR that will provide beams of antiprotons in the energy range 0.001--1000.0 eV. Antiprotons at these energies make these fundamentals particles available for experiments in condensed matter and atomicmore » physics. The recent speculation that antiprotons may form metastable states in some forms of normal matter could open many new avenues of basic and applied research. 7 refs., 3 figs.« less

Total Phenol Content and In Vitro Antioxidant Potential of Helicanthus elastica (Desr.) Danser-A Less-explored Indian Mango Mistletoe

PubMed Central

Sunil Kumar, Koppala Narayana; Saraswathy, Ariyamuthu; Amerjothy, Swaminathan; Susan, Thomas; Ravishankar, Basaviah

2014-01-01

Natural products are an important source of antioxidant molecules like tannins, phenolic compounds, flavonoids, etc., Helicanthus elastica (Desr.) Danser (Loranthaceae) is one such plant belonging to the category of mistletoe, and grows commonly on the mango trees in India. In the present study, an attempt has been made to assess the antioxidant properties of the plant. Ethanol extract of H. elastica growing on mango tree was studied using different in vitro models. Shade-dried whole plant material was extracted with ethanol by cold percolation. Fifty milligrams of the alcohol extract of H. elastica was weighed and dissolved in 10 ml of methanol. The resultant 5 mg/ml solution was suitably diluted to obtain different concentrations. Total phenol content, reducing power assay, and scavenging of free radicals like nitric oxide, hydroxyl, hydrogen peroxide, and 1,1-diphenyl-2-picrylhydrazyl were studied by standardized in vitro chemical methods using ascorbic acid as the standard. The total phenol content of the plant was found to be 1.89% w/w. The extract showed good reducing power as well as scavenging of free radicals (nitric oxide, hydroxyl, superoxide anion, and hydrogen peroxide) at concentrations ranging from 5 to 100 μg/ml. The study revealed the antioxidant potential of H. elastica. PMID:25379473

Production cross sections of cosmic antiprotons in the light of new data from the NA61 and LHCb experiments

NASA Astrophysics Data System (ADS)

Korsmeier, Michael; Donato, Fiorenza; Di Mauro, Mattia

2018-05-01

The cosmic-ray flux of antiprotons is measured with high precision by the space-borne particle spectrometers AMS-02. Its interpretation requires a correct description of the dominant production process for antiprotons in our Galaxy, namely, the interaction of cosmic-ray proton and helium with the interstellar medium. In light of new cross section measurements by the NA61 experiment of p +p →p ¯+X and the first ever measurement of p +He →p ¯+X by the LHCb experiment, we update the parametrization of proton-proton and proton-nucleon cross sections. We find that the LHCb p He data constrain a shape for the cross section at high energies and show for the first time how well the rescaling from the p p channel applies to a helium target. By using p p , p He and p C data we estimate the uncertainty on the Lorentz invariant cross section for p +He →p ¯+X . We use these new cross sections to compute the source term for all the production channels, considering also nuclei heavier than He both in cosmic rays and the interstellar medium. The uncertainties on the total source term are up to ±20 % and slightly increase below antiproton energies of 5 GeV. This uncertainty is dominated by the p +p →p ¯+X cross section, which translates into all channels since we derive them using the p p cross sections. The cross sections to calculate the source spectra from all relevant cosmic-ray isotopes are provided in Supplemental Material. We finally quantify the necessity of new data on antiproton production cross sections, and pin down the kinematic parameter space which should be covered by future data.

Technical design report for the overline{P}ANDA (Anti Proton Annihilations at Darmstadt) Straw Tube Tracker. Strong interaction studies with antiprotons

NASA Astrophysics Data System (ADS)

Erni, W.; Keshelashvili, I.; Krusche, B.; Steinacher, M.; Heng, Y.; Liu, Z.; Liu, H.; Shen, X.; Wang, Q.; Xu, H.; Aab, A.; Albrecht, M.; Becker, J.; Csapó, A.; Feldbauer, F.; Fink, M.; Friedel, P.; Heinsius, F. H.; Held, T.; Klask, L.; Koch, H.; Kopf, B.; Leiber, S.; Leyhe, M.; Motzko, C.; Pelizäus, M.; Pychy, J.; Roth, B.; Schröder, T.; Schulze, J.; Sowa, C.; Steinke, M.; Trifterer, T.; Wiedner, U.; Zhong, J.; Beck, R.; Bianco, S.; Brinkmann, K. T.; Hammann, C.; Hinterberger, F.; Kaiser, D.; Kliemt, R.; Kube, M.; Pitka, A.; Quagli, T.; Schmidt, C.; Schmitz, R.; Schnell, R.; Thoma, U.; Vlasov, P.; Walther, D.; Wendel, C.; Würschig, T.; Zaunick, H. G.; Bianconi, A.; Bragadireanu, M.; Caprini, M.; Pantea, D.; Pantelica, D.; Pietreanu, D.; Serbina, L.; Tarta, P. D.; Kaplan, D.; Fiutowski, T.; Idzik, M.; Mindur, B.; Przyborowski, D.; Swientek, K.; Czech, B.; Kistryn, M.; Kliczewski, S.; Kozela, A.; Kulessa, P.; Lebiedowicz, P.; Pysz, K.; Schäfer, W.; Siudak, R.; Szczurek, A.; Jowzaee, S.; Kajetanowicz, M.; Kamys, B.; Kistryn, S.; Korcyl, G.; Korcyl, K.; Krzemien, W.; Magiera, A.; Moskal, P.; Palka, M.; Rudy, Z.; Salabura, P.; Smyrski, J.; Wrońska, A.; Augustin, I.; Lehmann, I.; Nimorus, D.; Schepers, G.; Al-Turany, M.; Arora, R.; Deppe, H.; Flemming, H.; Gerhardt, A.; Götzen, K.; Jordi, A. F.; Kalicy, G.; Karabowicz, R.; Lehmann, D.; Lewandowski, B.; Lühning, J.; Maas, F.; Orth, H.; Patsyuk, M.; Peters, K.; Saito, T.; Schepers, G.; Schmidt, C. J.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Voss, B.; Wieczorek, P.; Wilms, A.; Zühlsdorf, M.; Abazov, V. M.; Alexeev, G.; Arefiev, A.; Astakhov, V. I.; Barabanov, M. Yu.; Batyunya, B. V.; Davydov, Yu. I.; Dodokhov, V. Kh.; Efremov, A. A.; Fedunov, A. G.; Festchenko, A. A.; Galoyan, A. S.; Grigoryan, S.; Karmokov, A.; Koshurnikov, E. K.; Lobanov, V. I.; Lobanov, Yu. Yu.; Makarov, A. F.; Malinina, L. V.; Malyshev, V. L.; Mustafaev, G. A.; Olshevskiy, A.; Pasyuk, M. A.; Perevalova, E. A.; Piskun, A. A.; Pocheptsov, T. A.; Pontecorvo, G.; Rodionov, V. K.; Rogov, Yu. N.; Salmin, R. A.; Samartsev, A. G.; Sapozhnikov, M. G.; Shabratova, G. S.; Skachkova, A. N.; Skachkov, N. B.; Strokovsky, E. A.; Suleimanov, M. K.; Teshev, R. Sh.; Tokmenin, V. V.; Uzhinsky, V. V.; Vodopyanov, A. S.; Zaporozhets, S. A.; Zhuravlev, N. I.; Zorin, A. G.; Branford, D.; Glazier, D.; Watts, D.; Woods, P.; Britting, A.; Eyrich, W.; Lehmann, A.; Uhlig, F.; Dobbs, S.; Metreveli, Z.; Seth, K.; Tomaradze, A.; Xiao, T.; Bettoni, D.; Carassiti, V.; Cotta Ramusino, A.; Dalpiaz, P.; Drago, A.; Fioravanti, E.; Garzia, I.; Savriè, M.; Stancari, G.; Bianchi, N.; Gianotti, P.; Guaraldo, C.; Lucherini, V.; Orecchini, D.; Pace, E.; Bersani, A.; Bracco, G.; Macri, M.; Parodi, R. F.; Bremer, D.; Dormenev, V.; Drexler, P.; Düren, M.; Eissner, T.; Föhl, K.; Galuska, M.; Gessler, T.; Hayrapetyan, A.; Hu, J.; Koch, P.; Kröck, B.; Kühn, W.; Lange, S.; Liang, Y.; Merle, O.; Metag, V.; Moritz, M.; Münchow, D.; Nanova, M.; Novotny, R.; Spruck, B.; Stenzel, H.; Ullrich, T.; Werner, M.; Xu, H.; Euan, C.; Hoek, M.; Ireland, D.; Keri, T.; Montgomery, R.; Protopopescu, D.; Rosner, G.; Seitz, B.; Babai, M.; Glazenborg-Kluttig, A.; Kavatsyuk, M.; Lemmens, P.; Lindemulder, M.; Löhner, H.; Messchendorp, J.; Moeini, H.; Schakel, P.; Schreuder, F.; Smit, H.; Tambave, G.; van der Weele, J. C.; Veenstra, R.; Sohlbach, H.; Büscher, M.; Deermann, D.; Dosdall, R.; Esch, S.; Gillitzer, A.; Goldenbaum, F.; Grunwald, D.; Henssler, S.; Herten, A.; Hu, Q.; Kemmerling, G.; Kleines, H.; Kozlov, V.; Lehrach, A.; Maier, R.; Mertens, M.; Ohm, H.; Orfanitski, S.; Prasuhn, D.; Randriamalala, T.; Ritman, J.; Röder, M.; Schadmand, S.; Serdyuk, V.; Sterzenbach, G.; Stockmanns, T.; Wintz, P.; Wüstner, P.; Xu, H.; Kisiel, J.; Li, S.; Li, Z.; Sun, Z.; Xu, H.; Rigato, V.; Fissum, S.; Hansen, K.; Isaksson, L.; Lundin, M.; Schröder, B.; Achenbach, P.; Bleser, S.; Cahit, U.; Cardinali, M.; Denig, A.; Distler, M.; Fritsch, M.; Jasinski, P.; Kangh, D.; Karavdina, A.; Lauth, W.; Merkel, H.; Michel, M.; Mora Espi, M. C.; Müller, U.; Pochodzalla, J.; Sanchez, S.; Sanchez-Lorente, A.; Schlimme, S.; Sfienti, C.; Thiel, M.; Weber, T.; Dormenev, V. I.; Fedorov, A. A.; Korzhik, M. V.; Missevitch, O. V.; Balanutsa, V.; Chernetsky, V.; Demekhin, A.; Dolgolenko, A.; Fedorets, P.; Gerasimov, A.; Goryachev, V.; Varentsov, V.; Boukharov, A.; Malyshev, O.; Marishev, I.; Semenov, A.; Böhmer, F.; Dørheim, S.; Ketzer, B.; Paul, S.; Hergemöller, A. K.; Khoukaz, A.; Köhler, E.; Täschner, A.; Wessels, J.; Varma, R.; Chaterjee, A.; Jha, V.; Kailas, S.; Roy, B. J.; Yan, Y.; Chinorat, K.; Khanchai, K.; Ayut, L.; Pomrad, S.; Baldin, E.; Kotov, K.; Peleganchuk, S.; Tikhonov, Yu.; Boucher, J.; Chambert, V.; Dbeyssi, A.; Gumberidze, M.; Hennino, T.; Imre, M.; Kunne, R.; Le Galliard, C.; Ma, B.; Marchand, D.; Maroni, A.; Ong, S.; Ramstein, B.; Rosier, P.; Tomasi-Gustafsson, E.; Van de Wiele, J.; Boca, G.; Braghieri, A.; Costanza, S.; Genova, P.; Lavezzi, L.; Montagna, P.; Rotondi, A.; Abramov, V.; Belikov, N.; Davidenko, A.; Derevschikov, A.; Goncharenko, Y.; Grishin, V.; Kachanov, V.; Konstantinov, D.; Kormilitsin, V.; Melnik, Y.; Levin, A.; Minaev, N.; Mochalov, V.; Morozov, D.; Nogach, L.; Poslavskiy, S.; Ryazantsev, A.; Ryzhikov, S.; Semenov, P.; Shein, I.; Uzunian, A.; Vasiliev, A.; Yakutin, A.; Bäck, T.; Cederwall, B.; Makónyi, K.; Tegnér, P. E.; von Würtemberg, K. M.; Belostotski, S.; Gavrilov, G.; Itzotov, A.; Kashchuk, A.; Kisselev, A.; Kravchenko, P.; Levitskaya, O.; Manaenkov, S.; Miklukho, O.; Naryshkin, Y.; Veretennikov, D.; Vikhrov, V.; Zhadanov, A.; Alberto, D.; Amoroso, A.; Bussa, M. P.; Busso, L.; De Mori, F.; Destefanis, M.; Fava, L.; Ferrero, L.; Greco, M.; Maggiora, M.; Marcello, S.; Sosio, S.; Spataro, S.; Zotti, L.; Calvo, D.; Coli, S.; De Remigis, P.; Filippi, A.; Giraudo, G.; Lusso, S.; Mazza, G.; Morra, O.; Rivetti, A.; Wheadon, R.; Iazzi, F.; Lavagno, A.; Younis, H.; Birsa, R.; Bradamante, F.; Bressan, A.; Martin, A.; Clement, H.; Galander, B.; Caldeira Balkeståhl, L.; Calén, H.; Fransson, K.; Johansson, T.; Kupsc, A.; Marciniewski, P.; Thomé, E.; Wolke, M.; Zlomanczuk, J.; Díaz, J.; Ortiz, A.; Dmowski, K.; Duda, P.; Korzeniewski, R.; Slowinski, B.; Chlopik, A.; Guzik, Z.; Kosinski, K.; Melnychuk, D.; Wasilewski, A.; Wojciechowski, M.; Wronka, S.; Wysocka, A.; Zwieglinski, B.; Bühler, P.; Hartman, O. N.; Kienle, P.; Marton, J.; Suzuki, K.; Widmann, E.; Zmeskal, J.

2013-02-01

This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the overline{P}ANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole overline{P}ANDA scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.

Antiproton powered propulsion with magnetically confined plasma engines

NASA Technical Reports Server (NTRS)

Lapointe, Michael R.

1989-01-01

Matter-antimatter annihilation releases more energy per unit mass than any other method of energy production, making it an attractive energy source for spacecraft propulsion. In the magnetically confined plasma engine, antiproton beams are injected axially into a pulsed magnetic mirror system, where they annihilate with an initially neutral hydrogen gas. The resulting charged annihilation products transfer energy to the hydrogen propellant, which is then exhausted through one end of the pulsed mirror system to provide thrust. The calculated energy transfer efficiencies for a low number density (10(14)/cu cm) hydrogen propellant are insufficient to warrant operating the engine in this mode. Efficiencies are improved using moderate propellant number densities (10(16)/cu cm), but the energy transferred to the plasma in a realistic magnetic mirror system is generally limited to less than 2 percent of the initial proton-antiproton annihilation energy. The energy transfer efficiencies are highest for high number density (10(18)/cu cm) propellants, but plasma temperatures are reduced by excessive radiation losses. Low to moderate thrust over a wide range of specific impulse can be generated with moderate propellant number densities, while higher thrust but lower specific impulse may be generated using high propellant number densities. Significant mass will be required to shield the superconducting magnet coils from the high energy gamma radiation emitted by neutral pion decay. The mass of such a radiation shield may dominate the total engine mass, and could severely diminish the performance of antiproton powered engines which utilize magnetic confinement. The problem is compounded in the antiproton powered plasma engine, where lower energy plasma bremsstrahlung radiation may cause shield surface ablation and degradation.

Cosmic ray proton spectra at low rigidities

NASA Technical Reports Server (NTRS)

Seo, E. S.; Ormes, J. F.; Streitmatter, R. E.; Lloyd-Evans, J.; Jones, W. V.

1990-01-01

The cosmic ray proton rigidity spectra have been investigated with data collected in the Low Energy Antiproton (LEAP) balloon flight experiment flown from Prince Albert, Canada in 1987. The LEAP apparatus was designed to measure antiprotons using a superconducting magnet spectrometer with ancillary scintillator, time-of-flight, and liquid Cherenkov detectors. After reaching float altitude the balloon drifted south and west to higher geomagnetic cutoffs. The effect of the changing geomagnetic cutoff on the observed spectra was observed during analysis of the proton data along the balloon trajectory. This is the first measurement of the primary and splash albedo spectra over a wide rigidity range (few hundred MV to about 100 GV) with a single instrument.

Potential effect of the medicinal plants Calotropis procera, Ficus elastica and Zingiber officinale against Schistosoma mansoni in mice.

PubMed

Seif el-Din, Sayed H; El-Lakkany, Naglaa M; Mohamed, Mona A; Hamed, Manal M; Sterner, Olov; Botros, Sanaa S

2014-02-01

Calotropis procera (Ait.) R. Br. (Asclepiadaceae), Ficus elastica Roxb. (Moraceae) and Zingiber officinale Roscoe (Zingiberaceae) have been traditionally used to treat many diseases. The antischistosomal activity of these plant extracts was evaluated against Schistosoma mansoni. Male mice exposed to 80 ± 10 cercariae per mouse were divided into two batches. The first was divided into five groups: (I) infected untreated, while groups from (II-V) were treated orally (500 mg/kg for three consecutive days) by aqueous stem latex and flowers of C. procera, latex of F. elastica and ether extract of Z. officinale, respectively. The second batch was divided into four comparable groups (except Z. officinale-treated group) similarly treated as the first batch in addition to the antacid ranitidine (30 mg/kg) 1 h before extract administration. Safety, worm recovery, tissues egg load and oogram pattern were assessed. Calotropis procera latex and flower extracts are toxic (50-70% mortality) even in a small dose (250 mg/kg) before washing off their toxic rubber. Zingiber officinale extract insignificantly decrease (7.26%) S. mansoni worms. When toxic rubber was washed off and ranitidine was used, C. procera (stem latex and flowers) and F. elastica extracts revealed significant S. mansoni worm reductions by 45.31, 53.7 and 16.71%, respectively. Moreover, C. procera extracts produced significant reductions in tissue egg load (∼34-38.5%) and positively affected oogram pattern. The present study may be useful to supplement information with regard to C. procera and F. elastica antischistosomal activity and provide a basis for further experimental trials.

Study of muons associated with jets in proton-antiproton collisions at $$\\sqrt{s}$$ = 1.8-TeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, David Austen

1988-11-01

Production of heavy quark flavors in proton-antiproton collisions with a centerof- mass energy of 1.8 X 10 12 electron volts is studied for events containing hadronic jets with a nearby muon track, where both the jet and the muon are produced at large angles from the incident beams. The muon tracking system and pattern recognition are described. Detailed calculations of the muon background due to meson decay and hadron noninteractive punchthrough are presented, and other background sources are evaluated. Distributions of muon transverse momentum relative to the beam and to the jet axis agree with QCD expectations for semileptonicmore » charm and beauty decay. Muon identification cuts and background subtraction leave 57.5 ± 17.1 muon-jet pairs, a rate consistent with the established production cross sections for charm and beauty quarks and the acceptance for minimum ionizing particles overlapping with nearby jets. A small dimuon sample clarifies the muon signature. No signatures of undiscovered phenomena are observed in this new energy domain. 111« less

Flexive and Propulsive Dynamics of Elastica at Low Reynolds Number

NASA Astrophysics Data System (ADS)

Wiggins, Chris H.; Goldstein, Raymond E.

1998-04-01

A stiff one-armed swimmer in glycerine goes nowhere. However, if its arm is elastic, the swimmer can go on its way. Quantifying this observation, we study a hyperdiffusion equation for the shape of the elastica in a viscous fluid, find solutions for impulsive or oscillatory forcing, and elucidate relevant aspects of propulsion. These results have application in a variety of physical and biological contexts, from dynamic experiments measuring biopolymer bending moduli to instabilities of twisted elastic filaments.

Magnesium affects rubber biosynthesis and particle stability in Ficus elastica, Hevea brasiliensis and Parthenium argentatum

USDA-ARS?s Scientific Manuscript database

Natural rubber biosynthesis occurs in laticifers of Ficus elastica and Hevea brasiliensis, and in parenchyma cells of Parthenium argentatum. Natural rubber is synthesized by rubber transferase using allylic pyrophosphates as initiators, isopentenyl pyrophosphate as monomeric substrate and magnesium ...

New Experiments with Antiprotons

NASA Astrophysics Data System (ADS)

Kaplan, D. M.

2011-12-01

Fermilab operates the world's most intense antiproton source. Recently proposed experiments can use those antiprotons either parasitically during Teva-tron Collider running or after the Tevatron Collider finishes in about 2011. For example, the annihilation of 8 GeV antiprotons might make the world's most intense source of tagged D0 mesons, and thus the best near-term opportunity to study charm mixing and search for new physics via its CP-violation signature. Other possible precision measurements include properties of the X(3872) and the charmonium system. An experiment using a Penning trap and an atom interferometer could make the world's first measurement of the gravitational force on antimatter. These and other potential measurements using antiprotons could yield a broad physics program at Fermilab in the post-Tevatron era.

Anitproton-matter interactions in antiproton applications

NASA Technical Reports Server (NTRS)

Morgan, David L., Jr.

1990-01-01

By virtue of the highly energetic particles released when they annihilate in matter, antiprotons have a variety of potentially important applications. Among others, these include remote 3-D density and composition imaging of the human body and also of thick, dense materials, cancer therapy, and spacecraft propulsion. Except for spacecraft propulsion, the required numbers of low energy antiprotons can be produced, stored, and transported through reliance on current or near term technology. Paramount to these applications and to fundamental research involving antiprotons is knowledge of how antiprotons interact with matter. The basic annihilation process is fairly well understood, but the antiproton annihilation and energy loss rates in matter depend in complex ways on a number of atomic processes. The rates, and the corresponding cross sections, were measured or are accurately predictable only for limited combinations of antiproton kinetic energy and material species.

Peeling off an elastica from a smooth attractive substrate

NASA Astrophysics Data System (ADS)

Oyharcabal, Xabier; Frisch, Thomas

2005-03-01

Using continuum mechanics, we study theoretically the unbinding of an inextensible rod with free ends attracted by a smooth substrate and submitted to a vertical force. We use the elastica model in a medium-range van der Waals potential. We numerically solve a nonlinear boundary value problem and obtain the force-stretching relation at zero temperature. We obtain the critical force for which the rod unbinds from the substrate as a function of three dimensionless parameters, and we find two different regimes of adhesion. We study analytically the contact potential case as the van der Waals radius goes to zero.

Towards Polarised Antiprotons: Machine Developments for Spin-Filtering Studies

NASA Astrophysics Data System (ADS)

Lenisa, Paolo

2016-02-01

We address the commissioning of the experimental equipment and the machine studies required for the first spin-filtering experiment with protons at the COSY ring in Jülich (Germany) at a beam kinetic energy of 49.3 MeV. The implementation of a low-beta insertion made it possible to achieve beam lifetimes of 8000 s in the presence of a dense polarized hydrogen storage cell target. The developed techniques can be directly applied to antiproton machines and allow for the determination of the spin-dependent pbar-p cross sections via spin-filtering.

Cosmic ray antiprotons at high energies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winkler, Martin Wolfgang, E-mail: martin.winkler@su.se

2017-02-01

Cosmic ray antiprotons provide a powerful tool to probe dark matter annihilations in our galaxy. The sensitivity of this important channel is, however, diluted by sizable uncertainties in the secondary antiproton background. In this work, we improve the calculation of secondary antiproton production with a particular focus on the high energy regime. We employ the most recent collider data and identify a substantial increase of antiproton cross sections with energy. This increase is driven by the violation of Feynman scaling as well as by an enhanced strange hyperon production. The updated antiproton production cross sections are made publicly available formore » independent use in cosmic ray studies. In addition, we provide the correlation matrix of cross section uncertainties for the AMS-02 experiment. At high energies, the new cross sections improve the compatibility of the AMS-02 data with a pure secondary origin of antiprotons in cosmic rays.« less

A unified account of tilt illusions, association fields, and contour detection based on elastica.

PubMed

Keemink, Sander W; van Rossum, Mark C W

2016-09-01

As expressed in the Gestalt law of good continuation, human perception tends to associate stimuli that form smooth continuations. Contextual modulation in primary visual cortex, in the form of association fields, is believed to play an important role in this process. Yet a unified and principled account of the good continuation law on the neural level is lacking. In this study we introduce a population model of primary visual cortex. Its contextual interactions depend on the elastica curvature energy of the smoothest contour connecting oriented bars. As expected, this model leads to association fields consistent with data. However, in addition the model displays tilt-illusions for stimulus configurations with grating and single bars that closely match psychophysics. Furthermore, the model explains not only pop-out of contours amid a variety of backgrounds, but also pop-out of single targets amid a uniform background. We thus propose that elastica is a unifying principle of the visual cortical network. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Antiproton Production by CR on Air Nuclei

NASA Technical Reports Server (NTRS)

Maskalenko, I. V.; Mashnik, S. G.

2003-01-01

Recent measurements of the cosmic ray (CR) antiproton flux have been shown to challenge existing CR propagation models. In particular, the conventional reacceleration model designed to match secondary/primary nuclei ratios produces too few antiprotons. Recently there appear some indications that the atmospheric contribution to antiproton production is considerably underestimated, which implies that antiproton CR flux might be lower. This may be the primary reason of the discrepancy discovered in CR propagation. We use the Los Alamos version of the Quark-Gluon String Model code LAQGSM together with available data on antiproton production on nuclei to analyse the accuracy of existing parameterizations of antiproton production cross section. The LAQGSM model has been shown to reproduce well nuclear reactions and hadronic data in the range 0.01-800 GeV/nucleon.

Measurement of the resonance parameters of the chi(1)(1**3P(1)) and chi(2)(1**3P(2)) states of charmonium formed in antiproton-proton annihilations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andreotti, M.; Bagnasco, S.; Baldini, W.

2005-03-01

The authors have studied the {sup 3}P{sub J} ({chi}{sub e}) states of charmonium in formation by antiproton-proton annihilations in experiment E835 at the Fermilab Antiproton Source. The authors report new measurements of the mass, width, and B({chi}{sub cJ} {yields} {bar p}p) x {Lambda}({chi}{sub eJ} {yields} J/{psi} + anything) for the {chi}{sub c1} and {chi}{sub c2} by means of the inclusive reaction {bar p}p {yields} {chi}{sub cJ} {yields} J/{psi} + anything {yields} (e{sup +}e{sup -}) + anything. Using the subsample of events where {chi}{sub cJ} {yields} {gamma} + J/{psi} {yields} {gamma} + (e{sup +}e{sup -}) is fully reconstructed, we derive B({chi}{submore » cJ} {yields} {bar p}p) x {Lambda}({chi}{sub cJ} {yields} J/{psi} + {gamma}). They summarize the results of the E760 (updated) and E835 measurements of mass, width and B({chi}{sub cJ} {yields} {bar p}p){Lambda}({chi}{sub cJ} {yields} J/{psi} + {gamma}) (J = 0,1,2) and discuss the significance of these measurements.« less

Flexive and Propulsive Dynamics of Elastica at Low Reynolds Numbers

NASA Astrophysics Data System (ADS)

Wiggins, Chris; Goldstein, Raymond

1997-11-01

A stiff one-armed swimmer in glycerine goes nowhere. However, if its arm is elastic, exerting a restorative torque proportional to local curvature, the swimmer can go on its way. Considering this happy consequence, we study a hyperdiffusion equation for the shape of the elastica in viscous flow, find solutions for impulsive or oscillatory forcing, and elucidate relevant aspects of propulsion. We illustrate an experiment which, coupled with this analysis, provides verification of the hyperdiffusive nature of elastohydrodynamics as well as a novel technique for measuring biopolymer bending moduli. Extensions necessary to study the viscous dynamics of twist and writhe are elucidated.

Galactic cosmic ray antiprotons and supersymmetry

NASA Technical Reports Server (NTRS)

Stecker, F. W.; Walsh, T.; Rudaz, S.

1985-01-01

The physics of the annihilation of photinos is considered as a function of mass in detail, in order to obtain the energy spectra of the cosmic ray antiprotons produced under the assumption that photinos make up the missing mass in the galactic halo. The modulated spectrum is at 1 a.w. with the cosmic ray antiprotons data. A very intriguing fit is obtained to all of the present antiprotons up to 13.4 GeV data for similar to 15 GeV. A cutoff is predicted in the antiprotons spectrum at E = photino mass above which only a small flux from secondary production should remain.

Correlated stopping, proton clusters and higher order proton cumulants

DOE PAGES

Bzdak, Adam; Koch, Volker; Skokov, Vladimir

2017-05-05

Here, we investigate possible effects of correlations between stopped nucleons on higher order proton cumulants at low energy heavy-ion collisions. We find that fluctuations of the number of wounded nucleons N part lead to rather nontrivial dependence of the correlations on the centrality; however, this effect is too small to explain the large and positive four-proton correlations found in the preliminary data collected by the STAR collaboration at √s = 7.7 GeV. We further demonstrate that, by taking into account additional proton clustering, we are able to qualitatively reproduce the preliminary experimental data. We speculate that this clustering may originatemore » either from collective/multi-collision stopping which is expected to be effective at lower energies or from a possible first-order phase transition, or from (attractive) final state interactions. To test these ideas we propose to measure a mixed multi-particle correlation between stopped protons and a produced particle (e.g. pion, antiproton).« less

Search for Polarization Effects in the Antiproton Production Process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grzonka, D.; Kilian, K.; Ritman, J.

For the production of a polarized antiproton beam, various methods have been suggested including the possibility that antiprotons may be produced polarized which will be checked experimentally. The polarization of antiprotons produced under typical conditions for antiproton beam preparation will be measured at the CERN/PS. If the production process creates some polarization, a polarized antiproton beam could be prepared by a rather simple modification of the antiproton beam facility. The detection setup and the expected experimental conditions are described.

A program to study antiprotons in the cosmic rays: Arizona collaboration

NASA Technical Reports Server (NTRS)

Bowen, Theodore

1992-01-01

The Cherenkov detector designed and built for the LEAP (Low Energy AntiProton) experiment utilized a novel design to achieve appreciable sensitive area (02. sq m) with a refractive index of 1.25 in a magnetic fringe field region (500-1000 Gauss). The weight was held to only 64 kg by using 16 unshielded Hamamatsu R2490-01 photomultiplier tubes, each aligned with its local magnetic field. A filling and reservoir system for the highly volatile FC-72 liquid Cherenkov radiator also presented many design challenges. Relativistic particles yielded about 72 photoelectrons, total.

Toward polarized antiprotons: Machine development for spin-filtering experiments

NASA Astrophysics Data System (ADS)

Weidemann, C.; Rathmann, F.; Stein, H. J.; Lorentz, B.; Bagdasarian, Z.; Barion, L.; Barsov, S.; Bechstedt, U.; Bertelli, S.; Chiladze, D.; Ciullo, G.; Contalbrigo, M.; Dymov, S.; Engels, R.; Gaisser, M.; Gebel, R.; Goslawski, P.; Grigoriev, K.; Guidoboni, G.; Kacharava, A.; Kamerdzhiev, V.; Khoukaz, A.; Kulikov, A.; Lehrach, A.; Lenisa, P.; Lomidze, N.; Macharashvili, G.; Maier, R.; Martin, S.; Mchedlishvili, D.; Meyer, H. O.; Merzliakov, S.; Mielke, M.; Mikirtychiants, M.; Mikirtychiants, S.; Nass, A.; Nikolaev, N. N.; Oellers, D.; Papenbrock, M.; Pesce, A.; Prasuhn, D.; Retzlaff, M.; Schleichert, R.; Schröer, D.; Seyfarth, H.; Soltner, H.; Statera, M.; Steffens, E.; Stockhorst, H.; Ströher, H.; Tabidze, M.; Tagliente, G.; Engblom, P. Thörngren; Trusov, S.; Valdau, Yu.; Vasiliev, A.; Wüstner, P.

2015-02-01

The paper describes the commissioning of the experimental equipment and the machine studies required for the first spin-filtering experiment with protons at a beam kinetic energy of 49.3 MeV in COSY. The implementation of a low-β insertion made it possible to achieve beam lifetimes of τb=8000 s in the presence of a dense polarized hydrogen storage-cell target of areal density dt=(5.5 ±0.2 )×1 013 atoms /cm2 . The developed techniques can be directly applied to antiproton machines and allow the determination of the spin-dependent p ¯p cross sections via spin filtering.

Positron cooling of antiprotons: precursor of recombination

NASA Astrophysics Data System (ADS)

Tan, J. N.; Estrada, J.; Yesley, P.; Bowden, N.; Oxley, P.; Storry, C.; Wessels, M.; Tan, J.; Gabrielse, G.; Oelert, W.; Scheppers, G.; Gronzonka, D.; Sefsick, T.; Fermann, H.; Zmeskal, H.; Breunlich, W.; Kalinowsky, H.; Wesdorp, C.

2001-05-01

The quest for cold antihydrogen, interrupted with the shut-down of LEAR, resumed with the operation of the newest antiproton decelerator (AD) at CERN.[See G.Gabrielse,Adv. in AMO Physics,vol.45,pp.1-38(2001).] Antiprotons injected into the AD with 2.75 GeV of kinetic energy slow to 5.31 MeV before extraction into the ATRAP apparatus, built for antihydrogen recombination experiments. Antiprotons extracted from the AD and positrons emitted from a 112 mCi ^22Na source are simultaneously accumulated in the ultra-high vacuum and 6 T field of a prototype Penning trap incorporating a miniature rotatable electrode. Preloaded electrons are used to thermalize ~ 10^5 antiprotons with the LHe-cooled trap (4.2K). Over 10^6 positrons/hr can be loaded with a new mechanism involving Rydberg positronium. After accumulation, the positrons are moved through the rotatable electrode into close proximity with the antiprotons to study their interactions. We report the first observation of positron cooling of antiprotons in a nested trap configuration suited for three-body recombination and other mechanisms.

Emilio Segrè, the Antiproton, Technetium, and Astatine

Science.gov Websites

of U238, DOE Technical Report, 1942 Spontaneous Fission, DOE Technical Report, November 1950 Observation of Antiprotons, DOE Technical Report, October 1955 Antiprotons, DOE Technical Report, November 1955 The Antiproton-Nucleon Annihilation Process (Antiproton Collaboration Experiment), DOE Technical

Commissioning of the PRIOR proton microscope

DOE PAGES

Varentsov, D.; Antonov, O.; Bakhmutova, A.; ...

2016-02-18

Recently, a new high energy proton microscopy facility PRIOR (Proton Microscope for FAIR Facility for Anti-proton and Ion Research) has been designed, constructed, and successfully commissioned at GSI Helmholtzzentrum für Schwerionenforschung (Darmstadt, Germany). As a result of the experiments with 3.5–4.5 GeV proton beams delivered by the heavy ion synchrotron SIS-18 of GSI, 30 μm spatial and 10 ns temporal resolutions of the proton microscope have been demonstrated. A new pulsed power setup for studying properties of matter under extremes has been developed for the dynamic commissioning of the PRIOR facility. This study describes the PRIOR setup as well asmore » the results of the first static and dynamic protonradiography experiments performed at GSI.« less

Commissioning of the PRIOR proton microscope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varentsov, D.; Antonov, O.; Bakhmutova, A.

Recently, a new high energy proton microscopy facility PRIOR (Proton Microscope for FAIR Facility for Anti-proton and Ion Research) has been designed, constructed, and successfully commissioned at GSI Helmholtzzentrum für Schwerionenforschung (Darmstadt, Germany). As a result of the experiments with 3.5–4.5 GeV proton beams delivered by the heavy ion synchrotron SIS-18 of GSI, 30 μm spatial and 10 ns temporal resolutions of the proton microscope have been demonstrated. A new pulsed power setup for studying properties of matter under extremes has been developed for the dynamic commissioning of the PRIOR facility. This study describes the PRIOR setup as well asmore » the results of the first static and dynamic protonradiography experiments performed at GSI.« less

The Early Antiproton Work [Nobel Lecture

DOE R&D Accomplishments Database

Chamberlain, O.

1959-12-15

Early work on the antiproton, particularly that part which led to the first paper on the subject, is described. Conclusions that can be drawn purely from the existence of the antiproton are discussed. (W.D.M.)

Antimicrobial Potential of Helicanthus elastica (Desr.) Danser - A less explored Indian mistletoe Growing on Mango Trees

PubMed Central

Sunil Kumar, Koppala Narayana; Saraswathy, Ariyamuthu; Amerjothy, Swaminathan; Ravishankar, Basaviah

2014-01-01

Helicanthus elastica (Desr.) Danser (Loranthaceae) is a less-known medicinally important mistletoe species occurring in India. It is used to check abortion, and also in vesical calculi and kidney affections. There are no detailed studies reporting the antimicrobial potential of this plant. Based on the traditional use and the rich phenolic composition of the whole plant, the antimicrobial property of the alcohol extract was analyzed and the results are outlined in the present paper. For the analysis, zone of inhibition, and minimum inhibitory concentration were used, and the total activity was assayed by standard methodologies. The antimicrobial activity was studied against bacteria like Aeromonas hydrophila, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pyogenes, Vibrio fischeri, and a fungus Candida albicans. Of the eight tested bacteria, the alcoholic extract of H. elastica was found to be active against K. pneumoniae, A. hydrophila, E. coli, and V. fischeri at concentration ranging from 250 to 500 μg/ml. C. albicans showed inhibition only at a concentration of 2000 μg/ml. PMID:25379468

A parts-per-billion measurement of the antiproton magnetic moment

NASA Astrophysics Data System (ADS)

Smorra, C.; Sellner, S.; Borchert, M. J.; Harrington, J. A.; Higuchi, T.; Nagahama, H.; Tanaka, T.; Mooser, A.; Schneider, G.; Bohman, M.; Blaum, K.; Matsuda, Y.; Ospelkaus, C.; Quint, W.; Walz, J.; Yamazaki, Y.; Ulmer, S.

2017-10-01

Precise comparisons of the fundamental properties of matter-antimatter conjugates provide sensitive tests of charge-parity-time (CPT) invariance, which is an important symmetry that rests on basic assumptions of the standard model of particle physics. Experiments on mesons, leptons and baryons have compared different properties of matter-antimatter conjugates with fractional uncertainties at the parts-per-billion level or better. One specific quantity, however, has so far only been known to a fractional uncertainty at the parts-per-million level: the magnetic moment of the antiproton, . The extraordinary difficulty in measuring with high precision is caused by its intrinsic smallness; for example, it is 660 times smaller than the magnetic moment of the positron. Here we report a high-precision measurement of in units of the nuclear magneton μN with a fractional precision of 1.5 parts per billion (68% confidence level). We use a two-particle spectroscopy method in an advanced cryogenic multi-Penning trap system. Our result  = -2.7928473441(42)μN (where the number in parentheses represents the 68% confidence interval on the last digits of the value) improves the precision of the previous best measurement by a factor of approximately 350. The measured value is consistent with the proton magnetic moment, μp = 2.792847350(9)μN, and is in agreement with CPT invariance. Consequently, this measurement constrains the magnitude of certain CPT-violating effects to below 1.8 × 10-24 gigaelectronvolts, and a possible splitting of the proton-antiproton magnetic moments by CPT-odd dimension-five interactions to below 6 × 10-12 Bohr magnetons.

A parts-per-billion measurement of the antiproton magnetic moment.

PubMed

Smorra, C; Sellner, S; Borchert, M J; Harrington, J A; Higuchi, T; Nagahama, H; Tanaka, T; Mooser, A; Schneider, G; Bohman, M; Blaum, K; Matsuda, Y; Ospelkaus, C; Quint, W; Walz, J; Yamazaki, Y; Ulmer, S

2017-10-18

Precise comparisons of the fundamental properties of matter-antimatter conjugates provide sensitive tests of charge-parity-time (CPT) invariance, which is an important symmetry that rests on basic assumptions of the standard model of particle physics. Experiments on mesons, leptons and baryons have compared different properties of matter-antimatter conjugates with fractional uncertainties at the parts-per-billion level or better. One specific quantity, however, has so far only been known to a fractional uncertainty at the parts-per-million level: the magnetic moment of the antiproton, . The extraordinary difficulty in measuring with high precision is caused by its intrinsic smallness; for example, it is 660 times smaller than the magnetic moment of the positron. Here we report a high-precision measurement of in units of the nuclear magneton μ N with a fractional precision of 1.5 parts per billion (68% confidence level). We use a two-particle spectroscopy method in an advanced cryogenic multi-Penning trap system. Our result  = -2.7928473441(42)μ N (where the number in parentheses represents the 68% confidence interval on the last digits of the value) improves the precision of the previous best measurement by a factor of approximately 350. The measured value is consistent with the proton magnetic moment, μ p  = 2.792847350(9)μ N , and is in agreement with CPT invariance. Consequently, this measurement constrains the magnitude of certain CPT-violating effects to below 1.8 × 10 -24 gigaelectronvolts, and a possible splitting of the proton-antiproton magnetic moments by CPT-odd dimension-five interactions to below 6 × 10 -12 Bohr magnetons.

Antiproton beam polarizer using a dense polarized target

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wojtsekhowski, Bogdan

2011-05-01

We describe considerations regarding the spin filtering method for the antiproton beam. The proposed investigation of the double polarization cross section for antiproton to nucleon interaction is outlined. It will use a single path of the antiproton beam through a dense polarized target, e.g. 3He or CH2, followed by a polarimeter.

Antiproton Trapping for Advanced Space Propulsion Applications

NASA Technical Reports Server (NTRS)

Smith, Gerald A.

1998-01-01

The Summary of Research parallels the Statement of Work (Appendix I) submitted with the proposal, and funded effective Feb. 1, 1997 for one year. A proposal was submitted to CERN in October, 1996 to carry out an experiment on the synthesis and study of fundamental properties of atomic antihydrogen. Since confined atomic antihydrogen is potentially the most powerful and elegant source of propulsion energy known, its confinement and properties are of great interest to the space propulsion community. Appendix II includes an article published in the technical magazine Compressed Air, June 1997, which describes CERN antiproton facilities, and ATHENA. During the period of this grant, Prof. Michael Holzscheiter served as spokesman for ATHENA and, in collaboration with Prof. Gerald Smith, worked on the development of the antiproton confinement trap, which is an important part of the ATHENA experiment. Appendix III includes a progress report submitted to CERN on March 12, 1997 concerning development of the ATHENA detector. Section 4.1 reviews technical responsibilities within the ATHENA collaboration, including the Antiproton System, headed by Prof. Holzscheiter. The collaboration was advised (see Appendix IV) on June 13, 1997 that the CERN Research Board had approved ATHENA for operation at the new Antiproton Decelerator (AD), presently under construction. First antiproton beams are expected to be delivered to experiments in about one year. Progress toward assembly of the ATHENA detector and initial testing expected in 1999 has been excellent. Appendix V includes a copy of the minutes of the most recently documented collaboration meeting held at CERN of October 24, 1997, which provides more information on development of systems, including the antiproton trapping apparatus. On February 10, 1998 Prof. Smith gave a 3 hour lecture on the Physics of Antimatter, as part of the Physics for the Third Millennium Lecture Series held at MSFC. Included in Appendix VI are notes and

Antiproton catalyzed microfission/fusion propulsion

NASA Technical Reports Server (NTRS)

Chiang, Pi-Ren; Lewis, Raymond A.; Smith, Gerald A.; Newton, Richard; Dailey, James; Werthman, W. Lance; Chakrabarti, Suman

1994-01-01

Inertial confinement fusion (ICF) utilizing an antiproton catalyzed hybrid fission/fusion target is discussed as a potential energy source for interplanetary propulsion. A proof-of-principle experiment underway at Phillips Laboratory, Kirtland AFB and antiproton trapping experiments at CERN, Geneva, Switzerland, are presented. The ICAN propulsion concept is described and results of performance analyses are reviewed. Future work to further define the ICAN concept is outlined.

Antiproton Production in Relativistic Heavy Ion Collisions

NASA Astrophysics Data System (ADS)

Greene, Senta Victoria

The E814 collaboration has made a systematic study of antiproton production in collisions of ^ {28}Si ions at 14.6 GeV per nucleon with targets of Pb, Cu, and Al. This study was motivated by the expectation that antiprotons will be a useful probe of the system produced in relativistic heavy ion collisions. The large annihilation cross section for antiprotons makes the antiproton survival probability sensitive to the baryon density of the system in which they are created. It has also been suggested that a transition to the quark-gluon plasma phase may produce an enhancement of antibaryon production. The E814 spectrometer consists of three tracking chambers for momentum measurement, a scintillator hodoscope to measure charge and time of flight, and a sampling calorimeter. The spectrometer accepts all particles produced within a rectangular aperture centered on the beam axis, with delta theta_{x}=37.6mr and deltatheta_{y}=24.1mr. A trigger based on the flight time of particles through the spectrometer enhances the selection of events which produce negatively charged particles having a rapidity within 0.5 units of the center of mass rapidity. Measurements of the antiproton yield per interaction and the invariant cross section for production at zero degrees are presented and discussed. The time-of-flight trigger allows for an unbiased measurement of the probability to produce antiprotons as a function of the impact parameter of the collision. Several measures of collision centrality are used. The energy produced transverse to the beam direction is measured with the target calorimeter, an array of NaI crystals surrounding the target assembly with a pseudorapidity coverage of -0.5

Annihilation of Antiprotons in Heavy Nuclei.

DTIC Science & Technology

1986-04-01

Scattering Models, Acta Physica Polonica 1311, 425 (1980). T.E. Kalogeropoalos, L. Gray, A . Nandy, and J. Roy, Antiproton-nucleon Annihilation into...I th a Rpor Annihilation of AntiprotonsI the period ,- tpril 1985 to in Heavy Nuclei December 1985 April 1986 Author: Lawrence Livermore National...will be available to the general public, including foreign nationals. A ~AY 2 - >i K2U~ prepared for the: Air Force Rocket Propulsion Laboratory Air

The Bess Investigation of the Origin of Cosmic-ray Antiprotons and Search for Cosmological Antimatter

NASA Technical Reports Server (NTRS)

Mitchell, John; Yamamoto, Akira; Yoshimura, Koji; Makida, Yasuhiro; Matsuda, Shinya; Hasegawa, Masaya; Horikoshi, Atsushi; Tanaka,Ken-ichi; Suzuki, Junichi; Nishimura, Jun;

On the utility of antiprotons as drivers for inertial confinement fusion

NASA Astrophysics Data System (ADS)

Perkins, L. John; Orth, Charles D.; Tabak, Max

2004-10-01

In contrast to the large mass, complexity and recirculating power of conventional drivers for inertial confinement fusion (ICF), antiproton annihilation offers a specific energy of 90 MJ µg-1 and thus a unique form of energy packaging and delivery. In principle, antiproton drivers could provide a profound reduction in system mass for advanced space propulsion by ICF. We examine the physics underlying the use of antiprotons ( \\bar{p} ) to drive various classes of high-yield ICF targets by the methods of volumetric ignition, hotspot ignition and fast ignition. The useable fraction of annihilation deposition energy is determined for both \\bar{p} -driven ablative compression and \\bar{p} -driven fast ignition, in association with zero- and one-dimensional target burn models. Thereby, we deduce scaling laws for the number of injected antiprotons required per capsule, together with timing and focal spot requirements. The kinetic energy of the injected antiproton beam required to penetrate to the desired annihilation point is always small relative to the deposited annihilation energy. We show that heavy metal seeding of the fuel and/or ablator is required to optimize local deposition of annihilation energy and determine that a minimum of ~3 × 1015 injected antiprotons will be required to achieve high yield (several hundred megajoules) in any target configuration. Target gains—i.e. fusion yields divided by the available p- \\bar{p} annihilation energy from the injected antiprotons ( 1.88\\,GeV/\\bar{p} )—range from ~3 for volumetric ignition targets to ~600 for fast ignition targets. Antiproton-driven ICF is a speculative concept, and the handling of antiprotons and their required injection precision—temporally and spatially—will present significant technical challenges. The storage and manipulation of low-energy antiprotons, particularly in the form of antihydrogen, is a science in its infancy and a large scale-up of antiproton production over present supply

Experimental results on antiproton-nuclei annihilation cross section at very low energies

NASA Astrophysics Data System (ADS)

Aghai-Khozani, H.; Barna, D.; Corradini, M.; Hayano, R.; Hori, M.; Kobayashi, T.; Leali, M.; Lodi-Rizzini, E.; Mascagna, V.; Prest, M.; Soter, A.; Todoroki, K.; Vallazza, E.; Venturelli, L.; Zurlo, N.

2014-03-01

Investigating the antiproton cross section on nuclei at low energies (1 eV - 1 MeV) is of great interest for fundamental cosmology and nuclear physics as well. The process is of great relevance for the models which try to explain the matter/antimatter asymmetry in the universe assuming the existence of the so-called "island" where antinucleon-nucleon annihilations occur in the border region [1]. For the nuclear physics point of view, the annihilation process is considered a useful tool to evaluate the neutron/proton ratio probing the external region of the nucleus. Moreover, the cross section measured at LEAR in the 80s-90s showed an unexpected behaviour for energies below 1 MeV. The results showed a saturation with the atomic mass number against the A2/3 trend which is known for higher energies. The ASACUSA collaboration at CERN measured 5.3 MeV antiproton annihilation cross section on different nuclei whose results demonstrated to be consistent with the black-disk model with the Coulomb correction [2]. So far, experimental limits prevented the data acquisition for energies below 1 MeV. In 2012 the 100 keV region has been investigated for the first time [3]. We present here the results of the experiment.

Search for Standard Model Higgs Boson Produced in Association with a Top-Antitop Quark Pair in 1.96 TeV Proton-Antiproton Collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lai, Stanley T.

2007-01-01

This thesis describes the first search for Standard Model Higgs boson production in association with a top-antitop quark pair in proton-antiproton collisions at a centre of mass energy of 1.96 TeV. The integrated luminosity for othis search corresponds to 319 pb -1 of data recorded by the Collider Detector at Fermilab. We outline the even selection criteria, evaluate the even acceptance and estimate backgrounds from Standard Model sources. These events are observed that satisfy our event selection, while 2.16 ± 0.66 events are expected from background processes. no significant excess of events above background is thus observed, and we set 95% confidence level upper limits on the production cross section for this process as a function of the Higgs mass. For a Higgs boson mass of 115 GeV/c 2 we find that σ more » $$t\\bar{t}H$$ x BR (H → bb) < 690 fb at 95% C.L. These are the first limits set for $$t\\bar{t}H$$ production. This search also allows us to anticipate the challenges and necessary strategies needed for future searches of $$t\\bar{t}H$$ production.« less

Proton: The Particle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suit, Herman

The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10{sup 80}. Protons were created atmore » 10{sup −6} –1 second after the Big Bang at ≈1.37 × 10{sup 10} years beforethe present. Proton life span has been experimentally determined to be ≥10{sup 34} years; that is, the age of the universe is 10{sup −24}th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W{sup +}, W{sup −}, Z{sup 0}, and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving

Proton: the particle.

PubMed

Suit, Herman

2013-11-01

The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10(80). Protons were created at 10(-6) -1 second after the Big Bang at ≈1.37 × 10(10) years beforethe present. Proton life span has been experimentally determined to be ≥10(34) years; that is, the age of the universe is 10(-24)th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W(+), W(-), Z(0), and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter. Copyright © 2013 Elsevier Inc. All

Densidad de artrópodos activos en la superficie del suelo de un bosque novedoso de Castilla elastica

Treesearch

Maria Rivera; Ariel E. Lugo; Shalom V. Vázquez

2008-01-01

During the month of June 2008 we collected arthropods active on the surface of the ground in a forest of Castilla elastica located in the northern karst’s Tallonal Reserve in Arecibo, Puerto Rico. In each of 4 plots of 10 m x 10 m we placed three randomly distributed pitfall traps. The traps, which allowed the passage of organisms smaller than 5 mm wide, remained on...

Slowing down of 100 keV antiprotons in Al foils

NASA Astrophysics Data System (ADS)

Nordlund, K.

2018-03-01

Using energy degrading foils to slow down antiprotons is of interest for producing antihydrogen atoms. I consider here the slowing down of 100 keV antiprotons, that will be produced in the ELENA storage ring under construction at CERN, to energies below 10 keV. At these low energies, they are suitable for efficient antihydrogen production. I simulate the antihydrogen motion and slowing down in Al foils using a recently developed molecular dynamics approach. The results show that the optimal Al foil thickness for slowing down the antiprotons to below 5 keV is 910 nm, and to below 10 keV is 840 nm. Also the lateral spreading of the transmitted antiprotons is reported and the uncertainties discussed.

Compression of a mixed antiproton and electron non-neutral plasma to high densities

NASA Astrophysics Data System (ADS)

Aghion, Stefano; Amsler, Claude; Bonomi, Germano; Brusa, Roberto S.; Caccia, Massimo; Caravita, Ruggero; Castelli, Fabrizio; Cerchiari, Giovanni; Comparat, Daniel; Consolati, Giovanni; Demetrio, Andrea; Di Noto, Lea; Doser, Michael; Evans, Craig; Fanì, Mattia; Ferragut, Rafael; Fesel, Julian; Fontana, Andrea; Gerber, Sebastian; Giammarchi, Marco; Gligorova, Angela; Guatieri, Francesco; Haider, Stefan; Hinterberger, Alexander; Holmestad, Helga; Kellerbauer, Alban; Khalidova, Olga; Krasnický, Daniel; Lagomarsino, Vittorio; Lansonneur, Pierre; Lebrun, Patrice; Malbrunot, Chloé; Mariazzi, Sebastiano; Marton, Johann; Matveev, Victor; Mazzotta, Zeudi; Müller, Simon R.; Nebbia, Giancarlo; Nedelec, Patrick; Oberthaler, Markus; Pacifico, Nicola; Pagano, Davide; Penasa, Luca; Petracek, Vojtech; Prelz, Francesco; Prevedelli, Marco; Rienaecker, Benjamin; Robert, Jacques; Røhne, Ole M.; Rotondi, Alberto; Sandaker, Heidi; Santoro, Romualdo; Smestad, Lillian; Sorrentino, Fiodor; Testera, Gemma; Tietje, Ingmari C.; Widmann, Eberhard; Yzombard, Pauline; Zimmer, Christian; Zmeskal, Johann; Zurlo, Nicola; Antonello, Massimiliano

2018-04-01

We describe a multi-step "rotating wall" compression of a mixed cold antiproton-electron non-neutral plasma in a 4.46 T Penning-Malmberg trap developed in the context of the AEḡIS experiment at CERN. Such traps are routinely used for the preparation of cold antiprotons suitable for antihydrogen production. A tenfold antiproton radius compression has been achieved, with a minimum antiproton radius of only 0.17 mm. We describe the experimental conditions necessary to perform such a compression: minimizing the tails of the electron density distribution is paramount to ensure that the antiproton density distribution follows that of the electrons. Such electron density tails are remnants of rotating wall compression and in many cases can remain unnoticed. We observe that the compression dynamics for a pure electron plasma behaves the same way as that of a mixed antiproton and electron plasma. Thanks to this optimized compression method and the high single shot antiproton catching efficiency, we observe for the first time cold and dense non-neutral antiproton plasmas with particle densities n ≥ 1013 m-3, which pave the way for an efficient pulsed antihydrogen production in AEḡIS.

Challenging Cosmic Ray Propagation with Antiprotons: Evidence for a "Fresh" Nuclei Component?

NASA Technical Reports Server (NTRS)

Moskalenko, Igor V.; Strong, Andrew W.; Mashnik, Stepan G.; Ormes, Jonathan F.

2002-01-01

Recent measurements of the cosmic ray (CR) antiproton flux have been shown to challenge existing CR propagation models. It was shown that the reacceleration models designed to match secondary to primary nuclei ratio (e.g., Boron/Carbon) produce too few antiprotons, while the traditional non-reacceleration models can reproduce the antiproton flux but fall short of explaining the low-energy decrease in the secondary to primary nuclei ratio. Matching both the secondary to primary nuclei ratio and antiproton flux requires artificial breaks in the diffusion coefficient and the primary injection spectrum suggesting the need for other approaches. In the present paper we discuss one possibility to overcome these difficulties. Using the measured antiproton flux to fix the diffusion coefficient, we show that the spectra of primary nuclei as measured in the heliosphere may contain a fresh local unprocessed component at low energies, thus decreasing the measured secondary to primary nuclei ratio. A model reproducing antiprotons, B/C ratio, and abundances up to Ni is presented.

Extended Glauber Model of Antiproton-Nucleus Annihilation for All Energies and Mass Numbers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Teck-Ghee; Wong, Cheuk-Yin

2014-01-01

Previous analytical formulas in the Glauber model for high-energy nucleus-nucleus collisions developed by Wong are utilized and extended to study Antiproton-nucleus annihilations for both high and low energies, after taking into account the effects of Coulomb and nuclear interactions, and the change of the antiproton momentum inside a nucleus. The extended analytical formulas capture the main features of the experimental antiproton-nucleus annihilation cross sections for all energies and mass numbers. At high antiproton energies, they exhibit the granular property for the lightest nuclei and the black-disk limit for the heavy nuclei. At low antiproton energies, they display the effect ofmore » the antiproton momentum increase due to the nuclear interaction for the light nuclei, and the effect of the magnification due to the attractive Coulomb interaction for the heavy nuclei.« less

The presence of cutan limits the interpretation of cuticular chemistry and structure: Ficus elastica leaf as an example.

PubMed

Guzmán-Delgado, Paula; Graça, José; Cabral, Vanessa; Gil, Luis; Fernández, Victoria

2016-06-01

Plant cuticles have been traditionally classified on the basis of their ultrastructure, with certain chemical composition assumptions. However, the nature of the plant cuticle may be misinterpreted in the prevailing model, which was established more than 150 years ago. Using the adaxial leaf cuticle of Ficus elastica, a study was conducted with the aim of analyzing cuticular ultrastructure, chemical composition and the potential relationship between structure and chemistry. Gradual chemical extractions and diverse analytical and microscopic techniques were performed on isolated leaf cuticles of two different stages of development (i.e. young and mature leaves). Evidence for the presence of cutan in F. elastica leaf cuticles has been gained after chemical treatments and tissue analysis by infrared spectroscopy and electron microscopy. Significant calcium, boron and silicon concentrations were also measured in the cuticle of this species. Such mineral elements which are often found in plant cell walls may play a structural role and their presence in isolated cuticles further supports the interpretation of the cuticle as the most external region of the epidermal cell wall. The complex and heterogeneous nature of the cuticle, and constraints associated with current analytical procedures may limit the chance for establishing a relationship between cuticle chemical composition and structure also in relation to organ ontogeny. © 2016 Scandinavian Plant Physiology Society.

Measurement of inelastic, single- and double-diffraction cross sections in proton-proton collisions at the LHC with ALICE.

PubMed

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Ferreiro, E G; González-Trueba, L H; González-Zamora, P; Gorbunov, S; Goswami, A; Gotovac, S; Grabski, V; Graczykowski, L K; Grajcarek, R; Grelli, A; Grigoras, C; Grigoras, A; Grigoriev, V; Grigoryan, S; Grigoryan, A; Grinyov, B; Grion, N; Gros, P; Grosse-Oetringhaus, J F; Grossiord, J-Y; Grosso, R; Guber, F; Guernane, R; Guerra Gutierrez, C; Guerzoni, B; Guilbaud, M; Gulbrandsen, K; Gunji, T; Gupta, A; Gupta, R; Gutbrod, H; Haaland, Ø; Hadjidakis, C; Haiduc, M; Hamagaki, H; Hamar, G; Han, B H; Hanratty, L D; Hansen, A; Harmanová-Tóthová, Z; Harris, J W; Hartig, M; Hasegan, D; Hatzifotiadou, D; Hayrapetyan, A; Heckel, S T; Heide, M; Helstrup, H; Herghelegiu, A; Herrera Corral, G; Herrmann, N; Hess, B A; Hetland, K F; Hicks, B; Hille, P T; Hippolyte, B; Horaguchi, T; Hori, Y; Hristov, P; Hřivnáčová, I; Huang, M; Humanic, T J; Hwang, D S; Ichou, R; Ilkaev, R; Ilkiv, I; Inaba, M; Incani, E; Innocenti, P G; Innocenti, G M; Ippolitov, M; Irfan, M; Ivan, C; Ivanov, A; Ivanov, M; Ivanov, V; Ivanytskyi, O; 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Marquard, M; Martashvili, I; Martinengo, P; Martínez, M I; Martínez Davalos, A; Martínez García, G; Martynov, Y; Mas, A; Masciocchi, S; Masera, M; Masoni, A; Massacrier, L; Mastroserio, A; Matthews, Z L; Matyja, A; Mayer, C; Mazer, J; Mazzoni, M A; Meddi, F; Menchaca-Rocha, A; Mercado Pérez, J; Meres, M; Miake, Y; Milano, L; Milosevic, J; Mischke, A; Mishra, A N; Miśkowiec, D; Mitu, C; Mlynarz, J; Mohanty, B; Molnar, L; Montaño Zetina, L; Monteno, M; Montes, E; Moon, T; Morando, M; Moreira De Godoy, D A; Moretto, S; Morsch, A; Muccifora, V; Mudnic, E; Muhuri, S; Mukherjee, M; Müller, H; Munhoz, M G; Musa, L; Musso, A; Nandi, B K; Nania, R; Nappi, E; Nattrass, C; Naumov, N P; Navin, S; Nayak, T K; Nazarenko, S; Nazarov, G; Nedosekin, A; Nicassio, M; Niculescu, M; Nielsen, B S; Niida, T; Nikolaev, S; Nikolic, V; Nikulin, S; Nikulin, V; Nilsen, B S; Nilsson, M S; Noferini, F; Nomokonov, P; Nooren, G; Novitzky, N; Nyanin, A; Nyatha, A; Nygaard, C; Nystrand, J; Ochirov, A; Oeschler, H; Oh, S; Oh, S K; Oleniacz, J; Oppedisano, C; Ortiz Velasquez, A; Ortona, G; Oskarsson, A; Ostrowski, P; Otwinowski, J; Oyama, K; Ozawa, K; Pachmayer, Y; Pachr, M; Padilla, F; Pagano, P; Paić, G; Painke, F; Pajares, C; Pal, S K; Palaha, A; Palmeri, A; Papikyan, V; Pappalardo, G S; Park, W J; Passfeld, A; Pastirčák, B; Patalakha, D I; Paticchio, V; Pavlinov, A; Pawlak, T; Peitzmann, T; Pereira Da Costa, H; Pereira De Oliveira Filho, E; Peresunko, D; Pérez Lara, C E; Perez Lezama, E; Perini, D; Perrino, D; Peryt, W; Pesci, A; Peskov, V; Pestov, Y; Petráček, V; Petran, M; Petris, M; Petrov, P; Petrovici, M; Petta, C; Piano, S; Piccotti, A; Pikna, M; Pillot, P; Pinazza, O; Pinsky, L; Pitz, N; Piyarathna, D B; Planinic, M; Płoskoń, M; Pluta, J; Pocheptsov, T; Pochybova, S; Podesta-Lerma, P L M; Poghosyan, M G; Polák, K; Polichtchouk, B; Pop, A; Porteboeuf-Houssais, S; Pospíšil, V; Potukuchi, B; Prasad, S K; Preghenella, R; Prino, F; Pruneau, C A; Pshenichnov, I; Puchagin, S; Puddu, G; Pulvirenti, A; Punin, V; Putiš, M; Putschke, J; Quercigh, E; Qvigstad, H; Rachevski, A; Rademakers, A; Räihä, T S; Rak, J; Rakotozafindrabe, A; Ramello, L; Ramírez Reyes, A; Raniwala, S; Raniwala, R; Räsänen, S S; Rascanu, B T; Rathee, D; Read, K F; Real, J S; Redlich, K; Reichelt, P; Reicher, M; Renfordt, R; Reolon, A R; Reshetin, A; Rettig, F; Revol, J-P; Reygers, K; Riccati, L; Ricci, R A; Richert, T; Richter, M; Riedler, P; Riegler, W; Riggi, F; Rodrigues Fernandes Rabacal, B; Rodríguez Cahuantzi, M; Rodriguez Manso, A; Røed, K; Rohr, D; Röhrich, D; Romita, R; Ronchetti, F; Rosnet, P; Rossegger, S; Rossi, A; Roy, P; Roy, C; Rubio Montero, A J; Rui, R; Russo, R; Ryabinkin, E; Rybicki, A; Sadovsky, S; Šafařík, K; Sahoo, R; Sahu, P K; Saini, J; Sakaguchi, H; Sakai, S; Sakata, D; Salgado, C A; Salzwedel, J; Sambyal, S; Samsonov, V; Sanchez Castro, X; Šándor, L; Sandoval, A; Sano, M; Sano, S; Santo, R; Santoro, R; Sarkamo, J; Scapparone, E; Scarlassara, F; Scharenberg, R P; Schiaua, C; Schicker, R; Schmidt, C; Schmidt, H R; Schreiner, S; Schuchmann, S; Schukraft, J; Schutz, Y; Schwarz, K; Schweda, K; Scioli, G; Scomparin, E; Scott, R; Segato, G; Selyuzhenkov, I; Senyukov, S; Seo, J; Serci, S; Serradilla, E; Sevcenco, A; Shabetai, A; Shabratova, G; Shahoyan, R; Sharma, N; Sharma, S; Rohni, S; Shigaki, K; Shimomura, M; Shtejer, K; Sibiriak, Y; Siciliano, M; Sicking, E; Siddhanta, S; Siemiarczuk, T; Silvermyr, D; Silvestre, C; Simatovic, G; Simonetti, G; Singaraju, R; Singh, R; Singha, S; Singhal, V; Sinha, B C; Sinha, T; Sitar, B; Sitta, M; Skaali, T B; Skjerdal, K; Smakal, R; Smirnov, N; Snellings, R J M; Søgaard, C; Soltz, R; Son, H; Song, M; Song, J; Soos, C; Soramel, F; Sputowska, I; Spyropoulou-Stassinaki, M; Srivastava, B K; Stachel, J; Stan, I; Stan, I; Stefanek, G; Steinpreis, M; Stenlund, E; Steyn, G; Stiller, J H; Stocco, D; Stolpovskiy, M; Strabykin, K; Strmen, P; Suaide, A A P; Subieta Vásquez, M A; Sugitate, T; Suire, C; Sukhorukov, M; Sultanov, R; Šumbera, M; Susa, T; Symons, T J M; Szanto de Toledo, A; Szarka, I; Szczepankiewicz, A; Szostak, A; Szymański, M; Takahashi, J; Tapia Takaki, J D; Tauro, A; Tejeda Muñoz, G; Telesca, A; Terrevoli, C; Thäder, J; Thomas, D; Tieulent, R; Timmins, A R; Tlusty, D; Toia, A; Torii, H; Toscano, L; Trubnikov, V; Truesdale, D; Trzaska, W H; Tsuji, T; Tumkin, A; Turrisi, R; Tveter, T S; Ulery, J; Ullaland, K; Ulrich, J; Uras, A; Urbán, J; Urciuoli, G M; Usai, G L; Vajzer, M; Vala, M; Valencia Palomo, L; Vallero, S; Vande Vyvre, P; van Leeuwen, M; Vannucci, L; Vargas, A; Varma, R; Vasileiou, M; Vasiliev, A; Vechernin, V; Veldhoen, M; Venaruzzo, M; Vercellin, E; Vergara, S; Vernet, R; Verweij, M; Vickovic, L; Viesti, G; Vikhlyantsev, O; Vilakazi, Z; Villalobos Baillie, O; Vinogradov, Y; Vinogradov, A; Vinogradov, L; Virgili, T; Viyogi, Y P; Vodopyanov, A; Voloshin, S; Voloshin, K; Volpe, G; von Haller, B; Vranic, D; Øvrebekk, G; Vrláková, J; Vulpescu, B; Vyushin, A; Wagner, V; Wagner, B; Wan, R; Wang, M; Wang, D; Wang, Y; Wang, Y; Watanabe, K; Weber, M; Wessels, J P; Westerhoff, U; Wiechula, J; Wikne, J; Wilde, M; Wilk, A; Wilk, G; Williams, M C S; Windelband, B; Xaplanteris Karampatsos, L; Yaldo, C G; Yamaguchi, Y; Yang, H; Yang, S; Yasnopolskiy, S; Yi, J; Yin, Z; Yoo, I-K; Yoon, J; Yu, W; Yuan, X; Yushmanov, I; Zaccolo, V; Zach, C; Zampolli, C; Zaporozhets, S; Zarochentsev, A; Závada, P; Zaviyalov, N; Zbroszczyk, H; Zelnicek, P; Zgura, I S; Zhalov, M; Zhang, X; Zhang, H; Zhou, D; Zhou, Y; Zhou, F; Zhu, J; Zhu, J; Zhu, X; Zichichi, A; Zimmermann, A; Zinovjev, G; Zoccarato, Y; Zynovyev, M; Zyzak, M

Measurements of cross sections of inelastic and diffractive processes in proton-proton collisions at LHC energies were carried out with the ALICE detector. The fractions of diffractive processes in inelastic collisions were determined from a study of gaps in charged particle pseudorapidity distributions: for single diffraction (diffractive mass M X <200 GeV/ c 2 ) [Formula: see text], and [Formula: see text], respectively at centre-of-mass energies [Formula: see text]; for double diffraction (for a pseudorapidity gap Δ η >3) σ DD / σ INEL =0.11±0.03,0.12±0.05, and [Formula: see text], respectively at [Formula: see text]. To measure the inelastic cross section, beam properties were determined with van der Meer scans, and, using a simulation of diffraction adjusted to data, the following values were obtained: [Formula: see text] mb at [Formula: see text] and [Formula: see text] at [Formula: see text]. The single- and double-diffractive cross sections were calculated combining relative rates of diffraction with inelastic cross sections. The results are compared to previous measurements at proton-antiproton and proton-proton colliders at lower energies, to measurements by other experiments at the LHC, and to theoretical models.

Spectroscopy of antiprotonic helium atoms and its contribution to the fundamental physical constants

PubMed Central

Hayano, Ryugo S.

2010-01-01

Antiprotonic helium atom, a metastable neutral system consisting of an antiproton, an electron and a helium nucleus, was serendipitously discovered, and has been studied at CERN’s antiproton decelerator facility. Its transition frequencies have recently been measured to nine digits of precision by laser spectroscopy. By comparing these experimental results with three-body QED calculations, the antiproton-to-electron massratio was determined as 1836.152674(5). This result contributed to the CODATA recommended values of the fundamental physical constants. PMID:20075605

A Scintillation Counter System Design To Detect Antiproton Annihilation using the High Performance Antiproton Trap(HiPAT)

NASA Technical Reports Server (NTRS)

Martin, James J.; Lewis, Raymond A.; Stanojev, Boris

2003-01-01

The High Performance Antiproton Trap (HiPAT), a system designed to hold up to l0(exp 12) charge particles with a storage half-life of approximately 18 days, is a tool to support basic antimatter research. NASA's interest stems from the energy density represented by the annihilation of matter with antimatter, 10(exp 2)MJ/g. The HiPAT is configured with a Penning-Malmberg style electromagnetic confinement region with field strengths up to 4 Tesla, and 20kV. To date a series of normal matter experiments, using positive and negative ions, have been performed evaluating the designs performance prior to operations with antiprotons. The primary methods of detecting and monitoring stored normal matter ions and antiprotons within the trap includes a destructive extraction technique that makes use of a micro channel plate (MCP) device and a non-destractive radio frequency scheme tuned to key particle frequencies. However, an independent means of detecting stored antiprotons is possible by making use of the actual annihilation products as a unique indicator. The immediate yield of the annihilation event includes photons and pie mesons, emanating spherically from the point of annihilation. To "count" these events, a hardware system of scintillators, discriminators, coincident meters and multi channel scalars (MCS) have been configured to surround much of the HiPAT. Signal coincidence with voting logic is an essential part of this system, necessary to weed out the single cosmic ray events from the multi-particle annihilation shower. This system can be operated in a variety of modes accommodating various conditions. The first is a low-speed sampling interval that monitors the background loss or "evaporation" rate of antiprotons held in the trap during long storage periods; provides an independent method of validating particle lifetimes. The second is a high-speed sample rate accumulating information on a microseconds time-scale; useful when trapped antiparticles are extracted

Measurement of antiproton annihilation on Cu, Ag and Au with emulsion films

NASA Astrophysics Data System (ADS)

Aghion, S.; Amsler, C.; Ariga, A.; Ariga, T.; Bonomi, G.; Bräunig, P.; Brusa, R. S.; Cabaret, L.; Caccia, M.; Caravita, R.; Castelli, F.; Cerchiari, G.; Comparat, D.; Consolati, G.; Demetrio, A.; Di Noto, L.; Doser, M.; Ereditato, A.; Evans, C.; Ferragut, R.; Fesel, J.; Fontana, A.; Gerber, S.; Giammarchi, M.; Gligorova, A.; Guatieri, F.; Haider, S.; Hinterberger, A.; Holmestad, H.; Huse, T.; Kawada, J.; Kellerbauer, A.; Kimura, M.; Krasnický, D.; Lagomarsino, V.; Lansonneur, P.; Lebrun, P.; Malbrunot, C.; Mariazzi, S.; Matveev, V.; Mazzotta, Z.; Müller, S. R.; Nebbia, G.; Nedelec, P.; Oberthaler, M.; Pacifico, N.; Pagano, D.; Penasa, L.; Petracek, V.; Pistillo, C.; Prelz, F.; Prevedelli, M.; Ravelli, L.; Rienaecker, B.; RØhne, O. M.; Rotondi, A.; Sacerdoti, M.; Sandaker, H.; Santoro, R.; Scampoli, P.; Simon, M.; Smestad, L.; Sorrentino, F.; Testera, G.; Tietje, I. C.; Vamosi, S.; Vladymyrov, M.; Widmann, E.; Yzombard, P.; Zimmer, C.; Zmeskal, J.; Zurlo, N.

2017-04-01

The characteristics of low energy antiproton annihilations on nuclei (e.g. hadronization and product multiplicities) are not well known, and Monte Carlo simulation packages that use different models provide different descriptions of the annihilation events. In this study, we measured the particle multiplicities resulting from antiproton annihilations on nuclei. The results were compared with predictions obtained using different models in the simulation tools GEANT4 and FLUKA. For this study, we exposed thin targets (Cu, Ag and Au) to a very low energy antiproton beam from CERN's Antiproton Decelerator, exploiting the secondary beamline available in the AEgIS experimental zone. The antiproton annihilation products were detected using emulsion films developed at the Laboratory of High Energy Physics in Bern, where they were analysed at the automatic microscope facility. The fragment multiplicity measured in this study is in good agreement with results obtained with FLUKA simulations for both minimally and heavily ionizing particles.

Measurement of Long-Range Angular Correlation and Quadrupole Anisotropy of Pions and (Anti)Protons in Central d+Au Collisions at sqrt[s_{NN}]=200 GeV.

PubMed

Adare, A; Aidala, C; Ajitanand, N N; Akiba, Y; Akimoto, R; Al-Bataineh, H; Al-Ta'ani, H; Alexander, J; Andrews, K R; Angerami, A; Aoki, K; Apadula, N; Appelt, E; Aramaki, Y; Armendariz, R; Aschenauer, E C; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Bannier, B; Barish, K N; Bassalleck, B; Basye, A T; Bathe, S; Baublis, V; Baumann, C; Bazilevsky, A; Belikov, S; Belmont, R; Ben-Benjamin, J; Bennett, R; Bhom, J H; Blau, D S; Bok, J S; Boyle, K; Brooks, M L; Broxmeyer, D; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Campbell, S; Caringi, A; Castera, P; Chen, C-H; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Chvala, O; Cianciolo, V; Citron, Z; Cole, B A; Conesa Del Valle, Z; Connors, M; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Das, K; Datta, A; David, G; Dayananda, M K; Denisov, A; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Dion, A; Donadelli, M; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; Dutta, D; D'Orazio, L; Edwards, S; Efremenko, Y V; Ellinghaus, F; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Fadem, B; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gal, C; Garishvili, I; Glenn, A; Gong, H; Gong, X; Gonin, M; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grim, G; Grosse Perdekamp, M; Gunji, T; Guo, L; Gustafsson, H-Å; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Han, R; Hanks, J; Harper, C; Hashimoto, K; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hill, J C; Hohlmann, M; Hollis, R S; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hori, Y; Hornback, D; Huang, S; Ichihara, T; Ichimiya, R; Iinuma, H; Ikeda, Y; Imai, K; Inaba, M; Iordanova, A; Isenhower, D; Ishihara, M; Issah, M; Ivanischev, D; Iwanaga, Y; Jacak, B V; Jia, J; Jiang, X; Jin, J; John, D; Johnson, B M; Jones, T; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kamin, J; Kaneti, S; Kang, B H; Kang, J H; Kang, J S; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Khanzadeev, A; Kijima, K M; Kikuchi, J; Kim, A; Kim, B I; Kim, D J; Kim, E-J; Kim, Y-J; Kim, Y K; Kinney, E; Kiss, Á; Kistenev, E; Kleinjan, D; Kline, P; Kochenda, L; Komkov, B; Konno, M; Koster, J; Kotov, D; Král, A; Kravitz, A; Kunde, G J; Kurita, K; Kurosawa, M; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, D M; Lee, J; Lee, K B; Lee, K S; Lee, S H; Lee, S R; Leitch, M J; Leite, M A L; Li, X; Lichtenwalner, P; Liebing, P; Lim, S H; Linden Levy, L A; Liška, T; Liu, H; Liu, M X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Malik, M D; Manion, A; Manko, V I; Mannel, E; Mao, Y; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Means, N; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Miki, K; Milov, A; Mitchell, J T; Miyachi, Y; Mohanty, A K; Moon, H J; Morino, Y; Morreale, A; Morrison, D P; Motschwiller, S; Moukhanova, T V; Murakami, T; Murata, J; Nagamiya, S; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nam, S; Newby, J; Nguyen, M; Nihashi, M; Nouicer, R; Nyanin, A S; Oakley, C; O'Brien, E; Oda, S X; Ogilvie, C A; Oka, M; Okada, K; Onuki, Y; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, B H; Park, I H; Park, S K; Park, W J; Pate, S F; Patel, L; Pei, H; Peng, J-C; Pereira, H; Peressounko, D Yu; Petti, R; Pinkenburg, C; Pisani, R P; Proissl, M; Purschke, M L; Qu, H; Rak, J; Ravinovich, I; Read, K F; Rembeczki, S; Reygers, K; Riabov, V; Riabov, Y; Richardson, E; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rosen, C A; Rosendahl, S S E; Ružička, P; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakashita, K; Samsonov, V; Sano, S; Sarsour, M; Sato, T; Savastio, M; Sawada, S; Sedgwick, K; Seele, J; Seidl, R; Seto, R; Sharma, D; Shein, I; Shibata, T-A; Shigaki, K; Shim, H H; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Slunečka, M; Sodre, T; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Stankus, P W; Stenlund, E; Stoll, S P; Sugitate, T; Sukhanov, A; Sun, J; Sziklai, J; Takagui, E M; Takahara, A; Taketani, A; Tanabe, R; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tennant, E; Themann, H; Thomas, D; Thomas, T L; Togawa, M; Toia, A; Tomášek, L; Tomášek, M; Torii, H; Towell, R S; Tserruya, I; Tsuchimoto, Y; Utsunomiya, K; Vale, C; Valle, H; van Hecke, H W; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Virius, M; Vossen, A; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Wei, R; Wessels, J; White, S N; Winter, D; Woody, C L; Wright, R M; Wysocki, M; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Ying, J; Yokkaichi, S; Yoo, J S; You, Z; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zelenski, A; Zhou, S

2015-05-15

We present azimuthal angular correlations between charged hadrons and energy deposited in calorimeter towers in central d+Au and minimum bias p+p collisions at sqrt[s_{NN}]=200 GeV. The charged hadron is measured at midrapidity |η|<0.35, and the energy is measured at large rapidity (-3.7<η<-3.1, Au-going direction). An enhanced near-side angular correlation across |Δη|>2.75 is observed in d+Au collisions. Using the event plane method applied to the Au-going energy distribution, we extract the anisotropy strength v_{2} for inclusive charged hadrons at midrapidity up to p_{T}=4.5 GeV/c. We also present the measurement of v_{2} for identified π^{±} and (anti)protons in central d+Au collisions, and observe a mass-ordering pattern similar to that seen in heavy-ion collisions. These results are compared with viscous hydrodynamic calculations and measurements from p+Pb at sqrt[s_{NN}]=5.02 TeV. The magnitude of the mass ordering in d+Au is found to be smaller than that in p+Pb collisions, which may indicate smaller radial flow in lower energy d+Au collisions.

Collisions involving antiprotons and antihydrogen: an overview

NASA Astrophysics Data System (ADS)

Jonsell, S.

2018-03-01

I give an overview of experimental and theoretical results for antiproton and antihydrogen scattering with atoms and molecules (in particular H, He). At low energies (>1 keV) there are practically no experimental data available. Instead I compare the results from different theoretical calculations, of various degrees of sophistication. At energies up to a few tens of eV, I focus on simple approximations that give reasonably accurate results, as these allow quick estimates of collision rates without embarking on a research project. This article is part of the Theo Murphy meeting issue `Antiproton physics in the ELENA era'.

Correlation functions of net-proton multiplicity distributions in Au + Au collisions at energies available at the BNL Relativistic Heavy Ion Collider from a multiphase transport model

NASA Astrophysics Data System (ADS)

Lin, Yufu; Chen, Lizhu; Li, Zhiming

2017-10-01

Fluctuations of conserved quantities are believed to be sensitive observables to probe the signature of the QCD phase transition and critical point. It was argued recently that measuring the genuine correlation functions (CFs) could provide cleaner information on possible nontrivial dynamics in heavy-ion collisions. With the AMPT (a multiphase transport) model, the centrality and energy dependence of various orders of CFs of net protons in Au + Au collisions at √{sN N}=7.7 , 11.5, 19.6, 27, 39, 62.4, and 200 GeV are investigated. The model results show that the number of antiprotons is important and should be taken into account in the calculation of CFs at high energy and/or in peripheral collisions. It is also found that the contribution of antiprotons is more important for higher order correlations than for lower ones. The CFs of antiprotons and mixed correlations play roles comparable to those of protons at high energies. Finally, we make comparisons between the model calculation and experimental data measured in the STAR experiment at the BNL Relativistic Heavy Ion Collider.

Antiproton--neutron bound state

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ju, I.; Tomozawa, Y.

1972-08-01

The possibility of an antiproton-neutron bound state for explaining a narrow peak which was found recently in the experiment p + n yields 4 pi and 6 pi is discussed. It is pointed out that the state is likely to be a /sup 1/P/ sub 1/ state or a higher angular momentum state. (auth)

Measurement of Long-Range Angular Correlation and Quadrupole Anisotropy of Pions and (Anti)Protons in Central d +Au Collisions at √{sN N }=200 GeV

NASA Astrophysics Data System (ADS)

Adare, A.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Al-Bataineh, H.; Al-Ta'Ani, H.; Alexander, J.; Andrews, K. R.; Angerami, A.; Aoki, K.; Apadula, N.; Appelt, E.; Aramaki, Y.; Armendariz, R.; Aschenauer, E. C.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Baksay, G.; Baksay, L.; Bannier, B.; Barish, K. N.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Baublis, V.; Baumann, C.; Bazilevsky, A.; Belikov, S.; Belmont, R.; Ben-Benjamin, J.; Bennett, R.; Bhom, J. H.; Blau, D. S.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Broxmeyer, D.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Butsyk, S.; Campbell, S.; Caringi, A.; Castera, P.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Conesa Del Valle, Z.; Connors, M.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Das, K.; Datta, A.; David, G.; Dayananda, M. K.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Dion, A.; Donadelli, M.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; Dutta, D.; D'Orazio, L.; Edwards, S.; Efremenko, Y. V.; Ellinghaus, F.; Engelmore, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Fadem, B.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fusayasu, T.; Gal, C.; Garishvili, I.; Glenn, A.; Gong, H.; Gong, X.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grim, G.; Grosse Perdekamp, M.; Gunji, T.; Guo, L.; Gustafsson, H.-Å.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Han, R.; Hanks, J.; Harper, C.; Hashimoto, K.; Haslum, E.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hohlmann, M.; Hollis, R. S.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hori, Y.; Hornback, D.; Huang, S.; Ichihara, T.; Ichimiya, R.; Iinuma, H.; Ikeda, Y.; Imai, K.; Inaba, M.; Iordanova, A.; Isenhower, D.; Ishihara, M.; Issah, M.; Ivanischev, D.; Iwanaga, Y.; Jacak, B. V.; Jia, J.; Jiang, X.; Jin, J.; John, D.; Johnson, B. M.; Jones, T.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kamin, J.; Kaneti, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kempel, T.; Khanzadeev, A.; Kijima, K. M.; Kikuchi, J.; Kim, A.; Kim, B. I.; Kim, D. J.; Kim, E.-J.; Kim, Y.-J.; Kim, Y. K.; Kinney, E.; Kiss, Á.; Kistenev, E.; Kleinjan, D.; Kline, P.; Kochenda, L.; Komkov, B.; Konno, M.; Koster, J.; Kotov, D.; Král, A.; Kravitz, A.; Kunde, G. J.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, D. M.; Lee, J.; Lee, K. B.; Lee, K. S.; Lee, S. H.; Lee, S. R.; Leitch, M. J.; Leite, M. A. L.; Li, X.; Lichtenwalner, P.; Liebing, P.; Lim, S. H.; Linden Levy, L. A.; Liška, T.; Liu, H.; Liu, M. X.; Love, B.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Malik, M. D.; Manion, A.; Manko, V. I.; Mannel, E.; Mao, Y.; Masui, H.; Matathias, F.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Means, N.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Mignerey, A. C.; Miki, K.; Milov, A.; Mitchell, J. T.; Miyachi, Y.; Mohanty, A. K.; Moon, H. J.; Morino, Y.; Morreale, A.; Morrison, D. P.; Motschwiller, S.; Moukhanova, T. V.; Murakami, T.; Murata, J.; Nagamiya, S.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nam, S.; Newby, J.; Nguyen, M.; Nihashi, M.; Nouicer, R.; Nyanin, A. S.; Oakley, C.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Oka, M.; Okada, K.; Onuki, Y.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, B. H.; Park, I. H.; Park, S. K.; Park, W. J.; Pate, S. F.; Patel, L.; Pei, H.; Peng, J.-C.; Pereira, H.; Peressounko, D. Yu.; Petti, R.; Pinkenburg, C.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Qu, H.; Rak, J.; Ravinovich, I.; Read, K. F.; Rembeczki, S.; Reygers, K.; Riabov, V.; Riabov, Y.; Richardson, E.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Ružička, P.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakashita, K.; Samsonov, V.; Sano, S.; Sarsour, M.; Sato, T.; Savastio, M.; Sawada, S.; Sedgwick, K.; Seele, J.; Seidl, R.; Seto, R.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shim, H. H.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Sodre, T.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Stankus, P. W.; Stenlund, E.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sun, J.; Sziklai, J.; Takagui, E. M.; Takahara, A.; Taketani, A.; Tanabe, R.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tennant, E.; Themann, H.; Thomas, D.; Thomas, T. L.; Togawa, M.; Toia, A.; Tomášek, L.; Tomášek, M.; Torii, H.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Utsunomiya, K.; Vale, C.; Valle, H.; van Hecke, H. W.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Virius, M.; Vossen, A.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; Wei, R.; Wessels, J.; White, S. N.; Winter, D.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Ying, J.; Yokkaichi, S.; Yoo, J. S.; You, Z.; Young, G. R.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zelenski, A.; Zhou, S.; Phenix Collaboration

2015-05-01

We present azimuthal angular correlations between charged hadrons and energy deposited in calorimeter towers in central d +Au and minimum bias p +p collisions at √{sN N }=200 GeV . The charged hadron is measured at midrapidity |η |<0.35 , and the energy is measured at large rapidity (-3.7 <η <-3.1 , Au-going direction). An enhanced near-side angular correlation across |Δ η |>2.75 is observed in d +Au collisions. Using the event plane method applied to the Au-going energy distribution, we extract the anisotropy strength v2 for inclusive charged hadrons at midrapidity up to pT=4.5 GeV /c . We also present the measurement of v2 for identified π± and (anti)protons in central d +Au collisions, and observe a mass-ordering pattern similar to that seen in heavy-ion collisions. These results are compared with viscous hydrodynamic calculations and measurements from p +Pb at √{sN N }=5.02 TeV . The magnitude of the mass ordering in d +Au is found to be smaller than that in p +Pb collisions, which may indicate smaller radial flow in lower energy d +Au collisions.

Measurement of the W boson production charge asymmetry in proton-antiproton collisions

NASA Astrophysics Data System (ADS)

Han, Bo-Young

We present a measurement of the W boson production charge asymmetry using the W → enu decay channel. We use data collected the Collider Detector at Fermilab (CDF) from pp¯ collisions at s = 1.96 TeV. The data were collected up to February 2006 (Run II) and represent an integrated luminosity of 1 fb-1. The experimental measurement of W production charge asymmetry is compared to higher order QCD predictions generated using MRST2006 and CTEQ6 parton distribution functions (PDF). The asymmetry provides new input on the momentum fraction dependence of the u and d quark parton distribution functions (PDF) within the proton over the fraction of proton's momentum range from 0.002 < x < 0.8 corresponding to -3.0 < yW < 3.0 at Q 2 ≈ M2W .

Measurement of long-range angular correlation and quadrupole anisotropy of pions and (anti)protons in central d + Au collisions at s N N = 200 GeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adare, A.; Aidala, C.; Ajitanand, N. N.

2015-05-12

In this study, we present azimuthal angular correlations between charged hadrons and energy deposited in calorimeter towers in central d+Au and aluminum bias p+p collisions at √s NN = 200 GeV. The charged hadron is measured at midrapidity lηl < 0.35, and the energy us measured at large rapidity (–3.7 < η < –3.1, Au-going direction). An enhanced near-side angular correlation across lΔηl > 2.75 is observed in d+Au collisions. Using the event plane method applied to the Au-going energy distribution, we extract the anisotropy strength v₂ for inclusive charged hadrons at midrapidity up to p T = 4.5 GeV/c.more » We also present the measurement of v₂ for identified π ± and (anti)protons in central d+Au collisions, and observe a mass-ordering pattern similar to that seen in heavy ion collisions. These results are compared with viscous hydrodynamic calculations and measurements from p+Pb at √s NN = 5.02 TeV. The magnitude of the mass-ordering in d+Au is found to be smaller than that in p+Pb collisions, which may indicate smaller radial flow in lower energy d+Au collisions.« less

Comparison of electromagnetic and hadronic models generated using Geant 4 with antiproton dose measured in CERN.

PubMed

Tavakoli, Mohammad Bagher; Reiazi, Reza; Mohammadi, Mohammad Mehdi; Jabbari, Keyvan

2015-01-01

After proposing the idea of antiproton cancer treatment in 1984 many experiments were launched to investigate different aspects of physical and radiobiological properties of antiproton, which came from its annihilation reactions. One of these experiments has been done at the European Organization for Nuclear Research known as CERN using the antiproton decelerator. The ultimate goal of this experiment was to assess the dosimetric and radiobiological properties of beams of antiprotons in order to estimate the suitability of antiprotons for radiotherapy. One difficulty on this way was the unavailability of antiproton beam in CERN for a long time, so the verification of Monte Carlo codes to simulate antiproton depth dose could be useful. Among available simulation codes, Geant4 provides acceptable flexibility and extensibility, which progressively lead to the development of novel Geant4 applications in research domains, especially modeling the biological effects of ionizing radiation at the sub-cellular scale. In this study, the depth dose corresponding to CERN antiproton beam energy by Geant4 recruiting all the standard physics lists currently available and benchmarked for other use cases were calculated. Overall, none of the standard physics lists was able to draw the antiproton percentage depth dose. Although, with some models our results were promising, the Bragg peak level remained as the point of concern for our study. It is concluded that the Bertini model with high precision neutron tracking (QGSP_BERT_HP) is the best to match the experimental data though it is also the slowest model to simulate events among the physics lists.

Review of the High Performance Antiproton Trap (HiPAT) Experiment

NASA Technical Reports Server (NTRS)

Martin, James J.; Lewis, Raymond A.; Pearson, J. Boise; Sims, W. Herb; Chakrabarti, Suman; Fant, Wallace E.; McDonald, Stan

2003-01-01

Many space propulsion concepts exist that use matter-antimatter reactions. Current antiproton production rates are enough to conduct proof-of-principle evaluation of these concepts. One enabling technology for such experiments is portable storage of low energy antiprotons, to transport antiprotons to experimental facilities. To address this need, HiPAT is being developed, with a design goal of containing 10(exp 12) particles for up to 18 days. HiPAT is a Penning-Malmberg trap with a 4 Tesla superconductor, 20kV electrodes, radio frequency (RF) network, and 10(exp -13) Torr vacuum. 'Normal' matter is being used to evaluate the system. An electron beam ionizes background gas in situ, and particle beams are captured dynamically. The experiment examines ion storage lifetimes, RF plasma diagnostics, charge exchange with background gases, and dynamic ion beam capture.

A Measurement of Z Boson Production and Rapidity Distribution in Proton-Antiproton Collisions at √s = 1.96 TeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robson, Aidan

2004-12-25

High-precision measurements are made of Z boson production in proton-antiproton collisions at √s = 1.96 TeV recorded by the Collider Detector at Fermilab, using the electron decay channel. The cross-section times branching ratio is measured to be σ Z · Br(Z → e +e -) = (255.7 ± 2.4 stat ± 5.2 sys ± 15.2 lum)pb in a dataset of 194 pb -1 collected between March 2002 and June 2003. This agrees well with theoretical predictions. The cross-section for W boson production in the electron channel has also been measured in the subset of this dataset of 72 pb -1more » collected up until January 2003. Using this smaller dataset the ratio of cross-sections is determined to be R ≡ σ W · Br(W → eν)/σ Z · Br(Z → ee) = 10.82 ± 0.18 stat ± 0.16 sys. Combining these results with measurements made in the muon channel gives R = 10.92 ± 0.15 stat ± 0.14 sys (e + μ channels), from which the branching ratio of the W to electrons and muons, and the total width of the W, have been extracted: Br(W → lν) = 0.1089 ± 0.0022 (l = e,μ); Γ(W) = 2078.8 ± 41.4 MeV, which are in good agreement with the Standard Model values and with other measurements. The CKM quark mixing matrix element |V cs| has been extracted: |V cs| = 0.967 ± 0.030. The rapidity distribution dσ/dy for Z → ee has also been measured over close to the full kinematic range using 194 pb -1 of data, and is found to be in good agreement with the NNLO prediction.« less

Elastic scattering, polarization and absorption of relativistic antiprotons on nuclei

NASA Astrophysics Data System (ADS)

Larionov, A. B.; Lenske, H.

2017-01-01

We perform Glauber model calculations of the antiproton-nucleus elastic and quasielastic scattering and absorption in the beam momentum range ∼ 0.5 ÷ 10 GeV / c. A good agreement of our calculations with available LEAR data and with earlier Glauber model studies of the p bar A elastic scattering allows us to make predictions at the beam momenta of ∼10 GeV/c, i.e. at the regime of the PANDA experiment at FAIR. The comparison with the proton-nucleus elastic scattering cross sections shows that the diffractive minima are much deeper in the p bar A case due to smaller absolute value of the ratio of the real-to-imaginary part of the elementary elastic amplitude. Significant polarization signal for p bar A elastic scattering at 10 GeV/c is expected. We have also revealed a strong dependence of the p bar A absorption cross section on the slope parameter of the transverse momentum dependence of the elementary p bar N amplitude. The p bar A optical potential is discussed.

Centrality and collision system dependence of antiproton production from p+A to Au+Au collisions at AGS energies

NASA Technical Reports Server (NTRS)

Sako, H.; Ahle, L.; Akiba, Y.; Ashktorab, K.; Baker, M. D.; Beavis, D.; Britt, H. C.; Chang, J.; Chasman, C.; Chen, Z.;

Antiproton Studies in Penning Traps

DTIC Science & Technology

1988-12-31

14. SUBjeCT TERMSOS NUMBER_,Of PAGES antimatter , antiproton, trapping IL________COCK_ I?.SE -’IY- CLASSiFCAM*O fl. SECURITY CLSSIFICATIO it. SECURIT...incernational Conference on Low Energy Antimatter , Karlsruhe, GOrmlay (invited lecture) R’ NOV e 󈨝 10:59 U OF W GCS JM-Z4 PAGE.094 .... --. 89 WED er7:56 I

Measurement of the single top production cross section in proton-antiproton collisions at 1.96 TeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanasijczuk, Andres Jorge

2010-03-25

This thesis describes a search for singly produced top quarks via an electroweak vertex in head-on proton-antiproton collisions at a center of mass energy of √s = 1.96 TeV. The analysis uses a total of 2.3 fb -1 of data collected with the D0 detector at Fermilab, corresponding to two different run periods of the Tevatron collider. Two channels contribute to single top quark production at the Tevatron, the s-channel and the t-channel. In the s-channel, a virtual W boson is produced from the aniquilation of a quark and an antiquark and a top and a bottom quarks are produced from the W decay. The top quark decays almost exclusively into a W boson and a bottom quark. Final states are considered in which the W boson decays leptonically into an electron or a muon plus a neutrino. Thus, at the detector level, the final state characterizing the s-channel contains one lepton, missing energy accounting for the neutrino, and two jets from the two bottom quarks. In the t-channel, the final state has an additional jet coming from a light quark. Clearly, a precise reconstruction of the events requires a precise measurement of the energy of the jets. A multivariate technique, Bayesian neural networks, is used to extract the single top signal from the overwhelming background still left after event selection. A Bayesian likelihood probability is then computed to measure the single top cross section. Assuming the observed excess is due to single top events, the measured single top quark production cross section is σ(pmore » $$\\bar{p}$$ → tb + X, tqb + X) = 4.70 +1.18 -0.93 pb. The observed excess is associated with a p-value of (3.2 ± 2.3) x 10 -8, assuming the background-only hypothesis. This p-value corresponds to an excess over background of 5.4 standard deviations for a Gaussian density. The p-value computed using the standard model signal cross section of 3.46 pb is (22.7 ± 0.6) x 10 -6, corresponding to an expected significance of 4.08 standard deviations.« less

Direct detection of antiprotons with the Timepix3 in a new electrostatic selection beamline

NASA Astrophysics Data System (ADS)

Pacifico, N.; Aghion, S.; Alozy, J.; Amsler, C.; Ariga, A.; Ariga, T.; Bonomi, G.; Bräunig, P.; Bremer, J.; Brusa, R. S.; Cabaret, L.; Caccia, M.; Campbell, M.; Caravita, R.; Castelli, F.; Cerchiari, G.; Chlouba, K.; Cialdi, S.; Comparat, D.; Consolati, G.; Demetrio, A.; Di Noto, L.; Doser, M.; Dudarev, A.; Ereditato, A.; Evans, C.; Ferragut, R.; Fesel, J.; Fontana, A.; Gerber, S.; Giammarchi, M.; Gligorova, A.; Guatieri, F.; Haider, S.; Holmestad, H.; Huse, T.; Jordan, E.; Kellerbauer, A.; Kimura, M.; Krasnický, D.; Lagomarsino, V.; Lansonneur, P.; Lawler, G.; Lebrun, P.; Llopart, X.; Malbrunot, C.; Mariazzi, S.; Marx, L.; Matveev, V.; Mazzotta, Z.; Nebbia, G.; Nedelec, P.; Oberthaler, M.; Pagano, D.; Penasa, L.; Petracek, V.; Pistillo, C.; Prelz, F.; Prevedelli, M.; Ravelli, L.; Resch, L.; Røhne, O. M.; Rotondi, A.; Sacerdoti, M.; Sandaker, H.; Santoro, R.; Scampoli, P.; Smestad, L.; Sorrentino, F.; Spacek, M.; Storey, J.; Strojek, I. M.; Testera, G.; Tietje, I.; Tlustos, L.; Widmann, E.; Yzombard, P.; Zavatarelli, S.; Zmeskal, J.; Zurlo, N.

2016-09-01

We present here the first results obtained employing the Timepix3 for the detection and tagging of annihilations of low energy antiprotons. The Timepix3 is a recently developed hybrid pixel detector with advanced Time-of-Arrival and Time-over-Threshold capabilities and has the potential of allowing precise kinetic energy measurements of low energy charged particles from their time of flight. The tagging of the characteristic antiproton annihilation signature, already studied by our group, is enabled by the high spatial and energy resolution of this detector. In this study we have used a new, dedicated, energy selection beamline (GRACE). The line is symbiotic to the AEgIS experiment at the CERN Antiproton Decelerator and is dedicated to detector tests and possibly antiproton physics experiments. We show how the high resolution of the Timepix3 on the Time-of-Arrival and Time-over-Threshold information allows for a precise 3D reconstruction of the annihilation prongs. The presented results point at the potential use of the Timepix3 in antimatter-research experiments where a precise and unambiguous tagging of antiproton annihilations is required.

Modified Penning-Malmberg Trap for Storing Antiprotons

NASA Technical Reports Server (NTRS)

Sims, William H.; Martin, James; Lewis, Raymond

2005-01-01

A modified Penning-Malmberg trap that could store a small cloud of antiprotons for a relatively long time (weeks) has been developed. This trap is intended for use in research on the feasibility of contemplated future matter/antimatter-annihilation systems as propulsion sources for spacecraft on long missions. This trap is also of interest in its own right as a means of storing and manipulating antiprotons for terrestrial scientific experimentation. The use of Penning-Malmberg traps to store antiprotons is not new. What is new here is the modified trap design, which utilizes state-of-the-art radiofrequency (RF) techniques, including ones that, heretofore, have been used in radio-communication applications but not in iontrap applications. A basic Penning-Malmberg trap includes an evacuated round tube that contains or is surrounded by three or more collinear tube electrodes. A steady axial magnetic field that reaches a maximum at the geometric center of the tube is applied by an external source, and DC bias voltages that give rise to an electrostatic potential that reaches a minimum at the center are applied to the electrodes. The combination of electric and magnetic fields confines the charged particles (ions or electrons) for which it was designed to a prolate spheroidal central region. However, geometric misalignments and the diffusive cooling process prevent the steady fields of a basic Penning- Malmberg trap from confining the particles indefinitely. In the modified Penning-Malmberg trap, the loss of antiprotons is reduced or eliminated by use of a "rotating-wall" RF stabilization scheme that also heats the antiproton cloud to minimize loss by matter/antimatter annihilation. The scheme involves the superposition of a quadrupole electric field that rotates about the cylindrical axis at a suitably chosen radio frequency. The modified Penning-Malmberg trap (see Figure 1) includes several collinear sets of electrodes inside a tubular vacuum chamber. Each set

Sixfold improved single particle measurement of the magnetic moment of the antiproton.

PubMed

Nagahama, H; Smorra, C; Sellner, S; Harrington, J; Higuchi, T; Borchert, M J; Tanaka, T; Besirli, M; Mooser, A; Schneider, G; Blaum, K; Matsuda, Y; Ospelkaus, C; Quint, W; Walz, J; Yamazaki, Y; Ulmer, S

2017-01-18

Our current understanding of the Universe comes, among others, from particle physics and cosmology. In particle physics an almost perfect symmetry between matter and antimatter exists. On cosmological scales, however, a striking matter/antimatter imbalance is observed. This contradiction inspires comparisons of the fundamental properties of particles and antiparticles with high precision. Here we report on a measurement of the g-factor of the antiproton with a fractional precision of 0.8 parts per million at 95% confidence level. Our value /2=2.7928465(23) outperforms the previous best measurement by a factor of 6. The result is consistent with our proton g-factor measurement g p /2=2.792847350(9), and therefore agrees with the fundamental charge, parity, time (CPT) invariance of the Standard Model of particle physics. Additionally, our result improves coefficients of the standard model extension which discusses the sensitivity of experiments with respect to CPT violation by up to a factor of 20.

Sixfold improved single particle measurement of the magnetic moment of the antiproton

PubMed Central

Nagahama, H.; Smorra, C.; Sellner, S.; Harrington, J.; Higuchi, T.; Borchert, M. J.; Tanaka, T.; Besirli, M.; Mooser, A.; Schneider, G.; Blaum, K.; Matsuda, Y.; Ospelkaus, C.; Quint, W.; Walz, J.; Yamazaki, Y.; Ulmer, S.

2017-01-01

Our current understanding of the Universe comes, among others, from particle physics and cosmology. In particle physics an almost perfect symmetry between matter and antimatter exists. On cosmological scales, however, a striking matter/antimatter imbalance is observed. This contradiction inspires comparisons of the fundamental properties of particles and antiparticles with high precision. Here we report on a measurement of the g-factor of the antiproton with a fractional precision of 0.8 parts per million at 95% confidence level. Our value /2=2.7928465(23) outperforms the previous best measurement by a factor of 6. The result is consistent with our proton g-factor measurement gp/2=2.792847350(9), and therefore agrees with the fundamental charge, parity, time (CPT) invariance of the Standard Model of particle physics. Additionally, our result improves coefficients of the standard model extension which discusses the sensitivity of experiments with respect to CPT violation by up to a factor of 20. PMID:28098156

Proceedings of the Antiproton Science and Technology Workshop Held in Santa Monica, California on 6-9 October 1987

DTIC Science & Technology

1988-07-01

I Activities 1. Potential Low Energy Antiproton Sources in the United States 15 D.C. Peaslee (University of Maryland) 2. Low Energy Antiproton...Nieto, R.J. Hughes (Los Alamos National Laboratory) 2. Basic Physics Program for a Low Energy Antiproton Source in North America 245 B.E. Bonner (Rice...J.L. Callas (Jet Propulsioi< Laboratory) 5r> Energy Transfer in Antiproton Annihilation Rockets 577 B.N. Cassenti (United Technologies Research Center

Estudo do espalhamento elastico em colisoes pp a √s = 1.96 T eV com o Detector de Protons Frontais FPD (in Portuguese)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Molina, Jorge

Proton-antiproton elastic scattering was measured with the Forward Proton De- tectors installed in the Tevatron tunel near the DØ detector. Measurements were made at c.m.s. energies of √s = 1.96 T eV in the range of four momentum transfer 0.96 < |t| < 1.3 GeV 2. Data are well described by the exponential form of eb t with the slope given by b = −4.015 ± 0.193 GeV −2.

Possible Dark Matter Annihilation Signal in the AMS-02 Antiproton Data.

PubMed

Cui, Ming-Yang; Yuan, Qiang; Tsai, Yue-Lin Sming; Fan, Yi-Zhong

2017-05-12

Using the latest AMS-02 cosmic-ray antiproton flux data, we search for a potential dark matter annihilation signal. The background parameters about the propagation, source injection, and solar modulation are not assumed a priori but based on the results inferred from the recent B/C ratio and proton data measurements instead. The possible dark matter signal is incorporated into the model self-consistently under a Bayesian framework. Compared with the astrophysical background-only hypothesis, we find that a dark matter signal is favored. The rest mass of the dark matter particles is ∼20-80  GeV, and the velocity-averaged hadronic annihilation cross section is about (0.2-5)×10^{-26}  cm^{3} s^{-1}, in agreement with that needed to account for the Galactic center GeV excess and/or the weak GeV emission from dwarf spheroidal galaxies Reticulum 2 and Tucana III. Tight constraints on the dark matter annihilation models are also set in a wide mass region.

Estructura y química del suelo en un bosque de Castilla elastica en el carso del norte de Puerto Rico: resultados de una calicata

Treesearch

Christian A. Viera Martinez; Oscar Abelleira; Ariel E. Lugo

2008-01-01

We dug a soil pit of 1m x 1m x 1m in a forest dominated by Castilla elastica, a tree for shade coffee introduced in the karst of northern Puerto Rico. We found four soil horizons (designation notes in parenthesis) (A) organic soil matter (E) mineral soil leachate (B) aerobic mineral soil, and (C) saturated soil. The total storage of soil organic matter was 143 Mg/ha....

Antiproton signatures from astrophysical and dark matter sources at the galactic center

NASA Astrophysics Data System (ADS)

Cembranos, J. A. R.; Gammaldi, V.; Maroto, A. L.

2015-03-01

The center of our Galaxy is a complex region characterized by extreme phenomena. The presence of the supermassive Sagittarius A* black hole, a high dark matter density and an even higher baryonic density are able to produce very energetic processes. Indeed, high energetic gamma-rays have been observed by different telescopes, although their origin is not clear. In this work, we estimate the possible antiproton flux component associated with this signal. The expected secondary astrophysical antiproton background already saturates the observed data. It implies that any other important astrophysical source leads to an inconsistent excess. We estimate the sensitivity of PAMELA to this new primary antiproton source, which depends on the diffusion model and its spectral features. In particular, we consider antiproton spectra described by a power-law, a monochromatic signal and a Standard Model particle-antiparticle channel production. This latter spectrum is typical in the production from annihilating or decaying dark matter. We pay particular attention to the case of a heavy dark matter candidate, which could be associated with the High Energy Stereoscopic System (HESS) data observed from the J1745-290 source.

Antiproton signatures from astrophysical and dark matter sources at the galactic center

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cembranos, J.A.R.; Gammaldi, V.; Maroto, A.L., E-mail: cembra@ucm.es, E-mail: vivigamm@ucm.es, E-mail: maroto@fis.ucm.es

2015-03-01

The center of our Galaxy is a complex region characterized by extreme phenomena. The presence of the supermassive Sagittarius A* black hole, a high dark matter density and an even higher baryonic density are able to produce very energetic processes. Indeed, high energetic gamma-rays have been observed by different telescopes, although their origin is not clear. In this work, we estimate the possible antiproton flux component associated with this signal. The expected secondary astrophysical antiproton background already saturates the observed data. It implies that any other important astrophysical source leads to an inconsistent excess. We estimate the sensitivity of PAMELAmore » to this new primary antiproton source, which depends on the diffusion model and its spectral features. In particular, we consider antiproton spectra described by a power-law, a monochromatic signal and a Standard Model particle-antiparticle channel production. This latter spectrum is typical in the production from annihilating or decaying dark matter. We pay particular attention to the case of a heavy dark matter candidate, which could be associated with the High Energy Stereoscopic System (HESS) data observed from the J1745-290 source.« less

Antihydrogen from positronium impact with cold antiprotons: a Monte Carlo simulation

NASA Astrophysics Data System (ADS)

Cassidy, D. B.; Merrison, J. P.; Charlton, M.; Mitroy, J.; Ryzhikh, G.

1999-04-01

A Monte Carlo simulation of the reaction to form antihydrogen by positronium impact upon antiprotons has been undertaken. Total and differential cross sections have been utilized as inputs to the simulation which models the conditions foreseen in planned antihydrogen formation experiments using positrons and antiprotons held in Penning traps. Thus, predictions of antihydrogen production rates, angular distributions and the variation of the mean antihydrogen temperature as a function of incident positronium kinetic energy have been produced.

Measurement of the antiproton-nucleus annihilation cross-section at low energy

NASA Astrophysics Data System (ADS)

Aghai-Khozani, H.; Bianconi, A.; Corradini, M.; Hayano, R.; Hori, M.; Leali, M.; Lodi Rizzini, E.; Mascagna, V.; Murakami, Y.; Prest, M.; Vallazza, E.; Venturelli, L.; Yamada, H.

2018-02-01

Systematic measurements of the annihilation cross sections of low energy antinucleons were performed at CERN in the 80's and 90's. However the antiproton data on medium-heavy and heavy nuclear targets are scarce. The ASACUSA Collaboration at CERN has measured the antiproton annihilation cross section on carbon at 5.3 MeV: the value is (1.73 ± 0.25) barn. The result is compared with the antineutron experimental data and with the theoretical previsions.

WiZard - an experiment to measure the cosmic rays including anti-protons, positrons, nuclei and to conduct a search for primordial antimatter

NASA Astrophysics Data System (ADS)

Golden, R. L.

1990-03-01

The WiZard experiment will utilize the Astromag magnet facility onboard Space Station Freedom to explore the composition and energy spectra of low-Z cosmic rays. Particular emphasis will be placed on a search for primordial antimatter and measurement of antiproton and positron fluxes at energies up to 400 GeV. This paper presents the scientific goals and rationale; the experimental method is described and the present status of the WiZard project is summarized.

Search for the production of ZW and ZZ boson pairs decaying into charged leptons and jets in proton-antiproton collisions at sqrt[s]=1.96 TeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aaltonen, Timo Antero; et al,

2013-11-01

We present a measurement of the production cross section for ZW and ZZ boson pairs in final states with a pair of charged leptons, from the decay of a Z boson, and at least two jets, from the decay of a W or Z boson, using the full sample of proton-antiproton collisions recorded with the CDF II detector at the Tevatron, corresponding to 8.9 fb^(-1) of integrated luminosity. We increase the sensitivity to vector boson decays into pairs of quarks using a neural network discriminant that exploits the differences between the spatial spread of energy depositions and charged-particle momenta containedmore » within the jet of particles originating from quarks and gluons. Additionally, we employ new jet energy corrections to Monte Carlo simulations that account for differences in the observed energy scales for quark and gluon jets. The number of signal events is extracted through a simultaneous fit to the dijet mass spectrum in three classes of events: events likely to contain jets with a heavy-quark decay, events likely to contain jets originating from light quarks, and events that fail these identification criteria. We determine the production cross section to be 2.5 +2.0 -1.0 pb (< 6.1 pb at the 95% confidence level), consistent with the standard model prediction of 5.1 pb.« less

Pseudostate methods and differential cross sections for antiproton ionization of atomic hydrogen and helium

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGovern, M.; Walters, H. R. J.; Assafrao, D.

2010-03-15

A relaxed form of a recent impact parameter coupled pseudostate approximation of McGovern et al. [Phys. Rev. A 79, 042707 (2009)] for calculating differential ionization cross sections is proposed. This greatly eases the computational burden in cases where a range of ejected electron energies has to be considered. The relaxed approximation is tested against exact first Born calculations for antiproton impact on H and nonperturbatively for the highly nonperturbative system of Au{sup 53+} incident upon He. The approximation performs well in these tests. It is shown how, with a little further approximation, the relaxed theory leads to a widely usedmore » prescription for the total ionization cross section. Results for differential ionization of H and He by antiprotons are presented. These reveal the growing dominance of the interaction between the antiproton and the target nucleus at low impact energies and show the changing importance of the role of the postcollisional interaction between the antiproton and the ejected electron.« less

High-Energy Cosmic-Ray Antiprotons with the CAPRICE98 experiment

NASA Astrophysics Data System (ADS)

Boezio, M.; Ambriola, M.; Bartalucci, S.; Bellotti, R.; Bergström, D.; Bonvicini, V.; Bravar, U.; Cafagna, F.; Carlson, P.; Casolino, M.; Ciacio, F.; Circella, M.; De Marzo, C. N.; De Pascale, M. P.; Finetti, N.; Francke, T.; Hansen, P.; Hof, M.; Kremer, J.; Menn, W.; Mitchell, J. W.; Mocchitti, E.; Morselli, A.; Ormes, J. F.; Papini, P.; Piccardi, S.; Picozza, P.; Ricci, M.; Schiavon, P.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stephens, S. A.; Stochaj, S. J.; Streitmatter, R. E.; Suffert, M.; Vacchi, A.; Vannuccini, E.; Zampa, N.; WIZARD/CAPRICE Collaboration

2001-08-01

Observations of cosmic-ray antiprotons were performed by the balloon-borne experiment CAPRICE98 that was flown on 28-29 May 1998 from Fort Sumner, New Mexico, USA. The experiment used the NMSU-WIZARD/CAPRICE98 balloon-borne magnet spectrometer equipped with a gas Ring Imaging Cherenkov detector, a time-of-flight system, a tracking device consisting of drift chambers and a superconducting magnet and a silicon-tungsten calorimeter. We report on the absolute-antiproton-energy spectrum determined in the kinetic energy region at the top of the atmosphere between 3.2 and 49.1 GeV.

Measurement of Z+ γ production and search for anomalous triple gauge couplings in proton-antiproton collisions at √S = 1.96 TeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, Jianrong

2008-01-01

The author presents a measurement of pmore » $$\\bar{p}$$ → Zγ + X → e +e -γ + X production using proton-antiproton collisions data collected at the Collider Detector at Fermilab at a center of mass energy of 1.96 TeV. Zγ production provides a direct test of the triple neutral gauge couplings. A measurement of Zγ production cross section and search for anomalous ZZγ and Zγγ couplings are presented. The data presented are from 1.1 fb -1 of p$$\\bar{p}$$ integrated luminosity collected at the CDF Detector. Electrons from Z decays are selected with E t > 20 Gev. Photons (E t > 7 GeV) are required to be well-separated from the electrons. There are 390 eeγ candidate events found with 1.1 fb -1 of data, compared to the SM prediction of 375.3 ± 25.2 events. The Standard Model prediction for the cross section for p$$\\bar{p}$$ → e +e -γ + X production at √s = 1.96 TeV is 4.5 ± 0.4 pb. The measured cross section is 4.7 ± 0.6 pb. The cross section and kinematic distributions of the eeγ events are in good agreement with theoretical predictions. Limits on the ZZγ and Zγγ couplings are extracted using the photon E t distribution of eeγ events with m eeγ > 100 GeV/c 2. These are the first limits measured using CDF Run II data. These limits provide important test of the interaction of the photon and the Z boson.« less

Simulation study on beam loss in the alpha bucket regime during SIS-100 proton operation

NASA Astrophysics Data System (ADS)

Sorge, S.

2018-02-01

Crossing the transition energy γt in synchrotrons for high intensity proton beams requires well tuned jump schemes and is usually accompanied by longitudinal emittance growth. In order to avoid γt crossing during proton operation in the projected SIS-100 synchrotron special high-γt lattice settings have been developed, in order to keep γt above the beam extraction energy. A further advantage of this scheme is the formation of alpha buckets which naturally lead to short proton bunches, required for the foreseen production and storage of antiprotons for the FAIR facility. Special attention is turned on the imperfections of the superconducting SIS-100 magnets because together with the high-γt lattice settings, they could potentially lead to enhanced beam loss. The aim of the present work is to estimate the beam loss by means of particle tracking simulations.

Overview of the High Performance Antiproton (HiPAT) Experiment

NASA Technical Reports Server (NTRS)

Martin, James J.; Sims, William H.; Chakrabarti, Suman; Pearson, Boise; Fant, Wallace E.; Lewis, Raymond A.; Rodgers, Stephen (Technical Monitor)

2002-01-01

The annihilation of matter with antimatter represents the highest energy density of any known reaction, producing 10(exp 8) MJ/g, approximately 10 orders of magnitude more energy per unit mass than chemical based combustion. To take the first step towards using this energy for propulsion applications the NASA MSFC Propulsion Research Center (PRC) has initiated a research activity examining the storage of low energy antiprotons. Storage was identified as a key enabling technology since it builds the experience base necessary to understand the handling of antiprotons for virtually all utilization and high-density storage concepts. To address this need, a device referred to as the High Performance Antiproton Trap (HiPAT) is under development at the NASA MSFC PRC. The HiPAT is an electromagnetic system (Penning-Malmberg design) consisting of a 4 Tesla superconductor, a high voltage confinement electrode system (operation up to 20 KV), and an ultra high vacuum test section (operating in the 10(exp -12) torr range). The system was designed to be portable with an ultimate goal of maintaining 10(exp 12) charged particles with a half-life of 18 days. Currently, this system is being experimentally evaluated using normal matter ions which are cheap to produce and relatively easy to handle. These normal ions provide a good indication of overall trap behavior, with the exception of assessing annihilation losses. The ions are produced external to HiPAT using two hydrogen ion sources, with adjustable beam energy and current. Ion are transported in a beam line and controlled through the use of electrostatic optics. These optics serve to both focus and gate the incoming ions, providing microsecond-timed pulses that are dynamically captured by cycling the HiPAT electric containment field like a 'trap door'. The layout of this system more closely simulates the operations expected at an actual antiproton production facility where 'packets' of antiprotons with pulse widths measured in

Measurement of the top quark/anti-top quark production cross section in the lepton plus jets channel in proton- antiproton collisions at 1.8 TeV

NASA Astrophysics Data System (ADS)

Miao, Chyi-Chang

1997-08-01

The direct observation of the top quark was first achieved at the Tevatron proton-antiproton collider at Fermilab. This discovery completed the third generation fermion sector where the top quark is expected to accompany the bottom quark in the weak isospin doublet. This dissertation will discuss the experimental verification of the production cross section as predicted by the Standard Model. A measurement of the tt production cross section using 110 pb-1 of pp Collisions at /sqrt[s]=1.8 TeV collected with the Collider Detector at Fermilab between August of 1992 and February of 1996 is presented. The measurement focuses on the tt production in the 'lepton plus jets' final state in which one of the W bosons from tt decay subsequently decays leptonically to an e or /mu, and the other hadronically, i.e., t/bar t to(q/bar q/sp/prime b)(e/nu/bar b), or t/bar t to(q/bar q/sp/prime b)(/mu/nu/bar b). The b-tagging technique which utilizes the precision silicon detector tracking is used to enhance the signal, relative to the backgrounds for tt events, by identification the bottom quark from its measurable lifetime. With the top mass found to be 175 GeV/c2 in CDF, the tt production cross section is measured to be σt/bar t=6.0- 1.8+2.2pb.

Testing Quantum Chromodynamics with Antiprotons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brodsky, S.

2004-10-21

The antiproton storage ring HESR to be constructed at GSI will open up a new range of perturbative and nonperturbative tests of QCD in exclusive and inclusive reactions. I discuss 21 tests of QCD using antiproton beams which can illuminate novel features of QCD. The proposed experiments include the formation of exotic hadrons, measurements of timelike generalized parton distributions, the production of charm at threshold, transversity measurements in Drell-Yan reactions, and searches for single-spin asymmetries. The interactions of antiprotons in nuclear targets will allow tests of exotic nuclear phenomena such as color transparency, hidden color, reduced nuclear amplitudes, and themore » non-universality of nuclear antishadowing. The central tool used in these lectures are light-front Fock state wavefunctions which encode the bound-state properties of hadrons in terms of their quark and gluon degrees of freedom at the amplitude level. The freedom to choose the light-like quantization four-vector provides an explicitly covariant formulation of light-front quantization and can be used to determine the analytic structure of light-front wave functions. QCD becomes scale free and conformally symmetric in the analytic limit of zero quark mass and zero {beta} function. This ''conformal correspondence principle'' determines the form of the expansion polynomials for distribution amplitudes and the behavior of non-perturbative wavefunctions which control hard exclusive processes at leading twist. The conformal template also can be used to derive commensurate scale relations which connect observables in QCD without scale or scheme ambiguity. The AdS/CFT correspondence of large N{sub C} supergravity theory in higher-dimensional anti-de Sitter space with supersymmetric QCD in 4-dimensional space-time has important implications for hadron phenomenology in the conformal limit, including the nonperturbative derivation of counting rules for exclusive processes and the behavior

Constraining heavy dark matter with cosmic-ray antiprotons

NASA Astrophysics Data System (ADS)

Cuoco, Alessandro; Heisig, Jan; Korsmeier, Michael; Krämer, Michael

2018-04-01

Cosmic-ray observations provide a powerful probe of dark matter annihilation in the Galaxy. In this paper we derive constraints on heavy dark matter from the recent precise AMS-02 antiproton data. We consider all possible annihilation channels into pairs of standard model particles. Furthermore, we interpret our results in the context of minimal dark matter, including higgsino, wino and quintuplet dark matter. We compare the cosmic-ray antiproton limits to limits from γ-ray observations of dwarf spheroidal galaxies and to limits from γ-ray and γ-line observations towards the Galactic center. While the latter limits are highly dependent on the dark matter density distribution and only exclude a thermal wino for cuspy profiles, the cosmic-ray limits are more robust, strongly disfavoring the thermal wino dark matter scenario even for a conservative estimate of systematic uncertainties.

The History of the Planar Elastica: Insights into Mechanics and Scientific Method

NASA Astrophysics Data System (ADS)

Goss, Victor Geoffrey Alan

2009-08-01

Euler’s formula for the buckling of an elastic column is widely used in engineering design. However, only a handful of engineers will be familiar with Euler’s classic paper De Curvis Elasticis in which the formula is derived. In addition to the Euler Buckling Formula, De Curvis Elasticis classifies all the bent configurations of elastic rod—a landmark in the development of a rational theory of continuum mechanics. As a historical case study, Euler’s work on elastic rods offers an insight into some important concepts which underlie mechanics. It sheds light on the search for unifying principles of mechanics and the role of analysis. The connection between results obtained from theory and those obtained from experiments on rods, highlights two different approaches to scientific discovery, which can be traced back to Bacon, Descartes and Galileo. The bent rod also has an analogy in dynamics, with a pendulum, which highlights the crucial distinctions between initial value and boundary value problems and between linear and nonlinear differential equations. In addition to benefiting from the overview which a historical study provides, the particular problem of the elastica offers students of science and engineering a clear elucidation of the connection between mathematics and real-world engineering, issues which still have relevance today.

Constraints on Exotic Spin-Dependent Interactions Between Matter and Antimatter from Antiprotonic Helium Spectroscopy.

PubMed

Ficek, Filip; Fadeev, Pavel; Flambaum, Victor V; Jackson Kimball, Derek F; Kozlov, Mikhail G; Stadnik, Yevgeny V; Budker, Dmitry

2018-05-04

Heretofore undiscovered spin-0 or spin-1 bosons can mediate exotic spin-dependent interactions between standard model particles. Here, we carry out the first search for semileptonic spin-dependent interactions between matter and antimatter. We compare theoretical calculations and spectroscopic measurements of the hyperfine structure of antiprotonic helium to constrain exotic spin- and velocity-dependent interactions between electrons and antiprotons.

Constraints on Exotic Spin-Dependent Interactions Between Matter and Antimatter from Antiprotonic Helium Spectroscopy

NASA Astrophysics Data System (ADS)

Ficek, Filip; Fadeev, Pavel; Flambaum, Victor V.; Jackson Kimball, Derek F.; Kozlov, Mikhail G.; Stadnik, Yevgeny V.; Budker, Dmitry

2018-05-01

Heretofore undiscovered spin-0 or spin-1 bosons can mediate exotic spin-dependent interactions between standard model particles. Here, we carry out the first search for semileptonic spin-dependent interactions between matter and antimatter. We compare theoretical calculations and spectroscopic measurements of the hyperfine structure of antiprotonic helium to constrain exotic spin- and velocity-dependent interactions between electrons and antiprotons.

A New Measurement of the Cosmic-Ray Proton and Helium Spectra

NASA Astrophysics Data System (ADS)

Mocchiutti, E.; Ambriola, M.; Bartalucci, S.; Bellotti, R.; Bergström, D.; Boezio, M.; Bonicini, V.; Bravar, U.; Cafagna, F.; Carlson, P.; Casolino, M.; Ciacio, F.; Circella, M.; De Marzo, C. N.; De Pascale, M. P.; Finetti, N.; Francke, T.; Hansen, P.; Hof, M.; Kremer, J.; Menn, W.; Mitchell, J. W.; Mocchiutti, E.; Morselli, A.; Ormes, J. F.; Papini, P.; Piccardi, S.; Picozza, P.; Ricci, M.; Schiavon, P.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stephens, S. A.; Stochaj, S. J.; Streitmatter, R. E.; Suffert, M.; Vacchi, A.; Vannuccini, E.; Zampa, N.; WIZARD/CAPRICE Collaboration

2001-08-01

A new measurement of the primary cosmic ray spectra was performed during the balloon-borne CAPRICE experiment in 1998. This apparatus consists of a magnet spectrometer, with a superconducting magnet and a driftchamber tracking device, a time of flight scintillator system, a silicon-tungsten imaging calorimeter and a gas ring imaging Cherenkov detector. This combination of state-of-the-art detectors provides excellent particle discrimination capabilities, such that detailed investigations of the antiproton, electron/positron, muon and primary components of cosmic rays have been performed. The analysis of the primary proton component is illustrated in this paper.

Antiproton Studies in Penning Traps

DTIC Science & Technology

1993-09-30

applications to MRI imaging. This is by far the most sensitive test of CPT invariance with a baryon system and is one of the most accurate tests of CPT...system which has likely applications to MRI imaging. This is by far the most sensitive test of CPT invariance with a baryon system and is one of the...a thin window of matter . In a second 24 hour demonstration experiment, we managed to capture a few antiprotons in the small volume of an ion trap.1

Upper limits of the proton magnetic form factor in the time-like region from p¯p--> e+e- at the CERN-ISR

NASA Astrophysics Data System (ADS)

Baglin, C.; Baird, S.; Bassompierre, G.; Borreani, G.; Brient, J. C.; Broll, C.; Brom, J. M.; Bugge, L.; Buran, T.; Burq, J. P.; Bussière, A.; Buzzo, A.; Cester, R.; Chemarin, M.; Chevallier, M.; Escoubes, B.; Fay, J.; Ferroni, S.; Gracco, V.; Guillaud, J. P.; Khan-Aronsen, E.; Kirsebom, K.; Ille, B.; Lambert, M.; Leistam, L.; Lundby, A.; Macri, M.; Marchetto, F.; Mattera, L.; Menichetti, E.; Mouellic, B.; Pastrone, N.; Petrillo, L.; Pia, M. G.; Poulet, M.; Pozzo, A.; Rinaudo, G.; Santroni, A.; Severi, M.; Skjevling, G.; Stapnes, S.; Stugu, B.; Tomasini, F.; Valbusa, U.

1985-11-01

From the measurement of e+e- pairs from the reaction p¯p-->e+e- at the CERN-ISR, using an antiproton beam and a hydrogen jet target, we derived upper limits for the proton magnetic form factor in the time-like region at Q2⋍8.9(GeV/c)2 and Q2⋍12.5(GeV/c)2.

Measurements of Cosmic-Ray Proton and Helium Spectra from the BESS-Polar Long-Duration Balloon Flights Over Antarctica

NASA Technical Reports Server (NTRS)

Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Itazaki, A.; Kim, K. C.; Kumazawa, T.; Kusumoto, A.;

Report of the Snowmass M6 Working Group on high intensity proton sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiren Chou and J. Wei

The U.S. high-energy physics program needs an intense proton source, a 1-4 MW Proton Driver (PD), by the end of this decade. This machine will serve as a stand-alone facility that will provide neutrino superbeams and other high intensity secondary beams such as kaons, muons, neutrons, and anti-protons (cf. E1 and E5 group reports) and also serve as the first stage of a neutrino factory (cf. M1 group report). It can also be a high brightness source for a VLHC. Based on present accelerator technology and project construction experience, it is both feasible and cost-effective to construct a 1-4 MWmore » Proton Driver. Two recent PD design studies have been made, one at FNAL and the other at the BNL. Both designed PD's for 1 MW proton beams at a cost of about U.S. $200M (excluding contingency and overhead) and both designs were upgradeable to 4 MW. An international collaboration between FNAL, BNL and KEK on high intensity proton facilities is addressing a number of key design issues. The superconducting (sc) RF cavities, cryogenics, and RF controls developed for the SNS can be directly adopted to save R&D efforts, cost, and schedule. PD studies are also actively being pursued at Europe and Japan.« less

Heating {sup 197}Au nuclei with 8 GeV antiproton and {pi}- beams.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Back, B.; Beaulieu, L.; Breuer, H.

1999-05-03

This contribution stresses results recently obtained from experiment E900 performed at the Brookhaven AGS accelerator with 8 GeV/c antiproton and negative pion beams using the Indiana Silicon Sphere detector array. An investigation of the reaction mechanism is presented, along with source characteristics deduced from a two-component fit to the spectra. An enhancement of deposition energy with the antiproton beam with respect to the pion beam is observed. The results are qualitatively consistent with predictions of an intranuclear cascade code.

Antiproton production in central Si+Au collisions at 14.6A GeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rothschild, P.J.

1994-05-01

Antiproton measurements made by E802 have been extended to lower rapidities, while in those y-p{sub T} regions already studied the statistics have been improved by approximately an order of magnitude. The author presents the dn/dy distribution for antiproton production in central 14.6 A{center_dot}GeV/c Si+Au collisions in the rapidity range 0.8 < y < 1.8. In addition, antilambda production has been detected for the first time in these collisions at the AGS.

Proceedings of the Antiproton Technology Workshop Held in Upton, New York on 10 May 1989

DTIC Science & Technology

1989-05-01

Antimatter , CP Violation 20 1 08 1 19. ABSTRACT (COntinue on reverse if necessary and identify by block number) This workshop, held at Brookhaven...medical, and industrial uses could result from ntiproton experiments proposed by workshop participants. Antiprotons are particles of antimatter ...industry and academic researchers at Brookhaven National Laboratory, Wednesday 10 May 1989. Antiprotons are particles of antimatter which release

Elastica solution for a nanotube formed by self-adhesion of a folded thin film

NASA Astrophysics Data System (ADS)

Glassmaker, N. J.; Hui, C. Y.

2004-09-01

Schmidt and Eberl demonstrated the construction of tubes with submicron diameters by the method of folding thin solid films [Nature (London) 410, 168 (2001)]. In their method, a thin film is folded 180° and brought into adhesive contact with itself. The resulting sealed loop forms a nanotube with the thickness of the tube walls equal to the thickness of the thin film. The calculation of the diameter of the tube and the shape of its cross section in equilibrium are the subjects of this study. The tube is modeled as a two-dimensional elastica when viewed in cross section, and adhesive behavior is governed by an energy release rate criterion. A numerical technique is used to find elastic equilibria for a large range of material parameters. With these solutions in hand, the problem of designing a nanotube becomes transparent. It is shown that one dimensionless parameter determines the diameter of the nanotube, while another fixes its shape. Each of these parameters is a ratio involving the material's mechanical properties and the film thickness. Before concluding, we verify our model by comparing its results with the experimental observations of Schmidt and Eberl, for their materials.

Measurement of the top quark pair production cross-section in dimuon final states in proton-antiproton collisions at 1.96 TeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Konrath, Jens Peter

2008-10-24

Particle physics deals with the fundamental building blocks of matter and their interactions. The vast number of subatomic particles can be reduced to twelve fundamental fermions, which interact by the exchange of spin-1 particles as described in the Standard Model (SM) of particle physics. The SM provides the best description of the subatomic world to date, despite the fact it does not include gravitation. Following the relation Λ = h/p, where h is Planck's constant, for the examination of physics at subatomic scales with size Λ probes with high momenta p are necessary. These high energies are accessible through particlemore » colliders. Here, particles are accelerated and brought to collision at interaction points at which detectors are installed to record these particle collisions. Until the anticipated start-up of the Large Hadron Collider at CERN, the Tevatron collider at Fermilab near Chicago is the highest energy collider operating in the world, colliding protons and anti-protons at a center-of-mass energy of √s = 1.96 TeV. Its two interaction points are covered by the multi purpose particle detectors D0 and CDF. During the first data-taking period, known as Run I, the Tevatron operated at a center-of-mass energy of 1.8 TeV. This run period lasted from 1992 to 1996. During this period, the long-predicted top quark was discovered. From 1996 and 2001, the accelerator was upgraded to deliver higher instantaneous luminosities at its current center-of-mass energy. At the same time, the experiments were upgraded to take full advantage of the upgraded accelerator complex. The Tevatron is currently the only accelerator in the world with a sufficient energy to produce top quarks. Studying top quark production, decay and properties is an important part of the D0 and CDF physics programs. Because of its large mass, the top quark is a unique probe of the Standard Model, and an interesting environment to search for new physics. In this thesis, a measurement of the

The characterization of ficaprenol-10, -11 and -12 from the leaves of Ficus elastica (decorative rubber plant)

PubMed Central

Stone, K. J.; Wellburn, A. R.; Hemming, F. W.; Pennock, J. F.

1967-01-01

Evidence from mass, nuclear-magnetic-resonance and infrared spectrometry and from gas–liquid and thin-layer chromatography is presented in favour of the presence of cis–trans-decaprenol, -undecaprenol and -dodecaprenol in the mixture of polyprenols (2·6mg./g.) isolated from leaf tissue of Ficus elastica. The trivial names ficaprenol-10, -11 and -12 are proposed. Nuclear-magnetic-resonance studies showed that each of these prenols contains three trans internal isoprene residues and a cis `OH-terminal' isoprene residue. Ficaprenol-11 is the major component of the mixture. Chromatographic evidence suggests the presence also of small amounts of ficaprenol-9 and -13. The precise position of the three trans internal isoprene residues was not determined but it is suggested that these are adjacent to the ω-terminal isoprene residue and that the ficaprenols are formed from all-trans-geranylgeranyl pyrophosphate. It is also suggested that ficaprenol-10, -11, -12 and -13 are probably the same compounds as castaprenol-10, -11, -12 and -13. PMID:6030292

Stability of the Helium-Antiproton System

NASA Technical Reports Server (NTRS)

Drachman, Richard J.

2006-01-01

In the course of their Born-Oppenheimer calculations of this system Todd and Armour noted that the lowest-lying state closely resembles the hydrogen negative ion, since the antiproton lies very close to the helium nucleus and shields one unit of nuclear charge. In the present paper this observation will be taken seriously to produce a variationally correct estimate of the total energy of this system, along with a similar estimate of the energy of the once-ionized system. The nonadiabatic effect of exactly treating the reduced masses improves the results.

Postbuckling and vibration of end-supported elastica pipes conveying fluid and columns under follower loads

NASA Astrophysics Data System (ADS)

Plaut, R. H.

2006-01-01

Fluid-conveying pipes with supported ends buckle when the fluid velocity reaches a critical value. For higher velocities, the postbuckled equilibrium shape can be directly related to that for a column under a follower end load. However, the corresponding vibration frequencies are different due to the Coriolis force associated with the fluid flow. Clamped-clamped, pinned-pinned, and clamped-pinned pipes are considered first. Axial sliding is permitted at the downstream end. The pipe is modeled as an inextensible elastica. The equilibrium shape may have large displacements, and small motions about that shape are analyzed. The behavior is conservative in the prebuckling range and nonconservative in the postbuckling range (during which the Coriolis force does work and the motions decay). Next, related columns are studied, first with a concentrated follower load at the axially sliding end, and then with a distributed follower load. In all cases, a shooting method is used to solve the nonlinear boundary-value problem for the equilibrium configuration, and to solve the linear boundary-value problem for the first four vibration frequencies. The results for the three different types of loading are compared.

The BESS Program

NASA Technical Reports Server (NTRS)

Mitchell, J. W.; Abe, K.; Anraku, K.; Fuke, H.; Haino, S.; Hams, T.; Imori, M.; Itazaki, A.; Izumi, K.; Kumazawa, T.

2004-01-01

In nine flights between 1993 and 2002, the Balloon Borne Experiment with a Superconducting Spectrometer (BESS) has measured the energy spectrum of cosmic-ray antiprotons between 0.18 and 4.20 GeV, and the spectra of protons and helium to several hundred GeV. BESS has also placed stringent upper limits on the existence of antihelium and antiduterons. Above about 1 GeV, models in which antiprotons are secondary products of the interactions of primary cosmic rays with the ISM agree with the BESS spectrum. Below 1 GeV, BESS data suggest the presence of an additional source of antiprotons. The antiproton/proton ratios measured between 1993 and 1999, during the Sun's positive-polarity phase, are consistent with simple models of solar modulation. Results from the 2000 flight, following the solar magnetic field reversal, show a sudden increase in the antiproton/proton ratio and tend to favor a charge-sign-dependent drift model. To extend BESS measurements to lower energies, a new instrument, BESS-Polar, is under construction for a flight from Antarctica in 2004.

High energy proton induced radiation damage of rare earth permanent magnet quadrupoles

NASA Astrophysics Data System (ADS)

Schanz, M.; Endres, M.; Löwe, K.; Lienig, T.; Deppert, O.; Lang, P. M.; Varentsov, D.; Hoffmann, D. H. H.; Gutfleisch, O.

2017-12-01

Permanent magnet quadrupoles (PMQs) are an alternative to common electromagnetic quadrupoles especially for fixed rigidity beam transport scenarios at particle accelerators. Using those magnets for experimental setups can result in certain scenarios, in which a PMQ itself may be exposed to a large amount of primary and secondary particles with a broad energy spectrum, interacting with the magnetic material and affecting its magnetic properties. One specific scenario is proton microscopy, where a proton beam traverses an object and a collimator in which a part of the beam is scattered and deflected into PMQs used as part of a diagnostic system. During the commissioning of the PRIOR (Proton Microscope for Facility for Antiproton and Ion Research) high energy proton microscope facility prototype at Gesellschaft für Schwerionenforschung in 2014, a significant reduction of the image quality was observed which was partially attributed to the demagnetization of the used PMQ lenses and the corresponding decrease of the field quality. In order to study this phenomenon, Monte Carlo simulations were carried out and spare units manufactured from the same magnetic material—single wedges and a fully assembled PMQ module—were deliberately irradiated by a 3.6 GeV intense proton beam. The performed investigations have shown that in proton radiography applications the above described scattering may result in a high irradiation dose in the PMQ magnets. This did not only decrease the overall magnetic strength of the PMQs but also caused a significant degradation of the field quality of an assembled PMQ module by increasing the parasitic multipole field harmonics which effectively makes PMQs impractical for proton radiography applications or similar scenarios.

High energy proton induced radiation damage of rare earth permanent magnet quadrupoles.

PubMed

Schanz, M; Endres, M; Löwe, K; Lienig, T; Deppert, O; Lang, P M; Varentsov, D; Hoffmann, D H H; Gutfleisch, O

2017-12-01

Permanent magnet quadrupoles (PMQs) are an alternative to common electromagnetic quadrupoles especially for fixed rigidity beam transport scenarios at particle accelerators. Using those magnets for experimental setups can result in certain scenarios, in which a PMQ itself may be exposed to a large amount of primary and secondary particles with a broad energy spectrum, interacting with the magnetic material and affecting its magnetic properties. One specific scenario is proton microscopy, where a proton beam traverses an object and a collimator in which a part of the beam is scattered and deflected into PMQs used as part of a diagnostic system. During the commissioning of the PRIOR (Proton Microscope for Facility for Antiproton and Ion Research) high energy proton microscope facility prototype at Gesellschaft für Schwerionenforschung in 2014, a significant reduction of the image quality was observed which was partially attributed to the demagnetization of the used PMQ lenses and the corresponding decrease of the field quality. In order to study this phenomenon, Monte Carlo simulations were carried out and spare units manufactured from the same magnetic material-single wedges and a fully assembled PMQ module-were deliberately irradiated by a 3.6 GeV intense proton beam. The performed investigations have shown that in proton radiography applications the above described scattering may result in a high irradiation dose in the PMQ magnets. This did not only decrease the overall magnetic strength of the PMQs but also caused a significant degradation of the field quality of an assembled PMQ module by increasing the parasitic multipole field harmonics which effectively makes PMQs impractical for proton radiography applications or similar scenarios.

Facility for Antiproton and Ion Research, FAIR, at the GSI site

NASA Astrophysics Data System (ADS)

Rosner, Guenther

2006-11-01

FAIR is a new large-scale particle accelerator facility to be built at the GSI site in Germany. The research pursued at FAIR will cover a wide range of topics in nuclear and hadron physics, as well as high density plasma physics, atomic and antimatter physics, and applications in condensed matter physics and biology. The working horse of FAIR will be a 1.1km circumference double ring of rapidly cycling 100 and 300Tm synchrotrons, which will be used to produce high intensity secondary beams of short-lived radioactive ions or antiprotons. A subsequent suite of cooler and storage rings will deliver heavy ion and antiproton beams of unprecedented quality. Large experimental facilities are presently being designed by the NUSTAR, PANDA, PAX, CBM, SPARC, FLAIR, HEDgeHOB and BIOMAT collaborations.

Central exclusive diffractive production of p p ¯ pairs in proton-proton collisions at high energies

NASA Astrophysics Data System (ADS)

Lebiedowicz, Piotr; Nachtmann, Otto; Szczurek, Antoni

2018-05-01

We consider the central exclusive production of the p p ¯ in the continuum and via resonances in proton-proton collisions at high energies. We discuss the diffractive mechanism calculated within the tensor-Pomeron approach including Pomeron, Odderon, and Reggeon exchanges. The theoretical results are discussed in the context of existing WA102 and Intersecting Storage Rings experimental data, and predictions for planned or current experiments at the Relativistic Heavy Ion Collider and the LHC are presented. The distribution in ydiff, the rapidity distance between the proton and antiproton, is particularly interesting. We find a dip at ydiff=0 for the p p ¯ production, in contrast to the π+π- and K+K- production. We predict also the p p ¯ invariant-mass distribution to be less steep than for the pairs of pseudoscalar mesons. We argue that these specific differences for the p p ¯ production with respect to the pseudoscalar meson pair production can be attributed to the proper treatment of the spin of produced particles. We discuss asymmetries that are due to the interference of C =+1 and C =-1 amplitudes of p p ¯ production. We have also calculated the cross section for the p p →p p Λ Λ ¯ reaction. Here, the cross section is smaller, but the characteristic feature for d σ /d ydiff is predicted to be similar to p p ¯ production. The presence of resonances in the p p ¯ channel may destroy the dip at ydiff=0 . This opens the possibility to study diffractively produced resonances. We discuss the observables suited for this purpose.

Facility for Antiproton and Ion Research, FAIR, at the GSI site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosner, Guenther

FAIR is a new large-scale particle accelerator facility to be built at the GSI site in Germany. The research pursued at FAIR will cover a wide range of topics in nuclear and hadron physics, as well as high density plasma physics, atomic and antimatter physics, and applications in condensed matter physics and biology. The working horse of FAIR will be a 1.1km circumference double ring of rapidly cycling 100 and 300Tm synchrotrons, which will be used to produce high intensity secondary beams of short-lived radioactive ions or antiprotons. A subsequent suite of cooler and storage rings will deliver heavy ionmore » and antiproton beams of unprecedented quality. Large experimental facilities are presently being designed by the NUSTAR, PANDA, PAX, CBM, SPARC, FLAIR, HEDgeHOB and BIOMAT collaborations.« less

Antihydrogen Formation via Antiproton Scattering with Excited Positronium.

PubMed

Kadyrov, A S; Rawlins, C M; Stelbovics, A T; Bray, I; Charlton, M

2015-05-08

Utilizing the two-center convergent close-coupling method, we find a several order of magnitude enhancement in the formation of antihydrogen via antiproton scattering with positronium in an excited state over the ground state. The effect is greatest at the lowest energies considered, which encompass those achievable in experiment. This suggests a practical approach to creating neutral antimatter for testing its interaction with gravity and for spectroscopic measurements.

Double-trap measurement of the proton magnetic moment at 0.3 parts per billion precision.

PubMed

Schneider, Georg; Mooser, Andreas; Bohman, Matthew; Schön, Natalie; Harrington, James; Higuchi, Takashi; Nagahama, Hiroki; Sellner, Stefan; Smorra, Christian; Blaum, Klaus; Matsuda, Yasuyuki; Quint, Wolfgang; Walz, Jochen; Ulmer, Stefan

2017-11-24

Precise knowledge of the fundamental properties of the proton is essential for our understanding of atomic structure as well as for precise tests of fundamental symmetries. We report on a direct high-precision measurement of the magnetic moment μ p of the proton in units of the nuclear magneton μ N The result, μ p = 2.79284734462 (±0.00000000082) μ N , has a fractional precision of 0.3 parts per billion, improves the previous best measurement by a factor of 11, and is consistent with the currently accepted value. This was achieved with the use of an optimized double-Penning trap technique. Provided a similar measurement of the antiproton magnetic moment can be performed, this result will enable a test of the fundamental symmetry between matter and antimatter in the baryonic sector at the 10 -10 level. Copyright © 2017, American Association for the Advancement of Science.

The Typical Number of Antiprotons Necessary to Heat the Hot Spot in the D-T Fuel Doped with U

NASA Astrophysics Data System (ADS)

Shmatov, M. L.

Fast ignition scenario with heating the hot spot by products of annihilation of antiprotons in the D-T fuel doped with U238 is considered. It is shown that in this scenario the hot spot is being heated effectively only by the fission fragments arising due to annihilation of the antiprotons on the nuclei of uranium. The presented model predicts that fast ignition can be provided by injection of (1.3 to 4.4) x 1015 antiprotons into the D-T fuel compressed to the density of about 200 g/cm3 and containing one nucleus of U238 per about one thousand nuclei of hydrogen isotopes.

Direct high-precision measurement of the magnetic moment of the proton.

PubMed

Mooser, A; Ulmer, S; Blaum, K; Franke, K; Kracke, H; Leiteritz, C; Quint, W; Rodegheri, C C; Smorra, C; Walz, J

2014-05-29

One of the fundamental properties of the proton is its magnetic moment, µp. So far µp has been measured only indirectly, by analysing the spectrum of an atomic hydrogen maser in a magnetic field. Here we report the direct high-precision measurement of the magnetic moment of a single proton using the double Penning-trap technique. We drive proton-spin quantum jumps by a magnetic radio-frequency field in a Penning trap with a homogeneous magnetic field. The induced spin transitions are detected in a second trap with a strong superimposed magnetic inhomogeneity. This enables the measurement of the spin-flip probability as a function of the drive frequency. In each measurement the proton's cyclotron frequency is used to determine the magnetic field of the trap. From the normalized resonance curve, we extract the particle's magnetic moment in terms of the nuclear magneton: μp = 2.792847350(9)μN. This measurement outperforms previous Penning-trap measurements in terms of precision by a factor of about 760. It improves the precision of the forty-year-old indirect measurement, in which significant theoretical bound state corrections were required to obtain µp, by a factor of 3. By application of this method to the antiproton magnetic moment, the fractional precision of the recently reported value can be improved by a factor of at least 1,000. Combined with the present result, this will provide a stringent test of matter/antimatter symmetry with baryons.

Event simulation based on three-fluid hydrodynamics for collisions at energies available at the Dubna Nuclotron-based Ion Collider Facility and at the Facility for Antiproton and Ion Research in Darmstadt

NASA Astrophysics Data System (ADS)

Batyuk, P.; Blaschke, D.; Bleicher, M.; Ivanov, Yu. B.; Karpenko, Iu.; Merts, S.; Nahrgang, M.; Petersen, H.; Rogachevsky, O.

2016-10-01

We present an event generator based on the three-fluid hydrodynamics approach for the early stage of the collision, followed by a particlization at the hydrodynamic decoupling surface to join to a microscopic transport model, ultrarelativistic quantum molecular dynamics, to account for hadronic final-state interactions. We present first results for nuclear collisions of the Facility for Antiproton and Ion Research-Nuclotron-based Ion Collider Facility energy scan program (Au+Au collisions, √{sN N}=4 -11 GeV ). We address the directed flow of protons and pions as well as the proton rapidity distribution for two model equations of state, one with a first-order phase transition and the other with a crossover-type softening at high densities. The new simulation program has the unique feature that it can describe a hadron-to-quark matter transition which proceeds in the baryon stopping regime that is not accessible to previous simulation programs designed for higher energies.

Cosmic ray antimatter: Is it primary or secondary?

NASA Technical Reports Server (NTRS)

Stecker, F. W.; Protheroe, R. J.; Kazanas, D.

1981-01-01

The relative merits and difficulties of the primary and secondary origin hypotheses for the observed cosmic ray antiprotons, including the low energy measurement of Buffington, were examined. It is concluded that the cosmic ray antiproton data may be strong evidence for antimatter galaxies and baryon symmetric cosmology. The present antiproton data are consistent with a primary extragalactic component having antiproton/proton approximately equal to .0032 + or - 0.7.

Prospects for testing Lorentz and CPT symmetry with antiprotons

NASA Astrophysics Data System (ADS)

Vargas, Arnaldo J.

2018-03-01

A brief overview of the prospects of testing Lorentz and CPT symmetry with antimatter experiments is presented. The models discussed are applicable to atomic spectroscopy experiments, Penning-trap experiments and gravitational tests. Comments about the sensitivity of the most recent antimatter experiments to the models reviewed here are included. This article is part of the Theo Murphy meeting issue `Antiproton physics in the ELENA era'.

The design of an experiment to detect low energy antiprotons

NASA Technical Reports Server (NTRS)

Lloyd-Evans, J.; Acharya, B. S.; Balasubrahmanyan, V. K.; Ormes, J. F.; Streitmatter, R. E.; Stephens, S. A.

1985-01-01

The techniques to be used in a balloon borne experiment APEX to detect 220 MeV antiprotons are described, paying particular attention to potential sources of background. Event time history is shown to be very effective in eliminating this background. Results of laboratory tests on the timing resolution which may be achieved are presented.

Doubly Strange Hypernuclei Physics with antiprotons at PANDA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Szymanska, K.; Iazzi, F.

2010-04-26

The study of the double hypernuclei will be possible inside the future facility FAIR. A new technique for their production was recently proposed, based on high intensity antiproton beams in connection with a two-target set-up, for the future PANDA experiment at HESR. In particular, the production technique and optimized parameters for the primary target where the hyperon XI{sup -} is produced as well as the expected rates for the stoped XI{sup -} will be discussed.

Centrifugal fingering in a curved Hele-Shaw cell: A generalized Euler's elastica shape for the two-fluid interface

NASA Astrophysics Data System (ADS)

Miranda, Jose; Brandao, Rodolfo

2017-11-01

We study a family of generalized elastica-like equilibrium shapes that arise at the interface separating two fluids in a curved rotating Hele-Shaw cell. This family of stationary interface solutions consists of shapes that balance the competing capillary and centrifugal forces in such a curved flow environment. We investigate how the emerging interfacial patterns are impacted by changes in the geometric properties of the curved Hele-Shaw cell. A vortex-sheet formalism is used to calculate the two-fluid interface curvature, and a gallery of possible shapes is provided to highlight a number of peculiar morphological features. A linear perturbation theory is employed to show that the most prominent aspects of these complex stationary patterns can be fairly well reproduced by the interplay of just two interfacial modes. The connection of these dominant modes to the geometry of the curved cell, as well as to the fluid dynamic properties of the flow, is discussed. We thank CNPq (Brazilian Research Council) for financial support under Grant No. 304821/2015-2.

Selected Papers on Low-Energy Antiprotons and Possible Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Noble, Robert

1998-09-19

The only realistic means by which to create a facility at Fermilab to produce large amounts of low energy antiprotons is to use resources which already exist. There is simply too little money and manpower at this point in time to generate new accelerators on a time scale before the turn of the century. Therefore, innovation is required to modify existing equipment to provide the services required by experimenters.

Prospects for testing Lorentz and CPT symmetry with antiprotons.

PubMed

Vargas, Arnaldo J

2018-03-28

A brief overview of the prospects of testing Lorentz and CPT symmetry with antimatter experiments is presented. The models discussed are applicable to atomic spectroscopy experiments, Penning-trap experiments and gravitational tests. Comments about the sensitivity of the most recent antimatter experiments to the models reviewed here are included.This article is part of the Theo Murphy meeting issue 'Antiproton physics in the ELENA era'. © 2018 The Author(s).

SPECTRAL INTENSITIES OF ANTIPROTONS AND THE NESTED LEAKY-BOX MODEL FOR COSMIC RAYS IN THE GALAXY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cowsik, R.; Madziwa-Nussinov, T., E-mail: cowsik@physics.wustl.edu

2016-08-20

In this paper we note that the spectral intensities of antiprotons observed in Galactic cosmic rays in the energy range ∼1–300 GeV by BESS, PAMELA, and AMS instruments display nearly the same spectral shape as that generated by primary cosmic rays through their interaction with matter in the interstellar medium, without any significant modifications. More importantly, a constant residence time of ∼2.3 ± 0.7 million years in the Galactic volume, independent of the energy of cosmic rays, matches the observed intensities. A small additional component of secondary antiprotons in the energy range below 10 GeV, generated in cocoon-like regions surroundingmore » the cosmic-ray sources, seems to be present. We discuss this result in the context of observations of other secondary components such as positrons and boron, and the bounds on anisotropy of cosmic rays. In the nested leaky-box model the spectral intensities of antiprotons and positrons can be interpreted as secondary products of cosmic-ray interactions.« less

The BESS Search for Cosmic-Ray Antiproton Origins and for Cosmological Antimatter

NASA Technical Reports Server (NTRS)

Mitchell, John; Yamamoto, Akira

2009-01-01

The apex of the Balloon-borne Experiment with a Superconducting Spectrometer (BESS) program was reached with the Antarctic flight of BESS-Polar II, during the 2007-2008 Austral Summer, that obtained 24.5 days of data on over 4.7 billion cosmic-ray events. The US-Japan BESS Collaboration uses elementary particle measurements to study the early Universe and provides fundamental data on the spectra of light cosmic-ray elements and isotopes. BESS measures the energy spectra of cosmic-ray antiprotons to investigate signatures of possible exotic sources, such as dark-matter candidates, and searches for heavier antinuclei that might reach Earth from antimatter domains formed during symmetry breaking processes in the early Universe. Since 1993, BESS has carried out eleven high-latitude balloon flights, two of long duration, that together have defined the study of antiprotons below about 4 GeV, provided standard references for light element and isotope spectra, and set the most sensitive limits on the existence of antideuterons and antihelium. The BESS-Polar II flight took place at Solar Minimum, when the sensitivity of the low-energy antiproton measurements to a primary source is greatest. The rich BESS-Polar II dataset more than doubles the combined data from all earlier BESS flights and has 10-20 times the statistics of BESS data from the previous Solar Minimum. Here, we summarize the scientific results of BESS program, focusing on the results obtained using data from the long-duration flights of BESS-Polar I (2004) and BESS-Polar II.

The "heartbeat of the proton"

NASA Astrophysics Data System (ADS)

Weisskopf, Victor F.

Once Nino came to my office to tell me about his ideas of studying lepton pair production at PS. I was still not Director General, but Research Director at CERN. In addition to (e+e-) and (μ+μ-) pairs, he wanted to search for (e±μ∓) pairs as a signature of a new lepton carrying its own lepton number. He told me that if such a lepton existed with one GeV mass, it would have escaped detection in hadron accelerator experiments for two reasons: i) it would decay with a lifetime of order 10-11 sec and ii) because there is no π → μ mechanism for such a heavy new lepton: for its production a time-like photon would be needed. Time-like photons could be produced in hadronic interactions: for example in (bar{p}p) annihilation. This was before Lederman-Schwartz and Steinberger had discovered the two neutrinos. To think of a "sequential" Heavy Lepton and to work out the possible ways to get it in a hadron machine was for me extremely interesting Nino had just finished his first high precision work on the muon (g-2). It was some time after the Rochester Conference in 1960. I gave Nino the following suggestion: if you want to search for something so revolutionary as a Heavy Lepton carrying its own lepton number you should work out a proposal for a series of experiments where the study of lepton pairs (e+e-) and (μ+μ-) could be justified in terms of physics accepted by the community. In addition a high intensity antiproton beam was needed. He came later to tell me that he had two very good friends, both excellent engineers: Mario Morpurgo and Guido Petrucci. A very high intensity antiproton beam could be built to study the electromagnetic form factor of the proton in the time-like region. If the proton was "point-like" in the time-like region, the rate of time-like photons yielding (e+e-) and (μ+μ-) pairs could be accessible to experimental observation, thus allowing to establish some limits on the new Heavy Lepton mass, or to see it, via the (e±μ∓) channel. The

Cosmic-ray antiprotons, positrons, and gamma rays from halo dark matter annihilation

NASA Technical Reports Server (NTRS)

Rudaz, S.; Stecker, F. W.

1988-01-01

The subject of cosmic ray antiproton production is reexamined by considering other choices for the nature of the Majorana fermion chi other than the photino considered in a previous article. The calculations are extended to include cosmic-ray positrons and cosmic gamma rays as annihilation products. Taking chi to be a generic higgsino or simply a heavy Majorana neutrino with standard couplings to the Z-zero boson allows the previous interpretation of the cosmic antiproton data to be maintained. In this case also, the annihilation cross section can be calculated independently of unknown particle physics parameters. Whereas the relic density of photinos with the choice of parameters in the previous paper turned out to be only a few percent of the closure density, the corresponding value for Omega in the generic higgsino or Majorana case is about 0.2, in excellent agreement with the value associated with galaxies and one which is sufficient to give the halo mass.

A comparative study of silicon detector degradation under irradiation by heavy ions and relativistic protons

NASA Astrophysics Data System (ADS)

Eremin, V.; Mitina, D.; Fomichev, A.; Kiselev, O.; Egorov, N.; Eremin, I.; Shepelev, A.; Verbitskaya, E.

2018-01-01

Silicon detectors irradiated by 40Ar ions with the energy of 1.62 GeV were studied with the goal to find the parameters of radiation damage induced by ions. The measurements of the I-V characteristics, temperature dependences of the detector bulk current, deep level spectra and current pulse response were carried out for detectors irradiated within the fluence range 5×1010-2.3×1013 ion/cm2 and the obtained results were compared with the corresponding data for detectors irradiated by 23 GeV protons. It is shown that the processes of defect introduction by ions and overall radiation damage are similar to those induced by 23 GeV protons, while the introduction rates of radiation defects and current generation centers are about ten times higher for irradiation by 40Ar ions. The fact that these processes have much in common gives grounds to use the physical models and characteristic parametrization such as those developed earlier for detectors irradiated by protons and neutrons to build the long-term scenario of Si detector operation in the Time-Of-Flight diagnostic system of Super FRagment Separator designed at GSI for the future Facility for Antiproton and Ion Research, FAIR.

Excitation functions of parameters extracted from three-source (net-)proton rapidity distributions in Au-Au and Pb-Pb collisions over an energy range from AGS to RHIC

NASA Astrophysics Data System (ADS)

Gao, Li-Na; Liu, Fu-Hu; Sun, Yan; Sun, Zhu; Lacey, Roy A.

2017-03-01

Experimental results of the rapidity spectra of protons and net-protons (protons minus antiprotons) emitted in gold-gold (Au-Au) and lead-lead (Pb-Pb) collisions, measured by a few collaborations at the alternating gradient synchrotron (AGS), super proton synchrotron (SPS), and relativistic heavy ion collider (RHIC), are described by a three-source distribution. The values of the distribution width σC and fraction kC of the central rapidity region, and the distribution width σF and rapidity shift Δ y of the forward/backward rapidity regions, are then obtained. The excitation function of σC increases generally with increase of the center-of-mass energy per nucleon pair √{s_{NN}}. The excitation function of σF shows a saturation at √{s_{NN}}=8.8 GeV. The excitation function of kC shows a minimum at √{s_{NN}}=8.8 GeV and a saturation at √{s_{NN}} ≈ 17 GeV. The excitation function of Δ y increases linearly with ln(√{s_{NN}}) in the considered energy range.

Strange and non-strange particle production in antiproton-nucleus collisions in the UrQMD model

NASA Astrophysics Data System (ADS)

Limphirat, Ayut; Kobdaj, Chinorat; Bleicher, Marcus; Yan, Yupeng; Stöcker, Horst

2009-06-01

The capabilities of the ultra-relativistic quantum molecular dynamics (UrQMD) model in describing antiproton-nucleus collisions are presented. The model provides a good description of the experimental data on multiplicities, transverse momentum distributions and rapidity distributions in antiproton-nucleus collisions. Special emphasis is put on the comparison of strange particles in reactions with nuclear targets ranging from 7Li, 12C, 32S, 64Cu to 131Xe because of the important role of strangeness for the exploration of hypernuclei at PANDA-FAIR. The productions of the double strange baryons Ξ- and \\bar{\\Xi}^+ , which may be used to produce double Λ hypernuclei, are predicted in this work for the reactions \\skew2\\bar{p} + 24Mg, 64Cu and 197Au.

Search for Cosmic-Ray Antiproton Origins and for Cosmological Antimatter with BESS

NASA Technical Reports Server (NTRS)

Yamamoto, A.; Mitchell, J. W.; Yoshimura, K.; Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Itazaki, A.;

Observed antiprotons and energy dependent confinement of cosmic rays: A conflict?

NASA Technical Reports Server (NTRS)

Stephens, S. A.

1985-01-01

In the frame work of energy dependent confinement for cosmic rays, the energy spectrum inside the source is flatter than that observed. Antiproton observation suggests large amount of matter is being traversed by cosmic rays in some sources. As a result, secondary particles are produced in abundance. Their spectra was calculated and it is shown that the energy dependent confinement model is in conflict with some observations.

Electron cooling for the Fermilab recycler: Present concept and provisional parameters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagaitsev, S.

1997-09-01

In all scenarios of the possible Tevatron upgrades, luminosity is essentially proportional to the number of antiprotons. Thus, a tenfold increase in luminosity could be achieved by putting five times more protons on the antiproton production target and gaining an additional factor of two from recycling antiprotons left over from the previous store. Stacking and storing ten times more antiprotons puts an unbearable burden on the stochastic cooling system of the existing Accumulator Ring. Thus, one is led to consider an additional stage of antiproton storage the so called Recycler Ring. Electron cooling of the 8 GeV antiprotons in themore » Recycler could provide an attractive way around the problems of large stacks. Such a system would look much like the IUCF proposal to cool 12 GeV protons in the SSC Medium Energy Booster. Although electron cooling has now become a routine tool in many laboratories, its use has been restricted to lower energy accelerators (< 500 MeV/nucleon). An R&D program is currently underway at Fermilab to extend electron cooling technology to the GeV range. This paper describes the electron cooling system design as well as the Recycler ring parameters required to accommodate this system.« less

Prospects to verify a possible dark matter hint in cosmic antiprotons with antideuterons and antihelium

NASA Astrophysics Data System (ADS)

Korsmeier, Michael; Donato, Fiorenza; Fornengo, Nicolao

2018-05-01

Cosmic rays are an important tool to study dark matter (DM) annihilation in our Galaxy. Recently, a possible hint for dark matter annihilation was found in the antiproton spectrum measured by AMS-02, even though the result might be affected by theoretical uncertainties. A complementary way to test its dark matter interpretation would be the observation of low-energy antinuclei in cosmic rays. We determine the chances to observe antideuterons with GAPS and AMS-02 and the implications for the ongoing AMS-02 antihelium searches. We find that the corresponding antideuteron signal is within the GAPS and AMS-02 detection potential. If, more conservatively, the putative signal was considered as an upper limit on DM annihilation, our results would indicate the highest possible fluxes for antideuterons and antihelium compatible with current antiproton data.

Cosmic-ray antiprotons as a probe of a photino-dominated universe

NASA Technical Reports Server (NTRS)

Silk, J.; Srednicki, M.

1984-01-01

Observational tests of the hypothesis that the universe is flat and dominated by dark matter in the form of massive photinos include the production of significant fluxes of cosmic rays and gamma rays in our galactic halo. Specification of the cosmological photino density and the masses of scalar quarks and leptons determines the present annihilation rate. The predicted number of low-energy cosmic-ray antiprotons is comparable to the observed flux.

Cosmic-ray antimatter - A primary origin hypothesis

NASA Technical Reports Server (NTRS)

Stecker, F. W.; Protheroe, R. J.; Kazanas, D.

1983-01-01

The present investigation is concerned with the possibility that the observed cosmic-ray protons are of primary extragalactic origin, taking into account the significance of the current antiproton data. Attention is given to questions regarding primary antiprotons, antihelium fluxes, and the propagation of extragalactic cosmic rays. It is concluded that the primary origin hypothesis should be considered as a serious alternative explanation for the cosmic-ray antiproton fluxes. Such extragalactic primary origin can be considered in the context of a baryon symmetric domain cosmology. The fluxes and propagation characteristics suggested are found to be in rough agreement with the present antiproton data.

Reconstruction of bar {p}p events in PANDA

NASA Astrophysics Data System (ADS)

Spataro, S.

2012-08-01

The PANDA experiment will study anti-proton proton and anti-proton nucleus collisions in the HESR complex of the facility FAIR, in a beam momentum range from 2 GeV jc up to 15 GeV/c. In preparation for the experiment, a software framework based on ROOT (PandaRoot) is being developed for the simulation, reconstruction and analysis of physics events, running also on a GRID infrastructure. Detailed geometry descriptions and different realistic reconstruction algorithms are implemented, currently used for the realization of the Technical Design Reports. The contribution will report about the reconstruction capabilities of the Panda spectrometer, focusing mainly on the performances of the tracking system and the results for the analysis of physics benchmark channels.

Ion Storage with the High Performance Antiproton Trap (HiPAT)

NASA Technical Reports Server (NTRS)

Martin, James; Lewis, Raymond; Chakrabarti, Suman; Pearson, Boise

2002-01-01

The matter antimatter reaction represents the densest form of energy storage/release known to modern physics: as such it offers one of the most compact sources of power for future deep space exploration. To take the first steps along this path, NASA-Marshall Space Flight Center is developing a storage system referred to as the High Performance Antiproton Trap (HiPAT) with a goal of maintaining 10(exp 12) particles for up to 18 days. Experiments have been performed with this hardware using normal matter (positive hydrogen ions) to assess the device's ability to hold charged particles. These ions are currently created using an electron gun method to ionize background gas; however, this technique is limited by the quantity that can be captured. To circumvent this issue, an ion source is currently being commissioned which will greatly increase the number of ions captured and more closely simulate actual operations expected at an antiproton production facility. Ions have been produced, stored for various time intervals, and then extracted against detectors to measure species, quantity and energy. Radio frequency stabilization has been tested as a method to prolong ion lifetime: results show an increase in the baseline 1/e lifetime of trapped particles from hours to days. Impurities in the residual background gas (typically carbon-containing species CH4, CO, CO2, etc.) present a continuing problem by reducing the trapped hydrogen population through the mechanism of ion charge exchange.

Production of slow protonium in vacuum

NASA Astrophysics Data System (ADS)

Zurlo, N.; Rizzini, E. Lodi; Venturelli, L.; Amoretti, M.; Carraro, C.; Lagomarsino, V.; Macrì, M.; Manuzio, G.; Testera, G.; Variola, A.; Amsler, C.; Pruys, H.; Regenfus, C.; Bonomi, G.; Fontana, A.; Genova, P.; Montagna, P.; Rotondi, A.; Cesar, C. L.; Charlton, M.; Mitchard, D.; Jørgensen, L. V.; Madsen, N.; Van der Werf, D. P.; Doser, M.; Kellerbauer, A.; Landua, R.; Funakoshi, R.; Hayano, R. S.; Posada, L. G.; Yamazaki, Y.

We describe how protonium, the quasi-stable antiproton-proton bound system, has been synthesized following the interaction of antiprotons with the molecular ion H{2/+} in a nested Penning trap environment. From a careful analysis of the spatial distributions of antiproton annihilation events in the ATHENA experiment, evidence is presented for protonium production with sub-eV kinetic energies in states around n = 70, with iow angular momenta. This work provides a new two-body system for studies using laser spectroscopic techniques.

Production of slow protonium in vacuum

NASA Astrophysics Data System (ADS)

Zurlo, N.; Amoretti, M.; Amsler, C.; Bonomi, G.; Carraro, C.; Cesar, C. L.; Charlton, M.; Doser, M.; Fontana, A.; Funakoshi, R.; Genova, P.; Hayano, R. S.; Jørgensen, L. V.; Kellerbauer, A.; Lagomarsino, V.; Landua, R.; Lodi Rizzini, E.; Macrì, M.; Madsen, N.; Manuzio, G.; Mitchard, D.; Montagna, P.; Posada, L. G.; Pruys, H.; Regenfus, C.; Rotondi, A.; Testera, G.; van der Werf, D. P.; Variola, A.; Venturelli, L.; Yamazaki, Y.

2006-09-01

We descrbe how protonium, the quasi-stable antiproton-proton bound system, has been synthesized following the interaction of antiprotons with the molecular ion H_2^+ in a nested Penning trap environment. From a careful analysis of the spatial distributions of antiproton annihilation events in the ATHENA experiment, evidence is presented for protonium production with sub-eV kinetic energies in states around n = 70, with low angular momenta. This work provides a new two-body system for studies using laser spectroscopic techniques.

Liquid helium-free cryostat and hermetically sealed cryogenic microwave cavity for hyperfine spectroscopy of antiprotonic helium

PubMed Central

Massiczek, O.; Friedreich, S.; Juhász, B.; Widmann, E.; Zmeskal, J.

2011-01-01

The design and properties of a new cryogenic set-up for laser–microwave–laser hyperfine structure spectroscopy of antiprotonic helium – an experiment performed at the CERN-Antiproton Decelerator (AD), Geneva, Switzerland – are described. Similar experiments for 4He have been performed at the AD for several years. Due to the usage of a liquid helium operated cryostat and therefore necessary refilling of coolants, a loss of up to 10% beamtime occurred. The decision was made to change the cooling system to a closed-circuit cryocooler. New hermetically sealed target cells with minimised 3He gas volume and different dimensions of the microwave resonator for measuring the 3He transitions were needed. A new set-up has been designed and tested at Stefan Meyer Institute in Vienna before being used for the 2009 and 2010 beamtimes at the AD. PMID:22267883

Review of the High Performance Antiproton Trap (HiPAT) Experiment at the Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Pearson, J. B.; Sims, Herb; Martin, James; Chakrabarti, Suman; Lewis, Raymond; Fant, Wallace

2003-01-01

The significant energy density of matter-antimatter annihilation is attractive to the designers of future space propulsion systems, with the potential to offer a highly compact source of power. Many propulsion concepts exist that could take advantage of matter-antimatter reactions, and current antiproton production rates are sufficient to support basic proof-of-principle evaluation of technology associated with antimatter- derived propulsion. One enabling technology for such experiments is portable storage of low energy antiprotons, allowing antiprotons to be trapped, stored, and transported for use at an experimental facility. To address this need, the Marshall Space Flight Center's Propulsion Research Center is developing a storage system referred to as the High Performance Antiproton Trap (HiPAT) with a design goal of containing 10(exp 12) particles for up to 18 days. The HiPAT makes use of an electromagnetic system (Penning- Malmberg design) consisting of a 4 Telsa superconductor, high voltage electrode structure, radio frequency (RF) network, and ultra high vacuum system. To evaluate the system normal matter sources (both electron guns and ion sources) are used to generate charged particles. The electron beams ionize gas within the trapping region producing ions in situ, whereas the ion sources produce the particles external to the trapping region and required dynamic capture. A wide range of experiments has been performed examining factors such as ion storage lifetimes, effect of RF energy on storage lifetime, and ability to routinely perform dynamic ion capture. Current efforts have been focused on improving the FW rotating wall system to permit longer storage times and non-destructive diagnostics of stored ions. Typical particle detection is performed by extracting trapped ions from HiPAT and destructively colliding them with a micro-channel plate detector (providing number and energy information). This improved RF system has been used to detect various

THE INFLUENCE OF DISSIPATION RANGE POWER SPECTRA AND PLASMA-WAVE POLARIZATION ON COSMIC-RAY SCATTERING MEAN FREE PATH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schlickeiser, R.; Lazar, M.; Vukcevic, M., E-mail: rsch@tp4.rub.d, E-mail: mlazar@tp4.ruhr-uni-bochum.d, E-mail: vuk.mira@gmail.co

2010-08-20

The influence of the polarization state and the dissipation range spectral steepening of slab plasma waves on the scattering mean free path of single-charged cosmic-ray particles is investigated in a turbulence model, where the crucial scattering of cosmic-ray particles with small pitch-angle cosines is caused by resonant cyclotron interactions with slab plasma waves. Analytical expressions for the mean free path of protons, antiprotons, negatrons, and positrons are derived for the case of constant frequency-independent magnetic helicity values {sigma} and different values of the dissipation range spectral index k for characteristic interplanetary and interstellar plasma conditions. The positron mean free pathmore » is not affected by the dissipation range spectral index k as these particles can only cyclotron-resonate for rigidity values larger than R {sub 0} = m{sub p}c = 938 MV. Proton and antiproton mean free paths are only slightly affected by the dissipation range spectral index k at small rigidities R < R {sub 0}. The negatron mean free path is severely affected by the dissipation range spectral index k at rigidities smaller than R {sub 0}. At high rigidities R >> R {sub 0}, all particle species approach the same power-law dependence {proportional_to}R {sup 2-s} determined by the inertial range spectral index s = 5/3. The magnetic helicity value {sigma} affects the value of the mean free path. At all rigidities, the ratio of the antiproton to proton mean free paths equals the constant (1 + {sigma})/(1 - {sigma}), which also agrees with the ratio of the negatron to the proton and positron mean free paths at relativistic rigidities. At relativistic rigidities the positron and proton mean free paths agree, as do the negatron and antiproton mean free paths.« less

Effect of Coulomb interaction on time of flight of cold antiprotons launched from an ion trap

NASA Technical Reports Server (NTRS)

Camp, J. B.; Witteborn, F. C.

1993-01-01

Time-of-flight spectra for Maxwell-Boltzman (MB) distributions of antiprotons initially held in an ion trap and detected after being launched through a 50-cm-long shielding drift tube have been calculated. The distributions used are of temperature 0.4-40 K, cubic length 0.003-3.0 cm, and number 10-100 particles. The mutual Coulomb repulsion of the particles causes a reduction in the number of late arrival particles expected from the MB velocity distribution. The Coulomb energy is not equally divided among the particles during the expansion. The energy is transferred preferentially to the outer particles so that the reduction in the number of slow particles is not necessarily large. The reduction factor is found to be greater than unity when the potential energy of the trapped ions is greater than about 5 percent of the ions' kinetic energy and is about 2 for the launch parameters of the Los Alamos antiproton gravity experiment.

The physics of proton antiproton collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shochet, M.

1991-12-03

This paper contains information information on: accelerator and detector; QCD studies; studies of the electroweak force; The search for the top quark; {beta} physics at hadron colliders; and the search for exotic objects and prospects for the future.

Ion Dynamic Capture Experiments With The High Performance Antiproton Trap (HiPAT)

NASA Technical Reports Server (NTRS)

Martin, James; Lewis, Raymond; Chakrabarti, Suman; Sims, William H.; Pearson, J. Boise; Fant, Wallace E.

2002-01-01

To take the first step towards using the energy produced from the matter-antimatter annihilation for propulsion applications, the NASA Marshall Space Flight Center (MSFC) Propulsion Research Center (PRC) has initiated a research activity examining the storage of low energy antiprotons. The High Performance Antiproton Trap (HiPAT) is an electromagnetic system (Penning-Malmberg design) consisting of a 4 Tesla superconductor, a high voltage electrode confinement system, and an ultra high vacuum test section. It has been designed with an ultimate goal of maintaining 10(exp 12) charged particles with a half-life of 18 days. Currently, this system is being evaluated experimentally using normal matter ions that are cheap to produce, relatively easy to handle, and provide a good indication of overall trap behavior (with the exception of assessing annihilation losses). The ions are produced via a positive hydrogen ion source and transported to HiPAT in a beam line equipped with electrostatic optics. The optics serve to both focus and gate the incoming ions, providing microsecond-timed beam pulses that are dynamically captured by cycling the HiPAT forward containment field like a "trap door". Initial dynamic capture experiments have been successfully performed with beam energy and currents set to 1.9 kV and 23 micro-amps, respectively. At these settings up to 2x10(exp 9) ions have been trapped during a single dynamic cycle.

Antiproton-Induced Microfission

DTIC Science & Technology

1994-02-21

than chemical propulsion, other systems may prove even more efficient. Matter -antimatter reactions release enormous amounts of energy, mostly in the form...and matter -antimatter annihilation, to that of H2+0 2 combustion. Table 1.1 Theorectical specific energies of various reactions. System eth J/kg...For the case of hydrogen plasma, protons represent the ions. It would seem that two fluids interacting 25 would greatly complicate matters ; however

Cosmic ray positron research and silicon track detector development

NASA Technical Reports Server (NTRS)

Jones, W. Vernon; Wefel, John P.

1991-01-01

The purpose was to conduct research on: (1) position sensing detector systems, particularly those based upon silicon detectors, for use in future balloon and satellite experiments; and (2) positrons, electrons, proton, anti-protons, and helium particles as measured by the NASA NMSU Balloon Magnet Facility.

Impact of 7-TeV/c large hadron collider proton beam on a copper target

NASA Astrophysics Data System (ADS)

Tahir, N. A.; Goddard, B.; Kain, V.; Schmidt, R.; Shutov, A.; Lomonosov, I. V.; Piriz, A. R.; Temporal, M.; Hoffmann, D. H. H.; Fortov, V. E.

2005-04-01

The large hadron collider (LHC) will allow for collision between two 7TeV/c proton beams, each comprising 2808 bunches with 1.1×1011 protons per bunch, traveling in opposite direction. The bunch length is 0.5ns and two neighboring bunches are separated by 25ns so that the duration of the entire beam is about 89μs. The beam power profile in the transverse direction is a Gaussian with a standard deviation of 0.2mm. The energy stored in each beam is about 350MJ that is sufficient to melt 500kg of copper. In case of a failure in the machine protection systems, the entire beam could impact directly onto an accelerator equipment. A first estimate of the scale of damage resulting from such a failure has been assessed for a solid copper target hit by the beam by carrying out three-dimensional energy deposition calculations and two-dimensional numerical simulations of the hydrodynamic and thermodynamic response of the target. This work has shown that the penetration depth of the LHC protons will be between 10 and 40m in solid copper. These calculations show that material conditions obtained in the target are similar to those planned for beam impact at dedicated accelerators designed to study the physics of high-energy-density states of matter, for example, the Facility for Antiprotons and Ion Research at the Gesellschaft für Schwerionenforschung, Darmstadt [W. F. Henning, Nucl. Instrum Methods Phys. Res. B 214, 211 (2004)].

Higher moments of net-proton multiplicity distributions in a heavy-ion event pile-up scenario

NASA Astrophysics Data System (ADS)

Garg, P.; Mishra, D. K.

2017-10-01

High-luminosity modern accelerators, like the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) and Large Hadron Collider (LHC) at European Organization for Nuclear Research (CERN), inherently have event pile-up scenarios which significantly contribute to physics events as a background. While state-of-the-art tracking algorithms and detector concepts take care of these event pile-up scenarios, several offline analytical techniques are used to remove such events from the physics analysis. It is still difficult to identify the remaining pile-up events in an event sample for physics analysis. Since the fraction of these events is significantly small, it may not be as serious of an issue for other analyses as it would be for an event-by-event analysis. Particularly when the characteristics of the multiplicity distribution are observable, one needs to be very careful. In the present work, we demonstrate how a small fraction of residual pile-up events can change the moments and their ratios of an event-by-event net-proton multiplicity distribution, which are sensitive to the dynamical fluctuations due to the QCD critical point. For this study, we assume that the individual event-by-event proton and antiproton multiplicity distributions follow Poisson, negative binomial, or binomial distributions. We observe a significant effect in cumulants and their ratios of net-proton multiplicity distributions due to pile-up events, particularly at lower energies. It might be crucial to estimate the fraction of pile-up events in the data sample while interpreting the experimental observable for the critical point.

Highlights on gamma rays, neutrinos and antiprotons from TeV Dark Matter

NASA Astrophysics Data System (ADS)

Gammaldi, Viviana

2016-07-01

It has been shown that the gamma-ray flux observed by HESS from the J1745-290 Galactic Center source is well fitted as the secondary gamma-rays photons generated from Dark Matter annihilating into Standard Model particles in combination with a simple power law background. The neutrino flux expected from such Dark Matter source has been also analyzed. The main results of such analyses for 50 TeV Dark Matter annihilating into W+W- gauge boson and preliminary results for antiprotons are presented.

Proton-proton correlations observed in two-proton radioactivity of 94Ag.

PubMed

Mukha, Ivan; Roeckl, Ernst; Batist, Leonid; Blazhev, Andrey; Döring, Joachim; Grawe, Hubert; Grigorenko, Leonid; Huyse, Mark; Janas, Zenon; Kirchner, Reinhard; La Commara, Marco; Mazzocchi, Chiara; Tabor, Sam L; Van Duppen, Piet

2006-01-19

The stability and spontaneous decay of naturally occurring atomic nuclei have been much studied ever since Becquerel discovered natural radioactivity in 1896. In 1960, proton-rich nuclei with an odd or an even atomic number Z were predicted to decay through one- and two-proton radioactivity, respectively. The experimental observation of one-proton radioactivity was first reported in 1982, and two-proton radioactivity has now also been detected by experimentally studying the decay properties of 45Fe (refs 3, 4) and 54Zn (ref. 5). Here we report proton-proton correlations observed during the radioactive decay of a spinning long-lived state of the lightest known isotope of silver, 94Ag, which is known to undergo one-proton decay. We infer from these correlations that the long-lived state must also decay through simultaneous two-proton emission, making 94Ag the first nucleus to exhibit one- as well as two-proton radioactivity. We attribute the two-proton emission behaviour and the unexpectedly large probability for this decay mechanism to a very large deformation of the parent nucleus into a prolate (cigar-like) shape, which facilitates emission of protons either from the same or from opposite ends of the 'cigar'.

Stacking Multiple Ion Captures in The High Performance Antiproton Trap (HiPAT)

NASA Technical Reports Server (NTRS)

Martin, James J.; Lewis, Raymond A.; Sims, William H.; Chakrabarti, Suman; Pearson, Boise; Fant, Wallace E.

2004-01-01

The High performance Antiproton Trap (HiPAT) research project was initiated by the Marshall Space Flight Center's propulsion Research Center to examining the fundamental behavior of low energy antiprotons. Stored antiproton would ultimately be used for experimental demonstration of basic propulsive concepts. Matter-antimatter annihilation produces approximately 10(exp 8) MJ/g nearly 10 orders of magnitude more energy per unit mass than chemical based combustion, hence NASA's interest. To achieve containment, HiPAT utilizes a type of electromagnetic bottle know as a Penning trap positioned within an ultrahigh vacuum test section. Recently, the HiPAT hardware configuration has been enhanced to facilitate the capture of multiple normal matter ion burst. This endeavor is often referred to as "stacking" and used to increasing the number of captured particles. A prior normal matter experimental effort, successfully demonstrated the effectiveness of single burst capture. The stacking process is accomplished by manipulating the electric field generated by the confinement electrodes i.e. adjusting the well potential depth. These potential well values are initially configured to maximize the quantity of captured ions per burst; shallow wells with a depth of 100 volt or less (referenced to the incoming ion beam energy) are typically selected. Once captured, a cooling interval is required to reduce the energy of trapped particles below the lower extent of the "trap door" (or leading electrode) ion emitting potential. This is necessary such that a new burst of hot ions can be introduced while preventing those already inside from escaping. The cooling time is driven by a combination of mechanisms such as synchrotron radiation, background gas scattering, and resistive damping in a time scale on the order of minutes. A potential for reducing this hold period is to actively manipulate the electric field shape, using the power supply control system, to produce a deeper potential

Baryon-antibaryon dynamics in relativistic heavy-ion collisions

NASA Astrophysics Data System (ADS)

Seifert, E.; Cassing, W.

2018-04-01

The dynamics of baryon-antibaryon annihilation and reproduction (B B ¯↔3 M ) is studied within the Parton-Hadron-String Dynamics (PHSD) transport approach for Pb+Pb and Au+Au collisions as a function of centrality from lower Super Proton Synchrotron (SPS) up to Large Hadron Collider (LHC) energies on the basis of the quark rearrangement model. At Relativistic Heavy-Ion Collider (RHIC) energies we find a small net reduction of baryon-antibaryon (B B ¯ ) pairs while for the LHC energy of √{sN N}=2.76 TeV a small net enhancement is found relative to calculations without annihilation (and reproduction) channels. Accordingly, the sizable difference between data and statistical calculations in Pb+Pb collisions at √{sN N}=2.76 TeV for proton and antiproton yields [ALICE Collaboration, B. Abelev et al., Phys. Rev. C 88, 044910 (2013), 10.1103/PhysRevC.88.044910], where a deviation of 2.7 σ was claimed by the ALICE Collaboration, should not be attributed to a net antiproton annihilation. This is in line with the observation that no substantial deviation between the data and statistical hadronization model (SHM) calculations is seen for antihyperons, since according to the PHSD analysis the antihyperons should be modified by the same amount as antiprotons. As the PHSD results for particle ratios are in line with the ALICE data (within error bars) this might point towards a deviation from statistical equilibrium in the hadronization (at least for protons and antiprotons). Furthermore, we find that the B B ¯↔3 M reactions are more effective at lower SPS energies where a net suppression for antiprotons and antihyperons up to a factor of 2-2.5 can be extracted from the PHSD calculations for central Au+Au collisions.

Overview of the High Performance Antiproton Trap (HiPAT) Experiment

NASA Technical Reports Server (NTRS)

Martin, James; Chakrabarti, Suman; Pearson, Boise; Sims, W. Herbert; Lewis, Raymond; Fant, Wallace; Rodgers, Stephen (Technical Monitor)

2002-01-01

A general overview of the High Performance Antiproton Trap (HiPAT) Experiment is presented. The topics include: 1) Why Antimatter? 2) HiPAT Applicability; 3) Approach-Goals; 4) HiPAT General Layout; 5) Sizing For Containment; 6) Laboratory Operations; 7) Vacuum System Cleaning; 8) Ion Production Via Electron Gun; 9) Particle Capture Via Ion Sources; 10) Ion Beam Steering/Focusing; 11) Ideal Ion Stacking Sequence; 12) Setup For Dynamic Capture; 13) Dynamic Capture of H(+) Ions; 14) Dynamic Capture; 15) Radio Frequency Particle Detection; 16) Radio Frequency Antenna Modeling; and 17) R.F. Stabilization-Low Frequencies. A short presentation of propulsion applications of Antimatter is also given. This paper is in viewgraph form.

Top, electroweak and recent results from CDF and combinations from the Tevatron

DOE PAGES

Lucchesi, D.

2017-12-18

Data collected at the Tevatron proton-antiproton collider are still producing interesting results. Measurements of QCD, top and electroweak quantities are competitive to LHC because of the low center of mass energy, √ s = 1.96 GeV and due to the fact that this is proton-antiproton data. This report describes the CDF measurement of the prompt photon cross section and the determination of the effective leptonic electroweak mixing angle by CDF and D0 experiments. The combination of the two results gives a precise measurement of sin 2 θmore » $$lep\\atop{eff}$$ from which the W mass is inferred by using standard model calculations.« less

Top, electroweak and recent results from CDF and combinations from the Tevatron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lucchesi, D.

Data collected at the Tevatron proton-antiproton collider are still producing interesting results. Measurements of QCD, top and electroweak quantities are competitive to LHC because of the low center of mass energy, √ s = 1.96 GeV and due to the fact that this is proton-antiproton data. This report describes the CDF measurement of the prompt photon cross section and the determination of the effective leptonic electroweak mixing angle by CDF and D0 experiments. The combination of the two results gives a precise measurement of sin 2 θmore » $$lep\\atop{eff}$$ from which the W mass is inferred by using standard model calculations.« less

Evaluation on Geant4 Hadronic Models for Pion Minus, Pion Plus and Neutron Particles as Major Antiproton Annihilation Products

PubMed Central

Tavakoli, Mohammad Bagher; Mohammadi, Mohammad Mehdi; Reiazi, Reza; Jabbari, Keyvan

2015-01-01

Geant4 is an open source simulation toolkit based on C++, which its advantages progressively lead to applications in research domains especially modeling the biological effects of ionizing radiation at the sub-cellular scale. However, it was shown that Geant4 does not give a reasonable result in the prediction of antiproton dose especially in Bragg peak. One of the reasons could be lack of reliable physic model to predict the final states of annihilation products like pions. Considering the fact that most of the antiproton deposited dose is resulted from high-LET nuclear fragments following pion interaction in surrounding nucleons, we reproduced depth dose curves of most probable energy range of pions and neutron particle using Geant4. We consider this work one of the steps to understand the origin of the error and finally verification of Geant4 for antiproton tracking. Geant4 toolkit version 9.4.6.p01 and Fluka version 2006.3 were used to reproduce the depth dose curves of 220 MeV pions (both negative and positive) and 70 MeV neutrons. The geometry applied in the simulations consist a 20 × 20 × 20 cm3 water tank, similar to that used in CERN for antiproton relative dose measurements. Different physic lists including Quark-Gluon String Precompound (QGSP)_Binary Cascade (BIC)_HP, the recommended setting for hadron therapy, were used. In the case of pions, Geant4 resulted in at least 5% dose discrepancy between different physic lists at depth close to the entrance point. Even up to 15% discrepancy was found in some cases like QBBC compared to QGSP_BIC_HP. A significant difference was observed in dose profiles of different Geant4 physic list at small depths for a beam of pions. In the case of neutrons, large dose discrepancy was observed when LHEP or LHEP_EMV lists were applied. The magnitude of this dose discrepancy could be even 50% greater than the dose calculated by LHEP (or LHEP_EMV) at larger depths. We found that effect different Geant4 physic list in

Three new defined proton affinities for polybasic molecules in the gas-phase: Proton microaffinity, proton macroaffinity and proton overallaffinity

NASA Astrophysics Data System (ADS)

Salehzadeh, Sadegh; Bayat, Mehdi

2006-08-01

A theoretical study on complete protonation of a series of tetrabasic molecules with general formula N[(CH 2) nNH 2][(CH 2) mNH 2][(CH 2) pNH 2] (tren, pee, ppe, tpt, epb and ppb) is reported. For first time, three kinds of gas-phase proton affinities for each polybasic molecule are defined as: 'proton microaffinity (PA n, i)', 'proton macroaffinity (PA)' and 'proton overall affinity ( PA)'. The variations of calculated logPA in the series of these molecules is very similar to that of their measured log Kn. There is also a good correlation between the calculated gas-phase proton macroaffinities and proton overallaffinities with corresponding equilibrium macroconstants and overall protonation constants in solution.

Radiation Belts of Antiparticles in Planetary Magnetospheres

NASA Astrophysics Data System (ADS)

Pugacheva, G. I.; Gusev, A. A.; Jayanthi, U. B.; Martin, I. M.; Spjeldvik, W. N.

2007-05-01

The Earth's radiation belts could be populated, besides with electrons and protons, also by antiparticles, such as positrons (Basilova et al., 1982) and antiprotons (pbar). Positrons are born in the decay of pions that are directly produced in nuclear reactions of trapped relativistic inner zone protons with the residual atmosphere at altitudes in the range of about 500 to 3000 km over the Earth's surface. Antiprotons are born by high energy (E > 6 GeV) cosmic rays in p+p - p+p+p+ pbar and in p+p - p+p+n+nbar reactions. The trapping and storage of these charged anti-particles in the magnetosphere result in radiation belts similar to the classical Van Allen belts of protons and electrons. We describe the mathematical techniques used for numerical simulation of the trapped positron and antiproton belt fluxes. The pion and antiproton yields were simulated on the basis of the Russian nuclear reaction computer code MSDM, a Multy Stage Dynamical Model, Monte Carlo code, (i.e., Dementyev and Sobolevsky, 1999). For estimates of positron flux there we have accounted for ionisation, bremsstrahlung, and synchrotron energy losses. The resulting numerical estimates show that the positron flux with energy >100 MeV trapped into the radiation belt at L=1.2 is of the order ~1000 m-2 s-1 sr-1, and that it is very sensitive to the shape of the trapped proton spectrum. This confined positron flux is found to be greater than that albedo, not trapped, mixed electron/positron flux of about 50 m-2 s-1 sr-1 produced by CR in the same region at the top of the geomagnetic field line at L=1.2. As we show in report, this albedo flux also consists mostly of positrons. The trapped antiproton fluxes produced by CR in the Earth's upper rarified atmosphere were calculated in the energy range from 10 MeV to several GeV. In the simulations we included a mathematic consideration of the radial diffusion process, both an inner and an outer antiproton source, losses of particles due to ionization process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yokosawa, A.

We review activities with experiments using polarized protons and polarized antiprotons at Fermilab for future high-energy spin physics we describe an experimental program with polarized collider at RHIC.

High-energy Physics with Hydrogen Bubble Chambers

DOE R&D Accomplishments Database

Alvarez, L. W.

1958-03-07

Recent experience with liquid hydrogen bubble chambers of 25 and 40 cm dia. in high-energy physics experiments is discussed. Experiments described are: interactions of K{sup -} mesons with protons, interactions of antiprotons with protons, catalysis of nuclear fusion reactions by muons, and production and decay of hyperons from negative pions. (W.D.M.)

Protons and how they are transported by proton pumps.

PubMed

Buch-Pedersen, M J; Pedersen, B P; Veierskov, B; Nissen, P; Palmgren, M G

2009-01-01

The very high mobility of protons in aqueous solutions demands special features of membrane proton transporters to sustain efficient yet regulated proton transport across biological membranes. By the use of the chemical energy of ATP, plasma-membrane-embedded ATPases extrude protons from cells of plants and fungi to generate electrochemical proton gradients. The recently published crystal structure of a plasma membrane H(+)-ATPase contributes to our knowledge about the mechanism of these essential enzymes. Taking the biochemical and structural data together, we are now able to describe the basic molecular components that allow the plasma membrane proton H(+)-ATPase to carry out proton transport against large membrane potentials. When divergent proton pumps such as the plasma membrane H(+)-ATPase, bacteriorhodopsin, and F(O)F(1) ATP synthase are compared, unifying mechanistic premises for biological proton pumps emerge. Most notably, the minimal pumping apparatus of all pumps consists of a central proton acceptor/donor, a positively charged residue to control pK(a) changes of the proton acceptor/donor, and bound water molecules to facilitate rapid proton transport along proton wires.

Neutron and antineutron production in accretion onto compact objects

NASA Technical Reports Server (NTRS)

Dermer, C. D.; Ramaty, R.

1986-01-01

Nuclear reactions in the hot accretion plasma surrounding a collapsed star are a source of neutrons, primarily through spallation and pion-producing reactions, and antineutrons, principally through the reaction p+p yields p+p+n+anti-n. We calculate spectra of neutrons and antineutrons produced by a variety of nonthermal energetic particle distributions in which the target particles are either at rest or in motion. If only neutral particles are free to escape the interaction site, a component of the proton and antiproton fluxes in the cosmic radiation results from the neutrons and antineutrons which leave the accretion plasma and subsequently decay in the interstellar medium. This additional antiproton component could account for the enhanced flux of antiprotons in the cosmic radiation, compared to values expected from the standard leaky-box model of cosmic-ray propagation and confinement. Moreover, the low-energy antiproton flux measured by Buffington et al. (1981) could result from target-particle motion in the accretion plasma. This model for the origin of antiprotons predicts a narrow 2.223 MeV line which could be observable.

Spin Filtering Studies at COSY and AD

NASA Astrophysics Data System (ADS)

Nass, Alexander

2009-08-01

The high physics potential of experiments with stored high-energy polarized antiprotons led to the proposal of PAX (Polarized Antiproton eXperiment) [1] for the High Energy Storage Ring (HESR) of the FAIR at GSI (Darmstadt/Germany). It is proposed to polarize a stored antiproton beam by means of spin filtering with a polarized H (D) gas target. The feasibility of spin filtering has been demonstrated in the FILTEX experiment. The current interpretation foresees a self-cancellation of the electron contribution to the filtering process and only the hadronic contribution is effective. Several experimental studies with protons (at COSY/Jülich) as well as antiprotons (at AD/CERN) will be carried out to test the principle and measure p¯p⃗ and p¯d⃗ cross sections. A polarized internal gas target (PIT) with surrounding Silicon detectors immersed into a low-β section has to be set up.

Protonium production in ATHENA

NASA Astrophysics Data System (ADS)

Venturelli, L.; Amoretti, M.; Amsler, C.; Bonomi, G.; Carraro, C.; Cesar, C. L.; Charlton, M.; Doser, M.; Fontana, A.; Funakoshi, R.; Genova, P.; Hayano, R. S.; Jørgensen, L. V.; Kellerbauer, A.; Lagomarsino, V.; Landua, R.; Rizzini, E. Lodi; Macrì, M.; Madsen, N.; Manuzio, G.; Mitchard, D.; Montagna, P.; Posada, L. G.; Pruys, H.; Regenfus, C.; Rotondi, A.; Testera, G.; van der Werf, D. P.; Variola, A.; Yamazaki, Y.; Zurlo, N.; Athena Collaboration

2007-08-01

The ATHENA experiment at CERN, after producing cold antihydrogen atoms for the first time in 2002, has synthesised protonium atoms in vacuum at very low energies. Protonium, i.e. the antiproton-proton bound system, is of interest for testing fundamental physical theories. In the nested penning trap of the ATHENA apparatus protonium has been produced as result of a chemical reaction between an antiproton and the simplest matter molecule, H2+. The formed protonium atoms have kinetic energies in the range 40-700 meV and are metastable with mean lifetimes of the order of 1 μs. Our result shows that it will be possible to start measurements on protonium at low energy antiproton facilities, such as the AD at CERN or FLAIR at GSI.

Spin Filtering Studies at COSY and AD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nass, Alexander

2009-08-04

The high physics potential of experiments with stored high-energy polarized antiprotons led to the proposal of PAX (Polarized Antiproton eXperiment) for the High Energy Storage Ring (HESR) of the FAIR at GSI (Darmstadt/Germany). It is proposed to polarize a stored antiproton beam by means of spin filtering with a polarized H (D) gas target. The feasibility of spin filtering has been demonstrated in the FILTEX experiment. The current interpretation foresees a self-cancellation of the electron contribution to the filtering process and only the hadronic contribution is effective. Several experimental studies with protons (at COSY/Juelich) as well as antiprotons (at AD/CERN)more » will be carried out to test the principle and measure p-barp-vector and p-bard-vector cross sections. A polarized internal gas target (PIT) with surrounding Silicon detectors immersed into a low-beta section has to be set up.« less

Fermilab Tevatron and Pbar source status report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edwards, H.

1986-08-01

The antiproton production cycle is enumerated, and the commissioning of the antiproton source is described, giving milestones and major obstacles. The Tevatron collider operation is described, including procedure to load the Tevatron with three bunches of protons and three bunches of antiprotons. Commissioning of the Main Ring and Tevatron for collider operation is described. Development and accelerator studies in four areas were necessary: main ring RF manipulations; controls and applications software support; Tevatron storage and low-beta squeeze sequence; and study of various beam transfers, storage steps, and sequences. Final tests are described. A long range upgrade program is presently undermore » evaluation to accomplish these goals: luminosity increase to 5 x 10/sup 31/ cm/sup -2/sec/sup -1/, production rates up to 4 x 10/sup 11/ antiprotons/hr, and intensity increase for fixed target operation. Beam quality is to be improved by the injector and main ring upgrades, and the luminosity goal is addressed by the Collider upgrade. (LEW)« less

30. Photocopy of photograph (original print located in LBNL Photo ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

30. Photocopy of photograph (original print located in LBNL Photo Lab Collection). Photographer unknown. October 6, 1955. BEV-943. ANTI-PROTON EXPERIMENT. B-51. - University of California Radiation Laboratory, Bevatron, 1 Cyclotron Road, Berkeley, Alameda County, CA

Habilitation thesis on STT and Higgs searches in WH production (in FRENCH)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sonnenschein, Lars

The detector of the D0 experiment at the proton anti-proton collider Tevatron in Run II is discussed in detail. The performance of the collider and the experiment is presented. Standard model Higgs searches with integrated luminosities between 260 pb -1 and 950 pb -1 and their combination are performed. No deviation from SM background expectation has been observed. Sensitivity prospects at the Tevatron are shown.

Theoretical motivation for gravitation experiments on ultra-low energy antiprotons and antihydrogen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nieto, M.M.

1995-12-31

It is known that the generally accepted theories of gravity and quantum mechanics are fundamentally incompatible. Thus, when one tries to combine these theories, one must beware of physical pitfalls. Modern theories of quantum gravity are trying to overcome these problems. Any ideas must confront the present agreement with general relativity, but yet be free to wonder about not understood phenomena, such as the dark matter problem. This all has led some {open_quotes}intrepid{close_quotes} theorists to consider a new gravitational regime, that of antimatter. Even more {open_quotes}daring{close_quotes} experimentalists are attempting, or considering attempting, the measurement of the gravitational force on antimatter,more » including low-energy antiprotons and, perhaps most enticing, antihydrogen.« less

Charged hadron transverse momentum distributions in Au+Au collisions at √sNN=200 GeV

NASA Astrophysics Data System (ADS)

Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Ballintijn, M.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Lee, J. W.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Veres, G. I.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

2004-01-01

We present transverse momentum distributions of charged hadrons produced in Au+Au collisions at sNN=200 GeV. The spectra were measured for transverse momenta pT from 0.25 to 4.5 GeV/c in a pseudorapidity range of 0.2<η<1.4. The evolution of the spectra is studied as a function of collision centrality, from 65 to 344 participating nucleons. The results are compared to data from proton-antiproton collisions and Au+Au collisions at lower RHIC energies. We find a significant change of the spectral shape between proton-antiproton and semi-peripheral Au+Au collisions. Comparing semi-peripheral to central Au+Au collisions, we find that the yields at high pT exhibit approximate scaling with the number of participating nucleons, rather than scaling with the number of binary collisions.

Proton Radiography Imager:Generates Synthetic Proton Radiographs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilks, Scott C.; Black, Mason R.

ProRad is a computer program that is used to generate synthetic images of proton (or other charged particles) radiographs. The proton radiographs arc images that arc obtained by sending energetic protons (or electrons or positrons, for example) through 11 plasma where electric and/or magnetic fields alter the particles trajectory, Dnd the variations me imaged on RC film, image plate, or equivalent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yokosawa, A.

We summarize activities concerning the Fermilab polarized beam (proton and antiproton) with particular emphasis on asymmetry measurements in the {pi}{sup O} and {eta} production at high p{perpendicular} and at large x{sub F}. 14 refs., 8 figs.

Differential Cross Sections for Proton-Proton Elastic Scattering

NASA Technical Reports Server (NTRS)

Norman, Ryan B.; Dick, Frank; Norbury, John W.; Blattnig, Steve R.

2009-01-01

Proton-proton elastic scattering is investigated within the framework of the one pion exchange model in an attempt to model nucleon-nucleon interactions spanning the large range of energies important to cosmic ray shielding. A quantum field theoretic calculation is used to compute both differential and total cross sections. A scalar theory is then presented and compared to the one pion exchange model. The theoretical cross sections are compared to proton-proton scattering data to determine the validity of the models.

Proton radiography and tomography with application to proton therapy

PubMed Central

Allinson, N M; Evans, P M

2015-01-01

Proton radiography and tomography have long promised benefit for proton therapy. Their first suggestion was in the early 1960s and the first published proton radiographs and CT images appeared in the late 1960s and 1970s, respectively. More than just providing anatomical images, proton transmission imaging provides the potential for the more accurate estimation of stopping-power ratio inside a patient and hence improved treatment planning and verification. With the recent explosion in growth of clinical proton therapy facilities, the time is perhaps ripe for the imaging modality to come to the fore. Yet many technical challenges remain to be solved before proton CT scanners become commonplace in the clinic. Research and development in this field is currently more active than at any time with several prototype designs emerging. This review introduces the principles of proton radiography and tomography, their historical developments, the raft of modern prototype systems and the primary design issues. PMID:26043157

On the chemical reaction of matter with antimatter.

PubMed

Lodi Rizzini, Evandro; Venturelli, Luca; Zurlo, Nicola

2007-06-04

A chemical reaction between the building block antiatomic nucleus, the antiproton (p or H- in chemical notation), and the hydrogen molecular ion (H2+) has been observed by the ATHENA collaboration at CERN. The charged pair interact via the long-range Coulomb force in the environment of a Penning trap which is purpose-built to observe antiproton interactions. The net result of the very low energy collision of the pair is the creation of an antiproton-proton bound state, known as protonium (Pn), together with the liberation of a hydrogen atom. The Pn is formed in a highly excited, metastable, state with a lifetime against annihilation of around 1 micros. Effects are observed related to the temperature of the H2+ prior to the interaction, and this is discussed herein.

Proton-Proton Scattering at 105 Mev and 75 Mev

DOE R&D Accomplishments Database

Birge, R. W.; Kruse, U. E.; Ramsey, N. F.

1951-01-31

The scattering of protons by protons provides an important method for studying the nature of nuclear forces. Recent proton-proton scattering experiments at energies as high as thirty Mev{sup 1} have failed to show any appreciable contribution to the cross section from higher angular momentum states, but it is necessary to bring in tensor forces to explain the magnitude of the observed cross section.

35. Photocopy of photograph (original print located in LBNL Photo ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

35. Photocopy of photograph (original print located in LBNL Photo Lab Collection). Photographer unknown. April 27, 1960. BEV-2050. CLYDE WIEGAND; ANTI-PROTON SET-UP. B-51. - University of California Radiation Laboratory, Bevatron, 1 Cyclotron Road, Berkeley, Alameda County, CA

32. Photocopy of photograph (original print located in LBNL Photo ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

32. Photocopy of photograph (original print located in LBNL Photo Lab Collection). Photographer unknown. October 6, 1955. BEV-937. ANTI-PROTON SET-UP, EXTERIOR VIEW. B-51. - University of California Radiation Laboratory, Bevatron, 1 Cyclotron Road, Berkeley, Alameda County, CA

31. Photocopy of photograph (original print located in LBNL Photo ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

31. Photocopy of photograph (original print located in LBNL Photo Lab Collection). Photographer unknown. October 6, 1955. BEV-933. ANTI-PROTON SET-UP, INTERIOR VIEW. B-51. - University of California Radiation Laboratory, Bevatron, 1 Cyclotron Road, Berkeley, Alameda County, CA

Enantioselective Protonation

PubMed Central

Mohr, Justin T.; Hong, Allen Y.; Stoltz, Brian M.

2010-01-01

Enantioselective protonation is a common process in biosynthetic sequences. The decarboxylase and esterase enzymes that effect this valuable transformation are able to control both the steric environment around the proton acceptor (typically an enolate) and the proton donor (typically a thiol). Recently, several chemical methods to achieve enantioselective protonation have been developed by exploiting various means of enantiocontrol in different mechanisms. These laboratory transformations have proven useful for the preparation of a number of valuable organic compounds. PMID:20428461

Proton Transport

NASA Technical Reports Server (NTRS)

Pohorille, Andrew; DeVincenzi, Donald L. (Technical Monitor)

2001-01-01

The transport of protons across membranes is an essential process for both bioenergetics of modern cells and the origins of cellular life. All living systems make use of proton gradients across cell walls to convert environmental energy into a high-energy chemical compound, adenosine triphosphate (ATP), synthesized from adenosine diphosphate. ATP, in turn, is used as a source of energy to drive many cellular reactions. The ubiquity of this process in biology suggests that even the earliest cellular systems were relying on proton gradient for harvesting environmental energy needed to support their survival and growth. In contemporary cells, proton transfer is assisted by large, complex proteins embedded in membranes. The issue addressed in this Study was: how the same process can be accomplished with the aid of similar but much simpler molecules that could have existed in the protobiological milieu? The model system used in the study contained a bilayer membrane made of phospholipid, dimyristoylphosphatidylcholine (DMPC) which is a good model of the biological membranes forming cellular boundaries. Both sides of the bilayer were surrounded by water which simulated the environment inside and outside the cell. Embedded in the membrane was a fragment of the Influenza-A M$_2$ protein and enough sodium counterions to maintain system neutrality. This protein has been shown to exhibit remarkably high rates of proton transport and, therefore, is an excellent model to study the formation of proton gradients across membranes. The Influenza M$_2$ protein is 97 amino acids in length, but a fragment 25 amino acids long. which contains a transmembrane domain of 19 amino acids flanked by three amino acids on each side. is sufficient to transport protons. Four identical protein fragments, each folded into a helix, aggregate to form small channels spanning the membrane. Protons are conducted through a narrow pore in the middle of the channel in response to applied voltage. This

Measurement of the dijet transverse thrust distribution in proton - anti-proton collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sorin, Maria Veronica

2003-01-01

This dissertation presents the first measurement in a hadron collider of an event shape variable, the Dijet Transverse Thrust Tmore » $$t\\atop{2}$$ which is sensitive to the spatial jet distribution on the plane perpendicular to the colliding p$$\\bar{p}$$ beams. $$t\\atop{2}$$ is calculated with the two most energetic jets reconstructed with the k$$\\perp$$ algorithm, and it ranges from T$$t\\atop{2}$$ =1, for a pencil-like configuration, to T$$t\\atop{2}$$ =√2/2, for two equal energy jets at 90°. The measurement is based on 87.3 pb -1 of data collected with the D0 detector at the Fermilab Tevatron p$$\\bar{p}$$ Collider. The cross section is reported as a function of 1-T$$t\\atop{2}$$ and log (1-T$$t\\atop{2}$$), with enhances the high statistics T$$t\\atop{2}$$→1 region, and presented for four separate event energy ranges. The measurement is in good agreement with a fixed-order O(α$$3\\atop{s}$$) perturbative QCD prediction, except at high T$$t\\atop{2}$$, where resummation corrections are expected to be important, and below T$$t\\atop{2}$$≃√3/2, where the leading order diagrams contributing to T$$t\\atop{2}$$ are O(α$$4\\atop{s}$$). The data also show a very good level of agreement with a recent Next-to-Leading pQCD three jet generator which covers the full T$$t\\atop{2}$$ range, except for the T$$t\\atop{2}$$=1 point.« less

33. Photocopy of photograph (original print located in LBNL Photo ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

33. Photocopy of photograph (original print located in LBNL Photo Lab Collection). Photographer unknown. April 10, 1958. BEV-1515. ANTI-PROTON SET-UP; BRUCE CORK, GLENN LAMBERTSON. B-51. - University of California Radiation Laboratory, Bevatron, 1 Cyclotron Road, Berkeley, Alameda County, CA

Measurement of the Inclusive Leptonic Asymmetry in Top-Quark Pairs that Decay to Two Charged Leptons at CDF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aaltonen, Timo Antero; et al.,

2014-07-23

We measure the inclusive forward-backward asymmetry of the charged-lepton pseudorapidities from top-quark pairs produced in proton-antiproton collisions, and decaying to final states that contain two charged leptons (electrons or muons), using data collected with the Collider Detector at Fermilab.

ANTIMATTER PRODUCTION IN SUPERNOVA REMNANTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kachelriess, M.; Ostapchenko, S.; Tomas, R.

2011-06-01

We calculate the energy spectra of cosmic rays (CRs) and their secondaries produced in a supernova remnant (SNR) taking into account the time dependence of the SNR shock. We model the trajectories of charged particles as a random walk with a prescribed diffusion coefficient, accelerating the particles at each shock crossing. Secondary production by CRs colliding with gas is included as a Monte Carlo process. We find that SNRs produce less antimatter than suggested previously: the positron/electron ratio F{sub e}{sup +}/F{sub e}{sup +}{sub +e}{sup -} and the antiproton/proton ratio F{sub p-bar/}F{sub p-bar+p} are a few percent and few x 10{supmore » -5}, respectively. Moreover, the obtained positron/electron ratio decreases with energy, while the antiproton/proton ratio rises at most by a factor of two above 10 GeV.« less

Antimatter Production for Near-Term Propulsion Applications

NASA Technical Reports Server (NTRS)

Gerrish, Harold P.; Schmidt, George R.

1999-01-01

This presentation discusses the use and potential of power generated from Proton-Antiproton Annihilation. The problem is that there is not enough production of anti-protons, and that the production methods are inefficient. The cost for 1 gram of antiprotons is estimated at 62.5 trillion dollars. Applications which require large quantities (i.e., about 1 kg) will require dramatic improvements in the efficiency of the production of the antiprotons. However, applications which involve small quantities (i.e., 1 to 10 micrograms may be practical with a relative expansion of capacities. There are four "conventional" antimatter propulsion concepts which are: (1) the solid core, (2) the gas core, (3) the plasma core, and the (4) beam core. These are compared in terms of specific impulse, propulsive energy utilization and vehicle structure/propellant mass ratio. Antimatter-catalyzed fusion propulsion is also evaluated. The improvements outlined in the presentation to the Fermilab production, and other sites. capability would result in worldwide capacity of several micrograms per year, by the middle of the next decade. The conclusions drawn are: (1) the Conventional antimatter propulsion IS not practical due to large p-bar requirement; (2) Antimatter-catalyzed systems can be reasonably considered this "solves" energy cost problem by employing substantially smaller quantities; (3) With current infrastructure, cost for 1 microgram of p-bars is $62.5 million, but with near-term improvements cost should drop; (4) Milligram-scale facility would require a $15 billion investment, but could produce 1 mg, at $0.1/kW-hr, for $6.25 million.

[Proton imaging applications for proton therapy: state of the art].

PubMed

Amblard, R; Floquet, V; Angellier, G; Hannoun-Lévi, J M; Hérault, J

2015-04-01

Proton therapy allows a highly precise tumour volume irradiation with a low dose delivered to the healthy tissues. The steep dose gradients observed and the high treatment conformity require a precise knowledge of the proton range in matter and the target volume position relative to the beam. Thus, proton imaging allows an improvement of the treatment accuracy, and thereby, in treatment quality. Initially suggested in 1963, radiographic imaging with proton is still not used in clinical routine. The principal difficulty is the lack of spatial resolution, induced by the multiple Coulomb scattering of protons with nuclei. Moreover, its realization for all clinical locations requires relatively high energies that are previously not considered for clinical routine. Abandoned for some time in favor of X-ray technologies, research into new imaging methods using protons is back in the news because of the increase of proton radiation therapy centers in the world. This article exhibits a non-exhaustive state of the art in proton imaging. Copyright © 2015 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

Searching for Dark Matter with Cosmic Rays

NASA Astrophysics Data System (ADS)

Seo, Eun-Suk

2015-04-01

One of the most exciting possibilities in cosmic ray research is the potential to discover new phenomena. A number of elementary particles were discovered in cosmic rays before modern-day accelerators became available to study their detailed properties. Since the discovery of cosmic ray antiprotons in 1979 using a balloon-borne magnet spectrometer, a series of magnet spectrometers have been flown to search for the signature of dark matter annihilation in antiprotons and positrons. Being the same as particles except for their opposite charge sign, antiparticles are readily distinguished as they bend in opposite directions in the magnetic field. As long-duration balloon flights over Antarctica became available, not only antiproton to proton ratios but also measurements of antiproton energy spectra became possible. More recently, space missions are also providing precision measurements of electron and position energy spectra. With other measurements to constrain cosmic ray propagation models, these new measurements play key roles in constraining dark-matter models for understanding the nature of dark matter. Recent results, their implications, and outlook for the field will be presented.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kerns, Q.A.; Jackson, G.; Kerns, C.R.

This paper describes the damper design for 6 proton on 6 pbar bunches in the Tevatron collider. Signal pickup, transient phase detection, derivative networks, and phase correction via the high-level rf are covered. Each rf station is controlled by a slow feedback loop. In addition, global feedback loops control each set of four cavities, one set for protons and one set for antiprotons. Operational experience with these systems is discussed. 7 refs., 9 figs.

Measurement of Cosmic-Ray Antiproton Spectrum at Solar Minimum with a Long-Duration Balloon Flight in Antarctica

NASA Technical Reports Server (NTRS)

Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Kim, K. C.; Kusumoto, A.; Lee, M. H.; Makida, Y.;

Theoretical investigation of local proton conductance in the proton exchange membranes

NASA Astrophysics Data System (ADS)

Singh, Raman K.; Tsuneda, Takao; Miyatake, Kenji; Watanabe, Masahiro

2014-07-01

The hydrated structures of the proton exchange membranes were theoretically investigated using long-range corrected density functional theory to make clear why perfluorinated polymer membrane Nafion is superior to other membranes in the proton conductivity at low humidity. For exploring the possibility of the proton conductance in the vehicle mechanism with low hydration numbers, we examined the relay model of protonated water clusters between the sulfonic acid groups in Nafion and concluded that this relay model may contribute to the high proton conductivity of Nafion with less-hydrated sulfonic acid groups.

Proton Beam Therapy

NASA Astrophysics Data System (ADS)

Paganetti, Harald

2017-01-01

Cancer therapy is a multi-modality approach including surgery, systemic or targeted chemotherapy, radiation (external beam or radionuclide), and immunotherapy. Radiation is typically administered using external beam photon therapy. Proton therapy has been around for more than 60 years but was restricted to research laboratories until the 1990s. Since then clinical proton therapy has been growing rapidly with currently more than 50 facilities worldwide. The interest in proton therapy stems from the physical properties of protons allowing for advanced dose sculpting around the target and sparing of healthy tissue. This review first evaluates the basics of proton therapy physics and technology and then outlines some of the current physical, biological, and clinical challenges. Solving these will ultimately determine whether proton therapy will continue on its path to becoming mainstream.

Bunch-by-bunch detection of coherent transverse modes from digitized single-bpm signals in the Tevatron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stancari, G.; Valishev, A.; Semenov, A.

2010-05-01

A system was developed for bunch-by-bunch detection of transverse proton and antiproton coherent oscillations based on the signal from a single beam-position monitor (BPM) located in a region of the ring with large amplitude functions. The signal is digitized over a large number of turns and Fourier-analyzed offline with a dedicated algorithm. To enhance the signal, the beam is excited with band-limited noise for about one second, and this was shown not to significantly affect the circulating beams even at high luminosity. The system is used to measure betatron tunes of individual bunches and to study beam-beam effects. In particular,more » it is one of the main diagnostic tools in an ongoing study of nonlinear beam-beam compensation studies with Gaussian electron lenses. We present the design and operation of this tool, together with results obtained with proton and antiproton bunches.« less

AMS-02 positron excess and indirect detection of three-body decaying dark matter

NASA Astrophysics Data System (ADS)

Cheng, Hsin-Chia; Huang, Wei-Chih; Huang, Xiaoyuan; Low, Ian; Sming Tsai, Yue-Lin; Yuan, Qiang

2017-03-01

We consider indirect detection of meta-stable dark matter particles decaying into a stable neutral particle and a pair of standard model fermions. Due to the softer energy spectra from the three-body decay, such models could potentially explain the AMS-02 positron excess without being constrained by the Fermi-LAT gamma-ray data and the cosmic ray anti-proton measurements. We scrutinize over different final state fermions, paying special attention to handling of the cosmic ray background and including various contributions from cosmic ray propagation with the help of the LIKEDM package. It is found that primary decays into an electron-positron pair and a stable neutral particle could give rise to the AMS-02 positron excess and, at the same time, stay unscathed against the gamma-ray and anti-proton constraints. Decays to a muon pair or a mixed flavor electron-muon pair may also be viable depending on the propagation models. Decays to all other standard model fermions are severely disfavored.

Measurement of the Cosmic-Ray Antiproton Spectrum at Solar Minimum with a Long-Duration Balloon Flight over Antarctica

NASA Technical Reports Server (NTRS)

Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Kim, K. C.; Kusumoto, A.; Lee, M. H.; Makida, Y.;

Stereochemistry-Dependent Proton Conduction in Proton Exchange Membrane Fuel Cells.

PubMed

Thimmappa, Ravikumar; Devendrachari, Mruthyunjayachari Chattanahalli; Kottaichamy, Alagar Raja; Tiwari, Omshanker; Gaikwad, Pramod; Paswan, Bhuneshwar; Thotiyl, Musthafa Ottakam

2016-01-12

Graphene oxide (GO) is impermeable to H2 and O2 fuels while permitting H(+) shuttling, making it a potential candidate for proton exchange membrane fuel cells (PEMFC), albeit with a large anisotropy in their proton transport having a dominant in plane (σIP) contribution over the through plane (σTP). If GO-based membranes are ever to succeed in PEMFC, it inevitably should have a dominant through-plane proton shuttling capability (σTP), as it is the direction in which proton gets transported in a real fuel-cell configuration. Here we show that anisotropy in proton conduction in GO-based fuel cell membranes can be brought down by selectively tuning the geometric arrangement of functional groups around the dopant molecules. The results show that cis isomer causes a selective amplification of through-plane proton transport, σTP, pointing to a very strong geometry angle in ionic conduction. Intercalation of cis isomer causes significant expansion of GO (001) planes involved in σTP transport due to their mutual H-bonding interaction and efficient bridging of individual GO planes, bringing down the activation energy required for σTP, suggesting the dominance of a Grotthuss-type mechanism. This isomer-governed amplification of through-plane proton shuttling resulted in the overall boosting of fuel-cell performance, and it underlines that geometrical factors should be given prime consideration while selecting dopant molecules for bringing down the anisotropy in proton conduction and enhancing the fuel-cell performance in GO-based PEMFC.

Elementary Quantum Mechanics in a High-Energy Process

ERIC Educational Resources Information Center

Denville, A.; And Others

1978-01-01

Compares two approaches to strong absorption in elementary quantum mechanics; the black sphere and a model based on the continuum theory of nuclear reactions. Examines the application to proton-antiproton interactions at low momenta and concludes that the second model is the appropriate and simplest to use. (Author/GA)

Proton-proton bremsstrahlung towards the elastic limit

NASA Astrophysics Data System (ADS)

Mahjour-Shafiei, M.; Amir-Ahmadi, H. R.; Bacelar, J. C. S.; Castelijns, R.; Ermisch, K.; van Garderen, E.; Gašparić, I.; Harakeh, M. N.; Kalantar-Nayestanaki, N.; Kiš, M.; Löhner, H.

2005-05-01

In oder to study proton-proton bremsstrahlung moving towards the elastic limit, a detection system, consisting of Plastic-ball and SALAD, was set up and an experiment at 190 MeV incident beam energy was performed. Here, the experimental setup and the data analysis procedure along with some results obtained in the measurement are discussed.

Identified hadron transverse momentum spectra in Au+Au collisions at sNN=62.4 GeV

NASA Astrophysics Data System (ADS)

Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Halliwell, C.; Hamblen, J.; Hauer, M.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Reed, C.; Roland, C.; Roland, G.; Sagerer, J.; Seals, H.; Sedykh, I.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; Nieuwenhuizen, G. J. Van; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wysłouch, B.

2007-02-01

Transverse momentum spectra of pions, kaons, protons, and antiprotons from Au+Au collisions at sNN = 62.4 GeV have been measured by the PHOBOS experiment at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. The identification of particles relies on three different methods: low momentum particles stopping in the first detector layers; the specific energy loss (dE/dx) in the silicon spectrometer, and time-of-flight measurement. These methods cover the transverse momentum ranges 0.03 0.2, 0.2 1.0, and 0.5 3.0 GeV/c, respectively. Baryons are found to have substantially harder transverse momentum spectra than mesons. The pT region in which the proton to pion ratio reaches unity in central Au+Au collisions at sNN = 62.4 GeV fits into a smooth trend as a function of collision energy. At low transverse mass, the spectra of various species exhibit a significant deviation from transverse mass scaling. The observed particle yields at very low pT are comparable to extrapolations from higher pT for kaons, protons and antiprotons. By comparing our results to Au+Au collisions at sNN = 200 GeV, we conclude that the net proton yield at midrapidity is proportional to the number of participant nucleons in the collision.

An experiment to measure the energy spectrum of cosmic ray antiprotons from 100 to 1000 MeV

NASA Technical Reports Server (NTRS)

Salamon, M. H.; Price, P. B.; Barwick, S. W.; Lowder, D. M.; Ahlen, S. P.

1985-01-01

Production models were developed and the confirmation of each one had significant astrophysical impact. These include radical modifications of propagation models, cosmic ray antiprotons injection from neighboring domains of antimatter, p production by evaporating primordial black holes, and cosmic ray p's as annihilation products of supersymmetry particles that might make up the dark dynamical mass of the Galaxy. It is that p's originating from supersymmetric parents might have distinct spectral features that would survive solar modulation; in one model, higgsino annihilation proceeds through the bb quark-antiquark channel, producing a spectral bump at approx. 0.3 GeV in the p spectrum.

Proton transfer in organic scaffolds

NASA Astrophysics Data System (ADS)

Basak, Dipankar

This dissertation focuses on the fundamental understanding of the proton transfer process and translating the knowledge into design/development of new organic materials for efficient non-aqueous proton transport. For example, what controls the shuttling of a proton between two basic sites? a) Distance between two groups? or b) the basicity? c) What is the impact of protonation on molecular conformation when the basic sites are attached to rigid scaffolds? For this purpose, we developed several tunable proton sponges and studied proton transfer in these scaffolds theoretically as well as experimentally. Next we moved our attention to understand long-range proton conduction or proton transport. We introduced liquid crystalline (LC) proton conductor based on triphenylene molecule and established that activation energy barrier for proton transport is lower in the LC phase compared to the crystalline phase. Furthermore, we investigated the impact of several critical factors: the choice of the proton transferring groups, mobility of the charge carriers, intrinsic vs. extrinsic charge carrier concentrations and the molecular architectures on long-range proton transport. The outcome of this research will lead to a deeper understanding of non-aqueous proton transfer process and aid the design of next generation proton exchange membrane (PEM) for fuel cell.

Collision-induced dissociation processes of protonated benzoic acid and related compounds: competitive generation of protonated carbon dioxide or protonated benzene.

PubMed

Xu, Sihang; Pavlov, Julius; Attygalle, Athula B

2017-04-01

Upon activation in the gas phase, protonated benzoic acid (m/z 123) undergoes fragmentation by several mechanisms. In addition to the predictable water loss followed by a CO loss, the m/z 123 ion more intriguingly eliminates a molecule of benzene to generate protonated carbon dioxide (H - O +  ═ C ≡ O, m/z 45), or a molecule of carbon dioxide to yield protonated benzene (m/z 79). Experimental evidence shows that the incipient proton ambulates during the fragmentation processes. For the CO 2 or benzene loss, protonated benzoic acid transfers the charge-imparting proton initially to the ortho position and then to the ipso position to generate a transient species which dissociates to form an ion-neutral complex between benzene and protonated CO 2 . The formation of the m/z 45 ion is not a phenomenon unique to benzoic acid: spectra from protonated isophthalic acid, terephthalic acid, trans-cinnamic acid and some aliphatic acids also displayed a peak for m/z 45. However, the m/z 45 peak is structurally diagnostic only for certain benzene polycarboxylic acids because the spectra of compounds with two carboxyl groups on adjacent ring carbons do not produce a peak at m/z 45. For the m/z 79 ion to be formed, an intramolecular reaction should take place in which protonated CO 2 within the ion-neutral complex acts as the attacking electrophile to transfer a proton to benzene. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Probing dark matter annihilation in the Galaxy with antiprotons and gamma rays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cuoco, Alessandro; Heisig, Jan; Korsmeier, Michael

2017-10-01

A possible hint of dark matter annihilation has been found in Cuoco, Korsmeier and Krämer (2017) from an analysis of recent cosmic-ray antiproton data from AMS-02 and taking into account cosmic-ray propagation uncertainties by fitting at the same time dark matter and propagation parameters. Here, we extend this analysis to a wider class of annihilation channels. We find consistent hints of a dark matter signal with an annihilation cross-section close to the thermal value and with masses in range between 40 and 130 GeV depending on the annihilation channel. Furthermore, we investigate in how far the possible signal is compatiblemore » with the Galactic center gamma-ray excess and recent observation of dwarf satellite galaxies by performing a joint global fit including uncertainties in the dark matter density profile. As an example, we interpret our results in the framework of the Higgs portal model.« less

How proton pulse characteristics influence protoacoustic determination of proton-beam range: simulation studies.

PubMed

Jones, Kevin C; Seghal, Chandra M; Avery, Stephen

2016-03-21

The unique dose deposition of proton beams generates a distinctive thermoacoustic (protoacoustic) signal, which can be used to calculate the proton range. To identify the expected protoacoustic amplitude, frequency, and arrival time for different proton pulse characteristics encountered at hospital-based proton sources, the protoacoustic pressure emissions generated by 150 MeV, pencil-beam proton pulses were simulated in a homogeneous water medium. Proton pulses with Gaussian widths ranging up to 200 μs were considered. The protoacoustic amplitude, frequency, and time-of-flight (TOF) range accuracy were assessed. For TOF calculations, the acoustic pulse arrival time was determined based on multiple features of the wave. Based on the simulations, Gaussian proton pulses can be categorized as Dirac-delta-function-like (FWHM < 4 μs) and longer. For the δ-function-like irradiation, the protoacoustic spectrum peaks at 44.5 kHz and the systematic error in determining the Bragg peak range is <2.6 mm. For longer proton pulses, the spectrum shifts to lower frequencies, and the range calculation systematic error increases (⩽ 23 mm for FWHM of 56 μs). By mapping the protoacoustic peak arrival time to range with simulations, the residual error can be reduced. Using a proton pulse with FWHM = 2 μs results in a maximum signal-to-noise ratio per total dose. Simulations predict that a 300 nA, 150 MeV, FWHM = 4 μs Gaussian proton pulse (8.0 × 10(6) protons, 3.1 cGy dose at the Bragg peak) will generate a 146 mPa pressure wave at 5 cm beyond the Bragg peak. There is an angle dependent systematic error in the protoacoustic TOF range calculations. Placing detectors along the proton beam axis and beyond the Bragg peak minimizes this error. For clinical proton beams, protoacoustic detectors should be sensitive to <400 kHz (for -20 dB). Hospital-based synchrocyclotrons and cyclotrons are promising sources of proton pulses for generating clinically measurable protoacoustic

Results from ARGO-YBJ

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iacovacci, M.

2009-04-08

The ARGO-YBJ experiment has been put in stable data taking at the YangBaJing Cosmic Ray Laboratory (Tibet, P.R. China, 4300 m a.s.l.). In this paper we report a few selected results in Gamma-Ray Astronomy (Crab Nebula and Mrk421 observations, search for high energy tails of Gamma Ray Bursts) and Cosmic Ray Physics (Moon and Sun shadow observations, proton-air cross section measurement, preliminary measurement of the antiproton/proton ratio at TeV energies)

34. Photocopy of photograph (original print located in LBNL Photo ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

34. Photocopy of photograph (original print located in LBNL Photo Lab Collection). Photographer unknown. October 6, 1955. BEV-938. ANTI-PROTON SET-UP WITH WORK GROUP; E. SEGRE, C. WIEGAND, E. LOFGREN, O. CHAMBERLAIN, T. YPSILANTIS. B-51. - University of California Radiation Laboratory, Bevatron, 1 Cyclotron Road, Berkeley, Alameda County, CA

A Generalized Weizsacker-Williams Method Applied to Pion Production in Proton-Proton Collisions

NASA Technical Reports Server (NTRS)

Ahern, Sean C.; Poyser, William J.; Norbury, John W.; Tripathi, R. K.

2002-01-01

A new "Generalized" Weizsacker-Williams method (GWWM) is used to calculate approximate cross sections for relativistic peripheral proton-proton collisions. Instead of a mass less photon mediator, the method allows for the mediator to have mass for short range interactions. This method generalizes the Weizsacker-Williams method (WWM) from Coulomb interactions to GWWM for strong interactions. An elastic proton-proton cross section is calculated using GWWM with experimental data for the elastic p+p interaction, where the mass p+ is now the mediator. The resulting calculated cross sections is compared to existing data for the elastic proton-proton interaction. A good approximate fit is found between the data and the calculation.

Proton tracking in a high-granularity Digital Tracking Calorimeter for proton CT purposes

NASA Astrophysics Data System (ADS)

Pettersen, H. E. S.; Alme, J.; Biegun, A.; van den Brink, A.; Chaar, M.; Fehlker, D.; Meric, I.; Odland, O. H.; Peitzmann, T.; Rocco, E.; Ullaland, K.; Wang, H.; Yang, S.; Zhang, C.; Röhrich, D.

2017-07-01

Radiation therapy with protons as of today utilizes information from x-ray CT in order to estimate the proton stopping power of the traversed tissue in a patient. The conversion from x-ray attenuation to proton stopping power in tissue introduces range uncertainties of the order of 2-3% of the range, uncertainties that are contributing to an increase of the necessary planning margins added to the target volume in a patient. Imaging methods and modalities, such as Dual Energy CT and proton CT, have come into consideration in the pursuit of obtaining an as good as possible estimate of the proton stopping power. In this study, a Digital Tracking Calorimeter is benchmarked for proof-of-concept for proton CT purposes. The Digital Tracking Calorimeter was originally designed for the reconstruction of high-energy electromagnetic showers for the ALICE-FoCal project. The presented prototype forms the basis for a proton CT system using a single technology for tracking and calorimetry. This advantage simplifies the setup and reduces the cost of a proton CT system assembly, and it is a unique feature of the Digital Tracking Calorimeter concept. Data from the AGORFIRM beamline at KVI-CART in Groningen in the Netherlands and Monte Carlo simulation results are used to in order to develop a tracking algorithm for the estimation of the residual ranges of a high number of concurrent proton tracks. High energy protons traversing the detector leave a track through the sensor layers. These tracks are spread out through charge diffusion processes. A charge diffusion model is applied for acquisition of estimates of the deposited energy of the protons in each sensor layer by using the size of the charge diffused area. A model fit of the Bragg Curve is applied to each reconstructed track and through this, estimating the residual range of each proton. The range of the individual protons can at present be estimated with a resolution of 4%. The readout system for this prototype is able to

Evaluation of proton cross-sections for radiation sources in the proton accelerator

NASA Astrophysics Data System (ADS)

Cho, Young-Sik; Lee, Cheol-Woo; Lee, Young-Ouk

2007-08-01

Proton Engineering Frontier Project (PEFP) is currently building a proton accelerator in Korea which consists of a proton linear accelerator with 100 MeV of energy, 20 mA of current and various particle beam facilities. The final goal of this project consists of the production of 1 GeV proton beams, which will be used for various medical and industrial applications as well as for research in basic and applied sciences. Carbon and copper in the proton accelerator for PEPP, through activation, become radionuclides such as 7Be and 64Cu. Copper is a major element of the accelerator components and the carbon is planned to be used as a target material of the beam dump. A recent survey showed that the currently available cross-sections create a large difference from the experimental data in the production of some residual nuclides by the proton-induced reactions for carbon and copper. To more accurately estimate the production of radioactive nuclides in the accelerator, proton cross-sections for carbon and copper are evaluated. The TALYS code was used for the evaluation of the cross-sections for the proton-induced reactions. To obtain the cross-sections which best fits the experimental data, optical model parameters for the neutron, proton and other complex particles such as the deuteron and alpha were successively adjusted. The evaluated cross-sections in this study are compared with the measurements and other evaluations .

Parameterized spectral distributions for meson production in proton-proton collisions

NASA Technical Reports Server (NTRS)

Schneider, John P.; Norbury, John W.; Cucinotta, Francis A.

1995-01-01

Accurate semiempirical parameterizations of the energy-differential cross sections for charged pion and kaon production from proton-proton collisions are presented at energies relevant to cosmic rays. The parameterizations, which depend on both the outgoing meson parallel momentum and the incident proton kinetic energy, are able to be reduced to very simple analytical formulas suitable for cosmic ray transport through spacecraft walls, interstellar space, the atmosphere, and meteorites.

Neutrinos from the primary proton-proton fusion process in the Sun

NASA Astrophysics Data System (ADS)

BOREXINO Collaboration; Bellini, G.; Benziger, J.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Cadonati, L.; Calaprice, F.; Caminata, A.; Cavalcante, P.; Chavarria, A.; Chepurnov, A.; D'Angelo, D.; Davini, S.; Derbin, A.; Empl, A.; Etenko, A.; Fomenko, K.; Franco, D.; Gabriele, F.; Galbiati, C.; Gazzana, S.; Ghiano, C.; Giammarchi, M.; Göger-Neff, M.; Goretti, A.; Gromov, M.; Hagner, C.; Hungerford, E.; Ianni, Aldo; Ianni, Andrea; Kobychev, V.; Korablev, D.; Korga, G.; Kryn, D.; Laubenstein, M.; Lehnert, B.; Lewke, T.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Marcocci, S.; Meindl, Q.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Montuschi, M.; Mosteiro, P.; Muratova, V.; Oberauer, L.; Obolensky, M.; Ortica, F.; Otis, K.; Pallavicini, M.; Papp, L.; Perasso, L.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Rossi, N.; Saldanha, R.; Salvo, C.; Schönert, S.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Vignaud, D.; Vogelaar, R. B.; von Feilitzsch, F.; Wang, H.; Winter, J.; Wojcik, M.; Wright, A.; Wurm, M.; Zaimidoroga, O.; Zavatarelli, S.; Zuber, K.; Zuzel, G.

2014-08-01

In the core of the Sun, energy is released through sequences of nuclear reactions that convert hydrogen into helium. The primary reaction is thought to be the fusion of two protons with the emission of a low-energy neutrino. These so-called pp neutrinos constitute nearly the entirety of the solar neutrino flux, vastly outnumbering those emitted in the reactions that follow. Although solar neutrinos from secondary processes have been observed, proving the nuclear origin of the Sun's energy and contributing to the discovery of neutrino oscillations, those from proton-proton fusion have hitherto eluded direct detection. Here we report spectral observations of pp neutrinos, demonstrating that about 99 per cent of the power of the Sun, 3.84 × 1033 ergs per second, is generated by the proton-proton fusion process.

Sparse-view proton computed tomography using modulated proton beams.

PubMed

Lee, Jiseoc; Kim, Changhwan; Min, Byungjun; Kwak, Jungwon; Park, Seyjoon; Lee, Se Byeong; Park, Sungyong; Cho, Seungryong

2015-02-01

Proton imaging that uses a modulated proton beam and an intensity detector allows a relatively fast image acquisition compared to the imaging approach based on a trajectory tracking detector. In addition, it requires a relatively simple implementation in a conventional proton therapy equipment. The model of geometric straight ray assumed in conventional computed tomography (CT) image reconstruction is however challenged by multiple-Coulomb scattering and energy straggling in the proton imaging. Radiation dose to the patient is another important issue that has to be taken care of for practical applications. In this work, the authors have investigated iterative image reconstructions after a deconvolution of the sparsely view-sampled data to address these issues in proton CT. Proton projection images were acquired using the modulated proton beams and the EBT2 film as an intensity detector. Four electron-density cylinders representing normal soft tissues and bone were used as imaged object and scanned at 40 views that are equally separated over 360°. Digitized film images were converted to water-equivalent thickness by use of an empirically derived conversion curve. For improving the image quality, a deconvolution-based image deblurring with an empirically acquired point spread function was employed. They have implemented iterative image reconstruction algorithms such as adaptive steepest descent-projection onto convex sets (ASD-POCS), superiorization method-projection onto convex sets (SM-POCS), superiorization method-expectation maximization (SM-EM), and expectation maximization-total variation minimization (EM-TV). Performance of the four image reconstruction algorithms was analyzed and compared quantitatively via contrast-to-noise ratio (CNR) and root-mean-square-error (RMSE). Objects of higher electron density have been reconstructed more accurately than those of lower density objects. The bone, for example, has been reconstructed within 1% error. EM

Surface proton transport of fully protonated poly(aspartic acid) thin films on quartz substrates

NASA Astrophysics Data System (ADS)

Nagao, Yuki; Kubo, Takahiro

2014-12-01

Thin film structure and the proton transport property of fully protonated poly(aspartic acid) (P-Asp100) have been investigated. An earlier study assessed partially protonated poly(aspartic acid), highly oriented thin film structure and enhancement of the internal proton transport. In this study of P-Asp100, IR p-polarized multiple-angle incidence resolution (P-MAIR) spectra were measured to investigate the thin film structure. The obtained thin films, with thicknesses of 120-670 nm, had no oriented structure. Relative humidity dependence of the resistance, proton conductivity, and normalized resistance were examined to ascertain the proton transport property of P-Asp100 thin films. The obtained data showed that the proton transport of P-Asp100 thin films might occur on the surface, not inside of the thin film. This phenomenon might be related with the proton transport of the biological system.

Emission of neutron–proton and proton–proton pairs in neutrino scattering

DOE PAGES

Ruiz Simo, I.; Amaro, J. E.; Barbaro, M. B.; ...

2016-11-10

For this paper, we use a recently developed model of relativistic meson-exchange currents to compute the neutron–proton and proton–proton yields in (νμ, μ -)scattering from 12C in the 2p–2h channel. We compute the response functions and cross sections with the relativistic Fermi gas model for different kinematics from intermediate to high momentum transfers. We find a large contribution of neutron–proton configurations in the initial state, as compared to proton–proton pairs. In the case of charge-changing neutrino scattering the 2p–2h cross section of proton–proton emission (i.e.,np in the initial state) is much larger than for neutron–proton emission (i.e.,two neutrons in themore » initial state) by a (ω, q)-dependent factor. The different emission probabilities of distinct species of nucleon pairs are produced in our model only by meson-exchange currents, mainly by the Δ isobar current. We also analyze other effects including exchange contributions and the effect of the axial and vector currents.« less

Proton-driven amide bond-cleavage pathways of gas-phase peptide ions lacking mobile protons.

PubMed

Bythell, Benjamin J; Suhai, Sándor; Somogyi, Arpád; Paizs, Béla

2009-10-07

The mobile proton model (Dongre, A. R., Jones, J. L., Somogyi, A. and Wysocki, V. H. J. Am. Chem. Soc. 1996, 118 , 8365-8374) of peptide fragmentation states that the ionizing protons play a critical role in the gas-phase fragmentation of protonated peptides upon collision-induced dissociation (CID). The model distinguishes two classes of peptide ions, those with or without easily mobilizable protons. For the former class mild excitation leads to proton transfer reactions which populate amide nitrogen protonation sites. This enables facile amide bond cleavage and thus the formation of b and y sequence ions. In contrast, the latter class of peptide ions contains strongly basic functionalities which sequester the ionizing protons, thereby often hindering formation of sequence ions. Here we describe the proton-driven amide bond cleavages necessary to produce b and y ions from peptide ions lacking easily mobilizable protons. We show that this important class of peptide ions fragments by different means from those with easily mobilizable protons. We present three new amide bond cleavage mechanisms which involve salt-bridge, anhydride, and imine enol intermediates, respectively. All three new mechanisms are less energetically demanding than the classical oxazolone b(n)-y(m) pathway. These mechanisms offer an explanation for the formation of b and y ions from peptide ions with sequestered ionizing protons which are routinely fragmented in large-scale proteomics experiments.

Proton therapy in the clinic.

PubMed

DeLaney, Thomas F

2011-01-01

The clinical advantage for proton radiotherapy over photon approaches is the marked reduction in integral dose to the patient, due to the absence of exit dose beyond the proton Bragg peak. The integral dose with protons is approximately 60% lower than that with any external beam photon technique. Pediatric patients, because of their developing normal tissues and anticipated length of remaining life, are likely to have the maximum clinical gain with the use of protons. Proton therapy may also allow treatment of some adult tumors to much more effective doses, because of normal tissue sparing distal to the tumor. Currently, the most commonly available proton treatment technology uses 3D conformal approaches based on (a) distal range modulation, (b) passive scattering of the proton beam in its x- and y-axes, and (c) lateral beam-shaping. It is anticipated that magnetic pencil beam scanning will become the dominant mode of proton delivery in the future, which will lower neutron scatter associated with passively scattered beam lines, reduce the need for expensive beam-shaping devices, and allow intensity-modulated proton radiotherapy. Proton treatment plans are more sensitive to variations in tumor size and normal tissue changes over the course of treatment than photon plans, and it is expected that adaptive radiation therapy will be increasingly important for proton therapy as well. While impressive treatment results have been reported with protons, their cost is higher than for photon IMRT. Hence, protons should ideally be employed for anatomic sites and tumors not well treated with photons. While protons appear cost-effective for pediatric tumors, their cost-effectiveness for treatment of some adult tumors, such as prostate cancer, is uncertain. Comparative studies have been proposed or are in progress to more rigorously assess their value for a variety of sites. The utility of proton therapy will be enhanced by technological developments that reduce its cost

First Extraction of Transversity from a Global Analysis of Electron-Proton and Proton-Proton Data

NASA Astrophysics Data System (ADS)

Radici, Marco; Bacchetta, Alessandro

2018-05-01

We present the first extraction of the transversity distribution in the framework of collinear factorization based on the global analysis of pion-pair production in deep-inelastic scattering and in proton-proton collisions with a transversely polarized proton. The extraction relies on the knowledge of dihadron fragmentation functions, which are taken from the analysis of electron-positron annihilation data. For the first time, the transversity is extracted from a global analysis similar to what is usually done for the spin-averaged and helicity distributions. The knowledge of transversity is important for, among other things, detecting possible signals of new physics in high-precision low-energy experiments.

Traits and Resource Use of Co-Occurring Introduced and Native Trees in a Tropical Novel Forest

Treesearch

Jéssica Fonseca da Silva; Ernesto Medina; Ariel Lugo

2017-01-01

Novel forests are naturally regenerating forests that have established on degraded lands and have a species composition strongly influenced by introduced species. We studied ecophysiological traits of an introduced species (Castilla elastica Sessé) and several native species growing side by side in novel forests dominated by C. elastica ...

PREFACE: Transport phenomena in proton conducting media Transport phenomena in proton conducting media

NASA Astrophysics Data System (ADS)

Eikerling, Michael

2011-06-01

Proton transport phenomena are of paramount importance for acid-base chemistry, energy transduction in biological organisms, corrosion processes, and energy conversion in electrochemical systems such as polymer electrolyte fuel cells. The relevance for such a plethora of materials and systems, and the ever-lasting fascination with the highly concerted nature of underlying processes drive research across disciplines in chemistry, biology, physics and chemical engineering. A proton never travels alone. Proton motion is strongly correlated with its environment, usually comprised of an electrolyte and a solid or soft host material. For the transport in nature's most benign proton solvent and shuttle, water that is, insights from ab initio simulations, matured over the last 15 years, have furnished molecular details of the structural diffusion mechanism of protons. Excess proton movement in water consists of sequences of Eigen-Zundel-Eigen transitions, triggered by hydrogen bond breaking and making in the surrounding water network. Nowadays, there is little debate about the validity of this mechanism in water, which bears a stunning resemblance to the basic mechanistic picture put forward by de Grotthuss in 1806. While strong coupling of an excess proton with degrees of freedom of solvent and host materials facilitates proton motion, this coupling also creates negative synergies. In general, proton mobility in biomaterials and electrochemical proton conducting media is highly sensitive to the abundance and structure of the proton solvent. In polymer electrolyte membranes, in which protons are bound to move in nano-sized water-channels, evaporation of water or local membrane dehydration due to electro-osmotic coupling are well-known phenomena that could dramatically diminish proton conductivity. Contributions in this special issue address various vital aspects of the concerted nature of proton motion and they elucidate important structural and dynamic effects of solvent

Proton transfer events in GFP.

PubMed

Di Donato, Mariangela; van Wilderen, Luuk J G W; Van Stokkum, Ivo H M; Stuart, Thomas Cohen; Kennis, John T M; Hellingwerf, Klaas J; van Grondelle, Rienk; Groot, Marie Louise

2011-09-28

Proton transfer is one of the most important elementary processes in biology. Green fluorescent protein (GFP) serves as an important model system to elucidate the mechanistic details of this reaction, because in GFP proton transfer can be induced by light absorption. Illumination initiates proton transfer through a 'proton-wire', formed by the chromophore (the proton donor), water molecule W22, Ser205 and Glu222 (the acceptor), on a picosecond time scale. To obtain a more refined view of this process, we have used a combined approach of time resolved mid-infrared spectroscopy and visible pump-dump-probe spectroscopy to resolve with atomic resolution how and how fast protons move through this wire. Our results indicate that absorption of light by GFP induces in 3 ps (10 ps in D(2)O) a shift of the equilibrium positions of all protons in the H-bonded network, leading to a partial protonation of Glu222 and to a so-called low barrier hydrogen bond (LBHB) for the chromophore's proton, giving rise to dual emission at 475 and 508 nm. This state is followed by a repositioning of the protons on the wire in 10 ps (80 ps in D(2)O), ultimately forming the fully deprotonated chromophore and protonated Glu222.

Spin Transparent Siberian Snake And Spin Rotator With Solenoids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koop, I. A.; Otboyev, A. V.; Shatunov, P. Yu.

2007-06-13

For intermediate energies of electrons and protons it happens that it is more convenient to construct Siberian snakes and spin rotators using solenoidal fields. Strong coupling caused by the solenoids is suppressed by a number of skew and normal quadrupole magnets. More complicate problem of the spin transparency of such devices also can be solved. This paper gives two examples: spin rotator for electron ring in the eRHIC project and Siberian snake for proton (antiproton) storage ring HESR, which cover whole machines working energy region.

Measurements of the Top Quark Pair Production Cross Section in Lepton + Jets Final States using a Topological Multivariate Technique as well as Lifetime b-Tagging in Proton-Anti-proton Collisions at √s =1.96 TeV with the DØ Detector at the Tevatron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Golling, Tobias F.

Two alternative measurements of the t¯t production cross section at √s = 1.96 TeV in proton-antiproton collisions in the lepton+jets channel are presented. The t¯t production cross section is extracted by combining the kinematic event information in a multivariate discriminant. The measurement yields σ p¯p → t¯t + x = 5.13 -1.57 +1.76(stat) -1.10 +0.96(syst) ± 0.33 (lumi) pb in the muon+jets channel, using 229.1 pb -1, and in the combination with the electron+jets channel (226.3 pb -1) σ p¯p → t¯t + x = 6.60 -1.28 +1.37(stat) -1.11 +1.25(syst) ± 0.43 (lumi) pb. The second measurement presented reconstructs explicitlymore » secondary vertices to d lifetime b-tagging. The measurement combines the muon+jets and the electron+jets channel, using 158.4 pb -1 and 168.8 pb -1, respectively: σ p¯p → t¯t + x = 8.24 -1.25 +1.34(stat) -1.63 +1.89(syst) ± 0.54 (lumi) pb.« less

A maximum likelihood method for high resolution proton radiography/proton CT

NASA Astrophysics Data System (ADS)

Collins-Fekete, Charles-Antoine; Brousmiche, Sébastien; Portillo, Stephen K. N.; Beaulieu, Luc; Seco, Joao

2016-12-01

Multiple Coulomb scattering (MCS) is the largest contributor to blurring in proton imaging. In this work, we developed a maximum likelihood least squares estimator that improves proton radiography’s spatial resolution. The water equivalent thickness (WET) through projections defined from the source to the detector pixels were estimated such that they maximizes the likelihood of the energy loss of every proton crossing the volume. The length spent in each projection was calculated through the optimized cubic spline path estimate. The proton radiographies were produced using Geant4 simulations. Three phantoms were studied here: a slanted cube in a tank of water to measure 2D spatial resolution, a voxelized head phantom for clinical performance evaluation as well as a parametric Catphan phantom (CTP528) for 3D spatial resolution. Two proton beam configurations were used: a parallel and a conical beam. Proton beams of 200 and 330 MeV were simulated to acquire the radiography. Spatial resolution is increased from 2.44 lp cm-1 to 4.53 lp cm-1 in the 200 MeV beam and from 3.49 lp cm-1 to 5.76 lp cm-1 in the 330 MeV beam. Beam configurations do not affect the reconstructed spatial resolution as investigated between a radiography acquired with the parallel (3.49 lp cm-1 to 5.76 lp cm-1) or conical beam (from 3.49 lp cm-1 to 5.56 lp cm-1). The improved images were then used as input in a photon tomography algorithm. The proton CT reconstruction of the Catphan phantom shows high spatial resolution (from 2.79 to 5.55 lp cm-1 for the parallel beam and from 3.03 to 5.15 lp cm-1 for the conical beam) and the reconstruction of the head phantom, although qualitative, shows high contrast in the gradient region. The proposed formulation of the optimization demonstrates serious potential to increase the spatial resolution (up by 65 % ) in proton radiography and greatly accelerate proton computed tomography reconstruction.

A maximum likelihood method for high resolution proton radiography/proton CT.

PubMed

Collins-Fekete, Charles-Antoine; Brousmiche, Sébastien; Portillo, Stephen K N; Beaulieu, Luc; Seco, Joao

2016-12-07

Multiple Coulomb scattering (MCS) is the largest contributor to blurring in proton imaging. In this work, we developed a maximum likelihood least squares estimator that improves proton radiography's spatial resolution. The water equivalent thickness (WET) through projections defined from the source to the detector pixels were estimated such that they maximizes the likelihood of the energy loss of every proton crossing the volume. The length spent in each projection was calculated through the optimized cubic spline path estimate. The proton radiographies were produced using Geant4 simulations. Three phantoms were studied here: a slanted cube in a tank of water to measure 2D spatial resolution, a voxelized head phantom for clinical performance evaluation as well as a parametric Catphan phantom (CTP528) for 3D spatial resolution. Two proton beam configurations were used: a parallel and a conical beam. Proton beams of 200 and 330 MeV were simulated to acquire the radiography. Spatial resolution is increased from 2.44 lp cm -1 to 4.53 lp cm -1 in the 200 MeV beam and from 3.49 lp cm -1 to 5.76 lp cm -1 in the 330 MeV beam. Beam configurations do not affect the reconstructed spatial resolution as investigated between a radiography acquired with the parallel (3.49 lp cm -1 to 5.76 lp cm -1 ) or conical beam (from 3.49 lp cm -1 to 5.56 lp cm -1 ). The improved images were then used as input in a photon tomography algorithm. The proton CT reconstruction of the Catphan phantom shows high spatial resolution (from 2.79 to 5.55 lp cm -1 for the parallel beam and from 3.03 to 5.15 lp cm -1 for the conical beam) and the reconstruction of the head phantom, although qualitative, shows high contrast in the gradient region. The proposed formulation of the optimization demonstrates serious potential to increase the spatial resolution (up by 65[Formula: see text]) in proton radiography and greatly accelerate proton computed tomography reconstruction.

Antiproton identification below threshold with the AMS-02 RICH detector

NASA Astrophysics Data System (ADS)

Li, Zi-Yuan; Delgado Mendez, Carlos Jose; Giovacchini, Francesca; Haino, Sadakazu; Hoffman, Julia

2017-05-01

The Alpha Magnetic Spectrometer (AMS-02), which is installed on the International Space Station (ISS), has been collecting data successfully since May 2011. The main goals of AMS-02 are the search for cosmic anti-matter, dark matter and the precise measurement of the relative abundance of elements and isotopes in galactic cosmic rays. In order to identify particle properties, AMS-02 includes several specialized sub-detectors. Among these, the AMS-02 Ring Imaging Cherenkov detector (RICH) is designed to provide a very precise measurement of the velocity and electric charge of particles. We describe a method to reject the dominant electron background in antiproton identification with the use of the AMS-02 RICH detector as a veto for rigidities below 3 GV. A ray tracing integration method is used to maximize the statistics of p¯ with the lowest possible e- background, providing 4 times rejection power gain for e- background with respect to only 3% of p¯ signal efficiency loss. By using the collected cosmic-ray data, e- contamination can be well suppressed within 3% with β ≈ 1, while keeping 76% efficiency for p¯ below the threshold. Supported by China Scholarship Council (CSC) under Grant No.201306380027.

Proton therapy in clinical practice

PubMed Central

Liu, Hui; Chang, Joe Y.

2011-01-01

Radiation dose escalation and acceleration improves local control but also increases toxicity. Proton radiation is an emerging therapy for localized cancers that is being sought with increasing frequency by patients. Compared with photon therapy, proton therapy spares more critical structures due to its unique physics. The physical properties of a proton beam make it ideal for clinical applications. By modulating the Bragg peak of protons in energy and time, a conformal radiation dose with or without intensity modulation can be delivered to the target while sparing the surrounding normal tissues. Thus, proton therapy is ideal when organ preservation is a priority. However, protons are more sensitive to organ motion and anatomy changes compared with photons. In this article, we review practical issues of proton therapy, describe its image-guided treatment planning and delivery, discuss clinical outcome for cancer patients, and suggest challenges and the future development of proton therapy. PMID:21527064

Insight into proton transfer in phosphotungstic acid functionalized mesoporous silica-based proton exchange membrane fuel cells.

PubMed

Zhou, Yuhua; Yang, Jing; Su, Haibin; Zeng, Jie; Jiang, San Ping; Goddard, William A

2014-04-02

We have developed for fuel cells a novel proton exchange membrane (PEM) using inorganic phosphotungstic acid (HPW) as proton carrier and mesoporous silica as matrix (HPW-meso-silica) . The proton conductivity measured by electrochemical impedance spectroscopy is 0.11 S cm(-1) at 90 °C and 100% relative humidity (RH) with a low activation energy of ∼14 kJ mol(-1). In order to determine the energetics associated with proton migration within the HPW-meso-silica PEM and to determine the mechanism of proton hopping, we report density functional theory (DFT) calculations using the generalized gradient approximation (GGA). These DFT calculations revealed that the proton transfer process involves both intramolecular and intermolecular proton transfer pathways. When the adjacent HPWs are close (less than 17.0 Å apart), the calculated activation energy for intramolecular proton transfer within a HPW molecule is higher (29.1-18.8 kJ/mol) than the barrier for intermolecular proton transfer along the hydrogen bond. We find that the overall barrier for proton movement within the HPW-meso-silica membranes is determined by the intramolecular proton transfer pathway, which explains why the proton conductivity remains unchanged when the weight percentage of HPW on meso-silica is above 67 wt %. In contrast, the activation energy of proton transfer on a clean SiO2 (111) surface is computed to be as high as ∼40 kJ mol(-1), confirming the very low proton conductivity on clean silica surfaces observed experimentally.

Proton clouds to measure long-range contacts between nonexchangeable side chain protons in solid-state NMR.

PubMed

Sinnige, Tessa; Daniëls, Mark; Baldus, Marc; Weingarth, Markus

2014-03-26

We show that selective labeling of proteins with protonated amino acids embedded in a perdeuterated matrix, dubbed 'proton clouds', provides general access to long-range contacts between nonexchangeable side chain protons in proton-detected solid-state NMR, which is important to study protein tertiary structure. Proton-cloud labeling significantly improves spectral resolution by simultaneously reducing proton line width and spectral crowding despite a high local proton density in clouds. The approach is amenable to almost all canonical amino acids. Our method is demonstrated on ubiquitin and the β-barrel membrane protein BamA.

Moving protons with pendant amines: proton mobility in a nickel catalyst for oxidation of hydrogen.

PubMed

O'Hagan, Molly; Shaw, Wendy J; Raugei, Simone; Chen, Shentan; Yang, Jenny Y; Kilgore, Uriah J; DuBois, Daniel L; Bullock, R Morris

2011-09-14

Proton transport is ubiquitous in chemical and biological processes, including the reduction of dioxygen to water, the reduction of CO(2) to formate, and the production/oxidation of hydrogen. In this work we describe intramolecular proton transfer between Ni and positioned pendant amines for the hydrogen oxidation electrocatalyst [Ni(P(Cy)(2)N(Bn)(2)H)(2)](2+) (P(Cy)(2)N(Bn)(2) = 1,5-dibenzyl-3,7-dicyclohexyl-1,5-diaza-3,7-diphosphacyclooctane). Rate constants are determined by variable-temperature one-dimensional NMR techniques and two-dimensional EXSY experiments. Computational studies provide insight into the details of the proton movement and energetics of these complexes. Intramolecular proton exchange processes are observed for two of the three experimentally observable isomers of the doubly protonated Ni(0) complex, [Ni(P(Cy)(2)N(Bn)(2)H)(2)](2+), which have N-H bonds but no Ni-H bonds. For these two isomers, with pendant amines positioned endo to the Ni, the rate constants for proton exchange range from 10(4) to 10(5) s(-1) at 25 °C, depending on isomer and solvent. No exchange is observed for protons on pendant amines positioned exo to the Ni. Analysis of the exchange as a function of temperature provides a barrier for proton exchange of ΔG(‡) = 11-12 kcal/mol for both isomers, with little dependence on solvent. Density functional theory calculations and molecular dynamics simulations support the experimental observations, suggesting metal-mediated intramolecular proton transfers between nitrogen atoms, with chair-to-boat isomerizations as the rate-limiting steps. Because of the fast rate of proton movement, this catalyst may be considered a metal center surrounded by a cloud of exchanging protons. The high intramolecular proton mobility provides information directly pertinent to the ability of pendant amines to accelerate proton transfers during catalysis of hydrogen oxidation. These results may also have broader implications for proton movement in

The physics of proton therapy.

PubMed

Newhauser, Wayne D; Zhang, Rui

2015-04-21

The physics of proton therapy has advanced considerably since it was proposed in 1946. Today analytical equations and numerical simulation methods are available to predict and characterize many aspects of proton therapy. This article reviews the basic aspects of the physics of proton therapy, including proton interaction mechanisms, proton transport calculations, the determination of dose from therapeutic and stray radiations, and shielding design. The article discusses underlying processes as well as selected practical experimental and theoretical methods. We conclude by briefly speculating on possible future areas of research of relevance to the physics of proton therapy.

The physics of proton therapy

PubMed Central

Newhauser, Wayne D; Zhang, Rui

2015-01-01

The physics of proton therapy has advanced considerably since it was proposed in 1946. Today analytical equations and numerical simulation methods are available to predict and characterize many aspects of proton therapy. This article reviews the basic aspects of the physics of proton therapy, including proton interaction mechanisms, proton transport calculations, the determination of dose from therapeutic and stray radiations, and shielding design. The article discusses underlying processes as well as selected practical experimental and theoretical methods. We conclude by briefly speculating on possible future areas of research of relevance to the physics of proton therapy. PMID:25803097

Proton beams in radiotherapy

NASA Astrophysics Data System (ADS)

Khoroshkov, V. S.; Minakova, E. I.

1998-11-01

A branch of radiology, proton therapy employs fast protons as a tool for the treatment of various, mainly oncological, diseases. The features of tissue ionization by protons (Bragg peak) facilitate a further step towards solving the principal challenge in radiology: to deliver a sufficiently high and homogeneous dose to virtually any tumour, while sparing healthy neighbouring tissues, organs and structures. The state of the art of proton therapy is described, as well as the main technical, physics and clinical results gained since the 1950s at high-energy physics centres worldwide. The future of proton therapy is connected with the construction of hospital-based facilities with dedicated medical accelerators and modern technical instrumentation.

Proton permeation of lipid bilayers.

PubMed

Deamer, D W

1987-10-01

Proton permeation of the lipid bilayer barrier has two unique features. First, permeability coefficients measured at neutral pH ranges are six to seven orders of magnitude greater than expected from knowledge of other monovalent cations. Second, proton conductance across planar lipid bilayers varies at most by a factor of 10 when pH is varied from near 1 to near 11. Two mechanisms have been proposed to account for this anomalous behavior: proton conductance related to contaminants of lipid bilayers, and proton translocation along transient hydrogen-bonded chains (tHBC) of associated water molecules in the membrane. The weight of evidence suggests that trace contaminants may contribute to proton conductance across planar lipid membranes at certain pH ranges, but cannot account for the anomalous proton flux in liposome systems. Two new results will be reported here which were designed to test the tHBC model. These include measurements of relative proton/potassium permeability in the gramicidin channel, and plots of proton flux against the magnitude of pH gradients. (1) The relative permeabilities of protons and potassium through the gramicidin channel, which contains a single strand of hydrogen-bonded water molecules, were found to differ by at least four orders of magnitude when measured at neutral pH ranges. This result demonstrates that a hydrogen-bonded chain of water molecules can provide substantial discrimination between protons and other cations. It was also possible to calculate that if approximately 7% of bilayer water was present in a transient configuration similar to that of the gramicidin channel, it could account for the measured proton flux. (2) The plot of proton conductance against pH gradient across liposome membranes was superlinear, a result that is consistent with one of three alternative tHBC models for proton conductance described by Nagle elsewhere in this volume.

Proton beam deflection in MRI fields: Implications for MRI-guided proton therapy.

PubMed

Oborn, B M; Dowdell, S; Metcalfe, P E; Crozier, S; Mohan, R; Keall, P J

2015-05-01

This paper investigates, via magnetic modeling and Monte Carlo simulation, the ability to deliver proton beams to the treatment zone inside a split-bore MRI-guided proton therapy system. Field maps from a split-bore 1 T MRI-Linac system are used as input to geant4 Monte Carlo simulations which model the trajectory of proton beams during their paths to the isocenter of the treatment area. Both inline (along the MRI bore) and perpendicular (through the split-bore gap) orientations are simulated. Monoenergetic parallel and diverging beams of energy 90, 195, and 300 MeV starting from 1.5 and 5 m above isocenter are modeled. A phase space file detailing a 2D calibration pattern is used to set the particle starting positions, and their spatial location as they cross isocenter is recorded. No beam scattering, collimation, or modulation of the proton beams is modeled. In the inline orientation, the radial symmetry of the solenoidal style fringe field acts to rotate the protons around the beam's central axis. For protons starting at 1.5 m from isocenter, this rotation is 19° (90 MeV) and 9.8° (300 MeV). A minor focusing toward the beam's central axis is also seen, but only significant, i.e., 2 mm shift at 150 mm off-axis, for 90 MeV protons. For the perpendicular orientation, the main MRI field and near fringe field act as the strongest to deflect the protons in a consistent direction. When starting from 1.5 m above isocenter shifts of 135 mm (90 MeV) and 65 mm (300 MeV) were observed. Further to this, off-axis protons are slightly deflected toward or away from the central axis in the direction perpendicular to the main deflection direction. This leads to a distortion of the phase space pattern, not just a shift. This distortion increases from zero at the central axis to 10 mm (90 MeV) and 5 mm (300 MeV) for a proton 150 mm off-axis. In both orientations, there is a small but subtle difference in the deflection and distortion pattern between protons fired parallel to the

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Hsin-Chia; Huang, Wei-Chih; Huang, Xiaoyuan

We consider indirect detection of meta-stable dark matter particles decaying into a stable neutral particle and a pair of standard model fermions. Due to the softer energy spectra from the three-body decay, such models could potentially explain the AMS-02 positron excess without being constrained by the Fermi-LAT gamma-ray data and the cosmic ray anti-proton measurements. We scrutinize over different final state fermions, paying special attention to handling of the cosmic ray background and including various contributions from cosmic ray propagation with the help of the LIKEDM package. It is found that primary decays into an electron-positron pair and a stablemore » neutral particle could give rise to the AMS-02 positron excess and, at the same time, stay unscathed against the gamma-ray and anti-proton constraints. Decays to a muon pair or a mixed flavor electron-muon pair may also be viable depending on the propagation models. Decays to all other standard model fermions are severely disfavored.« less

Galactic cosmic-ray model in the light of AMS-02 nuclei data

NASA Astrophysics Data System (ADS)

Niu, Jia-Shu; Li, Tianjun

2018-01-01

Cosmic ray (CR) physics has entered a precision-driven era. With the latest AMS-02 nuclei data (boron-to-carbon ratio, proton flux, helium flux, and antiproton-to-proton ratio), we perform a global fitting and constrain the primary source and propagation parameters of cosmic rays in the Milky Way by considering 3 schemes with different data sets (with and without p ¯ /p data) and different propagation models (diffusion-reacceleration and diffusion-reacceleration-convection models). We find that the data set with p ¯/p data can remove the degeneracy between the propagation parameters effectively and it favors the model with a very small value of convection (or disfavors the model with convection). The separated injection spectrum parameters are used for proton and other nucleus species, which reveal the different breaks and slopes among them. Moreover, the helium abundance, antiproton production cross sections, and solar modulation are parametrized in our global fitting. Benefited from the self-consistence of the new data set, the fitting results show a little bias, and thus the disadvantages and limitations of the existed propagation models appear. Comparing to the best fit results for the local interstellar spectra (ϕ =0 ) with the VOYAGER-1 data, we find that the primary sources or propagation mechanisms should be different between proton and helium (or other heavier nucleus species). Thus, how to explain these results properly is an interesting and challenging question.

Hydrogen analysis for granite using proton-proton elastic recoil coincidence spectrometry.

PubMed

Komatsubara, T; Sasa, K; Ohshima, H; Kimura, H; Tajima, Y; Takahashi, T; Ishii, S; Yamato, Y; Kurosawa, M

2008-07-01

In an effort to develop DS02, a new radiation dosimetry system for the atomic bomb survivors of Hiroshima and Nagasaki, measurements of neutron-induced activities have provided valuable information to reconstruct the radiation situation at the time of the bombings. In Hiroshima, the depth profile of (152)Eu activity measured in a granite pillar of the Motoyasu Bridge (128 m from the hypocenter) was compared with that calculated using the DS02 methodology. For calculation of the (152)Eu production due to the thermal-neutron activation reaction, (151)Eu(n,gamma)(152)Eu, information on the hydrogen content in granite is important because the transport and slowing-down process of neutrons penetrating into the pillar is strongly affected by collisions with the protons of hydrogen. In this study, proton-proton elastic recoil coincidence spectrometry has been used to deduce the proton density in the Motoyasu pillar granite. Slices of granite samples were irradiated by a 20 MeV proton beam, and the energies of scattered and recoil protons were measured with a coincidence method. The water concentration in the pillar granite was evaluated to be 0.30 +/- 0.07%wt. This result is consistent with earlier data on adsorptive water (II) and bound water obtained by the Karl Fisher method.

Proton energy and scattering angle radiographs to improve proton treatment planning: a Monte Carlo study

NASA Astrophysics Data System (ADS)

Biegun, A. K.; Takatsu, J.; Nakaji, T.; van Goethem, M. J.; van der Graaf, E. R.; Koffeman, E. N.; Visser, J.; Brandenburg, S.

2016-12-01

The novel proton radiography imaging technique has a large potential to be used in direct measurement of the proton energy loss (proton stopping power, PSP) in various tissues in the patient. The uncertainty of PSPs, currently obtained from translation of X-ray Computed Tomography (xCT) images, should be minimized from 3-5% or higher to less than 1%, to make the treatment plan with proton beams more accurate, and thereby better treatment for the patient. With Geant4 we simulated a proton radiography detection system with two position-sensitive and residual energy detectors. A complex phantom filled with various materials (including tissue surrogates), was placed between the position sensitive detectors. The phantom was irradiated with 150 MeV protons and the energy loss radiograph and scattering angles were studied. Protons passing through different materials in the phantom lose energy, which was used to create a radiography image of the phantom. The multiple Coulomb scattering of a proton traversing different materials causes blurring of the image. To improve image quality and material identification in the phantom, we selected protons with small scattering angles. A good quality proton radiography image, in which various materials can be recognized accurately, and in combination with xCT can lead to more accurate relative stopping powers predictions.

Proton beam characterization in the experimental room of the Trento Proton Therapy facility

NASA Astrophysics Data System (ADS)

Tommasino, F.; Rovituso, M.; Fabiano, S.; Piffer, S.; Manea, C.; Lorentini, S.; Lanzone, S.; Wang, Z.; Pasini, M.; Burger, W. J.; La Tessa, C.; Scifoni, E.; Schwarz, M.; Durante, M.

2017-10-01

As proton therapy is becoming an established treatment methodology for cancer patients, the number of proton centres is gradually growing worldwide. The economical effort for building these facilities is motivated by the clinical aspects, but might be also supported by the potential relevance for the research community. Experiments with high-energy protons are needed not only for medical physics applications, but represent also an essential part of activities dedicated to detector development, space research, radiation hardness tests, as well as of fundamental research in nuclear and particle physics. Here we present the characterization of the beam line installed in the experimental room of the Trento Proton Therapy Centre (Italy). Measurements of beam spot size and envelope, range verification and proton flux were performed in the energy range between 70 and 228 MeV. Methods for reducing the proton flux from typical treatments values of 106-109 particles/s down to 101-105 particles/s were also investigated. These data confirm that a proton beam produced in a clinical centre build by a commercial company can be exploited for a broad spectrum of experimental activities. The results presented here will be used as a reference for future experiments.

Charmonium interaction in nuclear matter at FAIR

NASA Astrophysics Data System (ADS)

Pratim Bhaduri, Partha; Deveaux, Michael; Toia, Alberica

2018-05-01

We have studied the dissociation of J/ψ mesons in low energy proton-nucleus (p + A) collisions in the energy range of the future SIS100 accelerator at Facility for Anti-proton and Ion Research (FAIR). According to the results of our calculations, various scenarios of J/ψ absorption in nuclear matter show very distinct suppression patterns in the kinematic regime to be probed at FAIR. This suggests that the SIS100 energies are particularly suited to shed light on the issue of interaction of J/ψ resonance in nuclear medium.

200 MeV Proton Radiography Studies with a Hand Phantom Using a Prototype Proton CT Scanner

PubMed Central

Plautz, Tia; Bashkirov, V.; Feng, V.; Hurley, F.; Johnson, R.P.; Leary, C.; Macafee, S.; Plumb, A.; Rykalin, V.; Sadrozinski, H.F.-W.; Schubert, K.; Schulte, R.; Schultze, B.; Steinberg, D.; Witt, M.; Zatserklyaniy, A.

2014-01-01

Proton radiography has applications in patient alignment and verification procedures for proton beam radiation therapy. In this paper, we report an experiment which used 200 MeV protons to generate proton energy-loss and scattering radiographs of a hand phantom. The experiment used the first-generation proton CT scanner prototype, which was installed on the research beam line of the clinical proton synchrotron at Loma Linda University Medical Center (LLUMC). It was found that while both radiographs displayed anatomical details of the hand phantom, the energy-loss radiograph had a noticeably higher resolution. Nonetheless, scattering radiography may yield more contrast between soft and bone tissue than energy-loss radiography, however, this requires further study. This study contributes to the optimization of the performance of the next-generation of clinical proton CT scanners. Furthermore, it demonstrates the potential of proton imaging (proton radiography and CT), which is now within reach of becoming available as a new, potentially low-dose medical imaging modality. PMID:24710156

Measuring the Mass of the W Boson with the Last 3.7 fb -1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brochmann, Michelle

This thesis presents the results of an analysis of the 3.7 fb -1 of Tevatron proton-antiproton data collected with the DZero (D0) Detector at Fermilab during the "RunIIb34" period, with the goal of extracting an improved measurement of the W boson mass, which is currently measured to a precision of ≈ 20 MeV.

Proton therapy - Present and future.

PubMed

Mohan, Radhe; Grosshans, David

2017-01-15

In principle, proton therapy offers a substantial clinical advantage over conventional photon therapy. This is because of the unique depth-dose characteristics of protons, which can be exploited to achieve significant reductions in normal tissue doses proximal and distal to the target volume. These may, in turn, allow escalation of tumor doses and greater sparing of normal tissues, thus potentially improving local control and survival while at the same time reducing toxicity and improving quality of life. Protons, accelerated to therapeutic energies ranging from 70 to 250MeV, typically with a cyclotron or a synchrotron, are transported to the treatment room where they enter the treatment head mounted on a rotating gantry. The initial thin beams of protons are spread laterally and longitudinally and shaped appropriately to deliver treatments. Spreading and shaping can be achieved by electro-mechanical means to treat the patients with "passively-scattered proton therapy" (PSPT) or using magnetic scanning of thin "beamlets" of protons of a sequence of initial energies. The latter technique can be used to treat patients with optimized intensity modulated proton therapy (IMPT), the most powerful proton modality. Despite the high potential of proton therapy, the clinical evidence supporting the broad use of protons is mixed. It is generally acknowledged that proton therapy is safe, effective and recommended for many types of pediatric cancers, ocular melanomas, chordomas and chondrosarcomas. Although promising results have been and continue to be reported for many other types of cancers, they are based on small studies. Considering the high cost of establishing and operating proton therapy centers, questions have been raised about their cost effectiveness. General consensus is that there is a need to conduct randomized trials and/or collect outcomes data in multi-institutional registries to unequivocally demonstrate the advantage of protons. Treatment planning and plan

Energetic solar proton vs terrestrially trapped proton fluxes. [geocentric space missions shielding requirements

NASA Technical Reports Server (NTRS)

King, J. H.; Stassinopoulos, E. G.

1975-01-01

The relative importance of solar and trapped proton fluxes in the consideration of shielding requirements for geocentric space missions is analyzed. Using models of these particles, their fluences encountered by spacecraft in circular orbits are computed as functions of orbital altitude and inclination, mission duration, threshold energy (10 to 100 MeV), and risk factor (for solar protons only), and ratios of solar-to-trapped fluences are derived. It is shown that solar protons predominate for low-altitude polar and very high-altitude missions, while trapped protons predominate for missions at low and medium altitudes and low inclinations. It is recommended that if the ratio of solar-to-trapped protons falls between 0.1 and 10, both fluences should be considered in planning shielding systems.

Effects of Proton and Combined Proton and (56)Fe Radiation on the Hippocampus.

PubMed

Raber, Jacob; Allen, Antiño R; Sharma, Sourabh; Allen, Barrett; Rosi, Susanna; Olsen, Reid H J; Davis, Matthew J; Eiwaz, Massarra; Fike, John R; Nelson, Gregory A

2016-01-01

The space radiation environment contains protons and (56)Fe, which could pose a significant hazard to space flight crews during and after missions. The space environment involves complex radiation exposures, thus, the effects of a dose of protons might be modulated by a dose of heavy-ion radiation. The brain, and particularly the hippocampus, may be susceptible to space radiation-induced changes. In this study, we first determined the dose-response effect of proton radiation (150 MeV) on hippocampus-dependent cognition 1 and 3 months after exposure. Based on those results, we subsequently exposed mice to protons alone (150 MeV, 0.1 Gy), (56)Fe alone (600 MeV/n, 0.5 Gy) or combined proton and (56)Fe radiations (protons first) with the two exposures separated by 24 h. At one month postirradiation, all animal groups showed novel object recognition. However, at three months postirradiation, mice exposed to either protons or combined proton and (56)Fe radiations showed impaired novel object recognition, which was not observed in mice irradiated with (56)Fe alone. The mechanisms in these impairments might involve inflammation. In mice irradiated with protons alone or (56)Fe alone three months earlier, there was a negative correlation between a measure of novel object recognition and the number of newly born activated microglia in the dentate gyrus. Next, cytokine and chemokine levels were assessed in the hippocampus. At one month after exposure the levels of IL-12 were higher in mice exposed to combined radiations compared with sham-irradiated mice, while the levels of IFN-γ were lower in mice exposed to (56)Fe radiation alone or combined radiations. In addition, IL-4 levels were lower in (56)Fe-irradiated mice compared with proton-irradiated mice and TNF-α levels were lower in proton-irradiated mice than in mice receiving combined radiations. At three months after exposure, macrophage-derived chemokine (MDC) and eotaxin levels were lower in mice receiving combined

Feasibility study of proton-based quality assurance of proton range compensator

NASA Astrophysics Data System (ADS)

Park, S.; Jeong, C.; Min, B. J.; Kwak, J.; Lee, J.; Cho, S.; Shin, D.; Lim, Y. K.; Park, S. Y.; Lee, S. B.

2013-06-01

All patient specific range compensators (RCs) are customized for achieving distal dose conformity of target volume in passively scattered proton therapy. Compensators are milled precisely using a computerized machine. In proton therapy, precision of the compensator is critical and quality assurance (QA) is required to protect normal tissues and organs from radiation damage. This study aims to evaluate the precision of proton-based quality assurance of range compensator. First, the geometry information of two compensators was extracted from the DICOM Radiotherapy (RT) plan. Next, RCs were irradiated on the EBT film individually by proton beam which is modulated to have a photon-like percent depth dose (PDD). Step phantoms were also irradiated on the EBT film to generate calibration curve which indicates relationship between optical density of irradiated film and perpendicular depth of compensator. Comparisons were made using the mean absolute difference (MAD) between coordinate information from DICOM RT and converted depth information from the EBT film. MAD over the whole region was 1.7, and 2.0 mm. However, MAD over the relatively flat regions on each compensator selected for comparison was within 1 mm. These results shows that proton-based quality assurance of range compensator is feasible and it is expected to achieve MAD over the whole region less than 1 mm with further correction about scattering effect of proton imaging.

Electron-proton spectrometer design summary

NASA Technical Reports Server (NTRS)

1972-01-01

The electron-proton spectrometer (EPS) will be placed aboard the Skylab in order to provide data from which electron and proton radiation dose can be determined. The EPS has five sensors, each consisting of a shielded silicon detector. These provide four integral electron channels and five integral proton channels from which can be deduced four differential proton increments.

[Why proton therapy? And how?

PubMed

Thariat, Juliette; Habrand, Jean Louis; Lesueur, Paul; Chaikh, Abdulhamid; Kammerer, Emmanuel; Lecomte, Delphine; Batalla, Alain; Balosso, Jacques; Tessonnier, Thomas

2018-03-01

Proton therapy is a radiotherapy, based on the use of protons, charged subatomic particles that stop at a given depth depending on their initial energy (pristine Bragg peak), avoiding any output beam, unlike the photons used in most of the other modalities of radiotherapy. Proton therapy has been used for 60 years, but has only become ubiquitous in the last decade because of recent major advances in particle accelerator technology. This article reviews the history of clinical implementation of protons, the nature of the technological advances that now allows its expansion at a lower cost. It also addresses the technical and physical specificities of proton therapy and the clinical situations for which proton therapy may be relevant but requires evidence. Different proton therapy techniques are possible. These are explained in terms of their clinical potential by explaining the current terminology (such as cyclotrons, synchrotrons or synchrocyclotrons, using superconducting magnets, fixed line or arm rotary with passive diffusion delivery or active by scanning) in basic words. The requirements associated with proton therapy are increased due to the precision of the depth dose deposit. The learning curve of proton therapy requires that clinical indications be prioritized according to their associated uncertainties (such as range uncertainties and movement in lung tumors). Many clinical indications potentially fall under proton therapy ultimately. Clinical strategies are explained in a paralleled manuscript. Copyright © 2018 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.

Classical Molecular Dynamics with Mobile Protons.

PubMed

Lazaridis, Themis; Hummer, Gerhard

2017-11-27

An important limitation of standard classical molecular dynamics simulations is the inability to make or break chemical bonds. This restricts severely our ability to study processes that involve even the simplest of chemical reactions, the transfer of a proton. Existing approaches for allowing proton transfer in the context of classical mechanics are rather cumbersome and have not achieved widespread use and routine status. Here we reconsider the combination of molecular dynamics with periodic stochastic proton hops. To ensure computational efficiency, we propose a non-Boltzmann acceptance criterion that is heuristically adjusted to maintain the correct or desirable thermodynamic equilibria between different protonation states and proton transfer rates. Parameters are proposed for hydronium, Asp, Glu, and His. The algorithm is implemented in the program CHARMM and tested on proton diffusion in bulk water and carbon nanotubes and on proton conductance in the gramicidin A channel. Using hopping parameters determined from proton diffusion in bulk water, the model reproduces the enhanced proton diffusivity in carbon nanotubes and gives a reasonable estimate of the proton conductance in gramicidin A.

Surface Protonics Promotes Catalysis

PubMed Central

Manabe, R.; Okada, S.; Inagaki, R.; Oshima, K.; Ogo, S.; Sekine, Y.

2016-01-01

Catalytic steam reforming of methane for hydrogen production proceeds even at 473 K over 1 wt% Pd/CeO2 catalyst in an electric field, thanks to the surface protonics. Kinetic analyses demonstrated the synergetic effect between catalytic reaction and electric field, revealing strengthened water pressure dependence of the reaction rate when applying an electric field, with one-third the apparent activation energy at the lower reaction temperature range. Operando–IR measurements revealed that proton conduction via adsorbed water on the catalyst surface occurred during electric field application. Methane was activated by proton collision at the Pd–CeO2 interface, based on the inverse kinetic isotope effect. Proton conduction on the catalyst surface plays an important role in methane activation at low temperature. This report is the first describing promotion of the catalytic reaction by surface protonics. PMID:27905505

Study on patient-induced radioactivity during proton treatment in hengjian proton medical facility.

PubMed

Wu, Qingbiao; Wang, Qingbin; Liang, Tianjiao; Zhang, Gang; Ma, Yinglin; Chen, Yu; Ye, Rong; Liu, Qiongyao; Wang, Yufei; Wang, Huaibao

2016-09-01

At present, increasingly more proton medical facilities have been established globally for better curative effect and less side effect in tumor treatment. Compared with electron and photon, proton delivers more energy and dose at its end of range (Bragg peak), and has less lateral scattering for its much larger mass. However, proton is much easier to produce neutron and induced radioactivity, which makes radiation protection for proton accelerators more difficult than for electron accelerators. This study focuses on the problem of patient-induced radioactivity during proton treatment, which has been ignored for years. However, we confirmed it is a vital factor for radiation protection to both patient escort and positioning technician, by FLUKA's simulation and activation formula calculation of Hengjian Proton Medical Facility (HJPMF), whose energy ranges from 130 to 230MeV. Furthermore, new formulas for calculating the activity buildup process of periodic irradiation were derived and used to study the relationship between saturation degree and half-life of nuclides. Finally, suggestions are put forward to lessen the radiation hazard from patient-induced radioactivity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Elastogranular Mechanics: Buckling, Jamming, and Structure Formation

NASA Astrophysics Data System (ADS)

Schunter, David J.; Brandenbourger, Martin; Perriseau, Sophia; Holmes, Douglas P.

2018-02-01

Confinement of a slender body into a granular array induces stress localization in the geometrically nonlinear structure, and jamming, reordering, and vertical dislodging of the surrounding granular medium. By varying the initial packing density of grains and the length of a confined elastica, we identify the critical length necessary to induce jamming, and demonstrate how folds couple with the granular medium to localize along grain boundaries. Above the jamming threshold, the characteristic length of elastica deformation is shown to diverge in a manner that is coupled with the motion and rearrangement of the grains, suggesting the ordering of the granular array governs the deformation of the slender structure. However, overconfinement of the elastica will vertically dislodge grains, a form of stress relaxation in the granular medium that illustrates the intricate coupling in elastogranular interactions.

Elastogranular Mechanics: Buckling, Jamming, and Structure Formation.

PubMed

Schunter, David J; Brandenbourger, Martin; Perriseau, Sophia; Holmes, Douglas P

2018-02-16

Confinement of a slender body into a granular array induces stress localization in the geometrically nonlinear structure, and jamming, reordering, and vertical dislodging of the surrounding granular medium. By varying the initial packing density of grains and the length of a confined elastica, we identify the critical length necessary to induce jamming, and demonstrate how folds couple with the granular medium to localize along grain boundaries. Above the jamming threshold, the characteristic length of elastica deformation is shown to diverge in a manner that is coupled with the motion and rearrangement of the grains, suggesting the ordering of the granular array governs the deformation of the slender structure. However, overconfinement of the elastica will vertically dislodge grains, a form of stress relaxation in the granular medium that illustrates the intricate coupling in elastogranular interactions.

Modeling the Proton Radiation Belt With Van Allen Probes Relativistic Electron-Proton Telescope Data

NASA Technical Reports Server (NTRS)

Kanekal, S. G.; Li, X.; Baker, D. N.; Selesnick, R. S.; Hoxie, V. C.

2018-01-01

An empirical model of the proton radiation belt is constructed from data taken during 2013-2017 by the Relativistic Electron-Proton Telescopes on the Van Allen Probes satellites. The model intensity is a function of time, kinetic energy in the range 18-600 megaelectronvolts, equatorial pitch angle, and L shell of proton guiding centers. Data are selected, on the basis of energy deposits in each of the nine silicon detectors, to reduce background caused by hard proton energy spectra at low L. Instrument response functions are computed by Monte Carlo integration, using simulated proton paths through a simplified structural model, to account for energy loss in shielding material for protons outside the nominal field of view. Overlap of energy channels, their wide angular response, and changing satellite orientation require the model dependencies on all three independent variables be determined simultaneously. This is done by least squares minimization with a customized steepest descent algorithm. Model uncertainty accounts for statistical data error and systematic error in the simulated instrument response. A proton energy spectrum is also computed from data taken during the 8 January 2014 solar event, to illustrate methods for the simpler case of an isotropic and homogeneous model distribution. Radiation belt and solar proton results are compared to intensities computed with a simplified, on-axis response that can provide a good approximation under limited circumstances.

Modeling the Proton Radiation Belt With Van Allen Probes Relativistic Electron-Proton Telescope Data

NASA Astrophysics Data System (ADS)

Selesnick, R. S.; Baker, D. N.; Kanekal, S. G.; Hoxie, V. C.; Li, X.

2018-01-01

An empirical model of the proton radiation belt is constructed from data taken during 2013-2017 by the Relativistic Electron-Proton Telescopes on the Van Allen Probes satellites. The model intensity is a function of time, kinetic energy in the range 18-600 MeV, equatorial pitch angle, and L shell of proton guiding centers. Data are selected, on the basis of energy deposits in each of the nine silicon detectors, to reduce background caused by hard proton energy spectra at low L. Instrument response functions are computed by Monte Carlo integration, using simulated proton paths through a simplified structural model, to account for energy loss in shielding material for protons outside the nominal field of view. Overlap of energy channels, their wide angular response, and changing satellite orientation require the model dependencies on all three independent variables be determined simultaneously. This is done by least squares minimization with a customized steepest descent algorithm. Model uncertainty accounts for statistical data error and systematic error in the simulated instrument response. A proton energy spectrum is also computed from data taken during the 8 January 2014 solar event, to illustrate methods for the simpler case of an isotropic and homogeneous model distribution. Radiation belt and solar proton results are compared to intensities computed with a simplified, on-axis response that can provide a good approximation under limited circumstances.

GPU.proton.DOCK: Genuine Protein Ultrafast proton equilibria consistent DOCKing.

PubMed

Kantardjiev, Alexander A

2011-07-01

GPU.proton.DOCK (Genuine Protein Ultrafast proton equilibria consistent DOCKing) is a state of the art service for in silico prediction of protein-protein interactions via rigorous and ultrafast docking code. It is unique in providing stringent account of electrostatic interactions self-consistency and proton equilibria mutual effects of docking partners. GPU.proton.DOCK is the first server offering such a crucial supplement to protein docking algorithms--a step toward more reliable and high accuracy docking results. The code (especially the Fast Fourier Transform bottleneck and electrostatic fields computation) is parallelized to run on a GPU supercomputer. The high performance will be of use for large-scale structural bioinformatics and systems biology projects, thus bridging physics of the interactions with analysis of molecular networks. We propose workflows for exploring in silico charge mutagenesis effects. Special emphasis is given to the interface-intuitive and user-friendly. The input is comprised of the atomic coordinate files in PDB format. The advanced user is provided with a special input section for addition of non-polypeptide charges, extra ionogenic groups with intrinsic pK(a) values or fixed ions. The output is comprised of docked complexes in PDB format as well as interactive visualization in a molecular viewer. GPU.proton.DOCK server can be accessed at http://gpudock.orgchm.bas.bg/.

Proton irradiation on materials

NASA Technical Reports Server (NTRS)

Chang, C. Ken

1993-01-01

A computer code is developed by utilizing a radiation transport code developed at NASA Langley Research Center to study the proton radiation effects on materials which have potential application in NASA's future space missions. The code covers the proton energy from 0.01 Mev to 100 Gev and is sufficient for energetic protons encountered in both low earth and geosynchronous orbits. With some modification, the code can be extended for particles heavier than proton as the radiation source. The code is capable of calculating the range, stopping power, exit energy, energy deposition coefficients, dose, and cumulative dose along the path of the proton in a target material. The target material can be any combination of the elements with atomic number ranging from 1 to 92, or any compound with known chemical composition. The generated cross section for a material is stored and is reused in future to save computer time. This information can be utilized to calculate the proton dose a material would receive in an orbit when the radiation environment is known. It can also be used to determine, in the laboratory, the parameters such as beam current of proton and irradiation time to attain the desired dosage for accelerated ground testing of any material. It is hoped that the present work be extended to include polymeric and composite materials which are prime candidates for use as coating, electronic components, and structure building. It is also desirable to determine, for ground testing these materials, the laboratory parameters in order to simulate the dose they would receive in space environments. A sample print-out for water subject to 1.5 Mev proton is included as a reference.

Squeezing at Entrance of Proton Transport Pathway in Proton-translocating Pyrophosphatase upon Substrate Binding*

PubMed Central

Huang, Yun-Tzu; Liu, Tseng-Huang; Lin, Shih-Ming; Chen, Yen-Wei; Pan, Yih-Jiuan; Lee, Ching-Hung; Sun, Yuh-Ju; Tseng, Fan-Gang; Pan, Rong-Long

2013-01-01

Homodimeric proton-translocating pyrophosphatase (H+-PPase; EC 3.6.1.1) is indispensable for many organisms in maintaining organellar pH homeostasis. This unique proton pump couples the hydrolysis of PPi to proton translocation across the membrane. H+-PPase consists of 14–16 relatively hydrophobic transmembrane domains presumably for proton translocation and hydrophilic loops primarily embedding a catalytic site. Several highly conserved polar residues located at or near the entrance of the transport pathway in H+-PPase are essential for proton pumping activity. In this investigation single molecule FRET was employed to dissect the action at the pathway entrance in homodimeric Clostridium tetani H+-PPase upon ligand binding. The presence of the substrate analog, imidodiphosphate mediated two sites at the pathway entrance moving toward each other. Moreover, single molecule FRET analyses after the mutation at the first proton-carrying residue (Arg-169) demonstrated that conformational changes at the entrance are conceivably essential for the initial step of H+-PPase proton translocation. A working model is accordingly proposed to illustrate the squeeze at the entrance of the transport pathway in H+-PPase upon substrate binding. PMID:23720778

Enhanced proton conductivity of proton exchange membranes by incorporating sulfonated metal-organic frameworks

NASA Astrophysics Data System (ADS)

Li, Zhen; He, Guangwei; Zhao, Yuning; Cao, Ying; Wu, Hong; Li, Yifan; Jiang, Zhongyi

2014-09-01

In this study, octahedral crystal MIL101(Cr) with a uniform size of ∼400 nm is synthesized via hydrothermal reaction. It is then functionalized with sulfonic acid groups by concentrated sulfuric acid and trifluoromethanesulfonic anhydride in nitromethane. The sulfonated MIL101(Cr) are homogeneously incorporated into sulfonated poly(ether ether ketone) (SPEEK) matrix to prepare hybrid membranes. The performances of hybrid membranes are evaluated by proton conductivity, methanol permeability, water uptake and swelling property, and thermal stability. The methanol permeability increased slightly from 6.12 × 10-7 to 7.39 × 10-7 cm2 s-1 with the filler contents increasing from 0 to 10 wt. %. However, the proton conductivity of the hybrid membranes increased significantly. The proton conductivity is increased up to 0.306 S cm-1 at 75 °C and 100% RH, which is 96.2% higher than that of pristine membranes (0.156 S cm-1). The increment of proton conductivity is attributed to the following multiple functionalities of the sulfonated MIL101(Cr) in hybrid membranes: i) providing sulfonic acid groups as facile proton hopping sites; ii) forming additional proton-transport pathways at the interfaces of polymer and MOFs; iii) constructing hydrogen-bonded networks for proton conduction via -OH provided by the hydrolysis of coordinatively unsaturated metal sites.

Low-Energy Proton Testing Methodology

NASA Technical Reports Server (NTRS)

Pellish, Jonathan A.; Marshall, Paul W.; Heidel, David F.; Schwank, James R.; Shaneyfelt, Marty R.; Xapsos, M.A.; Ladbury, Raymond L.; LaBel, Kenneth A.; Berg, Melanie; Kim, Hak S.;

Restrained Proton Indicator in Combined Quantum-Mechanics/Molecular-Mechanics Dynamics Simulations of Proton Transfer through a Carbon Nanotube.

PubMed

Duster, Adam W; Lin, Hai

2017-09-14

Recently, a collective variable "proton indicator" was purposed for tracking an excess proton solvated in bulk water in molecular dynamics simulations. In this work, we demonstrate the feasibility of utilizing the position of this proton indicator as a reaction coordinate to model an excess proton migrating through a hydrophobic carbon nanotube in combined quantum-mechanics/molecular-mechanics simulations. Our results indicate that applying a harmonic restraint to the proton indicator in the bulk solvent near the nanotube pore entrance leads to the recruitment of water molecules into the pore. This is consistent with an earlier study that employed a multistate empirical valence bond potential and a different representation (center of excess charge) of the proton. We attribute this water recruitment to the delocalized nature of the solvated proton, which prefers to be in high-dielectric bulk solvent. While water recruitment into the pore is considered an artifact in the present simulations (because of the artificially imposed restraint on the proton), if the proton were naturally restrained, it could assist in building water wires prior to proton transfer through the pore. The potential of mean force for a proton translocation through the water-filled pore was computed by umbrella sampling, where the bias potentials were applied to the proton indicator. The free energy curve and barrier heights agree reasonably with those in the literature. The results suggest that the proton indicator can be used as a reaction coordinate in simulations of proton transport in confined environments.

Solution of Heliospheric Propagation: Unveiling the Local Interstellar Spectra of Cosmic-ray Species

NASA Astrophysics Data System (ADS)

Boschini, M. J.; Della Torre, S.; Gervasi, M.; Grandi, D.; Jóhannesson, G.; Kachelriess, M.; La Vacca, G.; Masi, N.; Moskalenko, I. V.; Orlando, E.; Ostapchenko, S. S.; Pensotti, S.; Porter, T. A.; Quadrani, L.; Rancoita, P. G.; Rozza, D.; Tacconi, M.

2017-05-01

Local interstellar spectra (LIS) for protons, helium, and antiprotons are built using the most recent experimental results combined with state-of-the-art models for propagation in the Galaxy and heliosphere. Two propagation packages, GALPROP and HelMod, are combined to provide a single framework that is run to reproduce direct measurements of cosmic-ray (CR) species at different modulation levels and at both polarities of the solar magnetic field. To do so in a self-consistent way, an iterative procedure was developed, where the GALPROP LIS output is fed into HelMod, providing modulated spectra for specific time periods of selected experiments to compare with the data; the HelMod parameter optimization is performed at this stage and looped back to adjust the LIS using the new GALPROP run. The parameters were tuned with the maximum likelihood procedure using an extensive data set of proton spectra from 1997 to 2015. The proposed LIS accommodate both the low-energy interstellar CR spectra measured by Voyager 1 and the high-energy observations by BESS, Pamela, AMS-01, and AMS-02 made from the balloons and near-Earth payloads; it also accounts for Ulysses counting rate features measured out of the ecliptic plane. The found solution is in a good agreement with proton, helium, and antiproton data by AMS-02, BESS, and PAMELA in the whole energy range.

VizieR Online Data Catalog: Local interstellar spectra of cosmic-ray species (Boschini+, 2017)

NASA Astrophysics Data System (ADS)

Boschini, M. J.; Torre, S. D.; Gervasi, M.; Grandi, D.; Johannesson, G.; Kachelriess, M.; La Vacca, G.; Masi, N.; Moskalenko, I. V.; Orlando, E.; Ostapchenko, S. S.; Pensotti, S.; Porter, T. A.; Quadrani, L.; Rancoita, P. G.; Rozza, D.; Tacconi, M.

2017-11-01

Local interstellar spectra (LIS) for protons, helium, and antiprotons are built using the most recent experimental results combined with state-of-the-art models for propagation in the Galaxy and heliosphere. Two propagation packages, GALPROP and HelMod, are combined to provide a single framework that is run to reproduce direct measurements of cosmic-ray (CR) species at different modulation levels and at both polarities of the solar magnetic field. To do so in a self-consistent way, an iterative procedure was developed, where the GALPROP LIS output is fed into HelMod, providing modulated spectra for specific time periods of selected experiments to compare with the data; the HelMod parameter optimization is performed at this stage and looped back to adjust the LIS using the new GALPROP run. The parameters were tuned with the maximum likelihood procedure using an extensive data set of proton spectra from 1997 to 2015. The proposed LIS accommodate both the low-energy interstellar CR spectra measured by Voyager 1 and the high-energy observations by BESS, Pamela, AMS-01, and AMS-02 made from the balloons and near-Earth payloads; it also accounts for Ulysses counting rate features measured out of the ecliptic plane. The found solution is in a good agreement with proton, helium, and antiproton data by AMS-02, BESS, and PAMELA in the whole energy range. (3 data files).

Solution of Heliospheric Propagation: Unveiling the Local Interstellar Spectra of Cosmic-ray Species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boschini, M. J.; Torre, S. Della; Gervasi, M.

2017-05-10

Local interstellar spectra (LIS) for protons, helium, and antiprotons are built using the most recent experimental results combined with state-of-the-art models for propagation in the Galaxy and heliosphere. Two propagation packages, GALPROP and HelMod, are combined to provide a single framework that is run to reproduce direct measurements of cosmic-ray (CR) species at different modulation levels and at both polarities of the solar magnetic field. To do so in a self-consistent way, an iterative procedure was developed, where the GALPROP LIS output is fed into HelMod, providing modulated spectra for specific time periods of selected experiments to compare with themore » data; the HelMod parameter optimization is performed at this stage and looped back to adjust the LIS using the new GALPROP run. The parameters were tuned with the maximum likelihood procedure using an extensive data set of proton spectra from 1997 to 2015. The proposed LIS accommodate both the low-energy interstellar CR spectra measured by Voyager 1 and the high-energy observations by BESS, Pamela, AMS-01, and AMS-02 made from the balloons and near-Earth payloads; it also accounts for Ulysses counting rate features measured out of the ecliptic plane. The found solution is in a good agreement with proton, helium, and antiproton data by AMS-02, BESS, and PAMELA in the whole energy range.« less

Hydrogen concentration analysis in clinopyroxene using proton-proton scattering analysis

NASA Astrophysics Data System (ADS)

Weis, Franz A.; Ros, Linus; Reichart, Patrick; Skogby, Henrik; Kristiansson, Per; Dollinger, Günther

2018-02-01

Traditional methods to measure water in nominally anhydrous minerals (NAMs) are, for example, Fourier transformed infrared (FTIR) spectroscopy or secondary ion mass spectrometry (SIMS). Both well-established methods provide a low detection limit as well as high spatial resolution yet may require elaborate sample orientation or destructive sample preparation. Here we analyze the water content in erupted volcanic clinopyroxene phenocrysts by proton-proton scattering and reproduce water contents measured by FTIR spectroscopy. We show that this technique provides significant advantages over other methods as it can provide a three-dimensional distribution of hydrogen within a crystal, making the identification of potential inclusions possible as well as elimination of surface contamination. The sample analysis is also independent of crystal structure and orientation and independent of matrix effects other than sample density. The results are used to validate the accuracy of wavenumber-dependent vs. mineral-specific molar absorption coefficients in FTIR spectroscopy. In addition, we present a new method for the sample preparation of very thin crystals suitable for proton-proton scattering analysis using relatively low accelerator potentials.

Proton channel models

PubMed Central

Pupo, Amaury; Baez-Nieto, David; Martínez, Agustín; Latorre, Ramón; González, Carlos

2014-01-01

Voltage-gated proton channels are integral membrane proteins with the capacity to permeate elementary particles in a voltage and pH dependent manner. These proteins have been found in several species and are involved in various physiological processes. Although their primary topology is known, lack of details regarding their structures in the open conformation has limited analyses toward a deeper understanding of the molecular determinants of their function and regulation. Consequently, the function-structure relationships have been inferred based on homology models. In the present work, we review the existing proton channel models, their assumptions, predictions and the experimental facts that support them. Modeling proton channels is not a trivial task due to the lack of a close homolog template. Hence, there are important differences between published models. This work attempts to critically review existing proton channel models toward the aim of contributing to a better understanding of the structural features of these proteins. PMID:24755912

Voltage-gated Proton Channels

PubMed Central

DeCoursey, Thomas E.

2014-01-01

Voltage-gated proton channels, HV1, have vaulted from the realm of the esoteric into the forefront of a central question facing ion channel biophysicists, namely the mechanism by which voltage-dependent gating occurs. This transformation is the result of several factors. Identification of the gene in 2006 revealed that proton channels are homologues of the voltage-sensing domain of most other voltage-gated ion channels. Unique, or at least eccentric, properties of proton channels include dimeric architecture with dual conduction pathways, perfect proton selectivity, a single-channel conductance ~103 smaller than most ion channels, voltage-dependent gating that is strongly modulated by the pH gradient, ΔpH, and potent inhibition by Zn2+ (in many species) but an absence of other potent inhibitors. The recent identification of HV1 in three unicellular marine plankton species has dramatically expanded the phylogenetic family tree. Interest in proton channels in their own right has increased as important physiological roles have been identified in many cells. Proton channels trigger the bioluminescent flash of dinoflagellates, facilitate calcification by coccolithophores, regulate pH-dependent processes in eggs and sperm during fertilization, secrete acid to control the pH of airway fluids, facilitate histamine secretion by basophils, and play a signaling role in facilitating B-cell receptor mediated responses in B lymphocytes. The most elaborate and best-established functions occur in phagocytes, where proton channels optimize the activity of NADPH oxidase, an important producer of reactive oxygen species. Proton efflux mediated by HV1 balances the charge translocated across the membrane by electrons through NADPH oxidase, minimizes changes in cytoplasmic and phagosomal pH, limits osmotic swelling of the phagosome, and provides substrate H+ for the production of H2O2 and HOCl, reactive oxygen species crucial to killing pathogens. PMID:23798303

A Conserved Asparagine in a P-type Proton Pump Is Required for Efficient Gating of Protons*

PubMed Central

Ekberg, Kira; Wielandt, Alex G.; Buch-Pedersen, Morten J.; Palmgren, Michael G.

2013-01-01

The minimal proton pumping machinery of the Arabidopsis thaliana P-type plasma membrane H+-ATPase isoform 2 (AHA2) consists of an aspartate residue serving as key proton donor/acceptor (Asp-684) and an arginine residue controlling the pKa of the aspartate. However, other important aspects of the proton transport mechanism such as gating, and the ability to occlude protons, are still unclear. An asparagine residue (Asn-106) in transmembrane segment 2 of AHA2 is conserved in all P-type plasma membrane H+-ATPases. In the crystal structure of the plant plasma membrane H+-ATPase, this residue is located in the putative ligand entrance pathway, in close proximity to the central proton donor/acceptor Asp-684. Substitution of Asn-106 resulted in mutant enzymes with significantly reduced ability to transport protons against a membrane potential. Sensitivity toward orthovanadate was increased when Asn-106 was substituted with an aspartate residue, but decreased in mutants with alanine, lysine, glutamine, or threonine replacement of Asn-106. The apparent proton affinity was decreased for all mutants, most likely due to a perturbation of the local environment of Asp-684. Altogether, our results demonstrate that Asn-106 is important for closure of the proton entrance pathway prior to proton translocation across the membrane. PMID:23420846

A conserved asparagine in a P-type proton pump is required for efficient gating of protons.

PubMed

Ekberg, Kira; Wielandt, Alex G; Buch-Pedersen, Morten J; Palmgren, Michael G

2013-04-05

The minimal proton pumping machinery of the Arabidopsis thaliana P-type plasma membrane H(+)-ATPase isoform 2 (AHA2) consists of an aspartate residue serving as key proton donor/acceptor (Asp-684) and an arginine residue controlling the pKa of the aspartate. However, other important aspects of the proton transport mechanism such as gating, and the ability to occlude protons, are still unclear. An asparagine residue (Asn-106) in transmembrane segment 2 of AHA2 is conserved in all P-type plasma membrane H(+)-ATPases. In the crystal structure of the plant plasma membrane H(+)-ATPase, this residue is located in the putative ligand entrance pathway, in close proximity to the central proton donor/acceptor Asp-684. Substitution of Asn-106 resulted in mutant enzymes with significantly reduced ability to transport protons against a membrane potential. Sensitivity toward orthovanadate was increased when Asn-106 was substituted with an aspartate residue, but decreased in mutants with alanine, lysine, glutamine, or threonine replacement of Asn-106. The apparent proton affinity was decreased for all mutants, most likely due to a perturbation of the local environment of Asp-684. Altogether, our results demonstrate that Asn-106 is important for closure of the proton entrance pathway prior to proton translocation across the membrane.

Antiproton constraints on the GeV gamma-ray excess: a comprehensive analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cirelli, Marco; Giesen, Gaëlle; Taoso, Marco

2014-12-01

A GeV gamma-ray excess has possibly been individuated in Fermi-LAT data from the Galactic Center and interpreted in terms of Dark Matter (DM) annihilations, either in hadronic (essentially b b-bar ) or leptonic channels. In order to test this tantalizing interpretation, we address two issues: (i) we improve the computation of secondary emission from DM (Inverse Compton and Bremsstrahlung) with respect to previous works, confirming it to be very relevant for determining the DM spectrum in the leptonic channels, so that any conclusion on the DM nature of the signal critically depends on this contribution; (ii) we consider the constraintsmore » from antiprotons on the DM hadronic channel, finding that the uncertainties on the propagation model, and in particular on the halo height, play a major role. Moreover, we discuss the role of solar modulation, taking into account possible charge dependent effects whose importance is estimated exploiting detailed numerical tools. The limits that we obtain severely constrain the DM interpretation of the excess in the hadronic channel, for standard assumptions on the Galactic propagation parameters and solar modulation. However, they considerably relax if more conservative choices are adopted.« less

Antiproton-impact ionization of hydrogen atom with Yukawa interaction

NASA Astrophysics Data System (ADS)

Jakimovski, Dragan; Grozdanov, Tasko P.; Janev, Ratko K.

2018-01-01

The process of ionization of hydrogen atom by antiproton impact is studied when the interparticle interactions in the system are described by screened interactions of Yukawa type. The collision dynamics is described by the semiclassical atomic-orbital close-coupling method in which the bound atomic states and positive energy continuum pseudostates are determined by diagonalization of target Hamiltonian in a sufficiently large even-tempered basis to ensure convergence of the results at each value of the screening length λ of the interaction. With decreasing the screening length, the bound states in the Yukawa potential become unbound, thus increasing the number of continuum pseudostates. At low collision energies, this leads to the increase of the ionization cross section. It is observed that the energies of pseudostates, generated by the exit of nl bound states in the continuum, at certain critical values λ nl c exhibit series of avoided crossings when λ is varied. The avoided crossings appear between the ( n + k) l and ( n + k + 1) l ( n = 1, 2, 3, … ; k = 0, 1, 2, …) states at screening lengths close to the critical screening length λ nl c . The avoided crossings become increasingly less pronounced with increasing n, k and l. The matrix elements for the ( n + k) l - ( n + k + 1) l transitions at the avoided crossings λ x,(n+k)l (n+k+1)l exhibit maxima and are reflected in the structure of the cross sections for population of the lower nl pseudostates. These structures are, however, smeared out in the total ionization cross section.

Search for non-SM light Higgs Boson in the h $$\\to \\gamma \\gamma$$ channel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melnitchouk, Alexander Stepanovych

2004-05-01

We present first results on the search for Higgs Boson with an enhanced branching fraction into photons in the h → γγ decay channel using recent Run II data collected by the D0 detector at the Fermilab Tevatron proton-antiproton collider. We discuss event selection, backgrounds, analysis optimization, and the limits on the Higgs boson mass obtained in this analysis.

Proton-counting radiography for proton therapy: a proof of principle using CMOS APS technology

NASA Astrophysics Data System (ADS)

Poludniowski, G.; Allinson, N. M.; Anaxagoras, T.; Esposito, M.; Green, S.; Manolopoulos, S.; Nieto-Camero, J.; Parker, D. J.; Price, T.; Evans, P. M.

2014-06-01

Despite the early recognition of the potential of proton imaging to assist proton therapy (Cormack 1963 J. Appl. Phys. 34 2722), the modality is still removed from clinical practice, with various approaches in development. For proton-counting radiography applications such as computed tomography (CT), the water-equivalent-path-length that each proton has travelled through an imaged object must be inferred. Typically, scintillator-based technology has been used in various energy/range telescope designs. Here we propose a very different alternative of using radiation-hard CMOS active pixel sensor technology. The ability of such a sensor to resolve the passage of individual protons in a therapy beam has not been previously shown. Here, such capability is demonstrated using a 36 MeV cyclotron beam (University of Birmingham Cyclotron, Birmingham, UK) and a 200 MeV clinical radiotherapy beam (iThemba LABS, Cape Town, SA). The feasibility of tracking individual protons through multiple CMOS layers is also demonstrated using a two-layer stack of sensors. The chief advantages of this solution are the spatial discrimination of events intrinsic to pixelated sensors, combined with the potential provision of information on both the range and residual energy of a proton. The challenges in developing a practical system are discussed.

Proton-counting radiography for proton therapy: a proof of principle using CMOS APS technology

PubMed Central

Poludniowski, G; Allinson, N M; Anaxagoras, T; Esposito, M; Green, S; Manolopoulos, S; Nieto-Camero, J; Parker, D J; Price, T; Evans, P M

2014-01-01

Despite the early recognition of the potential of proton imaging to assist proton therapy the modality is still removed from clinical practice, with various approaches in development. For proton-counting radiography applications such as Computed Tomography (CT), the Water-Equivalent-Path-Length (WEPL) that each proton has travelled through an imaged object must be inferred. Typically, scintillator-based technology has been used in various energy/range telescope designs. Here we propose a very different alternative of using radiation-hard CMOS Active Pixel Sensor (APS) technology. The ability of such a sensor to resolve the passage of individual protons in a therapy beam has not been previously shown. Here, such capability is demonstrated using a 36 MeV cyclotron beam (University of Birmingham Cyclotron, Birmingham, UK) and a 200 MeV clinical radiotherapy beam (iThemba LABS, Cape Town, SA). The feasibility of tracking individual protons through multiple CMOS layers is also demonstrated using a two-layer stack of sensors. The chief advantages of this solution are the spatial discrimination of events intrinsic to pixelated sensors, combined with the potential provision of information on both the range and residual energy of a proton. The challenges in developing a practical system are discussed. PMID:24785680

Voltage-gated proton channel in a dinoflagellate

PubMed Central

Smith, Susan M. E.; Morgan, Deri; Musset, Boris; Cherny, Vladimir V.; Place, Allen R.; Hastings, J. Woodland; DeCoursey, Thomas E.

2011-01-01

Fogel and Hastings first hypothesized the existence of voltage-gated proton channels in 1972 in bioluminescent dinoflagellates, where they were thought to trigger the flash by activating luciferase. Proton channel genes were subsequently identified in human, mouse, and Ciona intestinalis, but their existence in dinoflagellates remained unconfirmed. We identified a candidate proton channel gene from a Karlodinium veneficum cDNA library based on homology with known proton channel genes. K. veneficum is a predatory, nonbioluminescent dinoflagellate that produces toxins responsible for fish kills worldwide. Patch clamp studies on the heterologously expressed gene confirm that it codes for a genuine voltage-gated proton channel, kHV1: it is proton-specific and activated by depolarization, its gH–V relationship shifts with changes in external or internal pH, and mutation of the selectivity filter (which we identify as Asp51) results in loss of proton-specific conduction. Indirect evidence suggests that kHV1 is monomeric, unlike other proton channels. Furthermore, kHV1 differs from all known proton channels in activating well negative to the Nernst potential for protons, EH. This unique voltage dependence makes the dinoflagellate proton channel ideally suited to mediate the proton influx postulated to trigger bioluminescence. In contrast to vertebrate proton channels, whose main function is acid extrusion, we propose that proton channels in dinoflagellates have fundamentally different functions of signaling and excitability. PMID:22006335

Maximum proton kinetic energy and patient-generated neutron fluence considerations in proton beam arc delivery radiation therapy.

PubMed

Sengbusch, E; Pérez-Andújar, A; DeLuca, P M; Mackie, T R

2009-02-01

Several compact proton accelerator systems for use in proton therapy have recently been proposed. Of paramount importance to the development of such an accelerator system is the maximum kinetic energy of protons, immediately prior to entry into the patient, that must be reached by the treatment system. The commonly used value for the maximum kinetic energy required for a medical proton accelerator is 250 MeV, but it has not been demonstrated that this energy is indeed necessary to treat all or most patients eligible for proton therapy. This article quantifies the maximum kinetic energy of protons, immediately prior to entry into the patient, necessary to treat a given percentage of patients with rotational proton therapy, and examines the impact of this energy threshold on the cost and feasibility of a compact, gantry-mounted proton accelerator treatment system. One hundred randomized treatment plans from patients treated with IMRT were analyzed. The maximum radiological pathlength from the surface of the patient to the distal edge of the treatment volume was obtained for 180 degrees continuous arc proton therapy and for 180 degrees split arc proton therapy (two 90 degrees arcs) using CT# profiles from the Pinnacle (Philips Medical Systems, Madison, WI) treatment planning system. In each case, the maximum kinetic energy of protons, immediately prior to entry into the patient, that would be necessary to treat the patient was calculated using proton range tables for various media. In addition, Monte Carlo simulations were performed to quantify neutron production in a water phantom representing a patient as a function of the maximum proton kinetic energy achievable by a proton treatment system. Protons with a kinetic energy of 240 MeV, immediately prior to entry into the patient, were needed to treat 100% of patients in this study. However, it was shown that 90% of patients could be treated at 198 MeV, and 95% of patients could be treated at 207 MeV. Decreasing the

Hardness assurance for proton direct ionization-induced SEEs using a high-energy proton beam

DOE PAGES

Dodds, Nathaniel Anson; Schwank, James R.; Shaneyfelt, Marty R.; ...

2014-11-06

The low-energy proton energy spectra of all shielded space environments have the same shape. This shape is easily reproduced in the laboratory by degrading a high-energy proton beam, producing a high-fidelity test environment. We use this test environment to dramatically simplify rate prediction for proton direct ionization effects, allowing the work to be done at high-energy proton facilities, on encapsulated parts, without knowledge of the IC design, and with little or no computer simulations required. Proton direct ionization (PDI) is predicted to significantly contribute to the total error rate under the conditions investigated. Scaling effects are discussed using data frommore » 65-nm, 45-nm, and 32-nm SOI SRAMs. These data also show that grazing-angle protons will dominate the PDI-induced error rate due to their higher effective LET, so PDI hardness assurance methods must account for angular effects to be conservative. As a result, we show that this angular dependence can be exploited to quickly assess whether an IC is susceptible to PDI.« less

Energy and Mass-Number Dependence of Hadron-Nucleus Total Reaction Cross Sections

NASA Astrophysics Data System (ADS)

Kohama, Akihisa; Iida, Kei; Oyamatsu, Kazuhiro

2016-09-01

We thoroughly investigate how proton-nucleus total reaction cross sections depend on the target mass number A and the proton incident energy. In doing so, we systematically analyze nuclear reaction data that are sensitive to nuclear size, namely, proton-nucleus total reaction cross sections and differential elastic cross sections, using a phenomenological black-sphere approximation of nuclei that we are developing. In this framework, the radius of the black sphere is found to be a useful length scale that simultaneously accounts for the observed proton-nucleus total reaction cross section and first diffraction peak in the proton elastic differential cross section. This framework, which is shown here to be applicable to antiprotons, is expected to be applicable to any kind of projectile that is strongly attenuated in the nucleus. On the basis of a cross-section formula constructed within this framework, we find that a less familiar A1/6 dependence plays a crucial role in describing the energy dependence of proton-nucleus total reaction cross sections.

Eta Meson Production in Proton-Proton and Nuclear Collisions

NASA Technical Reports Server (NTRS)

Norbury, John W.; Dick, Frank

2008-01-01

Total cross sections for eta meson production in proton - proton collisions are calculated. The eta meson is mainly produced via decay of the excited nucleon resonance at 1535 MeV. A scalar quantum field theory is used to calculate cross sections, which also include resonance decay. Comparison between theory and experiment is problematic near threshold when resonance decay is not included. When the decay is included, the comparison between theory and experiment is much better.

Modeling and optimization of a time-resolved proton radiographic imaging system for proton cancer treatment

NASA Astrophysics Data System (ADS)

Han, Bin

This dissertation describes a research project to test the clinical utility of a time-resolved proton radiographic (TRPR) imaging system by performing comprehensive Monte Carlo simulations of a physical device coupled with realistic lung cancer patient anatomy defined by 4DCT for proton therapy. A time-resolved proton radiographic imaging system was modeled through Monte Carlo simulations. A particle-tracking feature was employed to evaluate the performance of the proton imaging system, especially in its ability to visualize and quantify proton range variations during respiration. The Most Likely Path (MLP) algorithm was developed to approximate the multiple Coulomb scattering paths of protons for the purpose of image reconstruction. Spatial resolution of ˜ 1 mm and range resolution of 1.3% of the total range were achieved using the MLP algorithm. Time-resolved proton radiographs of five patient cases were reconstructed to track tumor motion and to calculate water equivalent length variations. By comparing with direct 4DCT measurement, the accuracy of tumor tracking was found to be better than 2 mm in five patient cases. Utilizing tumor tracking information to reduce margins to the planning target volume, a gated treatment plan was compared with un-gated treatment plan. The equivalent uniform dose (EUD) and the normal tissue complication probability (NTCP) were used to quantify the gain in the quality of treatments. The EUD of the OARs was found to be reduced up to 11% and the corresponding NTCP of organs at risk (OARs) was found to be reduced up to 16.5%. These results suggest that, with image guidance by proton radiography, dose to OARs can be reduced and the corresponding NTCPs can be significantly reduced. The study concludes that the proton imaging system can accurately track the motion of the tumor and detect the WEL variations, leading to potential gains in using image-guided proton radiography for lung cancer treatments.

Proton Translocation in Cytochrome c Oxidase: Insights from Proton Exchange Kinetics and Vibrational Spectroscopy

PubMed Central

Ishigami, Izumi; Hikita, Masahide; Egawa, Tsuyoshi; Yeh, Syun-Ru; Rousseau, Denis L.

2014-01-01

Cytochrome c oxidase is the terminal enzyme in the electron transfer chain. It reduces oxygen to water and harnesses the released energy to translocate protons across the inner mitochondrial membrane. The mechanism by which the oxygen chemistry is coupled to proton translocation is not yet resolved owing to the difficulty of monitoring dynamic proton transfer events. Here we summarize several postulated mechanisms for proton translocation, which have been supported by a variety of vibrational spectroscopic studies. We recently proposed a proton translocation model involving proton accessibility to the regions near the propionate groups of the heme a and heme a3 redox centers of the enzyme based by hydrogen/deuterium (H/D) exchange Raman scattering studies (Egawa et al., PLOS ONE 2013). To advance our understanding of this model and to refine the proton accessibility to the hemes, the H/D exchange dependence of the heme propionate group vibrational modes on temperature and pH was measured. The H/D exchange detected at the propionate groups of heme a3 takes place within a few seconds under all conditions. In contrast, that detected at the heme a propionates occurs in the oxidized but not the reduced enzyme and the H/D exchange is pH-dependent with a pKa of ~8.0 (faster at high pH). Analysis of the thermodynamic parameters revealed that, as the pH is varied, entropy/enthalpy compensation held the free energy of activation in a narrow range. The redox dependence of the possible proton pathways to the heme groups is discussed. PMID:25268561

Activation of acid-sensing ion channels by localized proton transient reveals their role in proton signaling.

PubMed

Zeng, Wei-Zheng; Liu, Di-Shi; Liu, Lu; She, Liang; Wu, Long-Jun; Xu, Tian-Le

2015-09-15

Extracellular transients of pH alterations likely mediate signal transduction in the nervous system. Neuronal acid-sensing ion channels (ASICs) act as sensors for extracellular protons, but the mechanism underlying ASIC activation remains largely unknown. Here, we show that, following activation of a light-activated proton pump, Archaerhodopsin-3 (Arch), proton transients induced ASIC currents in both neurons and HEK293T cells co-expressing ASIC1a channels. Using chimera proteins that bridge Arch and ASIC1a by a glycine/serine linker, we found that successful coupling occurred within 15 nm distance. Furthermore, two-cell sniffer patch recording revealed that regulated release of protons through either Arch or voltage-gated proton channel Hv1 activated neighbouring cells expressing ASIC1a channels. Finally, computational modelling predicted the peak proton concentration at the intercellular interface to be at pH 6.7, which is acidic enough to activate ASICs in vivo. Our results highlight the pathophysiological role of proton signalling in the nervous system.

Parameterized Cross Sections for Pion Production in Proton-Proton Collisions

NASA Technical Reports Server (NTRS)

Blattnig, Steve R.; Swaminathan, Sudha R.; Kruger, Adam T.; Ngom, Moussa; Norbury, John W.; Tripathi, R. K.

2000-01-01

An accurate knowledge of cross sections for pion production in proton-proton collisions finds wide application in particle physics, astrophysics, cosmic ray physics, and space radiation problems, especially in situations where an incident proton is transported through some medium and knowledge of the output particle spectrum is required when given the input spectrum. In these cases, accurate parameterizations of the cross sections are desired. In this paper much of the experimental data are reviewed and compared with a wide variety of different cross section parameterizations. Therefore, parameterizations of neutral and charged pion cross sections are provided that give a very accurate description of the experimental data. Lorentz invariant differential cross sections, spectral distributions, and total cross section parameterizations are presented.

Proton Therapy Verification with PET Imaging

PubMed Central

Zhu, Xuping; Fakhri, Georges El

2013-01-01

Proton therapy is very sensitive to uncertainties introduced during treatment planning and dose delivery. PET imaging of proton induced positron emitter distributions is the only practical approach for in vivo, in situ verification of proton therapy. This article reviews the current status of proton therapy verification with PET imaging. The different data detecting systems (in-beam, in-room and off-line PET), calculation methods for the prediction of proton induced PET activity distributions, and approaches for data evaluation are discussed. PMID:24312147

A determination of the fragmentation functions of pions, kaons, and protons with faithful uncertainties. The NNPDF Collaboration

NASA Astrophysics Data System (ADS)

Bertone, Valerio; Carrazza, Stefano; Hartland, Nathan P.; Nocera, Emanuele R.; Rojo, Juan

2017-08-01

We present NNFF1.0, a new determination of the fragmentation functions (FFs) of charged pions, charged kaons, and protons/antiprotons from an analysis of single-inclusive hadron production data in electron-positron annihilation. This determination, performed at leading, next-to-leading, and next-to-next-to-leading order in perturbative QCD, is based on the NNPDF methodology, a fitting framework designed to provide a statistically sound representation of FF uncertainties and to minimise any procedural bias. We discuss novel aspects of the methodology used in this analysis, namely an optimised parametrisation of FFs and a more efficient χ ^2 minimisation strategy, and validate the FF fitting procedure by means of closure tests. We then present the NNFF1.0 sets, and discuss their fit quality, their perturbative convergence, and their stability upon variations of the kinematic cuts and the fitted dataset. We find that the systematic inclusion of higher-order QCD corrections significantly improves the description of the data, especially in the small- z region. We compare the NNFF1.0 sets to other recent sets of FFs, finding in general a reasonable agreement, but also important differences. Together with existing sets of unpolarised and polarised parton distribution functions (PDFs), FFs and PDFs are now available from a common fitting framework for the first time.

Optimum designs for superpressure balloons

NASA Astrophysics Data System (ADS)

Smith, M. S.; Rainwater, E. L.

2004-01-01

The elastica shape is now well known to be the best basic shape for superpressure balloon design. This shape, also known as the pumpkin, or natural shape for balloons, has been well understood since the early 1900s when it was applied to the determination of the shape of descending parachutes. The elastica shape was also investigated in the 1950s when high strength films were used to produce superpressure cylinder balloons. The need for uniform stress distribution in shells of early superpressure balloons led to a long period of the development of spherical superpressure balloons. Not until the late 1970s was the elastica shape revisited for the purpose of the producing superpressure balloons. This paper will review various development efforts in the field of superpressure design and will elaborate on the current state-of-the-art with suggestions for future developments.

Recent results from the ARGO-YBJ experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Camarri, P.

2010-03-26

The ARGO-YBJ experiment at YangBaJing in Tibet (4300 m a.s.l.) has been taking data with its full layout since October 2007. Here we present the first significant results obtained in gamma-ray astronomy and cosmic-ray physics. Emphasis is placed on the analysis of gamma-ray emission from point-like sources (Crab Nebula, MRK 421), on the preliminary limit on the antiproton/proton flux ratio, on the large-scale cosmic-ray anisotropy and on the proton-air cross section. The performance of the detector is also discussed, and the perspectives of the experiment are outlined.

Triple Parton Scatterings in High-Energy Proton-Proton Collisions

NASA Astrophysics Data System (ADS)

d'Enterria, David; Snigirev, Alexander M.

2017-03-01

A generic expression to compute triple parton scattering cross sections in high-energy proton-proton (p p ) collisions is presented as a function of the corresponding single parton cross sections and the transverse parton profile of the proton encoded in an effective parameter σeff,TPS . The value of σeff,TPS is closely related to the similar effective cross section that characterizes double parton scatterings, and amounts to σeff,TPS=12.5 ±4.5 mb . Estimates for triple charm (c c ¯) and bottom (b b ¯) production in p p collisions at LHC and FCC energies are presented based on next-to-next-to-leading-order perturbative calculations for single c c ¯ , b b ¯ cross sections. At √{s }≈100 TeV , about 15% of the p p collisions produce three c c ¯ pairs from three different parton-parton scatterings.

Triple Parton Scatterings in High-Energy Proton-Proton Collisions.

PubMed

d'Enterria, David; Snigirev, Alexander M

2017-03-24

A generic expression to compute triple parton scattering cross sections in high-energy proton-proton (pp) collisions is presented as a function of the corresponding single parton cross sections and the transverse parton profile of the proton encoded in an effective parameter σ_{eff,TPS}. The value of σ_{eff,TPS} is closely related to the similar effective cross section that characterizes double parton scatterings, and amounts to σ_{eff,TPS}=12.5±4.5  mb. Estimates for triple charm (cc[over ¯]) and bottom (bb[over ¯]) production in pp collisions at LHC and FCC energies are presented based on next-to-next-to-leading-order perturbative calculations for single cc[over ¯], bb[over ¯] cross sections. At sqrt[s]≈100  TeV, about 15% of the pp collisions produce three cc[over ¯] pairs from three different parton-parton scatterings.

Transverse relaxation of scalar-coupled protons.

PubMed

Segawa, Takuya F; Baishya, Bikash; Bodenhausen, Geoffrey

2010-10-25

In a preliminary communication (B. Baishya, T. F. Segawa, G. Bodenhausen, J. Am. Chem. Soc. 2009, 131, 17538-17539), we recently demonstrated that it is possible to obtain clean echo decays of protons in biomolecules despite the presence of homonuclear scalar couplings. These unmodulated decays allow one to determine apparent transverse relaxation rates R(2) (app) of individual protons. Herein, we report the observation of R(2) (app) for three methyl protons, four amide H(N) protons, and all 11 backbone H(α) protons in cyclosporin A. If the proton resonances overlap, their R(2) (app) rates can be measured by transferring their magnetization to neighboring (13)C nuclei, which are less prone to overlap. The R(2) (app) rates of protons attached to (13)C are faster than those attached to (12)C because of (13)C-(1)H dipolar interactions. The differences of these rates allow the determination of local correlation functions. Backbone H(N) and H(α) protons that have fast decay rates R(2) (app) also feature fast longitudinal relaxation rates R(1) and intense NOESY cross peaks that are typical of crowded environments. Variations of R(2) (app) rates of backbone H(α) protons in similar amino acids reflect differences in local environments.

Proton Upset Monte Carlo Simulation

NASA Technical Reports Server (NTRS)

O'Neill, Patrick M.; Kouba, Coy K.; Foster, Charles C.

2009-01-01

The Proton Upset Monte Carlo Simulation (PROPSET) program calculates the frequency of on-orbit upsets in computer chips (for given orbits such as Low Earth Orbit, Lunar Orbit, and the like) from proton bombardment based on the results of heavy ion testing alone. The software simulates the bombardment of modern microelectronic components (computer chips) with high-energy (.200 MeV) protons. The nuclear interaction of the proton with the silicon of the chip is modeled and nuclear fragments from this interaction are tracked using Monte Carlo techniques to produce statistically accurate predictions.

Monte Carlo simulations for the shielding of the future high-intensity accelerator facility FAIR at GSI.

PubMed

Radon, T; Gutermuth, F; Fehrenbacher, G

2005-01-01

The Gesellschaft für Schwerionenforschung (GSI) is planning a significant expansion of its accelerator facilities. Compared to the present GSI facility, a factor of 100 in primary beam intensities and up to a factor of 10,000 in secondary radioactive beam intensities are key technical goals of the proposal. The second branch of the so-called Facility for Antiproton and Ion Research (FAIR) is the production of antiprotons and their storage in rings and traps. The facility will provide beam energies a factor of approximately 15 higher than presently available at the GSI for all ions, from protons to uranium. The shielding design of the synchrotron SIS 100/300 is shown exemplarily by using Monte Carlo calculations with the FLUKA code. The experimental area serving the investigation of compressed baryonic matter is analysed in the same way. In addition, a dose comparison is made for an experimental area operated with medium energy heavy-ion beams. Here, Monte Carlo calculations are performed by using either heavy-ion primary particles or proton beams with intensities scaled by the mass number of the corresponding heavy-ion beam.

Proton transport through aqueous Nafion membrane

NASA Astrophysics Data System (ADS)

Son, D. N.; Kasai, H.

2009-08-01

We introduce a new model for proton transport through a single proton-conducting channel of an aqueous Nafion membrane based on a mechanism in which protons move under electrostatic effect provided by the sulfonate ( SO3 -groups of the Nafion side chains, the spin effect of active components, the hydrogen bonding effect with water molecules, and the screening effect of water media. This model can describe the proton transport within various levels of humidification ranging from the low humidity to the high humidity as a function of operating temperature. At low humidity, this model approaches to the so-called surface mechanism, while at high humidity, it approaches the well-known Grotthuss one. Proton motion is considered as the transfer from cluster to cluster under a potential energy. A proton-proton interaction is comprised in the calculation. Using Green function method, we obtained the proton current as a function of the Nafion membrane temperature. We found that the lower the temperature, the higher the proton current transfer through the Nafion membrane in low temperatures compared to the critical point 10K, which separates magnetic regime from non-magnetic regime. The increasing of proton current at very low temperatures is attributed to the spin effect. As the membrane temperature is higher than 40 ° C , the decreasing of proton current is attributed to the loss of water uptake and the polymer contraction. The results of this study are qualitatively in good agreement with experiments. The expression for the critical temperature is also presented as a function of structural and tunable parameters, and interpreted by experimental data. in here

Protonated sugars: vibrational spectroscopy and conformational structure of protonated O-methyl α-D-galactopyranoside

NASA Astrophysics Data System (ADS)

Rudić, Svemir; Xie, Hong-bin; Gerber, R. Benny; Simons, John P.

2012-08-01

'Bridging' protons provide a common structural motif in biological assemblies such as proton wires and proton-bound dimers. Here we present a 'proof-of-principle' computational and vibrational spectroscopic investigation of an 'intra-molecular proton-bound dimer,' O-methyl α-D-galactopyranoside (αMeGal-H+), generated in the gas phase through photo-ionisation of its complex with phenol in a molecular beam. Its vibrational spectrum corresponds well with a classical molecular dynamics simulation conducted 'on-the-fly' and also with the lowest-energy structures predicted by DFT and ab initio calculations. They reveal proton-bound structures that bridge neighbouring pairs of oxygen atoms, preferentially O6 and O4, linked together within the carbohydrate scaffold. Motivated by the possibility of an entry into the microscopic mechanism of its acid (or enzyme)-catalysed hydrolysis, we also report the corresponding predictions for its singly hydrated complex.

Proton affinity determinations and proton-bound dimer structure indications in C2 to C15, (alpha),(omega)-alkyldiamines

NASA Technical Reports Server (NTRS)

Karpas, Z.; Harden, C. S.; Smith, P. B. W.

1995-01-01

The 'kinetic method' was used to determine the proton affinity (PA) of a,coalkyldiamines from collision induced dissociation (CID) studies of protonated heterodimers. These PA values were consistently lower than those reported in the proton affinity scale. The apparent discrepancy was rationalized in terms of differences in the conformation of the protonated diamine monomers. The minimum energy species, formed by equilibrium proton transfer processes, have a cyclic conformation and the ion charge is shared by both amino-groups which are bridged by the proton. On the other hand, the species formed through dissociation of protonated dimers have a linear structure and the charge is localized on one of the amino-groups. Thus, the difference in the PA values obtained by both methods is a measure of the additional stability acquired by the protonated diamines through cyclization and charge delocalization. The major collision dissociation pathway of the protonated diamine monomers involved elimination of an ammonia moiety. Other reactions observed included loss of the second amino-group and several other bond cleavages. CID of the protonated dimers involved primarily formation of a protonated monomer through cleavage of the weaker hydrogen bond and subsequently loss of ammonia at higher collision energies. As observed from the CID studies, doubly charged ions were also formed from the diamines under conditions of the electrospray ionization.

Apparatus for proton radiography

DOEpatents

Martin, Ronald L.

1976-01-01

An apparatus for effecting diagnostic proton radiography of patients in hospitals comprises a source of negative hydrogen ions, a synchrotron for accelerating the negative hydrogen ions to a predetermined energy, a plurality of stations for stripping extraction of a radiography beam of protons, means for sweeping the extracted beam to cover a target, and means for measuring the residual range, residual energy, or percentage transmission of protons that pass through the target. The combination of information identifying the position of the beam with information about particles traversing the subject and the back absorber is performed with the aid of a computer to provide a proton radiograph of the subject. In an alternate embodiment of the invention, a back absorber comprises a plurality of scintillators which are coupled to detectors.

Activation of acid-sensing ion channels by localized proton transient reveals their role in proton signaling

PubMed Central

Zeng, Wei-Zheng; Liu, Di-Shi; Liu, Lu; She, Liang; Wu, Long-Jun; Xu, Tian-Le

2015-01-01

Extracellular transients of pH alterations likely mediate signal transduction in the nervous system. Neuronal acid-sensing ion channels (ASICs) act as sensors for extracellular protons, but the mechanism underlying ASIC activation remains largely unknown. Here, we show that, following activation of a light-activated proton pump, Archaerhodopsin-3 (Arch), proton transients induced ASIC currents in both neurons and HEK293T cells co-expressing ASIC1a channels. Using chimera proteins that bridge Arch and ASIC1a by a glycine/serine linker, we found that successful coupling occurred within 15 nm distance. Furthermore, two-cell sniffer patch recording revealed that regulated release of protons through either Arch or voltage-gated proton channel Hv1 activated neighbouring cells expressing ASIC1a channels. Finally, computational modelling predicted the peak proton concentration at the intercellular interface to be at pH 6.7, which is acidic enough to activate ASICs in vivo. Our results highlight the pathophysiological role of proton signalling in the nervous system. PMID:26370138

Proton trapping in yttrium-doped barium zirconate

NASA Astrophysics Data System (ADS)

Yamazaki, Yoshihiro; Blanc, Frédéric; Okuyama, Yuji; Buannic, Lucienne; Lucio-Vega, Juan C.; Grey, Clare P.; Haile, Sossina M.

2013-07-01

The environmental benefits of fuel cells have been increasingly appreciated in recent years. Among candidate electrolytes for solid-oxide fuel cells, yttrium-doped barium zirconate has garnered attention because of its high proton conductivity, particularly in the intermediate-temperature region targeted for cost-effective solid-oxide fuel cell operation, and its excellent chemical stability. However, fundamental questions surrounding the defect chemistry and macroscopic proton transport mechanism of this material remain, especially in regard to the possible role of proton trapping. Here we show, through a combined thermogravimetric and a.c. impedance study, that macroscopic proton transport in yttrium-doped barium zirconate is limited by proton-dopant association (proton trapping). Protons must overcome the association energy, 29 kJ mol-1, as well as the general activation energy, 16 kJ mol-1, to achieve long-range transport. Proton nuclear magnetic resonance studies show the presence of two types of proton environment above room temperature, reflecting differences in proton-dopant configurations. This insight motivates efforts to identify suitable alternative dopants with reduced association energies as a route to higher conductivities.

Proton trapping in yttrium-doped barium zirconate.

PubMed

Yamazaki, Yoshihiro; Blanc, Frédéric; Okuyama, Yuji; Buannic, Lucienne; Lucio-Vega, Juan C; Grey, Clare P; Haile, Sossina M

2013-07-01

The environmental benefits of fuel cells have been increasingly appreciated in recent years. Among candidate electrolytes for solid-oxide fuel cells, yttrium-doped barium zirconate has garnered attention because of its high proton conductivity, particularly in the intermediate-temperature region targeted for cost-effective solid-oxide fuel cell operation, and its excellent chemical stability. However, fundamental questions surrounding the defect chemistry and macroscopic proton transport mechanism of this material remain, especially in regard to the possible role of proton trapping. Here we show, through a combined thermogravimetric and a.c. impedance study, that macroscopic proton transport in yttrium-doped barium zirconate is limited by proton-dopant association (proton trapping). Protons must overcome the association energy, 29 kJ mol(-1), as well as the general activation energy, 16 kJ mol(-1), to achieve long-range transport. Proton nuclear magnetic resonance studies show the presence of two types of proton environment above room temperature, reflecting differences in proton-dopant configurations. This insight motivates efforts to identify suitable alternative dopants with reduced association energies as a route to higher conductivities.

Perfluoroalkyl phosphonic and phosphinic acids as proton conductors for anhydrous proton-exchange membranes.

PubMed

Herath, Mahesha B; Creager, Stephen E; Kitaygorodskiy, Alex; DesMarteau, Darryl D

2010-09-10

A study of proton-transport rates and mechanisms under anhydrous conditions using a series of acid model compounds, analogous to comb-branch perfluorinated ionomers functionalized with phosphonic, phosphinic, sulfonic, and carboxylic acid protogenic groups, is reported. Model compounds are characterized with respect to proton conductivity, viscosity, proton, and anion (conjugate base) self-diffusion coefficients, and Hammett acidity. The highest conductivities, and also the highest viscosities, are observed for the phosphonic and phosphinic acid model compounds. Arrhenius analysis of conductivity and viscosity for these two acids reveals much lower activation energies for ion transport than for viscous flow. Additionally, the proton self-diffusion coefficients are much higher than the conjugate-base self-diffusion coefficients for these two acids. Taken together, these data suggest that anhydrous proton transport in the phosphonic and phosphinic acid model compounds occurs primarily by a structure-diffusion, hopping-based mechanism rather than a vehicle mechanism. Further analysis of ionic conductivity and ion self-diffusion rates by using the Nernst-Einstein equation reveals that the phosphonic and phosphinic acid model compounds are relatively highly dissociated even under anhydrous conditions. In contrast, sulfonic and carboxylic acid-based systems exhibit relatively low degrees of dissociation under anhydrous conditions. These findings suggest that fluoroalkyl phosphonic and phosphinic acids are good candidates for further development as anhydrous, high-temperature proton conductors.

Compelling evidence for Lucky Survivor and gas phase protonation: the unified MALDI analyte protonation mechanism.

PubMed

Jaskolla, Thorsten W; Karas, Michael

2011-06-01

This work experimentally verifies and proves the two long since postulated matrix-assisted laser desorption/ionization (MALDI) analyte protonation pathways known as the Lucky Survivor and the gas phase protonation model. Experimental differentiation between the predicted mechanisms becomes possible by the use of deuterated matrix esters as MALDI matrices, which are stable under typical sample preparation conditions and generate deuteronated reagent ions, including the deuterated and deuteronated free matrix acid, only upon laser irradiation in the MALDI process. While the generation of deuteronated analyte ions proves the gas phase protonation model, the detection of protonated analytes by application of deuterated matrix compounds without acidic hydrogens proves the survival of analytes precharged from solution in accordance with the predictions from the Lucky Survivor model. The observed ratio of the two analyte ionization processes depends on the applied experimental parameters as well as the nature of analyte and matrix. Increasing laser fluences and lower matrix proton affinities favor gas phase protonation, whereas more quantitative analyte protonation in solution and intramolecular ion stabilization leads to more Lucky Survivors. The presented results allow for a deeper understanding of the fundamental processes causing analyte ionization in MALDI and may alleviate future efforts for increasing the analyte ion yield.

WE-D-BRB-00: Basics of Proton Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The goal of this session is to review the physics of proton therapy, treatment planning techniques, and the use of volumetric imaging in proton therapy. The course material covers the physics of proton interaction with matter and physical characteristics of clinical proton beams. It will provide information on proton delivery systems and beam delivery techniques for double scattering (DS), uniform scanning (US), and pencil beam scanning (PBS). The session covers the treatment planning strategies used in DS, US, and PBS for various anatomical sites, methods to address uncertainties in proton therapy and uncertainty mitigation to generate robust treatment plans. Itmore » introduces the audience to the current status of image guided proton therapy and clinical applications of CBCT for proton therapy. It outlines the importance of volumetric imaging in proton therapy. Learning Objectives: Gain knowledge in proton therapy physics, and treatment planning for proton therapy including intensity modulated proton therapy. The current state of volumetric image guidance equipment in proton therapy. Clinical applications of CBCT and its advantage over orthogonal imaging for proton therapy. B. Teo, B.K Teo had received travel funds from IBA in 2015.« less

Bare Proton Contribution to the d / u Ratio in the Proton Sea

NASA Astrophysics Data System (ADS)

Fish, Aaron

2017-09-01

From perturbative processes, such as gluon splitting, we expect there to be symmetric distributions of d and u partons in the proton. partons in the proton. However, experiment has shown an excess of d over u . This has been qualitatively explained by the Meson Cloud Model (MCM), in which the non-perturbative processes of proton fluctuations into meson-baryon pairs, allowed by the Heisenberg uncertainty principle, create the flavor asymmetry. The x dependence of d and u in the nucleon sea is determined from a convolution of meson-baryon splitting functions and the parton distribution functions (pdfs) of the mesons and baryons in the cloud, as well as a contribution from the leading term in the MCM, the ``bare proton.'' We use a statistical model to calculate pdfs for the hadrons in the cloud, but modify the model for the bare proton in order to avoid double counting. We evolved our distributions in Q2 for comparison to experimental data from the Fermilab E866/NuSea experiment. We present predictions for the d / u ratio that is currently being examined by Fermilab's SeaQuest experiment, E906. This work is supported in part by the National Science Foundation under Grant No.1516105.

Simon van der Meer (1925-2011):. A Modest Genius of Accelerator Science

NASA Astrophysics Data System (ADS)

Chohan, Vinod C.

2011-02-01

Simon van der Meer was a brilliant scientist and a true giant of accelerator science. His seminal contributions to accelerator science have been essential to this day in our quest for satisfying the demands of modern particle physics. Whether we talk of long base-line neutrino physics or antiproton-proton physics at Fermilab or proton-proton physics at LHC, his techniques and inventions have been a vital part of the modern day successes. Simon van der Meer and Carlo Rubbia were the first CERN scientists to become Nobel laureates in Physics, in 1984. Van der Meer's lesserknown contributions spanned a whole range of subjects in accelerator science, from magnet design to power supply design, beam measurements, slow beam extraction, sophisticated programs and controls.

Measurement of the difference in CP-violating asymmetries in D(0)→K(+)K(-) and D(0)→π(+)π(-) decays at CDF.

PubMed

Aaltonen, T; Álvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Auerbach, B; Aurisano, A; Azfar, F; Badgett, W; Bae, T; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartos, P; Bauce, M; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Bhatti, A; Bisello, D; Bizjak, I; Bland, K R; Blumenfeld, B; Bocci, A; Bodek, A; Bortoletto, D; Boudreau, J; Boveia, A; Brigliadori, L; Bromberg, C; Brucken, E; Budagov, J; Budd, H S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Calamba, A; Calancha, C; Camarda, S; Campanelli, M; Campbell, M; Canelli, F; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chung, W H; Chung, Y S; Ciocci, M A; Clark, A; Clarke, C; Compostella, G; Convery, M E; Conway, J; Corbo, M; Cordelli, M; Cox, C A; Cox, D J; Crescioli, F; Cuevas, J; Culbertson, R; Dagenhart, D; d'Ascenzo, N; Datta, M; de Barbaro, P; Dell'Orso, M; Demortier, L; Deninno, M; Devoto, F; d'Errico, M; Di Canto, A; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Dorigo, M; Dorigo, T; Ebina, K; Elagin, A; Eppig, A; Erbacher, R; Errede, S; Ershaidat, N; Eusebi, R; Farrington, S; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Funakoshi, Y; Furic, I; Gallinaro, M; Garcia, J E; Garfinkel, A F; Garosi, P; Gerberich, H; Gerchtein, E; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Ginsburg, C M; Giokaris, N; Giromini, P; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldin, D; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Grinstein, S; Grosso-Pilcher, C; Group, R C; Guimaraes da Costa, J; Hahn, S R; Halkiadakis, E; Hamaguchi, A; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harr, R F; Hatakeyama, K; Hays, C; Heck, M; Heinrich, J; Herndon, M; Hewamanage, S; Hocker, A; Hopkins, W; Horn, D; Hou, S; Hughes, R E; Hurwitz, M; Husemann, U; Hussain, N; Hussein, M; Huston, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kamon, T; Karchin, P E; Kasmi, A; Kato, Y; Ketchum, W; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kim, Y J; Kimura, N; Kirby, M; Klimenko, S; Knoepfel, K; Kondo, K; Kong, D J; Konigsberg, J; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Kruse, M; Krutelyov, V; Kuhr, T; Kurata, M; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; LeCompte, T; Lee, E; Lee, H S; Lee, J S; Lee, S W; Leo, S; Leone, S; Lewis, J D; Limosani, A; Lin, C-J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, H; Liu, Q; Liu, T; Lockwitz, S; Loginov, A; Lucchesi, D; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lys, J; Lysak, R; Madrak, R; Maeshima, K; Maestro, P; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Martínez, M; Mastrandrea, P; Matera, K; Mattson, M E; Mazzacane, A; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Mesropian, C; Miao, T; Mietlicki, D; Mitra, A; Miyake, H; Moed, S; Moggi, N; Mondragon, M N; Moon, C S; Moore, R; Morello, M J; Morlock, J; Movilla Fernandez, P; Mukherjee, A; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nakano, I; Napier, A; Nett, J; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Noh, S Y; Norniella, O; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Ortolan, L; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pilot, J; Pitts, K; Plager, C; Pondrom, L; Poprocki, S; Potamianos, K; Prokoshin, F; Pranko, A; Ptohos, F; Punzi, G; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Renton, P; Rescigno, M; Riddick, T; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Ruffini, F; Ruiz, A; Russ, J; Rusu, V; Safonov, A; Sakumoto, W K; Sakurai, Y; Santi, L; Sato, K; Saveliev, V; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Seidel, S; Seiya, Y; Semenov, A; Sforza, F; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shochet, M; Shreyber-Tecker, I; Simonenko, A; Sinervo, P; Sliwa, K; Smith, J R; Snider, F D; Soha, A; Sorin, V; Song, H; Squillacioti, P; Stancari, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Sudo, Y; Sukhanov, A; Suslov, I; Takemasa, K; Takeuchi, Y; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thome, J; Thompson, G A; Thomson, E; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Trovato, M; Ukegawa, F; Uozumi, S; Varganov, A; Vázquez, F; Velev, G; Vellidis, C; Vidal, M; Vila, I; Vilar, R; Vizán, J; Vogel, M; Volpi, G; Wagner, P; Wagner, R L; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Wester, W C; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Wick, F; Williams, H H; Wilson, J S; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, H; Wright, T; Wu, X; Wu, Z; Yamamoto, K; Yamato, D; Yang, T; Yang, U K; Yang, Y C; Yao, W-M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanetti, A; Zeng, Y; Zhou, C; Zucchelli, S

2012-09-14

We report a measurement of the difference (ΔA(CP)) between time-integrated CP-violating asymmetries in D(0)→K(+)K(-) and D(0)→π(+)π(-) decays reconstructed in the full data set of proton-antiproton collisions collected by the Collider Detector at Fermilab, corresponding to 9.7  fb(-1) of integrated luminosity. The strong decay D(*+)→D(0)π(+) is used to identify the charm meson at production as D(0) or D[over ¯](0). We measure ΔA(CP)=[-0.62±0.21(stat)±0.10(syst)]%, which differs from zero by 2.7 Gaussian standard deviations. This result supports similar evidence for CP violation in charm-quark decays obtained in proton-proton collisions.

Tevatron Top-Quark Combinations and World Top-Quark Mass Combination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, Reinhild Yvonne

2014-11-04

Almost 20 years after its discovery, the top quark is still an interesting particle, undergoing precise investigation of its properties. For many years, the Tevatron proton antiproton collider at Fermilab was the only place to study top quarks in detail, while with the recent start of the LHC proton proton collider a top quark factory has opened. An important ingredient for the full understanding of the top quark is the combination of measurements from the individual experiments. In particular, the Tevaton combinations of single top-quark cross sections, the ttbar production cross section, the W helicity in top-quark decays as wellmore » as the Tevatron and the world combination of the top-quark mass are discussed.« less

Deformation of the proton emitter 113Cs from electromagnetic transition and proton-emission rates

NASA Astrophysics Data System (ADS)

Hodge, D.; Cullen, D. M.; Taylor, M. J.; Nara Singh, B. S.; Ferreira, L. S.; Maglione, E.; Smith, J. F.; Scholey, C.; Rahkila, P.; Grahn, T.; Braunroth, T.; Badran, H.; Capponi, L.; Girka, A.; Greenlees, P. T.; Julin, R.; Konki, J.; Mallaburn, M.; Nefodov, O.; O'Neill, G. G.; Pakarinen, J.; Papadakis, P.; Partanen, J.; Ruotsalainen, P.; Sandzelius, M.; Sarén, J.; Smolen, M.; Sorri, J.; Stolze, S.; Uusitalo, J.

2016-09-01

The lifetime of the (11 /2+ ) state in the band above the proton-emitting (3 /2+ ) state in 113Cs has been measured to be τ =24 (6 ) ps from a recoil-decay-tagged differential-plunger experiment. The measured lifetime was used to deduce the deformation of the states using wave functions from a nonadiabatic quasiparticle model to independently calculate both proton-emission and electromagnetic γ -ray transition rates as a function of deformation. The only quadrupole deformation, which was able to reproduce the experimental excitation energies of the states, the electromagnetic decay rate of the (11 /2+ ) state and the proton-emission rate of the (3 /2+ ) state, was found to be β2=0.22 (6 ) . This deformation is in agreement with the earlier proton emission studies which concluded that 113Cs was best described as a deformed proton emitter, however, it is now more firmly supported by the present measurement of the electromagnetic transition rate.

Shielding of relativistic protons.

PubMed

Bertucci, A; Durante, M; Gialanella, G; Grossi, G; Manti, L; Pugliese, M; Scampoli, P; Mancusi, D; Sihver, L; Rusek, A

2007-06-01

Protons are the most abundant element in the galactic cosmic radiation, and the energy spectrum peaks around 1 GeV. Shielding of relativistic protons is therefore a key problem in the radiation protection strategy of crewmembers involved in long-term missions in deep space. Hydrogen ions were accelerated up to 1 GeV at the NASA Space Radiation Laboratory, Brookhaven National Laboratory, New York. The proton beam was also shielded with thick (about 20 g/cm2) blocks of lucite (PMMA) or aluminium (Al). We found that the dose rate was increased 40-60% by the shielding and decreased as a function of the distance along the axis. Simulations using the General-Purpose Particle and Heavy-Ion Transport code System (PHITS) show that the dose increase is mostly caused by secondary protons emitted by the target. The modified radiation field after the shield has been characterized for its biological effectiveness by measuring chromosomal aberrations in human peripheral blood lymphocytes exposed just behind the shield block, or to the direct beam, in the dose range 0.5-3 Gy. Notwithstanding the increased dose per incident proton, the fraction of aberrant cells at the same dose in the sample position was not significantly modified by the shield. The PHITS code simulations show that, albeit secondary protons are slower than incident nuclei, the LET spectrum is still contained in the low-LET range (<10 keV/microm), which explains the approximately unitary value measured for the relative biological effectiveness.

What's In a Proton?

ScienceCinema

Brookhaven Lab

2017-12-09

Physicist Peter Steinberg explains that fundamental particles like protons are themselves made up of still smaller particles called quarks. He discusses how new particles are produced when quarks are liberated from protons...a process that can be observed

Mammalian complex I pumps 4 protons per 2 electrons at high and physiological proton motive force in living cells.

PubMed

Ripple, Maureen O; Kim, Namjoon; Springett, Roger

2013-02-22

Mitochondrial complex I couples electron transfer between matrix NADH and inner-membrane ubiquinone to the pumping of protons against a proton motive force. The accepted proton pumping stoichiometry was 4 protons per 2 electrons transferred (4H(+)/2e(-)) but it has been suggested that stoichiometry may be 3H(+)/2e(-) based on the identification of only 3 proton pumping units in the crystal structure and a revision of the previous experimental data. Measurement of proton pumping stoichiometry is challenging because, even in isolated mitochondria, it is difficult to measure the proton motive force while simultaneously measuring the redox potentials of the NADH/NAD(+) and ubiquinol/ubiquinone pools. Here we employ a new method to quantify the proton motive force in living cells from the redox poise of the bc(1) complex measured using multiwavelength cell spectroscopy and show that the correct stoichiometry for complex I is 4H(+)/2e(-) in mouse and human cells at high and physiological proton motive force.

Mammalian Complex I Pumps 4 Protons per 2 Electrons at High and Physiological Proton Motive Force in Living Cells*

PubMed Central

Ripple, Maureen O.; Kim, Namjoon; Springett, Roger

2013-01-01

Mitochondrial complex I couples electron transfer between matrix NADH and inner-membrane ubiquinone to the pumping of protons against a proton motive force. The accepted proton pumping stoichiometry was 4 protons per 2 electrons transferred (4H+/2e−) but it has been suggested that stoichiometry may be 3H+/2e− based on the identification of only 3 proton pumping units in the crystal structure and a revision of the previous experimental data. Measurement of proton pumping stoichiometry is challenging because, even in isolated mitochondria, it is difficult to measure the proton motive force while simultaneously measuring the redox potentials of the NADH/NAD+ and ubiquinol/ubiquinone pools. Here we employ a new method to quantify the proton motive force in living cells from the redox poise of the bc1 complex measured using multiwavelength cell spectroscopy and show that the correct stoichiometry for complex I is 4H+/2e− in mouse and human cells at high and physiological proton motive force. PMID:23306206

SOLARPROP: Charge-sign dependent solar modulation for everyone

NASA Astrophysics Data System (ADS)

Kappl, Rolf

2016-10-01

We present SOLARPROP, a tool to compute the influence of charge-sign dependent solar modulation for cosmic ray spectra. SOLARPROP is able to use the output of popular tools like GALPROP or DRAGON and offers the possibility to embed new models for solar modulation. We present some examples for proton, antiproton and positron fluxes in the light of the recent PAMELA and AMS-02 data.

A test of the Feynman scaling in the fragmentation region

NASA Technical Reports Server (NTRS)

Doke, T.; Innocente, V.; Kasahara, K.; Kikuchi, J.; Kashiwagi, T.; Lanzano, S.; Masuda, K.; Murakami, H.; Muraki, Y.; Nakada, T.

1985-01-01

The result of the direct measurement of the fragmentation region will be presented. The result will be obtained at the CERN proton-antiproton collider, being exposured the Silicon calorimeters inside beam pipe. This experiment clarifies a long riddle of cosmic ray physics, whether the Feynman scaling does villate at the fragmentation region or the Iron component is increasing at 10 to the 15th power eV.

Verification of charge sign for high-energy particles measured by magnetic tracking system of PAMELA spectrometer

NASA Astrophysics Data System (ADS)

Lukyanov, A. D.; Alekseev, V. V.; Bogomolov, Yu V.; Dunaeva, O. A.; Malakhov, V. V.; Mayorov, A. G.; Rodenko, S. A.

2017-01-01

Analysis of experimental data of primary positrons and antiprotons fluxes obtained by PAMELA spectrometer, recently confirmed by AMS-02 spectrometer, for some reasons is of big interest for scientific community, especially for energies higher than 100 GV, where appearance of signal coming from dark matter particles is possible. In this work we present a method for verification of charge sign for high-energy antiprotons, measured by magnetic tracking system of PAMELA spectrometer, which can be immitated by protons due to scattering or finite instrumental resolution at high energies (so-called “spillover”). We base our approach on developing2 a set of distinctive features represented by differently computed rigidities and training AdaBoost classifier, which shows good classification accuracy on Monte-Carlo simulation data of 98% for rigidity up to 600 GV.

N-Protonated Isomers and Coulombic Barriers to Dissociation of Doubly Protonated Ala8Arg

NASA Astrophysics Data System (ADS)

Haeffner, Fredrik; Irikura, Karl K.

2017-10-01

Collision-induced dissociation (or tandem mass spectrometry, MS/MS) of a protonated peptide results in a spectrum of fragment ions that is useful for inferring amino acid sequence. This is now commonplace and a foundation of proteomics. The underlying chemical and physical processes are believed to be those familiar from physical organic chemistry and chemical kinetics. However, first-principles predictions remain intractable because of the conflicting necessities for high accuracy (to achieve qualitatively correct kinetics) and computational speed (to compensate for the high cost of reliable calculations on such large molecules). To make progress, shortcuts are needed. Inspired by the popular mobile proton model, we have previously proposed a simplified theoretical model in which the gas-phase fragmentation pattern of protonated peptides reflects the relative stabilities of N-protonated isomers, thus avoiding the need for transition-state information. For singly protonated Ala n ( n = 3-11), the resulting predictions were in qualitative agreement with the results from low-energy MS/MS experiments. Here, the comparison is extended to a model tryptic peptide, doubly protonated Ala8Arg. This is of interest because doubly protonated tryptic peptides are the most important in proteomics. In comparison with experimental results, our model seriously overpredicts the degree of backbone fragmentation at N9. We offer an improved model that corrects this deficiency. The principal change is to include Coulombic barriers, which hinder the separation of the product cations from each other. Coulombic barriers may be equally important in MS/MS of all multiply charged peptide ions. [Figure not available: see fulltext.

NMR Observation of Mobile Protons in Proton-Implanted ZnO Nanorods

PubMed Central

Park, Jun Kue; Kwon, Hyeok-Jung; Lee, Cheol Eui

2016-01-01

The diffusion properties of H+ in ZnO nanorods are investigated before and after 20 MeV proton beam irradiation by using 1H nuclear magnetic resonance (NMR) spectroscopy. Herein, we unambiguously observe that the implanted protons occupy thermally unstable site of ZnO, giving rise to a narrow NMR line at 4.1 ppm. The activation barrier of the implanted protons was found to be 0.46 eV by means of the rotating-frame spin-lattice relaxation measurements, apparently being interstitial hydrogens. High-energy beam irradiation also leads to correlated jump diffusion of the surface hydroxyl group of multiple lines at ~1 ppm, implying the presence of structural disorder at the ZnO surface. PMID:26988733

Molecular mechanisms for generating transmembrane proton gradients

PubMed Central

Gunner, M.R.; Amin, Muhamed; Zhu, Xuyu; Lu, Jianxun

2013-01-01

Membrane proteins use the energy of light or high energy substrates to build a transmembrane proton gradient through a series of reactions leading to proton release into the lower pH compartment (P-side) and proton uptake from the higher pH compartment (N-side). This review considers how the proton affinity of the substrates, cofactors and amino acids are modified in four proteins to drive proton transfers. Bacterial reaction centers (RCs) and photosystem II (PSII) carry out redox chemistry with the species to be oxidized on the P-side while reduction occurs on the N-side of the membrane. Terminal redox cofactors are used which have pKas that are strongly dependent on their redox state, so that protons are lost on oxidation and gained on reduction. Bacteriorhodopsin is a true proton pump. Light activation triggers trans to cis isomerization of a bound retinal. Strong electrostatic interactions within clusters of amino acids are modified by the conformational changes initiated by retinal motion leading to changes in proton affinity, driving transmembrane proton transfer. Cytochrome c oxidase (CcO) catalyzes the reduction of O2 to water. The protons needed for chemistry are bound from the N-side. The reduction chemistry also drives proton pumping from N- to P-side. Overall, in CcO the uptake of 4 electrons to reduce O2 transports 8 charges across the membrane, with each reduction fully coupled to removal of two protons from the N-side, the delivery of one for chemistry and transport of the other to the P-side. PMID:23507617

Proton and non-proton activation of ASIC channels

PubMed Central

Gautschi, Ivan; van Bemmelen, Miguel Xavier; Schild, Laurent

2017-01-01

The Acid-Sensing Ion Channels (ASIC) exhibit a fast desensitizing current when activated by pH values below 7.0. By contrast, non-proton ligands are able to trigger sustained ASIC currents at physiological pHs. To analyze the functional basis of the ASIC desensitizing and sustained currents, we have used ASIC1a and ASIC2a mutants with a cysteine in the pore vestibule for covalent binding of different sulfhydryl reagents. We found that ASIC1a and ASIC2a exhibit two distinct currents, a proton-induced desensitizing current and a sustained current triggered by sulfhydryl reagents. These currents differ in their pH dependency, their sensitivity to the sulfhydryl reagents, their ionic selectivity and their relative magnitude. We propose a model for ASIC1 and ASIC2 activity where the channels can function in two distinct modes, a desensitizing mode and a sustained mode depending on the activating ligands. The pore vestibule of the channel represents a functional site for binding non-proton ligands to activate ASIC1 and ASIC2 at neutral pH and to prevent channel desensitization. PMID:28384246

Study and Analyze Energetic Particle and Magnetic Activity Data.

DTIC Science & Technology

1982-06-01

around the world , it has a value 1"’ont’, SSJ .3 1"N’!urnl III potential to which the electron flux fruin 0 to 9. In contrast, the could charge the...15.0000 .8348 760.1 24.000 1717.509 20.0000 . 8545 861.3 23.000 1516.909 20.0000 .8653 926.4 24.000 1617.934 30.0-OO0 .8940 1147.1 23.000 1411.760 30.0000...neutron Furthermore, we found experimentally, for the anomaly war ,cau . difusion orcan maei fin l decayit. 190The i- observed proton fluxes, that K

Quasi-monoenergetic proton beam from a proton-layer embedded metal foil irradiated by an intense laser pulse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Kyung Nam; Lee, Kitae, E-mail: klee@kaeri.re.kr; Kumar, Manoj

A target structure, ion-layer embedded foil (ILEF) is proposed for producing a quasi-monoenergetic proton beam by utilizing a bulk electrostatic field, which is generated by irradiating the target with an ultra-intense laser pulse, inside the plasma. Compared with the case of a single metal foil in which the proton layer is initially present on the surface, in the ILEF target, the proton layer is initially located inside a metal foil. A two-dimensional particle-in-cell (PIC) simulation shows that the target generates a proton beam with a narrow energy spread. With a laser intensity of 2 × 10{sup 19 }W/cm{sup 2}, a 22-MeV proton beammore » with an energy spread of 8% at the full-width-half-maximum (FWHM) is obtained when the proton layer is located at 0.4 μm inside the rear surface of a 2.4 μm-thick copper foil. When the proton layer moves toward the front side, a proton beam with a flat-top energy distribution ranging from 15 MeV to 35 MeV is obtained. Further, with a higher laser intensity of 10{sup 21 }W/cm{sup 2}, a proton beam with the maximum energy of 345 MeV and FWHM energy spread of 7.2% is obtained. The analysis of the PIC simulation with an aid of a fluid analysis shows that the spectrum is affected by the initial position of the proton layer, its initial spread during the formation of the sheath field, and the space charge effect.« less

Proton-coupled electron transfer and the role of water molecules in proton pumping by cytochrome c oxidase

PubMed Central

Sharma, Vivek; Enkavi, Giray; Vattulainen, Ilpo; Róg, Tomasz; Wikström, Mårten

2015-01-01

Molecular oxygen acts as the terminal electron sink in the respiratory chains of aerobic organisms. Cytochrome c oxidase in the inner membrane of mitochondria and the plasma membrane of bacteria catalyzes the reduction of oxygen to water, and couples the free energy of the reaction to proton pumping across the membrane. The proton-pumping activity contributes to the proton electrochemical gradient, which drives the synthesis of ATP. Based on kinetic experiments on the O–O bond splitting transition of the catalytic cycle (A → PR), it has been proposed that the electron transfer to the binuclear iron–copper center of O2 reduction initiates the proton pump mechanism. This key electron transfer event is coupled to an internal proton transfer from a conserved glutamic acid to the proton-loading site of the pump. However, the proton may instead be transferred to the binuclear center to complete the oxygen reduction chemistry, which would constitute a short-circuit. Based on atomistic molecular dynamics simulations of cytochrome c oxidase in an explicit membrane–solvent environment, complemented by related free-energy calculations, we propose that this short-circuit is effectively prevented by a redox-state–dependent organization of water molecules within the protein structure that gates the proton transfer pathway. PMID:25646428

Event generator tunes obtained from underlying event and multiparton scattering measurements.

PubMed

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New sets of parameters ("tunes") for the underlying-event (UE) modelling of the pythia8, pythia6 and herwig++ Monte Carlo event generators are constructed using different parton distribution functions. Combined fits to CMS UE proton-proton ([Formula: see text]) data at [Formula: see text] and to UE proton-antiproton ([Formula: see text]) data from the CDF experiment at lower [Formula: see text], are used to study the UE models and constrain their parameters, providing thereby improved predictions for proton-proton collisions at 13[Formula: see text]. In addition, it is investigated whether the values of the parameters obtained from fits to UE observables are consistent with the values determined from fitting observables sensitive to double-parton scattering processes. Finally, comparisons are presented of the UE tunes to "minimum bias" (MB) events, multijet, and Drell-Yan ([Formula: see text] lepton-antilepton+jets) observables at 7 and 8[Formula: see text], as well as predictions for MB and UE observables at 13[Formula: see text].

Proton radiography and proton computed tomography based on time-resolved dose measurements

NASA Astrophysics Data System (ADS)

Testa, Mauro; Verburg, Joost M.; Rose, Mark; Min, Chul Hee; Tang, Shikui; Hassane Bentefour, El; Paganetti, Harald; Lu, Hsiao-Ming

2013-11-01

We present a proof of principle study of proton radiography and proton computed tomography (pCT) based on time-resolved dose measurements. We used a prototype, two-dimensional, diode-array detector capable of fast dose rate measurements, to acquire proton radiographic images expressed directly in water equivalent path length (WEPL). The technique is based on the time dependence of the dose distribution delivered by a proton beam traversing a range modulator wheel in passive scattering proton therapy systems. The dose rate produced in the medium by such a system is periodic and has a unique pattern in time at each point along the beam path and thus encodes the WEPL. By measuring the time dose pattern at the point of interest, the WEPL to this point can be decoded. If one measures the time-dose patterns at points on a plane behind the patient for a beam with sufficient energy to penetrate the patient, the obtained 2D distribution of the WEPL forms an image. The technique requires only a 2D dosimeter array and it uses only the clinical beam for a fraction of second with negligible dose to patient. We first evaluated the accuracy of the technique in determining the WEPL for static phantoms aiming at beam range verification of the brain fields of medulloblastoma patients. Accurate beam ranges for these fields can significantly reduce the dose to the cranial skin of the patient and thus the risk of permanent alopecia. Second, we investigated the potential features of the technique for real-time imaging of a moving phantom. Real-time tumor tracking by proton radiography could provide more accurate validations of tumor motion models due to the more sensitive dependence of proton beam on tissue density compared to x-rays. Our radiographic technique is rapid (˜100 ms) and simultaneous over the whole field, it can image mobile tumors without the problem of interplay effect inherently challenging for methods based on pencil beams. Third, we present the reconstructed p

Protonation and Proton-Coupled Electron Transfer at S-Ligated [4Fe-4S] Clusters

PubMed Central

Morris, Wesley D.; Darcy, Julia W.; Mayer, James M.

2015-01-01

Biological [Fe-S] clusters are increasingly recognized to undergo proton-coupled electron transfer (PCET), but the site of protonation, mechanism, and role for PCET remains largely unknown. Here we explore this reactivity with synthetic model clusters. Protonation of the arylthiolate-ligated [4Fe-4S] cluster [Fe4S4(SAr)4]2- (1, SAr = S-2,4-6-(iPr)3C6H2) leads to thiol dissociation, reversibly forming [Fe4S4(SAr)3L]1- (2) + ArSH (L = solvent, and/or conjugate base). Solutions of 2 + ArSH react with the nitroxyl radical TEMPO to give [Fe4S4(SAr)4]1- (1ox) and TEMPOH. This reaction involves PCET coupled to thiolate association and may proceed via the unobserved protonated cluster [Fe4S4(SAr)3(HSAr)]1-(1-H). Similar reactions with this and related clusters proceed comparably. An understanding of the PCET thermochemistry of this cluster system has been developed, encompassing three different redox levels and two protonation states. PMID:25965413

Status of the Proton Therapy Project at IUCF and the Midwest Proton Radiotherapy Institute

NASA Astrophysics Data System (ADS)

Klein, Susan B.

2003-08-01

The first proton therapy patient was successfully treated for astrocytoma using a modified nuclear experimentation beam line and in-house treatment planning in 1993. In 1998, IUCF constructed an eye treatment clinic, and conducted a phase III clinical trial investigating proton radiation treatment of AMD. Treatment was planned using Eyeplan modified to match the IUCF beam characteristics. MPRI was conceptualized in 1996 by a consortium of physicians and physicists. Reconfiguration began in 2000; construction of the achromatic trunk line began in 2001, followed by manufacture of 4 energy selection lines and two fixed horizontal beam treatment lines. Two isocentric, rotational gantries will be installed following completion of the horizontal beam lines. A fifth line will supply the full-time radiation effects research station. Standard proton delivery out of the main stage is specified at 500 nA of 205 MeV. Clinic construction began in April, 2002 and will be completed by mid-December. Design, construction and operation of these proton facilities have been accomplished by the proton therapy group at IUCF.

High Temperature Protonic Conductors

NASA Technical Reports Server (NTRS)

Dynys, Fred; Berger, Marie-Helen; Sayir, Ali

2007-01-01

High Temperature Protonic Conductors (HTPC) with the perovskite structure are envisioned for electrochemical membrane applications such as H2 separation, H2 sensors and fuel cells. Successive membrane commercialization is dependent upon addressing issues with H2 permeation rate and environmental stability with CO2 and H2O. HTPC membranes are conventionally fabricated by solid-state sintering. Grain boundaries and the presence of intergranular second phases reduce the proton mobility by orders of magnitude than the bulk crystalline grain. To enhanced protonic mobility, alternative processing routes were evaluated. A laser melt modulation (LMM) process was utilized to fabricate bulk samples, while pulsed laser deposition (PLD) was utilized to fabricate thin film membranes . Sr3Ca(1+x)Nb(2-x)O9 and SrCe(1-x)Y(x)O3 bulk samples were fabricated by LMM. Thin film BaCe(0.85)Y(0.15)O3 membranes were fabricated by PLD on porous substrates. Electron microscopy with chemical mapping was done to characterize the resultant microstructures. High temperature protonic conduction was measured by impedance spectroscopy in wet air or H2 environments. The results demonstrate the advantage of thin film membranes to thick membranes but also reveal the negative impact of defects or nanoscale domains on protonic conductivity.

Protons -- The Future of Radiation Therapy?

NASA Astrophysics Data System (ADS)

Avery, Steven

2007-03-01

Cancer is the 2^nd highest cause of death in the United States. The challenges of controlling this disease remain more difficult as the population lives longer. Proton therapy offers another choice in the management of cancer care. Proton therapy has existed since the late 1950s and the first hospital based center in the United States opened in 1990. Since that time four hospital based proton centers are treating patients with other centers either under construction or under consideration. This talk will focus on an introduction to proton therapy: it's medical advantages over current treatment modalities, accelerators and beam delivery systems, applications to clinical radiation oncology and the future outlook for proton therapy.

Measurement of charged pion, kaon, and proton production in proton-proton collisions at s = 13 TeV

DOE PAGES

Sirunyan, A. M.; Tumasyan, A.; Adam, W.; ...

2017-12-05

Here, transverse momentum spectra of charged pions, kaons, and protons are measured in proton-proton collisions at √s = 13 TeV with the CMS detector at the LHC. The particles, identified via their energy loss in the silicon tracker, are measured in the transverse momentum range of p T ≈ 0.1–1.7 GeV/c and rapidities |y| < 1. The p T spectra and integrated yields are compared to previous results at smaller s and to predictions of Monte Carlo event generators. The average p T increases with particle mass and charged particle multiplicity of the event. Comparisons with previous CMS results at √smore » = 0.9, 2.76, and 7 TeV show that the average p T and the ratios of hadron yields feature very similar dependences on the particle multiplicity in the event, independently of the center-of-mass energy of the pp collision.« less

Flares, ejections, proton events

NASA Astrophysics Data System (ADS)

Belov, A. V.

2017-11-01

Statistical analysis is performed for the relationship of coronal mass ejections (CMEs) and X-ray flares with the fluxes of solar protons with energies >10 and >100 MeV observed near the Earth. The basis for this analysis was the events that took place in 1976-2015, for which there are reliable observations of X-ray flares on GOES satellites and CME observations with SOHO/LASCO coronagraphs. A fairly good correlation has been revealed between the magnitude of proton enhancements and the power and duration of flares, as well as the initial CME speed. The statistics do not give a clear advantage either to CMEs or the flares concerning their relation with proton events, but the characteristics of the flares and ejections complement each other well and are reasonable to use together in the forecast models. Numerical dependences are obtained that allow estimation of the proton fluxes to the Earth expected from solar observations; possibilities for improving the model are discussed.

A compact electron cyclotron resonance proton source for the Paul Scherrer Institute's proton accelerator facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baumgarten, C.; Barchetti, A.; Einenkel, H.

2011-05-15

A compact electron cyclotron resonance proton source has been developed and installed recently at thePaul Scherrer Institute's high intensity proton accelerator. Operation at the ion source test stand and the accelerator demonstrates a high reliability and stability of the new source. When operated at a 10 - 12 mA net proton current the lifetime of the source exceeds 2000 h. The essential development steps towards the observed performance are described.

Constituent Quark and Diquark Properties from Small Angle Proton--Proton Elastic Scattering at High Energies

NASA Astrophysics Data System (ADS)

Bialas, A.; Bzdak, A.

2007-01-01

Small momentum transfer elastic proton-proton cross-section at high energies is calculated assuming the nucleon composed of two constituents -- a quark and a diquark. A comparison to data (described very well up to -t approx 2 GeV2/c) allows to determine some properties of the constituents. While quark turns out fairly small, the diquark appears to be rather large, comparable to the size of the proton.

Local Equation of State for Protons, and Implications for Proton Heating in the Solar Wind.

NASA Astrophysics Data System (ADS)

Zaslavsky, A.; Maksimovic, M.; Kasper, J. C.

2017-12-01

The solar wind protons temperature is observed to decrease with distance to the Sun at a slower rate than expected from an adiabatic expansion law: the protons are therefore said to be heated. This observation raises the question of the evaluation of the heating rate, and the question of the heat source.These questions have been investigated by previous authors by gathering proton data on various distances to the Sun, using spacecraft as Helios or Ulysses, and then computing the radial derivative of the proton temperature in order to obtain a heating rate from the internal energy equation. The problem of such an approach is the computation of the radial derivative of the temperature profile, for which uncertainties are very large, given the dispersion of the temperatures measured at a given distance.An alternative approach, that we develop in this paper, consists in looking for an equation of state that links locally the pressure (or temperature) to the mass density. If such a relation exists then one can evaluate the proton heating rate on a local basis, without having any space derivative to compute.Here we use several years of STEREO and WIND proton data to search for polytropic equation of state. We show that such relationships are indeed a good approximation in given solar wind's velocity intervals and deduce the associated protons heating rates as a function of solar wind's speed. The obtained heating rates are shown to scale from around 1 kW/kg in the slow wind to around 10 kW/kg in the fast wind, in remarkable agreement with the rate of energy observed by previous authors to cascade in solar wind's MHD turbulence at 1 AU. These results therefore support the idea of proton turbulent heating in the solar wind.

Measuring the contribution of low Bjorken-x gluons to the proton spin with polarized proton-proton collisions

NASA Astrophysics Data System (ADS)

Wolin, Scott Justin

The PHENIX experiment is one of two detectors located at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory in Upton, NY. Understanding the spin structure of the proton is a central goal at RHIC, the only polarized proton-on-proton collider in existence. The PHENIX spin program has two primary objectives. The first is to improve the constraints on the polarized parton distributions of the anti-u and anti-d quarks within the proton. The second objective is to improve the constraint on the gluon spin contribution to the proton spin, DeltaG. The focus of this thesis is the second objective. PHENIX experiment has been successful at providing the first meaningful constraints on DeltaG, along with STAR, the other detector located at RHIC. These constraints have, in fact, eliminated the extreme scenarios for gluon polarization through measurements of the double spin asymmetry, ALL, between the cross section of like and unlike sign helicity pp interactions. ALL measurements can be performed with a variety of final states at PHENIX. Until 2009, these final states were only measured for pseudo-rapidities of |eta| < 0.35. This range of eta is referred to as mid-rapidity. These mid-rapidity measurements, like the polarized DIS measurements, suffer from a limited kinematic reach. Final states containing a measured particle with pT [special character omitted] 1 GeV/c are considered to have occurred in the hard scattering domain where the pp interaction is well approximated as an interaction of a quark or gluon in one proton and a quark or gluon in the second proton. Each of these interacting particles has a momentum fraction, x, of its parent proton's momentum. The gluon polarization is dependent on the momentum fraction and the net gluon polarization can be written as the integral of the momentum fraction dependent polarization: DeltaG = f(1,0)Delta g(x)dx. The momentum fractions of the two interacting particles give information about the final state

Photoproduction of vector mesons in proton-proton ultraperipheral collisions at the CERN Large Hadron Collider

NASA Astrophysics Data System (ADS)

Xie, Ya-Ping; Chen, Xurong

2018-05-01

Photoproduction of vector mesons is computed with dipole model in proton-proton ultraperipheral collisions (UPCs) at the CERN Large Hadron Collider (LHC). The dipole model framework is employed in the calculations of vector mesons production in diffractive processes. Parameters of the bCGC model are refitted with the latest inclusive deep inelastic scattering experimental data. Employing the bCGC model and boosted Gaussian light-cone wave function for vector mesons, we obtain the prediction of rapidity distributions of J/ψ and ψ(2s) mesons in proton-proton ultraperipheral collisions at the LHC. The predictions give a good description of the experimental data of LHCb. Predictions of ϕ and ω mesons are also evaluated in this paper.

Shrink-wrapping water to conduct protons

NASA Astrophysics Data System (ADS)

Shimizu, George K. H.

2017-11-01

For proton-conducting metal-organic frameworks (MOFs) to find application as the electrolyte in proton-exchange membrane fuel cells, materials with better stability and conductivity are required. Now, a structurally flexible MOF that is also highly stable is demonstrated to possess high proton conductivity over a range of humidities.

Measurement of charged pion, kaon, and proton production in proton-proton collisions at √{s }=13 TeV

NASA Astrophysics Data System (ADS)

Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragicevic, M.; Erö, J.; Flechl, M.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; König, A.; Krätschmer, I.; Liko, D.; Matsushita, T.; Mikulec, I.; Rabady, D.; Rad, N.; Rahbaran, B.; Rohringer, H.; Schieck, J.; Strauss, J.; Waltenberger, W.; Wulz, C.-E.; Dvornikov, O.; Makarenko, V.; Mossolov, V.; Suarez Gonzalez, J.; Zykunov, V.; Shumeiko, N.; Alderweireldt, S.; De Wolf, E. A.; Janssen, X.; Lauwers, J.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Abu Zeid, S.; Blekman, F.; D'Hondt, J.; Daci, N.; De Bruyn, I.; Deroover, K.; Lowette, S.; Moortgat, S.; Moreels, L.; Olbrechts, A.; Python, Q.; Skovpen, K.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Parijs, I.; Brun, H.; Clerbaux, B.; De Lentdecker, G.; Delannoy, H.; Fasanella, G.; Favart, L.; Goldouzian, R.; Grebenyuk, A.; Karapostoli, G.; Lenzi, T.; Léonard, A.; Luetic, J.; Maerschalk, T.; Marinov, A.; Randle-conde, A.; Seva, T.; Vander Velde, C.; Vanlaer, P.; Vannerom, D.; Yonamine, R.; Zenoni, F.; Zhang, F.; Cimmino, A.; Cornelis, T.; Dobur, D.; Fagot, A.; Gul, M.; Khvastunov, I.; Poyraz, D.; Salva, S.; Schöfbeck, R.; Tytgat, M.; Van Driessche, W.; Yazgan, E.; Zaganidis, N.; Bakhshiansohi, H.; Beluffi, C.; Bondu, O.; Brochet, S.; Bruno, G.; Caudron, A.; De Visscher, S.; Delaere, C.; Delcourt, M.; Francois, B.; Giammanco, A.; Jafari, A.; Komm, M.; Krintiras, G.; Lemaitre, V.; Magitteri, A.; Mertens, A.; Musich, M.; Piotrzkowski, K.; Quertenmont, L.; Selvaggi, M.; Vidal Marono, M.; Wertz, S.; Beliy, N.; Aldá Júnior, W. L.; Alves, F. L.; Alves, G. A.; Brito, L.; Hensel, C.; Moraes, A.; Pol, M. E.; Rebello Teles, P.; Belchior Batista Das Chagas, E.; Carvalho, W.; Chinellato, J.; Custódio, A.; Da Costa, E. M.; Da Silveira, G. G.; De Jesus Damiao, D.; De Oliveira Martins, C.; Fonseca De Souza, S.; Huertas Guativa, L. M.; Malbouisson, H.; Matos Figueiredo, D.; Mora Herrera, C.; Mundim, L.; Nogima, H.; Prado Da Silva, W. L.; Santoro, A.; Sznajder, A.; Tonelli Manganote, E. J.; Torres Da Silva De Araujo, F.; Vilela Pereira, A.; Ahuja, S.; Bernardes, C. A.; Dogra, S.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Mercadante, P. G.; Moon, C. S.; Novaes, S. F.; Padula, Sandra S.; Romero Abad, D.; Ruiz Vargas, J. C.; Aleksandrov, A.; Hadjiiska, R.; Iaydjiev, P.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Glushkov, I.; Litov, L.; Pavlov, B.; Petkov, P.; Fang, W.; Ahmad, M.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Chen, Y.; Cheng, T.; Jiang, C. H.; Leggat, D.; Liu, Z.; Romeo, F.; Ruan, M.; Shaheen, S. M.; Spiezia, A.; Tao, J.; Wang, C.; Wang, Z.; Zhang, H.; Zhao, J.; Ban, Y.; Chen, G.; Li, Q.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Xu, Z.; Avila, C.; Cabrera, A.; Chaparro Sierra, L. F.; Florez, C.; Gomez, J. P.; González Hernández, C. F.; Ruiz Alvarez, J. D.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Puljak, I.; Ribeiro Cipriano, P. M.; Sculac, T.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Ferencek, D.; Kadija, K.; Mesic, B.; Susa, T.; Ather, M. W.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Rykaczewski, H.; Finger, M.; Finger, M.; Carrera Jarrin, E.; Abdelalim, A. A.; Mohammed, Y.; Salama, E.; Kadastik, M.; Perrini, L.; Raidal, M.; Tiko, A.; Veelken, C.; Eerola, P.; Pekkanen, J.; Voutilainen, M.; Härkönen, J.; Järvinen, T.; Karimäki, V.; Kinnunen, R.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Tuominiemi, J.; Tuovinen, E.; Wendland, L.; Talvitie, J.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Favaro, C.; Ferri, F.; Ganjour, S.; Ghosh, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Kucher, I.; Locci, E.; Machet, M.; Malcles, J.; Rander, J.; Rosowsky, A.; Titov, M.; Abdulsalam, A.; Antropov, I.; Baffioni, S.; Beaudette, F.; Busson, P.; Cadamuro, L.; Chapon, E.; Charlot, C.; Davignon, O.; Granier de Cassagnac, R.; Jo, M.; Lisniak, S.; Miné, P.; Nguyen, M.; Ochando, C.; Ortona, G.; Paganini, P.; Pigard, P.; Regnard, S.; Salerno, R.; Sirois, Y.; Stahl Leiton, A. G.; Strebler, T.; Yilmaz, Y.; Zabi, A.; Zghiche, A.; Agram, J.-L.; Andrea, J.; Aubin, A.; Bloch, D.; Brom, J.-M.; Buttignol, M.; Chabert, E. C.; Chanon, N.; Collard, C.; Conte, E.; Coubez, X.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Le Bihan, A.-C.; Van Hove, P.; Gadrat, S.; Beauceron, S.; Bernet, C.; Boudoul, G.; Carrillo Montoya, C. A.; Chierici, R.; Contardo, D.; Courbon, B.; Depasse, P.; El Mamouni, H.; Fay, J.; Gascon, S.; Gouzevitch, M.; Grenier, G.; Ille, B.; Lagarde, F.; Laktineh, I. B.; Lethuillier, M.; Mirabito, L.; Pequegnot, A. L.; Perries, S.; Popov, A.; Sordini, V.; Vander Donckt, M.; Verdier, P.; Viret, S.; Toriashvili, T.; Tsamalaidze, Z.; Autermann, C.; Beranek, S.; Feld, L.; Kiesel, M. K.; Klein, K.; Lipinski, M.; Preuten, M.; Schomakers, C.; Schulz, J.; Verlage, T.; Albert, A.; Brodski, M.; Dietz-Laursonn, E.; Duchardt, D.; Endres, M.; Erdmann, M.; Erdweg, S.; Esch, T.; Fischer, R.; Güth, A.; Hamer, M.; Hebbeker, T.; Heidemann, C.; Hoepfner, K.; Knutzen, S.; Merschmeyer, M.; Meyer, A.; Millet, P.; Mukherjee, S.; Olschewski, M.; Padeken, K.; Pook, T.; Radziej, M.; Reithler, H.; Rieger, M.; Scheuch, F.; Sonnenschein, L.; Teyssier, D.; Thüer, S.; Cherepanov, V.; Flügge, G.; Kargoll, B.; Kress, T.; Künsken, A.; Lingemann, J.; Müller, T.; Nehrkorn, A.; Nowack, A.; Pistone, C.; Pooth, O.; Stahl, A.; Aldaya Martin, M.; Arndt, T.; Asawatangtrakuldee, C.; Beernaert, K.; Behnke, O.; Behrens, U.; Bin Anuar, A. A.; Borras, K.; Campbell, A.; Connor, P.; Contreras-Campana, C.; Costanza, F.; Diez Pardos, C.; Dolinska, G.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Eren, E.; Gallo, E.; Garay Garcia, J.; Geiser, A.; Gizhko, A.; Grados Luyando, J. M.; Grohsjean, A.; Gunnellini, P.; Harb, A.; Hauk, J.; Hempel, M.; Jung, H.; Kalogeropoulos, A.; Karacheban, O.; Kasemann, M.; Keaveney, J.; Kleinwort, C.; Korol, I.; Krücker, D.; Lange, W.; Lelek, A.; Lenz, T.; Leonard, J.; Lipka, K.; Lobanov, A.; Lohmann, W.; Mankel, R.; Melzer-Pellmann, I.-A.; Meyer, A. B.; Mittag, G.; Mnich, J.; Mussgiller, A.; Pitzl, D.; Placakyte, R.; Raspereza, A.; Roland, B.; Sahin, M. Ã.-.; Saxena, P.; Schoerner-Sadenius, T.; Spannagel, S.; Stefaniuk, N.; Van Onsem, G. P.; Walsh, R.; Wissing, C.; Blobel, V.; Centis Vignali, M.; Draeger, A. R.; Dreyer, T.; Garutti, E.; Gonzalez, D.; Haller, J.; Hoffmann, M.; Junkes, A.; Klanner, R.; Kogler, R.; Kovalchuk, N.; Lapsien, T.; Marchesini, I.; Marconi, D.; Meyer, M.; Niedziela, M.; Nowatschin, D.; Pantaleo, F.; Peiffer, T.; Perieanu, A.; Scharf, C.; Schleper, P.; Schmidt, A.; Schumann, S.; Schwandt, J.; Stadie, H.; Steinbrück, G.; Stober, F. M.; Stöver, M.; Tholen, H.; Troendle, D.; Usai, E.; Vanelderen, L.; Vanhoefer, A.; Vormwald, B.; Akbiyik, M.; Barth, C.; Baur, S.; Baus, C.; Berger, J.; Butz, E.; Caspart, R.; Chwalek, T.; Colombo, F.; De Boer, W.; Dierlamm, A.; Fink, S.; Freund, B.; Friese, R.; Giffels, M.; Gilbert, A.; Goldenzweig, P.; Haitz, D.; Hartmann, F.; Heindl, S. M.; Husemann, U.; Kassel, F.; Katkov, I.; Kudella, S.; Mildner, H.; Mozer, M. U.; Müller, Th.; Plagge, M.; Quast, G.; Rabbertz, K.; Röcker, S.; Roscher, F.; Schröder, M.; Shvetsov, I.; Sieber, G.; Simonis, H. J.; Ulrich, R.; Wayand, S.; Weber, M.; Weiler, T.; Williamson, S.; Wöhrmann, C.; Wolf, R.; Anagnostou, G.; Daskalakis, G.; Geralis, T.; Giakoumopoulou, V. A.; Kyriakis, A.; Loukas, D.; Topsis-Giotis, I.; Kesisoglou, S.; Panagiotou, A.; Saoulidou, N.; Tziaferi, E.; Evangelou, I.; Flouris, G.; Foudas, C.; Kokkas, P.; Loukas, N.; Manthos, N.; Papadopoulos, I.; Paradas, E.; Filipovic, N.; Pasztor, G.; Bencze, G.; Hajdu, C.; Horvath, D.; Sikler, F.; Veszpremi, V.; Vesztergombi, G.; Zsigmond, A. J.; Beni, N.; Czellar, S.; Karancsi, J.; Makovec, A.; Molnar, J.; Szillasi, Z.; Bartók, M.; Raics, P.; Trocsanyi, Z. L.; Ujvari, B.; Komaragiri, J. R.; Bahinipati, S.; Bhowmik, S.; Choudhury, S.; Mal, P.; Mandal, K.; Nayak, A.; Sahoo, D. K.; Sahoo, N.; Swain, S. K.; Bansal, S.; Beri, S. B.; Bhatnagar, V.; Bhawandeep, U.; Chawla, R.; Kalsi, A. K.; Kaur, A.; Kaur, M.; Kumar, R.; Kumari, P.; Mehta, A.; Mittal, M.; Singh, J. B.; Walia, G.; Kumar, Ashok; Bhardwaj, A.; Choudhary, B. C.; Garg, R. B.; Keshri, S.; Malhotra, S.; Naimuddin, M.; Ranjan, K.; Sharma, R.; Sharma, V.; Bhattacharya, R.; Bhattacharya, S.; Chatterjee, K.; Dey, S.; Dutt, S.; Dutta, S.; Ghosh, S.; Majumdar, N.; Modak, A.; Mondal, K.; Mukhopadhyay, S.; Nandan, S.; Purohit, A.; Roy, A.; Roy, D.; Roy Chowdhury, S.; Sarkar, S.; Sharan, M.; Thakur, S.; Behera, P. K.; Chudasama, R.; Dutta, D.; Jha, V.; Kumar, V.; Mohanty, A. K.; Netrakanti, P. K.; Pant, L. M.; Shukla, P.; Topkar, A.; Aziz, T.; Dugad, S.; Kole, G.; Mahakud, B.; Mitra, S.; Mohanty, G. B.; Parida, B.; Sur, N.; Sutar, B.; Banerjee, S.; Dewanjee, R. K.; Ganguly, S.; Guchait, M.; Jain, Sa.; Kumar, S.; Maity, M.; Majumder, G.; Mazumdar, K.; Sarkar, T.; Wickramage, N.; Chauhan, S.; Dube, S.; Hegde, V.; Kapoor, A.; Kothekar, K.; Pandey, S.; Rane, A.; Sharma, S.; Chenarani, S.; Eskandari Tadavani, E.; Etesami, S. M.; Khakzad, M.; Mohammadi Najafabadi, M.; Naseri, M.; Paktinat Mehdiabadi, S.; Rezaei Hosseinabadi, F.; Safarzadeh, B.; Zeinali, M.; Felcini, M.; Grunewald, M.; Abbrescia, M.; Calabria, C.; Caputo, C.; Colaleo, A.; Creanza, D.; Cristella, L.; De Filippis, N.; De Palma, M.; Fiore, L.; Iaselli, G.; Maggi, G.; Maggi, M.; Miniello, G.; My, S.; Nuzzo, S.; Pompili, A.; Pugliese, G.; Radogna, R.; Ranieri, A.; Selvaggi, G.; Sharma, A.; Silvestris, L.; Venditti, R.; Verwilligen, P.; Abbiendi, G.; Battilana, C.; Bonacorsi, D.; Braibant-Giacomelli, S.; Brigliadori, L.; Campanini, R.; Capiluppi, P.; Castro, A.; Cavallo, F. R.; Chhibra, S. S.; Codispoti, G.; Cuffiani, M.; Dallavalle, G. M.; Fabbri, F.; Fanfani, A.; Fasanella, D.; Giacomelli, P.; Grandi, C.; Guiducci, L.; Marcellini, S.; Masetti, G.; Montanari, A.; Navarria, F. L.; Perrotta, A.; Rossi, A. M.; Rovelli, T.; Siroli, G. P.; Tosi, N.; Albergo, S.; Costa, S.; Di Mattia, A.; Giordano, F.; Potenza, R.; Tricomi, A.; Tuve, C.; Barbagli, G.; Ciulli, V.; Civinini, C.; D'Alessandro, R.; Focardi, E.; Lenzi, P.; Meschini, M.; Paoletti, S.; Russo, L.; Sguazzoni, G.; Strom, D.; Viliani, L.; Benussi, L.; Bianco, S.; Fabbri, F.; Piccolo, D.; Primavera, F.; Calvelli, V.; Ferro, F.; Monge, M. R.; Robutti, E.; Tosi, S.; Brianza, L.; Brivio, F.; Ciriolo, V.; Dinardo, M. E.; Fiorendi, S.; Gennai, S.; Ghezzi, A.; Govoni, P.; Malberti, M.; Malvezzi, S.; Manzoni, R. A.; Menasce, D.; Moroni, L.; Paganoni, M.; Pedrini, D.; Pigazzini, S.; Ragazzi, S.; Tabarelli de Fatis, T.; Buontempo, S.; Cavallo, N.; De Nardo, G.; Di Guida, S.; Fabozzi, F.; Fienga, F.; Iorio, A. O. M.; Lista, L.; Meola, S.; Paolucci, P.; Sciacca, C.; Thyssen, F.; Azzi, P.; Bacchetta, N.; Benato, L.; Bisello, D.; Boletti, A.; Carlin, R.; Carvalho Antunes De Oliveira, A.; Checchia, P.; Dall'Osso, M.; De Castro Manzano, P.; Dorigo, T.; Dosselli, U.; Gasparini, F.; Gasparini, U.; Gozzelino, A.; Lacaprara, S.; Margoni, M.; Meneguzzo, A. T.; Pazzini, J.; Pozzobon, N.; Ronchese, P.; Simonetto, F.; Torassa, E.; Zanetti, M.; Zotto, P.; Zumerle, G.; Braghieri, A.; Fallavollita, F.; Magnani, A.; Montagna, P.; Ratti, S. P.; Re, V.; Riccardi, C.; Salvini, P.; Vai, I.; Vitulo, P.; Alunni Solestizi, L.; Bilei, G. M.; Ciangottini, D.; Fanò, L.; Lariccia, P.; Leonardi, R.; Mantovani, G.; Mariani, V.; Menichelli, M.; Saha, A.; Santocchia, A.; Androsov, K.; Azzurri, P.; Bagliesi, G.; Bernardini, J.; Boccali, T.; Castaldi, R.; Ciocci, M. A.; Dell'Orso, R.; Donato, S.; Fedi, G.; Giassi, A.; Grippo, M. T.; Ligabue, F.; Lomtadze, T.; Martini, L.; Messineo, A.; Palla, F.; Rizzi, A.; Savoy-Navarro, A.; Spagnolo, P.; Tenchini, R.; Tonelli, G.; Venturi, A.; Verdini, P. G.; Barone, L.; Cavallari, F.; Cipriani, M.; Del Re, D.; Diemoz, M.; Gelli, S.; Longo, E.; Margaroli, F.; Marzocchi, B.; Meridiani, P.; Organtini, G.; Paramatti, R.; Preiato, F.; Rahatlou, S.; Rovelli, C.; Santanastasio, F.; Amapane, N.; Arcidiacono, R.; Argiro, S.; Arneodo, M.; Bartosik, N.; Bellan, R.; Biino, C.; Cartiglia, N.; Cenna, F.; Costa, M.; Covarelli, R.; Degano, A.; Demaria, N.; Finco, L.; Kiani, B.; Mariotti, C.; Maselli, S.; Migliore, E.; Monaco, V.; Monteil, E.; Monteno, M.; Obertino, M. M.; Pacher, L.; Pastrone, N.; Pelliccioni, M.; Pinna Angioni, G. L.; Ravera, F.; Romero, A.; Ruspa, M.; Sacchi, R.; Shchelina, K.; Sola, V.; Solano, A.; Staiano, A.; Traczyk, P.; Belforte, S.; Casarsa, M.; Cossutti, F.; Della Ricca, G.; Zanetti, A.; Kim, D. H.; Kim, G. N.; Kim, M. S.; Lee, S.; Lee, S. W.; Oh, Y. D.; Sekmen, S.; Son, D. C.; Yang, Y. C.; Lee, A.; Kim, H.; Brochero Cifuentes, J. A.; Kim, T. J.; Cho, S.; Choi, S.; Go, Y.; Gyun, D.; Ha, S.; Hong, B.; Jo, Y.; Kim, Y.; Lee, K.; Lee, K. S.; Lee, S.; Lim, J.; Park, S. K.; Roh, Y.; Almond, J.; Kim, J.; Lee, H.; Oh, S. B.; Radburn-Smith, B. C.; Seo, S. h.; Yang, U. K.; Yoo, H. D.; Yu, G. B.; Choi, M.; Kim, H.; Kim, J. H.; Lee, J. S. H.; Park, I. C.; Ryu, G.; Ryu, M. S.; Choi, Y.; Goh, J.; Hwang, C.; Lee, J.; Yu, I.; Dudenas, V.; Juodagalvis, A.; Vaitkus, J.; Ahmed, I.; Ibrahim, Z. A.; Md Ali, M. A. B.; Mohamad Idris, F.; Wan Abdullah, W. A. T.; Yusli, M. N.; Zolkapli, Z.; Castilla-Valdez, H.; De La Cruz-Burelo, E.; Heredia-De La Cruz, I.; Hernandez-Almada, A.; Lopez-Fernandez, R.; Magaña Villalba, R.; Mejia Guisao, J.; Sanchez-Hernandez, A.; Carrillo Moreno, S.; Oropeza Barrera, C.; Vazquez Valencia, F.; Carpinteyro, S.; Pedraza, I.; Salazar Ibarguen, H. A.; Uribe Estrada, C.; Morelos Pineda, A.; Krofcheck, D.; Butler, P. H.; Ahmad, A.; Ahmad, M.; Hassan, Q.; Hoorani, H. R.; Khan, W. A.; Saddique, A.; Shah, M. A.; Shoaib, M.; Waqas, M.; Bialkowska, H.; Bluj, M.; Boimska, B.; Frueboes, T.; Górski, M.; Kazana, M.; Nawrocki, K.; Romanowska-Rybinska, K.; Szleper, M.; Zalewski, P.; Bunkowski, K.; Byszuk, A.; Doroba, K.; Kalinowski, A.; Konecki, M.; Krolikowski, J.; Misiura, M.; Olszewski, M.; Walczak, M.; Bargassa, P.; Beirão Da Cruz E Silva, C.; Calpas, B.; Di Francesco, A.; Faccioli, P.; Ferreira Parracho, P. G.; Gallinaro, M.; Hollar, J.; Leonardo, N.; Lloret Iglesias, L.; Nemallapudi, M. 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P.; Flix, J.; Fouz, M. C.; Garcia-Abia, P.; Gonzalez Lopez, O.; Goy Lopez, S.; Hernandez, J. M.; Josa, M. I.; Navarro De Martino, E.; Pérez-Calero Yzquierdo, A.; Puerta Pelayo, J.; Quintario Olmeda, A.; Redondo, I.; Romero, L.; Soares, M. S.; de Trocóniz, J. F.; Missiroli, M.; Moran, D.; Cuevas, J.; Fernandez Menendez, J.; Gonzalez Caballero, I.; González Fernández, J. R.; Palencia Cortezon, E.; Sanchez Cruz, S.; Suárez Andrés, I.; Vischia, P.; Vizan Garcia, J. M.; Cabrillo, I. J.; Calderon, A.; Curras, E.; Fernandez, M.; Garcia-Ferrero, J.; Gomez, G.; Lopez Virto, A.; Marco, J.; Martinez Rivero, C.; Matorras, F.; Piedra Gomez, J.; Rodrigo, T.; Ruiz-Jimeno, A.; Scodellaro, L.; Trevisani, N.; Vila, I.; Vilar Cortabitarte, R.; Abbaneo, D.; Auffray, E.; Auzinger, G.; Baillon, P.; Ball, A. 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A.; Mersi, S.; Meschi, E.; Milenovic, P.; Moortgat, F.; Morovic, S.; Mulders, M.; Neugebauer, H.; Orfanelli, S.; Orsini, L.; Pape, L.; Perez, E.; Peruzzi, M.; Petrilli, A.; Petrucciani, G.; Pfeiffer, A.; Pierini, M.; Racz, A.; Reis, T.; Rolandi, G.; Rovere, M.; Sakulin, H.; Sauvan, J. B.; Schäfer, C.; Schwick, C.; Seidel, M.; Sharma, A.; Silva, P.; Sphicas, P.; Steggemann, J.; Stoye, M.; Takahashi, Y.; Tosi, M.; Treille, D.; Triossi, A.; Tsirou, A.; Veckalns, V.; Veres, G. I.; Verweij, M.; Wardle, N.; Wöhri, H. K.; Zagozdzinska, A.; Zeuner, W. D.; Bertl, W.; Deiters, K.; Erdmann, W.; Horisberger, R.; Ingram, Q.; Kaestli, H. C.; Kotlinski, D.; Langenegger, U.; Rohe, T.; Wiederkehr, S. A.; Bachmair, F.; Bäni, L.; Bianchini, L.; Casal, B.; Dissertori, G.; Dittmar, M.; Donegà, M.; Grab, C.; Heidegger, C.; Hits, D.; Hoss, J.; Kasieczka, G.; Lustermann, W.; Mangano, B.; Marionneau, M.; Martinez Ruiz del Arbol, P.; Masciovecchio, M.; Meinhard, M. T.; Meister, D.; Micheli, F.; Musella, P.; Nessi-Tedaldi, F.; Pandolfi, F.; Pata, J.; Pauss, F.; Perrin, G.; Perrozzi, L.; Quittnat, M.; Rossini, M.; Schönenberger, M.; Starodumov, A.; Tavolaro, V. R.; Theofilatos, K.; Wallny, R.; Aarrestad, T. K.; Amsler, C.; Caminada, L.; Canelli, M. F.; De Cosa, A.; Galloni, C.; Hinzmann, A.; Hreus, T.; Kilminster, B.; Ngadiuba, J.; Pinna, D.; Rauco, G.; Robmann, P.; Salerno, D.; Seitz, C.; Yang, Y.; Zucchetta, A.; Candelise, V.; Doan, T. H.; Jain, Sh.; Khurana, R.; Konyushikhin, M.; Kuo, C. M.; Lin, W.; Pozdnyakov, A.; Yu, S. S.; Kumar, Arun; Chang, P.; Chang, Y. H.; Chao, Y.; Chen, K. F.; Chen, P. H.; Fiori, F.; Hou, W.-S.; Hsiung, Y.; Liu, Y. F.; Lu, R.-S.; Miñano Moya, M.; Paganis, E.; Psallidas, A.; Tsai, J. f.; Asavapibhop, B.; Singh, G.; Srimanobhas, N.; Suwonjandee, N.; Adiguzel, A.; Bakirci, M. N.; Cerci, S.; Damarseckin, S.; Demiroglu, Z. S.; Dozen, C.; Dumanoglu, I.; Girgis, S.; Gokbulut, G.; Guler, Y.; Hos, I.; Kangal, E. E.; Kara, O.; Kayis Topaksu, A.; Kiminsu, U.; Oglakci, M.; Onengut, G.; Ozdemir, K.; Tali, B.; Turkcapar, S.; Zorbakir, I. S.; Zorbilmez, C.; Bilin, B.; Bilmis, S.; Isildak, B.; Karapinar, G.; Yalvac, M.; Zeyrek, M.; Gülmez, E.; Kaya, M.; Kaya, O.; Yetkin, E. A.; Yetkin, T.; Cakir, A.; Cankocak, K.; Sen, S.; Grynyov, B.; Levchuk, L.; Sorokin, P.; Aggleton, R.; Ball, F.; Beck, L.; Brooke, J. J.; Burns, D.; Clement, E.; Cussans, D.; Flacher, H.; Goldstein, J.; Grimes, M.; Heath, G. P.; Heath, H. F.; Jacob, J.; Kreczko, L.; Lucas, C.; Newbold, D. M.; Paramesvaran, S.; Poll, A.; Sakuma, T.; Seif El Nasr-storey, S.; Smith, D.; Smith, V. J.; Bell, K. W.; Belyaev, A.; Brew, C.; Brown, R. M.; Calligaris, L.; Cieri, D.; Cockerill, D. J. A.; Coughlan, J. A.; Harder, K.; Harper, S.; Olaiya, E.; Petyt, D.; Shepherd-Themistocleous, C. H.; Thea, A.; Tomalin, I. R.; Williams, T.; Baber, M.; Bainbridge, R.; Buchmuller, O.; Bundock, A.; Burton, D.; Casasso, S.; Citron, M.; Colling, D.; Corpe, L.; Dauncey, P.; Davies, G.; De Wit, A.; Della Negra, M.; Di Maria, R.; Dunne, P.; Elwood, A.; Futyan, D.; Haddad, Y.; Hall, G.; Iles, G.; James, T.; Lane, R.; Laner, C.; Lucas, R.; Lyons, L.; Magnan, A.-M.; Malik, S.; Mastrolorenzo, L.; Nash, J.; Nikitenko, A.; Pela, J.; Penning, B.; Pesaresi, M.; Raymond, D. M.; Richards, A.; Rose, A.; Scott, E.; Seez, C.; Summers, S.; Tapper, A.; Uchida, K.; Vazquez Acosta, M.; Virdee, T.; Wright, J.; Zenz, S. C.; Cole, J. E.; Hobson, P. R.; Khan, A.; Kyberd, P.; Reid, I. D.; Symonds, P.; Teodorescu, L.; Turner, M.; Borzou, A.; Call, K.; Dittmann, J.; Hatakeyama, K.; Liu, H.; Pastika, N.; Bartek, R.; Dominguez, A.; Buccilli, A.; Cooper, S. 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R.; Olmedo Negrete, M.; Paneva, M. I.; Shrinivas, A.; Si, W.; Wei, H.; Wimpenny, S.; Yates, B. R.; Branson, J. G.; Cerati, G. B.; Cittolin, S.; Derdzinski, M.; Gerosa, R.; Holzner, A.; Klein, D.; Krutelyov, V.; Letts, J.; Macneill, I.; Olivito, D.; Padhi, S.; Pieri, M.; Sani, M.; Sharma, V.; Simon, S.; Tadel, M.; Vartak, A.; Wasserbaech, S.; Welke, C.; Wood, J.; Würthwein, F.; Yagil, A.; Zevi Della Porta, G.; Amin, N.; Bhandari, R.; Bradmiller-Feld, J.; Campagnari, C.; Dishaw, A.; Dutta, V.; Franco Sevilla, M.; George, C.; Golf, F.; Gouskos, L.; Gran, J.; Heller, R.; Incandela, J.; Mullin, S. D.; Ovcharova, A.; Qu, H.; Richman, J.; Stuart, D.; Suarez, I.; Yoo, J.; Anderson, D.; Bendavid, J.; Bornheim, A.; Bunn, J.; Duarte, J.; Lawhorn, J. M.; Mott, A.; Newman, H. B.; Pena, C.; Spiropulu, M.; Vlimant, J. R.; Xie, S.; Zhu, R. Y.; Andrews, M. B.; Ferguson, T.; Paulini, M.; Russ, J.; Sun, M.; Vogel, H.; Vorobiev, I.; Weinberg, M.; Cumalat, J. P.; Ford, W. 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M.; Maruyama, S.; Mason, D.; McBride, P.; Merkel, P.; Mrenna, S.; Nahn, S.; O'Dell, V.; Pedro, K.; Prokofyev, O.; Rakness, G.; Ristori, L.; Sexton-Kennedy, E.; Soha, A.; Spalding, W. J.; Spiegel, L.; Stoynev, S.; Strait, J.; Strobbe, N.; Taylor, L.; Tkaczyk, S.; Tran, N. V.; Uplegger, L.; Vaandering, E. W.; Vernieri, C.; Verzocchi, M.; Vidal, R.; Wang, M.; Weber, H. A.; Whitbeck, A.; Wu, Y.; Acosta, D.; Avery, P.; Bortignon, P.; Bourilkov, D.; Brinkerhoff, A.; Carnes, A.; Carver, M.; Curry, D.; Das, S.; Field, R. D.; Furic, I. K.; Konigsberg, J.; Korytov, A.; Low, J. F.; Ma, P.; Matchev, K.; Mei, H.; Mitselmakher, G.; Rank, D.; Shchutska, L.; Sperka, D.; Thomas, L.; Wang, J.; Wang, S.; Yelton, J.; Linn, S.; Markowitz, P.; Martinez, G.; Rodriguez, J. L.; Ackert, A.; Adams, T.; Askew, A.; Bein, S.; Hagopian, S.; Hagopian, V.; Johnson, K. F.; Kolberg, T.; Prosper, H.; Santra, A.; Yohay, R.; Baarmand, M. M.; Bhopatkar, V.; Colafranceschi, S.; Hohlmann, M.; Noonan, D.; Roy, T.; Yumiceva, F.; Adams, M. R.; Apanasevich, L.; Berry, D.; Betts, R. R.; Bucinskaite, I.; Cavanaugh, R.; Evdokimov, O.; Gauthier, L.; Gerber, C. E.; Hofman, D. J.; Jung, K.; Sandoval Gonzalez, I. D.; Varelas, N.; Wang, H.; Wu, Z.; Zakaria, M.; Zhang, J.; Bilki, B.; Clarida, W.; Dilsiz, K.; Durgut, S.; Gandrajula, R. P.; Haytmyradov, M.; Khristenko, V.; Merlo, J.-P.; Mermerkaya, H.; Mestvirishvili, A.; Moeller, A.; Nachtman, J.; Ogul, H.; Onel, Y.; Ozok, F.; Penzo, A.; Snyder, C.; Tiras, E.; Wetzel, J.; Yi, K.; Blumenfeld, B.; Cocoros, A.; Eminizer, N.; Fehling, D.; Feng, L.; Gritsan, A. V.; Maksimovic, P.; Roskes, J.; Sarica, U.; Swartz, M.; Xiao, M.; You, C.; Al-bataineh, A.; Baringer, P.; Bean, A.; Boren, S.; Bowen, J.; Castle, J.; Forthomme, L.; Kenny, R. P.; Khalil, S.; Kropivnitskaya, A.; Majumder, D.; Mcbrayer, W.; Murray, M.; Sanders, S.; Stringer, R.; Tapia Takaki, J. D.; Wang, Q.; Ivanov, A.; Kaadze, K.; Maravin, Y.; Mohammadi, A.; Saini, L. K.; Skhirtladze, N.; Toda, S.; Rebassoo, F.; Wright, D.; Anelli, C.; Baden, A.; Baron, O.; Belloni, A.; Calvert, B.; Eno, S. C.; Ferraioli, C.; Gomez, J. A.; Hadley, N. J.; Jabeen, S.; Jeng, G. Y.; Kellogg, R. G.; Kunkle, J.; Mignerey, A. C.; Ricci-Tam, F.; Shin, Y. H.; Skuja, A.; Tonjes, M. B.; Tonwar, S. C.; Abercrombie, D.; Allen, B.; Apyan, A.; Azzolini, V.; Barbieri, R.; Baty, A.; Bi, R.; Bierwagen, K.; Brandt, S.; Busza, W.; Cali, I. A.; D'Alfonso, M.; Demiragli, Z.; Gomez Ceballos, G.; Goncharov, M.; Hsu, D.; Iiyama, Y.; Innocenti, G. M.; Klute, M.; Kovalskyi, D.; Krajczar, K.; Lai, Y. S.; Lee, Y.-J.; Levin, A.; Luckey, P. D.; Maier, B.; Marini, A. C.; Mcginn, C.; Mironov, C.; Narayanan, S.; Niu, X.; Paus, C.; Roland, C.; Roland, G.; Salfeld-Nebgen, J.; Stephans, G. S. F.; Tatar, K.; Velicanu, D.; Wang, J.; Wang, T. W.; Wyslouch, B.; Benvenuti, A. C.; Chatterjee, R. M.; Evans, A.; Hansen, P.; Kalafut, S.; Kao, S. C.; Kubota, Y.; Lesko, Z.; Mans, J.; Nourbakhsh, S.; Ruckstuhl, N.; Rusack, R.; Tambe, N.; Turkewitz, J.; Acosta, J. G.; Oliveros, S.; Avdeeva, E.; Bloom, K.; Claes, D. R.; Fangmeier, C.; Gonzalez Suarez, R.; Kamalieddin, R.; Kravchenko, I.; Malta Rodrigues, A.; Monroy, J.; Siado, J. E.; Snow, G. R.; Stieger, B.; Alyari, M.; Dolen, J.; Godshalk, A.; Harrington, C.; Iashvili, I.; Kaisen, J.; Nguyen, D.; Parker, A.; Rappoccio, S.; Roozbahani, B.; Alverson, G.; Barberis, E.; Hortiangtham, A.; Massironi, A.; Morse, D. M.; Nash, D.; Orimoto, T.; Teixeira De Lima, R.; Trocino, D.; Wang, R.-J.; Wood, D.; Bhattacharya, S.; Charaf, O.; Hahn, K. A.; Kumar, A.; Mucia, N.; Odell, N.; Pollack, B.; Schmitt, M. H.; Sung, K.; Trovato, M.; Velasco, M.; Dev, N.; Hildreth, M.; Hurtado Anampa, K.; Jessop, C.; Karmgard, D. J.; Kellams, N.; Lannon, K.; Marinelli, N.; Meng, F.; Mueller, C.; Musienko, Y.; Planer, M.; Reinsvold, A.; Ruchti, R.; Rupprecht, N.; Smith, G.; Taroni, S.; Wayne, M.; Wolf, M.; Woodard, A.; Alimena, J.; Antonelli, L.; Bylsma, B.; Durkin, L. S.; Flowers, S.; Francis, B.; Hart, A.; Hill, C.; Hughes, R.; Ji, W.; Liu, B.; Luo, W.; Puigh, D.; Winer, B. L.; Wulsin, H. W.; Cooperstein, S.; Driga, O.; Elmer, P.; Hardenbrook, J.; Hebda, P.; Lange, D.; Luo, J.; Marlow, D.; Medvedeva, T.; Mei, K.; Ojalvo, I.; Olsen, J.; Palmer, C.; Piroué, P.; Stickland, D.; Svyatkovskiy, A.; Tully, C.; Malik, S.; Barker, A.; Barnes, V. E.; Folgueras, S.; Gutay, L.; Jha, M. K.; Jones, M.; Jung, A. W.; Khatiwada, A.; Miller, D. H.; Neumeister, N.; Schulte, J. F.; Shi, X.; Sun, J.; Wang, F.; Xie, W.; Parashar, N.; Stupak, J.; Adair, A.; Akgun, B.; Chen, Z.; Ecklund, K. M.; Geurts, F. J. M.; Guilbaud, M.; Li, W.; Michlin, B.; Northup, M.; Padley, B. P.; Roberts, J.; Rorie, J.; Tu, Z.; Zabel, J.; Betchart, B.; Bodek, A.; de Barbaro, P.; Demina, R.; Duh, Y. t.; Ferbel, T.; Galanti, M.; Garcia-Bellido, A.; Han, J.; Hindrichs, O.; Khukhunaishvili, A.; Lo, K. H.; Tan, P.; Verzetti, M.; Agapitos, A.; Chou, J. P.; Gershtein, Y.; Gómez Espinosa, T. A.; Halkiadakis, E.; Heindl, M.; Hughes, E.; Kaplan, S.; Kunnawalkam Elayavalli, R.; Kyriacou, S.; Lath, A.; Nash, K.; Osherson, M.; Saka, H.; Salur, S.; Schnetzer, S.; Sheffield, D.; Somalwar, S.; Stone, R.; Thomas, S.; Thomassen, P.; Walker, M.; Delannoy, A. G.; Foerster, M.; Heideman, J.; Riley, G.; Rose, K.; Spanier, S.; Thapa, K.; Bouhali, O.; Celik, A.; Dalchenko, M.; De Mattia, M.; Delgado, A.; Dildick, S.; Eusebi, R.; Gilmore, J.; Huang, T.; Juska, E.; Kamon, T.; Mueller, R.; Pakhotin, Y.; Patel, R.; Perloff, A.; Perniè, L.; Rathjens, D.; Safonov, A.; Tatarinov, A.; Ulmer, K. A.; Akchurin, N.; Damgov, J.; De Guio, F.; Dragoiu, C.; Dudero, P. R.; Faulkner, J.; Gurpinar, E.; Kunori, S.; Lamichhane, K.; Lee, S. W.; Libeiro, T.; Peltola, T.; Undleeb, S.; Volobouev, I.; Wang, Z.; Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Sheldon, P.; Tuo, S.; Velkovska, J.; Xu, Q.; Arenton, M. W.; Barria, P.; Cox, B.; Goodell, J.; Hirosky, R.; Ledovskoy, A.; Li, H.; Neu, C.; Sinthuprasith, T.; Sun, X.; Wang, Y.; Wolfe, E.; Xia, F.; Clarke, C.; Harr, R.; Karchin, P. E.; Sturdy, J.; Belknap, D. A.; Buchanan, J.; Caillol, C.; Dasu, S.; Dodd, L.; Duric, S.; Gomber, B.; Grothe, M.; Herndon, M.; Hervé, A.; Klabbers, P.; Lanaro, A.; Levine, A.; Long, K.; Loveless, R.; Perry, T.; Pierro, G. A.; Polese, G.; Ruggles, T.; Savin, A.; Smith, N.; Smith, W. H.; Taylor, D.; Woods, N.; CMS Collaboration

2017-12-01

Transverse momentum spectra of charged pions, kaons, and protons are measured in proton-proton collisions at √{s }=13 TeV with the CMS detector at the LHC. The particles, identified via their energy loss in the silicon tracker, are measured in the transverse momentum range of pT≈0.1 - 1.7 GeV /c and rapidities |y | <1 . The pT spectra and integrated yields are compared to previous results at smaller √{s } and to predictions of Monte Carlo event generators. The average pT increases with particle mass and charged particle multiplicity of the event. Comparisons with previous CMS results at √{s }=0.9 , 2.76, and 7 TeV show that the average pT and the ratios of hadron yields feature very similar dependences on the particle multiplicity in the event, independently of the center-of-mass energy of the pp collision.

High-energy proton imaging for biomedical applications

NASA Astrophysics Data System (ADS)

Prall, M.; Durante, M.; Berger, T.; Przybyla, B.; Graeff, C.; Lang, P. M.; Latessa, C.; Shestov, L.; Simoniello, P.; Danly, C.; Mariam, F.; Merrill, F.; Nedrow, P.; Wilde, C.; Varentsov, D.

2016-06-01

The charged particle community is looking for techniques exploiting proton interactions instead of X-ray absorption for creating images of human tissue. Due to multiple Coulomb scattering inside the measured object it has shown to be highly non-trivial to achieve sufficient spatial resolution. We present imaging of biological tissue with a proton microscope. This device relies on magnetic optics, distinguishing it from most published proton imaging methods. For these methods reducing the data acquisition time to a clinically acceptable level has turned out to be challenging. In a proton microscope, data acquisition and processing are much simpler. This device even allows imaging in real time. The primary medical application will be image guidance in proton radiosurgery. Proton images demonstrating the potential for this application are presented. Tomographic reconstructions are included to raise awareness of the possibility of high-resolution proton tomography using magneto-optics.

Stable transport in proton driven fast ignition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bret, A.

2009-09-15

Proton beam transport in the context of proton driven fast ignition is usually assumed to be stable due to proton high inertia, but an analytical analysis of the process is still lacking. The stability of a charge and current neutralized proton beam passing through a plasma is therefore conducted here, for typical proton driven fast ignition parameters. In the cold regime, two fast growing modes are found, with an inverse growth rate much smaller than the beam time of flight to the target core. The stability issue is thus not so obvious, and kinetic effects are investigated. One unstable modemore » is found stabilized by the background plasma proton and electron temperatures. The second mode is also damped, providing the proton beam thermal spread is larger than {approx}10 keV. In fusion conditions, the beam propagation should therefore be stable.« less

The pressure distribution inside the proton.

PubMed

Burkert, V D; Elouadrhiri, L; Girod, F X

2018-05-01

The proton, one of the components of atomic nuclei, is composed of fundamental particles called quarks and gluons. Gluons are the carriers of the force that binds quarks together, and free quarks are never found in isolation-that is, they are confined within the composite particles in which they reside. The origin of quark confinement is one of the most important questions in modern particle and nuclear physics because confinement is at the core of what makes the proton a stable particle and thus provides stability to the Universe. The internal quark structure of the proton is revealed by deeply virtual Compton scattering 1,2 , a process in which electrons are scattered off quarks inside the protons, which  subsequently emit high-energy photons, which are detected in coincidence with the scattered electrons and recoil protons. Here we report a measurement of the pressure distribution experienced by the quarks in the proton. We find a strong repulsive pressure near the centre of the proton (up to 0.6 femtometres) and a binding pressure at greater distances. The average peak pressure near the centre is about 10 35 pascals, which exceeds the pressure estimated for the most densely packed known objects in the Universe, neutron stars 3 . This work opens up a new area of research on the fundamental gravitational properties of protons, neutrons and nuclei, which can provide access to their physical radii, the internal shear forces acting on the quarks and their pressure distributions.

Proton transfer in microbial electrolysis cells

DOE PAGES

Borole, Abhijeet P.; Lewis, Alex J.

2017-02-15

Proton transfer and electron transfer are of prime importance in the development of microbial electrochemical cells. While electron transfer is primarily controlled by biology, proton transfer is controlled by process engineering and cell design. To develop commercially feasible technologies around the concept of a bioelectrochemical cell, real feedstocks have to be explored and associated limitations have to be identified. Here in this study, the proton transfer rate was quantified for a microbial electrolysis cell (MEC) and its dependence on process parameters was investigated using a proton balance model. The reaction system consisted of a biomass-derived pyrolytic aqueous stream as amore » substrate producing hydrogen in a flow-through MEC. The proton transfer rate increased with anode flow rate and organic loading rate up to a maximum of 0.36 ± 0.01 moles per m 2 per h, equivalent to a hydrogen production rate of 9.08 L per L per day. Higher rates of hydrogen production, reaching 11.7 ± 0.2 L per L per day were achieved, when additional protons were provided via the cathode buffer. Electrochemical impedance spectroscopy shows that proton transfer was the dominant resistance in the production of hydrogen. The quantification of proton transfer rates for MECs with potential for biorefinery application and the demonstration of high hydrogen production rates approaching those required for commercial consideration indicate the strong potential of this technology for renewable hydrogen production. Understanding the transport phenomenon in bioelectrochemical cells is of great significance since these systems have potential for wide-ranging applications including energy production, bioremediation, chemical and nanomaterial synthesis, electro-fermentation, energy storage, desalination, and produced water treatment. Electron transfer in anode biofilms has been investigated extensively, but proton transfer studies are also important, since many cathodic half reactions

Proton transfer in microbial electrolysis cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borole, Abhijeet P.; Lewis, Alex J.

Proton transfer and electron transfer are of prime importance in the development of microbial electrochemical cells. While electron transfer is primarily controlled by biology, proton transfer is controlled by process engineering and cell design. To develop commercially feasible technologies around the concept of a bioelectrochemical cell, real feedstocks have to be explored and associated limitations have to be identified. Here in this study, the proton transfer rate was quantified for a microbial electrolysis cell (MEC) and its dependence on process parameters was investigated using a proton balance model. The reaction system consisted of a biomass-derived pyrolytic aqueous stream as amore » substrate producing hydrogen in a flow-through MEC. The proton transfer rate increased with anode flow rate and organic loading rate up to a maximum of 0.36 ± 0.01 moles per m 2 per h, equivalent to a hydrogen production rate of 9.08 L per L per day. Higher rates of hydrogen production, reaching 11.7 ± 0.2 L per L per day were achieved, when additional protons were provided via the cathode buffer. Electrochemical impedance spectroscopy shows that proton transfer was the dominant resistance in the production of hydrogen. The quantification of proton transfer rates for MECs with potential for biorefinery application and the demonstration of high hydrogen production rates approaching those required for commercial consideration indicate the strong potential of this technology for renewable hydrogen production. Understanding the transport phenomenon in bioelectrochemical cells is of great significance since these systems have potential for wide-ranging applications including energy production, bioremediation, chemical and nanomaterial synthesis, electro-fermentation, energy storage, desalination, and produced water treatment. Electron transfer in anode biofilms has been investigated extensively, but proton transfer studies are also important, since many cathodic half reactions

Excited state of protonated benzene and toluene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Esteves-López, Natalia; Dedonder-Lardeux, Claude; Jouvet, Christophe, E-mail: Christophe.jouvet@univ-amu.fr

We present photo-fragmentation electronic spectra of the simplest protonated aromatic molecules, protonated benzene and toluene, recorded under medium resolution conditions and compared with the photo-fragmentation spectrum of protonated pyridine. Despite the resolution and cold temperature achieved in the experiment, the electronic spectra of protonated benzene and toluene are structure-less, thus intrinsically broadened. This is in agreement with the large geometrical changes and the fast dynamic toward internal conversion predicted by ab initio calculations for protonated benzene [Rode et al., J. Phys. Chem. A 113, 5865–5873 (2009)].

Selected Topics from Top Mass Measurements at the Tevatron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwienhorst, Reinhard

The most recent results of the top-quark mass measurements at the Tevatron at Fermilab are presented. Data were collected in proton-antiproton collisions at sqrt{s}=1.96 TeV by the CDF and D0 experiments. Top quark mass measurements in the lepton+jets, dilepton and alljet final states as well as their combination and the extraction of the mass from the cross-section measurement are presented.

WE-D-BRB-01: Basic Physics of Proton Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arjomandy, B.

The goal of this session is to review the physics of proton therapy, treatment planning techniques, and the use of volumetric imaging in proton therapy. The course material covers the physics of proton interaction with matter and physical characteristics of clinical proton beams. It will provide information on proton delivery systems and beam delivery techniques for double scattering (DS), uniform scanning (US), and pencil beam scanning (PBS). The session covers the treatment planning strategies used in DS, US, and PBS for various anatomical sites, methods to address uncertainties in proton therapy and uncertainty mitigation to generate robust treatment plans. Itmore » introduces the audience to the current status of image guided proton therapy and clinical applications of CBCT for proton therapy. It outlines the importance of volumetric imaging in proton therapy. Learning Objectives: Gain knowledge in proton therapy physics, and treatment planning for proton therapy including intensity modulated proton therapy. The current state of volumetric image guidance equipment in proton therapy. Clinical applications of CBCT and its advantage over orthogonal imaging for proton therapy. B. Teo, B.K Teo had received travel funds from IBA in 2015.« less

Proton decay of 73Rb

NASA Astrophysics Data System (ADS)

Rogers, Andrew; Anderson, C.; Barney, J.; Estee, J.; Lynch, W. G.; Manfredi, J.; Setiawan, H.; Showalter, R. H.; Sweany, S.; Tangwancharoen, S.; Tsang, M. B.; Winkelbauer, J. R.; Brown, K. W.; Elson, J. M.; Pruitt, C.; Sobotka, L. G.; Chajecki, Z.; Lee, J.

2017-09-01

Properties of nuclei beyond the proton drip-line are important for mass models, nuclear structure, and astrophysics. Weakly-bound or proton-unbound nuclei near the rp-process waiting points, such as the unbound Tz = -1/2 nucleus 73Rb, play a critical role in constraining calculations and observations of type I x-ray bursts. For instance, the rp process is greatly slowed near 72Kr (N = Z) due to its relatively long β-decay half life and inhibited proton capture. This waiting point, however, may be bypassed by sequential 2p-capture through 73Rb -a reaction which is sensitive to the 73Rb proton separation energy, Sp. Using invariant-mass spectroscopy, we have performed an experiment at NSCL to measure the decay of 73Rb ->p+72Kr in an attempt to directly determine Sp (73Rb) . Analysis of reconstructed proton-emission spectra and decay signatures will be discussed. This work is supported by the U.S. DOE Office of Nuclear Physics, Award No. DE-FG02-94ER40848.

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

DOE PAGES

Aad, G.; Abbott, B.; Abdallah, J.; ...

2013-03-02

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of √s = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K s and Λ particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scalemore » uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2–5 % for central isolated hadrons and 1–3 % for the final calorimeter jet energy scale.« less

Top anti-top Asymmetries at the Tevatron and the LHC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, Yvonne Reinhild

2012-11-01

The heaviest known elementary particle today, the top quark, has been discovered in 1995 by the CDF and D0 collaborations at the Tevatron proton antiproton collider at Fermilab. Recently, the CDF and D0 collaborations have studied the forward-backward asymmetry in ttbar events, resulting in measured values larger than the standard model prediction. With the start of the LHC at CERN in 2010, a new top quark factory has opened and asymmetry measurements in ttbar have also been performed in a proton proton environment with higher collision energy. No deviations from the standard model have been noticed so far in themore » measurements of ATLAS and CMS. This article discusses recent results of asymmetry measurements in ttbar events of the ATLAS, CDF, CMS and D0 collaborations.« less

High-energy proton imaging for biomedical applications

DOE PAGES

Prall, Matthias; Durante, Marco; Berger, Thomas; ...

2016-06-10

The charged particle community is looking for techniques exploiting proton interactions instead of X-ray absorption for creating images of human tissue. Due to multiple Coulomb scattering inside the measured object it has shown to be highly non-trivial to achieve sufficient spatial resolution. We present imaging of biological tissue with a proton microscope. This device relies on magnetic optics, distinguishing it from most published proton imaging methods. For these methods reducing the data acquisition time to a clinically acceptable level has turned out to be challenging. In a proton microscope, data acquisition and processing are much simpler. This device even allowsmore » imaging in real time. The primary medical application will be image guidance in proton radiosurgery. Proton images demonstrating the potential for this application are presented. As a result, tomographic reconstructions are included to raise awareness of the possibility of high-resolution proton tomography using magneto-optics.« less

High-energy proton imaging for biomedical applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prall, Matthias; Durante, Marco; Berger, Thomas

The charged particle community is looking for techniques exploiting proton interactions instead of X-ray absorption for creating images of human tissue. Due to multiple Coulomb scattering inside the measured object it has shown to be highly non-trivial to achieve sufficient spatial resolution. We present imaging of biological tissue with a proton microscope. This device relies on magnetic optics, distinguishing it from most published proton imaging methods. For these methods reducing the data acquisition time to a clinically acceptable level has turned out to be challenging. In a proton microscope, data acquisition and processing are much simpler. This device even allowsmore » imaging in real time. The primary medical application will be image guidance in proton radiosurgery. Proton images demonstrating the potential for this application are presented. As a result, tomographic reconstructions are included to raise awareness of the possibility of high-resolution proton tomography using magneto-optics.« less

Proton Therapy for Head and Neck Cancer.

PubMed

Kim, Joseph K; Leeman, Jonathan E; Riaz, Nadeem; McBride, Sean; Tsai, Chiaojung Jillian; Lee, Nancy Y

2018-05-09

The application of proton beam radiation therapy in the treatment of head and neck cancer has grown tremendously in the past few years. Globally, widespread interest in proton beam therapy has led to multiple research efforts regarding its therapeutic value and cost-effectiveness. The current standard of care using modern photon radiation technology has demonstrated excellent treatment outcomes, yet there are some situations where disease control remains suboptimal with the potential for detrimental acute and chronic toxicities. Due to the advantageous physical properties of the proton beam, proton beam therapy may be superior to photon therapy in some patient subsets for both disease control and patient quality of life. As enthusiasm and excitement for proton beam therapy continue to increase, clinical research and widespread adoption will elucidate the true value of proton beam therapy and give a greater understanding of the full risks and benefits of proton therapy in head and neck cancer.

Reconstruction for proton computed tomography by tracing proton trajectories: A Monte Carlo study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li Tianfang; Liang Zhengrong; Singanallur, Jayalakshmi V.

Proton computed tomography (pCT) has been explored in the past decades because of its unique imaging characteristics, low radiation dose, and its possible use for treatment planning and on-line target localization in proton therapy. However, reconstruction of pCT images is challenging because the proton path within the object to be imaged is statistically affected by multiple Coulomb scattering. In this paper, we employ GEANT4-based Monte Carlo simulations of the two-dimensional pCT reconstruction of an elliptical phantom to investigate the possible use of the algebraic reconstruction technique (ART) with three different path-estimation methods for pCT reconstruction. The first method assumes amore » straight-line path (SLP) connecting the proton entry and exit positions, the second method adapts the most-likely path (MLP) theoretically determined for a uniform medium, and the third method employs a cubic spline path (CSP). The ART reconstructions showed progressive improvement of spatial resolution when going from the SLP [2 line pairs (lp) cm{sup -1}] to the curved CSP and MLP path estimates (5 lp cm{sup -1}). The MLP-based ART algorithm had the fastest convergence and smallest residual error of all three estimates. This work demonstrates the advantage of tracking curved proton paths in conjunction with the ART algorithm and curved path estimates.« less

Ring current proton decay by charge exchange

NASA Technical Reports Server (NTRS)

Smith, P. H.; Hoffman, R. A.; Fritz, T.

1975-01-01

Explorer 45 measurements during the recovery phase of a moderate magnetic storm have confirmed that the charge exchange decay mechanism can account for the decay of the storm-time proton ring current. Data from the moderate magnetic storm of 24 February 1972 was selected for study since a symmetrical ring current had developed and effects due to asymmetric ring current losses could be eliminated. It was found that after the initial rapid decay of the proton flux, the equatorially mirroring protons in the energy range 5 to 30 keV decayed throughout the L-value range of 3.5 to 5.0 at the charge exchange decay rate calculated by Liemohn. After several days of decay, the proton fluxes reached a lower limit where an apparent equilibrium was maintained, between weak particle source mechanisms and the loss mechanisms, until fresh protons were injected into the ring current region during substorms. While other proton loss mechanisms may also be operating, the results indicate that charge exchange can entirely account for the storm-time proton ring current decay, and that this mechanism must be considered in all studies involving the loss of proton ring current particles.

Proton upsets in LSI memories in space

NASA Technical Reports Server (NTRS)

Mcnulty, P. J.; Wyatt, R. C.; Filz, R. C.; Rothwell, P. L.; Farrell, G. E.

1980-01-01

Two types of large scale integrated dynamic random access memory devices were tested and found to be subject to soft errors when exposed to protons incident at energies between 18 and 130 MeV. These errors are shown to differ significantly from those induced in the same devices by alphas from an Am-241 source. There is considerable variation among devices in their sensitivity to proton-induced soft errors, even among devices of the same type. For protons incident at 130 MeV, the soft error cross sections measured in these experiments varied from 10 to the -8th to 10 to the -6th sq cm/proton. For individual devices, however, the soft error cross section consistently increased with beam energy from 18-130 MeV. Analysis indicates that the soft errors induced by energetic protons result from spallation interactions between the incident protons and the nuclei of the atoms comprising the device. Because energetic protons are the most numerous of both the galactic and solar cosmic rays and form the inner radiation belt, proton-induced soft errors have potentially serious implications for many electronic systems flown in space.

Enhanced production of multi-strange hadrons in high-multiplicity proton-proton collisions

NASA Astrophysics Data System (ADS)

Adam, J.; Adamová, D.; Aggarwal, M. M.; Rinella, G. Aglieri; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, S.; Ahn, S. U.; Aiola, S.; Akindinov, A.; Alam, S. N.; Albuquerque, D. S. D.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Molina, R. Alfaro; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Prado, C. Alves Garcia; An, M.; Andrei, C.; Andrews, H. A.; Andronic, A.; Anguelov, V.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Arnaldi, R.; Arnold, O. W.; Arsene, I. C.; Arslandok, M.; Audurier, B.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Balasubramanian, S.; Baldisseri, A.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Barth, K.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Camejo, A. Batista; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Martinez, H. Bello; Bellwied, R.; Belmont, R.; Belmont-Moreno, E.; Beltran, L. G. E.; Belyaev, V.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biro, G.; Biswas, R.; Biswas, S.; Bjelogrlic, S.; Blair, J. T.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Boldizsár, L.; Bombara, M.; Bonora, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Bossú, F.; Botta, E.; Bourjau, C.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Butt, J. B.; Buxton, J. T.; Cabala, J.; Caffarri, D.; Cai, X.; Caines, H.; Diaz, L. Calero; Caliva, A.; Villar, E. Calvo; Camerini, P.; Carena, F.; Carena, W.; Carnesecchi, F.; Castellanos, J. Castillo; Castro, A. J.; Casula, E. A. R.; Sanchez, C. Ceballos; Cepila, J.; Cerello, P.; Cerkala, J.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chauvin, A.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Barroso, V. Chibante; Chinellato, D. D.; Cho, S.; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Balbastre, G. Conesa; Del Valle, Z. Conesa; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Morales, Y. Corrales; Maldonado, I. Cortés; Cortese, P.; Cosentino, M. R.; Costa, F.; Crkovska, J.; Crochet, P.; Albino, R. Cruz; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danisch, M. C.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; de, S.; de Caro, A.; de Cataldo, G.; de Conti, C.; de Cuveland, J.; de Falco, A.; de Gruttola, D.; De Marco, N.; de Pasquale, S.; de Souza, R. D.; Deisting, A.; Deloff, A.; Dénes, E.; Deplano, C.; Dhankher, P.; di Bari, D.; di Mauro, A.; di Nezza, P.; di Ruzza, B.; Corchero, M. A. Diaz; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Gimenez, D. Domenicis; Dönigus, B.; Dordic, O.; Drozhzhova, T.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Endress, E.; Engel, H.; Epple, E.; Erazmus, B.; Erdemir, I.; Erhardt, F.; Espagnon, B.; Estienne, M.; Esumi, S.; Eum, J.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabbietti, L.; Fabris, D.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Téllez, A. Fernández; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Feuillard, V. J. G.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. 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L.; La Rocca, P.; de Guevara, P. Ladron; Fernandes, C. Lagana; Lakomov, I.; Langoy, R.; Lapidus, K.; Lara, C.; Lardeux, A.; Lattuca, A.; Laudi, E.; Lea, R.; Leardini, L.; Lee, S.; Lehas, F.; Lehner, S.; Lemmon, R. C.; Lenti, V.; Leogrande, E.; Monzón, I. León; Vargas, H. León; Leoncino, M.; Lévai, P.; Li, S.; Li, X.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Ljunggren, H. M.; Lodato, D. F.; Loenne, P. I.; Loginov, V.; Loizides, C.; Lopez, X.; Torres, E. López; Lowe, A.; Luettig, P.; Lunardon, M.; Luparello, G.; Lupi, M.; Lutz, T. H.; Maevskaya, A.; Mager, M.; Mahajan, S.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Cervantes, I. Maldonado; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Margutti, J.; Marín, A.; Markert, C.; Marquard, M.; Martin, N. A.; Martinengo, P.; Martínez, M. I.; García, G. Martínez; Pedreira, M. Martinez; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Mastroserio, A.; Matyja, A.; Mayer, C.; Mazer, J.; Mazzilli, M.; Mazzoni, M. A.; McDonald, D.; Meddi, F.; Melikyan, Y.; Menchaca-Rocha, A.; Meninno, E.; Pérez, J. Mercado; Meres, M.; Mhlanga, S.; Miake, Y.; Mieskolainen, M. M.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Mischke, A.; Mishra, A. N.; Mishra, T.; Miśkowiec, D.; Mitra, J.; Mitu, C. M.; Mohammadi, N.; Mohanty, B.; Molnar, L.; Zetina, L. Montaño; Montes, E.; de Godoy, D. A. Moreira; Moreno, L. A. P.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Mühlheim, D.; Muhuri, S.; Mukherjee, M.; Mulligan, J. D.; Munhoz, M. G.; Münning, K.; Munzer, R. H.; Murakami, H.; Murray, S.; Musa, L.; Musinsky, J.; Naik, B.; Nair, R.; Nandi, B. K.; Nania, R.; Nappi, E.; Naru, M. U.; da Luz, H. Natal; Nattrass, C.; Navarro, S. R.; Nayak, K.; Nayak, R.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; de Oliveira, R. A. Negrao; Nellen, L.; Ng, F.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Noferini, F.; Nomokonov, P.; Nooren, G.; Noris, J. C. C.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Oh, S. K.; Ohlson, A.; Okatan, A.; Okubo, T.; Oleniacz, J.; da Silva, A. C. Oliveira; Oliver, M. H.; Onderwaater, J.; Oppedisano, C.; Orava, R.; Oravec, M.; Velasquez, A. Ortiz; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Ozdemir, M.; Pachmayer, Y.; Pagano, D.; Pagano, P.; Paić, G.; Pal, S. K.; Palni, P.; Pan, J.; Pandey, A. K.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, W. J.; Parmar, S.; Passfeld, A.; Paticchio, V.; Patra, R. N.; Paul, B.; Pei, H.; Peitzmann, T.; Peng, X.; da Costa, H. Pereira; Peresunko, D.; Lezama, E. Perez; Peskov, V.; Pestov, Y.; Petráček, V.; Petrov, V.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pimentel, L. O. D. L.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Płoskoń, M.; Planinic, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L. M.; Poghosyan, M. G.; Polichtchouk, B.; Poljak, N.; Poonsawat, W.; Pop, A.; Poppenborg, H.; Porteboeuf-Houssais, S.; Porter, J.; Pospisil, J.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Rami, F.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rascanu, B. T.; Rathee, D.; Ravasenga, I.; Read, K. F.; Redlich, K.; Reed, R. J.; Rehman, A.; Reichelt, P.; Reidt, F.; Ren, X.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Ristea, C.; Cahuantzi, M. Rodríguez; Manso, A. Rodriguez; Røed, K.; Rogochaya, E.; Rohr, D.; Röhrich, D.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Montero, A. J. Rubio; Rui, R.; Russo, R.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Saarinen, S.; Sadhu, S.; Sadovsky, S.; Šafařík, K.; Sahlmuller, B.; Sahoo, P.; Sahoo, R.; Sahoo, S.; Sahu, P. K.; Saini, J.; Sakai, S.; Saleh, M. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Šándor, L.; Sandoval, A.; Sano, M.; Sarkar, D.; Sarkar, N.; Sarma, P.; Scapparone, E.; Scarlassara, F.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schmidt, M.; Schuchmann, S.; Schukraft, J.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Šefčík, M.; Seger, J. E.; Sekiguchi, Y.; Sekihata, D.; Selyuzhenkov, I.; Senosi, K.; Senyukov, S.; Serradilla, E.; Sevcenco, A.; Shabanov, A.; Shabetai, A.; Shadura, O.; Shahoyan, R.; Shangaraev, A.; Sharma, A.; Sharma, M.; Sharma, M.; Sharma, N.; Sheikh, A. I.; Shigaki, K.; Shou, Q.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Sielewicz, K. M.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Simonetti, G.; Singaraju, R.; Singh, R.; Singhal, V.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Slupecki, M.; Smirnov, N.; Snellings, R. J. M.; Snellman, T. W.; Song, J.; Song, M.; Song, Z.; Soramel, F.; Sorensen, S.; Sozzi, F.; Spiriti, E.; Sputowska, I.; Spyropoulou-Stassinaki, M.; Stachel, J.; Stan, I.; Stankus, P.; Stenlund, E.; Steyn, G.; Stiller, J. H.; Stocco, D.; Strmen, P.; Suaide, A. A. P.; Sugitate, T.; Suire, C.; Suleymanov, M.; Suljic, M.; Sultanov, R.; Šumbera, M.; Sumowidagdo, S.; Swain, S.; Szabo, A.; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Tabassam, U.; Takahashi, J.; Tambave, G. J.; Tanaka, N.; Tarhini, M.; Tariq, M.; Tarzila, M. G.; Tauro, A.; Muñoz, G. Tejeda; Telesca, A.; Terasaki, K.; Terrevoli, C.; Teyssier, B.; Thäder, J.; Thakur, D.; Thomas, D.; Tieulent, R.; Tikhonov, A.; Timmins, A. R.; Toia, A.; Trogolo, S.; Trombetta, G.; Trubnikov, V.; Trzaska, W. H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ullaland, K.; Uras, A.; Usai, G. L.; Utrobicic, A.; Vala, M.; Palomo, L. Valencia; van der Maarel, J.; van Hoorne, J. W.; van Leeuwen, M.; Vanat, T.; Vyvre, P. Vande; Varga, D.; Vargas, A.; Vargyas, M.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vauthier, A.; Doce, O. Vázquez; Vechernin, V.; Veen, A. M.; Velure, A.; Vercellin, E.; Limón, S. Vergara; Vernet, R.; Vickovic, L.; Viinikainen, J.; Vilakazi, Z.; Baillie, O. Villalobos; Tello, A. Villatoro; Vinogradov, A.; Vinogradov, L.; Virgili, T.; Vislavicius, V.; Viyogi, Y. P.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; von Haller, B.; Vorobyev, I.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Wagner, B.; Wagner, J.; Wang, H.; Wang, M.; Watanabe, D.; Watanabe, Y.; Weber, M.; Weber, S. G.; Weiser, D. F.; Wessels, J. P.; Westerhoff, U.; Whitehead, A. M.; Wiechula, J.; Wikne, J.; Wilk, G.; Wilkinson, J.; Willems, G. A.; Williams, M. C. S.; Windelband, B.; Winn, M.; Yalcin, S.; Yang, P.; Yano, S.; Yin, Z.; Yokoyama, H.; Yoo, I.-K.; Yoon, J. H.; Yurchenko, V.; Zaborowska, A.; Zaccolo, V.; Zaman, A.; Zampolli, C.; Zanoli, H. J. C.; Zaporozhets, S.; Zardoshti, N.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zgura, I. S.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhang, C.; Zhang, Z.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, Y.; Zhou, Z.; Zhu, H.; Zhu, J.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zyzak, M.

2017-06-01

At sufficiently high temperature and energy density, nuclear matter undergoes a transition to a phase in which quarks and gluons are not confined: the quark-gluon plasma (QGP). Such an exotic state of strongly interacting quantum chromodynamics matter is produced in the laboratory in heavy nuclei high-energy collisions, where an enhanced production of strange hadrons is observed. Strangeness enhancement, originally proposed as a signature of QGP formation in nuclear collisions, is more pronounced for multi-strange baryons. Several effects typical of heavy-ion phenomenology have been observed in high-multiplicity proton-proton (pp) collisions, but the enhanced production of multi-strange particles has not been reported so far. Here we present the first observation of strangeness enhancement in high-multiplicity proton-proton collisions. We find that the integrated yields of strange and multi-strange particles, relative to pions, increases significantly with the event charged-particle multiplicity. The measurements are in remarkable agreement with the p-Pb collision results, indicating that the phenomenon is related to the final system created in the collision. In high-multiplicity events strangeness production reaches values similar to those observed in Pb-Pb collisions, where a QGP is formed.

Measuring the Weak Charge of the Proton via Elastic Electron-Proton Scattering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Donald C.

2015-10-01

The Qweak experiment which ran in Hall C at Jefferson Lab in Newport News, VA, and completed data taking in May 2012, measured the weak charge of the proton Q p W via elastic electron-proton scattering. Longitudinally polarized electrons were scattered from an unpolarized liquid hydrogen target. The helicity of the electron beam was flipped at approximately 1 kHz between left and right spin states. The Standard Model predicts a small parity-violating asymmetry of scattering rates between right and left helicity states due to the weak interaction. An initial result using 4% of the data was published in October 2013more » [1] with a measured parity-violating asymmetry of -279 ± 35(stat) ± 31 (syst) ppb. This asymmetry, along with other data from parity-violating electron scattering experiments, provided the world's first determination of the weak charge of the proton. The weak charge of the proton was found to be p W = 0.064 ± 0.012, in good agreement with the Standard Model prediction of p W(SM) = 0.0708 ± 0.0003[2].« less

High density scintillating glass proton imaging detector

NASA Astrophysics Data System (ADS)

Wilkinson, C. J.; Goranson, K.; Turney, A.; Xie, Q.; Tillman, I. J.; Thune, Z. L.; Dong, A.; Pritchett, D.; McInally, W.; Potter, A.; Wang, D.; Akgun, U.

2017-03-01

In recent years, proton therapy has achieved remarkable precision in delivering doses to cancerous cells while avoiding healthy tissue. However, in order to utilize this high precision treatment, greater accuracy in patient positioning is needed. An accepted approximate uncertainty of +/-3% exists in the current practice of proton therapy due to conversions between x-ray and proton stopping power. The use of protons in imaging would eliminate this source of error and lessen the radiation exposure of the patient. To this end, this study focuses on developing a novel proton-imaging detector built with high-density glass scintillator. The model described herein contains a compact homogeneous proton calorimeter composed of scintillating, high density glass as the active medium. The unique geometry of this detector allows for the measurement of both the position and residual energy of protons, eliminating the need for a separate set of position trackers in the system. Average position and energy of a pencil beam of 106 protons is used to reconstruct the image rather than by analyzing individual proton data. Simplicity and efficiency were major objectives in this model in order to present an imaging technique that is compact, cost-effective, and precise, as well as practical for a clinical setting with pencil-beam scanning proton therapy equipment. In this work, the development of novel high-density glass scintillator and the unique conceptual design of the imager are discussed; a proof-of-principle Monte Carlo simulation study is performed; preliminary two-dimensional images reconstructed from the Geant4 simulation are presented.

The pressure distribution inside the proton

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burkert, V. D.; Elouadrhiri, L.; Girod, F. X.

The proton, one of the components of atomic nuclei, is composed of fundamental particles called quarks and gluons. Gluons are the carriers of the force that binds quarks together, and free quarks are never found in isolation—that is, they are confined within the composite particles in which they reside. The origin of quark confinement is one of the most important questions in modern particle and nuclear physics because confinement is at the core of what makes the proton a stable particle and thus provides stability to the Universe. The internal quark structure of the proton is revealed by deeply virtualmore » Compton scattering1,2, a process in which electrons are scattered off quarks inside the protons, which subsequently emit high-energy photons, which are detected in coincidence with the scattered electrons and recoil protons. Here we report a measurement of the pressure distribution experienced by the quarks in the proton. We find a strong repulsive pressure near the centre of the proton (up to 0.6 femtometres) and a binding pressure at greater distances. The average peak pressure near the centre is about 1035 pascals, which exceeds the pressure estimated for the most densely packed known objects in the Universe, neutron stars3. This work opens up a new area of research on the fundamental gravitational properties of protons, neutrons and nuclei, which can provide access to their physical radii, the internal shear forces acting on the quarks and their pressure distributions.« less

Treatment planning optimisation in proton therapy

PubMed Central

McGowan, S E; Burnet, N G; Lomax, A J

2013-01-01

ABSTRACT. The goal of radiotherapy is to achieve uniform target coverage while sparing normal tissue. In proton therapy, the same sources of geometric uncertainty are present as in conventional radiotherapy. However, an important and fundamental difference in proton therapy is that protons have a finite range, highly dependent on the electron density of the material they are traversing, resulting in a steep dose gradient at the distal edge of the Bragg peak. Therefore, an accurate knowledge of the sources and magnitudes of the uncertainties affecting the proton range is essential for producing plans which are robust to these uncertainties. This review describes the current knowledge of the geometric uncertainties and discusses their impact on proton dose plans. The need for patient-specific validation is essential and in cases of complex intensity-modulated proton therapy plans the use of a planning target volume (PTV) may fail to ensure coverage of the target. In cases where a PTV cannot be used, other methods of quantifying plan quality have been investigated. A promising option is to incorporate uncertainties directly into the optimisation algorithm. A further development is the inclusion of robustness into a multicriteria optimisation framework, allowing a multi-objective Pareto optimisation function to balance robustness and conformity. The question remains as to whether adaptive therapy can become an integral part of a proton therapy, to allow re-optimisation during the course of a patient's treatment. The challenge of ensuring that plans are robust to range uncertainties in proton therapy remains, although these methods can provide practical solutions. PMID:23255545

Measurement of pion, kaon and proton production in proton-proton collisions at [Formula: see text] TeV.

PubMed

Adam, J; Adamová, D; Aggarwal, M M; Rinella, G Aglieri; Agnello, M; Agrawal, N; Ahammed, Z; Ahmed, I; Ahn, S U; Aimo, I; Aiola, S; Ajaz, M; Akindinov, A; Alam, S N; Aleksandrov, D; Alessandro, B; Alexandre, D; Molina, R Alfaro; Alici, A; Alkin, A; Alme, J; Alt, T; Altinpinar, S; Altsybeev, I; Prado, C Alves Garcia; Andrei, C; Andronic, A; Anguelov, V; Anielski, J; Antičić, T; Antinori, F; Antonioli, P; Aphecetche, L; Appelshäuser, H; Arcelli, S; Armesto, N; Arnaldi, R; Aronsson, T; Arsene, I C; Arslandok, M; Augustinus, A; Averbeck, R; Azmi, M D; Bach, M; Badalà, A; Baek, Y W; Bagnasco, S; Bailhache, R; Bala, R; Baldisseri, A; Ball, M; Pedrosa, F Baltasar Dos Santos; Baral, R C; Barbano, A M; Barbera, R; Barile, F; Barnaföldi, G G; Barnby, L S; Barret, V; Bartalini, P; Bartke, J; Bartsch, E; Basile, M; Bastid, N; Basu, S; Bathen, B; Batigne, G; Camejo, A Batista; Batyunya, B; Batzing, P C; Bearden, I G; Beck, H; Bedda, C; Behera, N K; Belikov, I; Bellini, F; Martinez, H Bello; Bellwied, R; Belmont, R; Belmont-Moreno, E; Belyaev, V; Bencedi, G; Beole, S; Berceanu, I; Bercuci, A; Berdnikov, Y; Berenyi, D; Bertens, R A; Berzano, D; Betev, L; Bhasin, A; Bhat, I R; Bhati, A K; Bhattacharjee, B; Bhom, J; Bianchi, L; Bianchi, N; Bianchin, C; Bielčík, J; Bielčíková, J; Bilandzic, A; Biswas, S; Bjelogrlic, S; Blanco, F; Blau, D; Blume, C; Bock, F; Bogdanov, A; Bøggild, H; Boldizsár, L; Bombara, M; Book, J; Borel, H; Borissov, A; Borri, M; Bossú, F; Botje, M; Botta, E; Böttger, S; Braun-Munzinger, P; Bregant, M; Breitner, T; Broker, T A; Browning, T A; Broz, M; Brucken, E J; Bruna, E; Bruno, G E; Budnikov, D; Buesching, H; Bufalino, S; Buncic, P; Busch, O; Buthelezi, Z; Buxton, J T; Caffarri, D; Cai, X; Caines, H; Diaz, L Calero; Caliva, A; Villar, E Calvo; Camerini, P; Carena, F; Carena, W; Castellanos, J Castillo; Castro, A J; Casula, E A R; Cavicchioli, C; Sanchez, C Ceballos; Cepila, J; Cerello, P; Chang, B; Chapeland, S; Chartier, M; Charvet, J L; Chattopadhyay, S; Chattopadhyay, S; 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Elia, D; Engel, H; Erazmus, B; Erhardt, F; Eschweiler, D; Espagnon, B; Estienne, M; Esumi, S; Eum, J; Evans, D; Evdokimov, S; Eyyubova, G; Fabbietti, L; Fabris, D; Faivre, J; Fantoni, A; Fasel, M; Feldkamp, L; Felea, D; Feliciello, A; Feofilov, G; Ferencei, J; Téllez, A Fernández; Ferreiro, E G; Ferretti, A; Festanti, A; Figiel, J; Figueredo, M A S; Filchagin, S; Finogeev, D; Fionda, F M; Fiore, E M; Fleck, M G; Floris, M; Foertsch, S; Foka, P; Fokin, S; Fragiacomo, E; Francescon, A; Frankenfeld, U; Fuchs, U; Furget, C; Furs, A; Girard, M Fusco; Gaardhøje, J J; Gagliardi, M; Gago, A M; Gallio, M; Gangadharan, D R; Ganoti, P; Gao, C; Garabatos, C; Garcia-Solis, E; Gargiulo, C; Gasik, P; Germain, M; Gheata, A; Gheata, M; Ghosh, P; Ghosh, S K; Gianotti, P; Giubellino, P; Giubilato, P; Dziadus, E Gladysz; Glässel, P; Ramirez, A Gomez; Zamora, P González; Gorbunov, S; Görlich, L; Gotovac, S; Grabski, V; Graczykowski, L K; Grelli, A; Grigoras, A; Grigoras, C; Grigoriev, V; Grigoryan, A; Grigoryan, S; Grinyov, B; Grion, N; Grosse-Oetringhaus, J F; Grossiord, J-Y; Grosso, R; Guber, F; Guernane, R; Guerzoni, B; Gulbrandsen, K; Gulkanyan, H; Gunji, T; Gupta, A; Gupta, R; Haake, R; Haaland, Ø; Hadjidakis, C; Haiduc, M; Hamagaki, H; Hamar, G; Hanratty, L D; Hansen, A; Harris, J W; Hartmann, H; Harton, A; Hatzifotiadou, D; Hayashi, S; Heckel, S T; Heide, M; Helstrup, H; Herghelegiu, A; Corral, G Herrera; Hess, B A; Hetland, K F; Hilden, T E; Hillemanns, H; Hippolyte, B; Hristov, P; Huang, M; Humanic, T J; Hussain, N; Hussain, T; Hutter, D; Hwang, D S; Ilkaev, R; Ilkiv, I; Inaba, M; Ionita, C; Ippolitov, M; Irfan, M; Ivanov, M; Ivanov, V; Izucheev, V; Jacobs, P M; Jahnke, C; Jang, H J; Janik, M A; Jayarathna, P H S Y; Jena, C; Jena, S; Bustamante, R T Jimenez; Jones, P G; Jung, H; Jusko, A; Kalinak, P; Kalweit, A; Kamin, J; Kang, J H; Kaplin, V; Kar, S; Uysal, A Karasu; Karavichev, O; Karavicheva, T; Karpechev, E; Kebschull, U; Keidel, R; Keijdener, D L D; Keil, M; Khan, K H; Khan, M M; Khan, P; Khan, S A; Khanzadeev, A; Kharlov, Y; Kileng, B; Kim, B; Kim, D W; Kim, D J; Kim, H; Kim, J S; Kim, M; Kim, M; Kim, S; Kim, T; Kirsch, S; Kisel, I; Kiselev, S; Kisiel, A; Kiss, G; Klay, J L; Klein, C; Klein, J; Klein-Bösing, C; Kluge, A; Knichel, M L; Knospe, A G; Kobayashi, T; Kobdaj, C; Kofarago, M; Köhler, M K; Kollegger, T; Kolojvari, A; Kondratiev, V; Kondratyeva, N; Kondratyuk, E; Konevskikh, A; Kouzinopoulos, C; Kovalenko, O; Kovalenko, V; Kowalski, M; Kox, S; Meethaleveedu, G Koyithatta; Kral, J; Králik, I; Kravčáková, A; Krelina, M; Kretz, M; Krivda, M; Krizek, F; Kryshen, E; Krzewicki, M; Kubera, A M; Kučera, V; Kucheriaev, Y; Kugathasan, T; Kuhn, C; Kuijer, P G; Kulakov, I; Kumar, J; Kumar, L; Kurashvili, P; Kurepin, A; Kurepin, A B; Kuryakin, A; Kushpil, S; Kweon, M J; Kwon, Y; Pointe, S L La; Rocca, P La; Fernandes, C Lagana; Lakomov, I; Langoy, R; Lara, C; Lardeux, A; Lattuca, A; Laudi, E; Lea, R; Leardini, L; Lee, G R; Lee, S; Legrand, I; Lehnert, J; Lemmon, R C; Lenti, V; Leogrande, E; Monzón, I León; Leoncino, M; Lévai, P; Li, S; Li, X; Lien, J; Lietava, R; Lindal, S; Lindenstruth, V; Lippmann, C; Lisa, M A; Ljunggren, H M; Lodato, D F; Loenne, P I; Loggins, V R; Loginov, V; Loizides, C; Lopez, X; Torres, E López; Lowe, A; Lu, X-G; Luettig, P; Lunardon, M; Luparello, G; Maevskaya, A; Mager, M; Mahajan, S; Mahmood, S M; Maire, A; Majka, R D; Malaev, M; Cervantes, I Maldonado; Malinina, L; Mal'Kevich, D; Malzacher, P; Mamonov, A; Manceau, L; Manko, V; Manso, F; Manzari, V; Marchisone, M; Mareš, J; Margagliotti, G V; Margotti, A; Margutti, J; Marín, A; Markert, C; Marquard, M; Martin, N A; Blanco, J Martin; Martinengo, P; Martínez, M I; Martínez García, G; Pedreira, M Martinez; Martynov, Y; Mas, A; Masciocchi, S; Masera, M; Masoni, A; Massacrier, L; Mastroserio, A; Masui, H; Matyja, A; Mayer, C; Mazer, J; Mazzoni, M A; Mcdonald, D; Meddi, F; Menchaca-Rocha, A; Meninno, E; Pérez, J Mercado; Meres, M; Miake, Y; Mieskolainen, M M; Mikhaylov, K; Milano, L; Milosevic, J; Minervini, L M; Mischke, A; Mishra, A N; Miśkowiec, D; Mitra, J; Mitu, C M; Mohammadi, N; Mohanty, B; Molnar, L; Zetina, L Montaño; Montes, E; Morando, M; Godoy, D A Moreira De; Moretto, S; Morreale, A; Morsch, A; Muccifora, V; Mudnic, E; Mühlheim, D; Muhuri, S; Mukherjee, M; Müller, H; Mulligan, J D; Munhoz, M G; Murray, S; Musa, L; Musinsky, J; Nandi, B K; Nania, R; Nappi, E; Naru, M U; Nattrass, C; Nayak, K; Nayak, T K; Nazarenko, S; Nedosekin, A; Nellen, L; Ng, F; Nicassio, M; Niculescu, M; Niedziela, J; Nielsen, B S; Nikolaev, S; Nikulin, S; Nikulin, V; Noferini, F; Nomokonov, P; Nooren, G; Norman, J; Nyanin, A; Nystrand, J; Oeschler, H; Oh, S; Oh, S K; Ohlson, A; Okatan, A; Okubo, T; Olah, L; Oleniacz, J; Silva, A C Oliveira Da; Oliver, M H; Onderwaater, J; Oppedisano, C; Velasquez, A Ortiz; Oskarsson, A; Otwinowski, J; Oyama, K; Ozdemir, M; Pachmayer, Y; Pagano, P; Paić, G; Pajares, C; Pal, S K; Pan, J; Pandey, A K; Pant, D; Papikyan, V; Pappalardo, G S; Pareek, P; Park, W J; Parmar, S; Passfeld, A; Paticchio, V; Paul, B; Pawlak, T; Peitzmann, T; Costa, H Pereira Da; Filho, E Pereira De Oliveira; Peresunko, D; Lara, C E Pérez; Peskov, V; Pestov, Y; Petráček, V; Petrov, V; Petrovici, M; Petta, C; Piano, S; Pikna, M; Pillot, P; Pinazza, O; Pinsky, L; Piyarathna, D B; Płoskoń, M; Planinic, M; Pluta, J; Pochybova, S; Podesta-Lerma, P L M; Poghosyan, M G; Polichtchouk, B; Poljak, N; Poonsawat, W; Pop, A; Porteboeuf-Houssais, S; Porter, J; Pospisil, J; Prasad, S K; Preghenella, R; Prino, F; Pruneau, C A; Pshenichnov, I; Puccio, M; Puddu, G; Pujahari, P; Punin, V; Putschke, J; Qvigstad, H; Rachevski, A; Raha, S; Rajput, S; Rak, J; Rakotozafindrabe, A; Ramello, L; Raniwala, R; Raniwala, S; Räsänen, S S; Rascanu, B T; Rathee, D; Razazi, V; Read, K F; Real, J S; Redlich, K; Reed, R J; Rehman, A; Reichelt, P; Reicher, M; Reidt, F; Ren, X; Renfordt, R; Reolon, A R; Reshetin, A; Rettig, F; Revol, J-P; Reygers, K; Riabov, V; Ricci, R A; Richert, T; Richter, M; Riedler, P; Riegler, W; Riggi, F; Ristea, C; Rivetti, A; Rocco, E; Cahuantzi, M Rodríguez; Manso, A Rodriguez; Røed, K; Rogochaya, E; Rohr, D; Röhrich, D; Romita, R; Ronchetti, F; Ronflette, L; Rosnet, P; Rossi, A; Roukoutakis, F; Roy, A; Roy, C; Roy, P; Montero, A J Rubio; Rui, R; Russo, R; Ryabinkin, E; Ryabov, Y; Rybicki, A; Sadovsky, S; Šafařík, K; Sahlmuller, B; Sahoo, P; Sahoo, R; Sahoo, S; Sahu, P K; Saini, J; Sakai, S; Saleh, M A; Salgado, C A; Salzwedel, J; Sambyal, S; Samsonov, V; Castro, X Sanchez; Šándor, L; Sandoval, A; Sano, M; Santagati, G; Sarkar, D; Scapparone, E; Scarlassara, F; Scharenberg, R P; Schiaua, C; Schicker, R; Schmidt, C; Schmidt, H R; Schuchmann, S; Schukraft, J; Schulc, M; Schuster, T; Schutz, Y; Schwarz, K; Schweda, K; Scioli, G; Scomparin, E; Scott, R; Seeder, K S; Seger, J E; Sekiguchi, Y; Selyuzhenkov, I; Senosi, K; Seo, J; Serradilla, E; Sevcenco, A; Shabanov, A; Shabetai, A; Shadura, O; Shahoyan, R; Shangaraev, A; Sharma, A; Sharma, N; Shigaki, K; Shtejer, K; Sibiriak, Y; Siddhanta, S; Sielewicz, K M; Siemiarczuk, T; Silvermyr, D; Silvestre, C; Simatovic, G; Simonetti, G; Singaraju, R; Singh, R; Singha, S; Singhal, V; Sinha, B C; Sinha, T; Sitar, B; Sitta, M; Skaali, T B; Slupecki, M; Smirnov, N; Snellings, R J M; Snellman, T W; Søgaard, C; Soltz, R; Song, J; Song, M; Song, Z; Soramel, F; Sorensen, S; Spacek, M; Spiriti, E; Sputowska, I; Stassinaki, M Spyropoulou; Srivastava, B K; Stachel, J; Stan, I; Stefanek, G; Steinpreis, M; Stenlund, E; Steyn, G; Stiller, J H; Stocco, D; Strmen, P; Suaide, A A P; Sugitate, T; Suire, C; Suleymanov, M; Sultanov, R; Šumbera, M; Symons, T J M; Szabo, A; Toledo, A Szanto de; Szarka, I; Szczepankiewicz, A; Szymanski, M; Takahashi, J; Tanaka, N; Tangaro, M A; Takaki, J D Tapia; Peloni, A Tarantola; Tariq, M; Tarzila, M G; Tauro, A; Muñoz, G Tejeda; Telesca, A; Terasaki, K; Terrevoli, C; Teyssier, B; Thäder, J; Thomas, D; Tieulent, R; Timmins, A R; Toia, A; Trogolo, S; Trubnikov, V; Trzaska, W H; Tsuji, T; Tumkin, A; Turrisi, R; Tveter, T S; Ullaland, K; Uras, A; Usai, G L; Utrobicic, A; Vajzer, M; Vala, M; Palomo, L Valencia; Vallero, S; Maarel, J Van Der; Hoorne, J W Van; Leeuwen, M van; Vanat, T; Vyvre, P Vande; Varga, D; Vargas, A; Vargyas, M; Varma, R; Vasileiou, M; Vasiliev, A; Vauthier, A; Vechernin, V; Veen, A M; Veldhoen, M; Velure, A; Venaruzzo, M; Vercellin, E; Limón, S Vergara; Vernet, R; Verweij, M; Vickovic, L; Viesti, G; Viinikainen, J; Vilakazi, Z; Baillie, O Villalobos; Vinogradov, A; Vinogradov, L; Vinogradov, Y; Virgili, T; Vislavicius, V; Viyogi, Y P; Vodopyanov, A; Völkl, M A; Voloshin, K; Voloshin, S A; Volpe, G; Haller, B von; Vorobyev, I; Vranic, D; Vrláková, J; Vulpescu, B; Vyushin, A; Wagner, B; Wagner, J; Wang, H; Wang, M; Wang, Y; Watanabe, D; Weber, M; Weber, S G; Wessels, J P; Westerhoff, U; Wiechula, J; Wikne, J; Wilde, M; Wilk, G; Wilkinson, J; Williams, M C S; Windelband, B; Winn, M; Yaldo, C G; Yamaguchi, Y; Yang, H; Yang, P; Yano, S; Yasnopolskiy, S; Yin, Z; Yokoyama, H; Yoo, I-K; Yurchenko, V; Yushmanov, I; Zaborowska, A; Zaccolo, V; Zaman, A; Zampolli, C; Zanoli, H J C; Zaporozhets, S; Zarochentsev, A; Závada, P; Zaviyalov, N; Zbroszczyk, H; Zgura, I S; Zhalov, M; Zhang, H; Zhang, X; Zhang, Y; Zhao, C; Zhigareva, N; Zhou, D; Zhou, Y; Zhou, Z; Zhu, H; Zhu, J; Zhu, X; Zichichi, A; Zimmermann, A; Zimmermann, M B; Zinovjev, G; Zyzak, M

The measurement of primary [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] production at mid-rapidity ([Formula: see text] 0.5) in proton-proton collisions at [Formula: see text][Formula: see text] 7 TeV performed with a large ion collider experiment at the large hadron collider (LHC) is reported. Particle identification is performed using the specific ionisation energy-loss and time-of-flight information, the ring-imaging Cherenkov technique and the kink-topology identification of weak decays of charged kaons. Transverse momentum spectra are measured from 0.1 up to 3 GeV/[Formula: see text] for pions, from 0.2 up to 6 GeV/[Formula: see text] for kaons and from 0.3 up to 6 GeV/[Formula: see text] for protons. The measured spectra and particle ratios are compared with quantum chromodynamics-inspired models, tuned to reproduce also the earlier measurements performed at the LHC. Furthermore, the integrated particle yields and ratios as well as the average transverse momenta are compared with results at lower collision energies.

χ cJ polarization in polarized proton-proton collisions at RHIC

NASA Astrophysics Data System (ADS)

Nayak, Gouranga C.

2017-01-01

We study inclusive χ cJ production with definite polarizations in polarized proton-proton collisions at √ s = 200 and 500 GeV at RHIC by using non-relativistic QCD (NRQCD) color-octet mechanism. We present results of rapidity distribution of χ c0, χ c1 and χ c2 production with specific polarizations in polarized p-p collisions at RHIC within the PHENIX detector acceptance range. We also present the corresponding results for the spin asymmetries.

Development of a Multileaf Collimator for Proton Radiotherapy

DTIC Science & Technology

2007-06-01

for proton radiotherapy, and the first year of the project to develop image guided treatment protocols for proton therapy . This research...multileaf collimator (MLC) for proton therapy and investigates the issues that must be resolved to use an MLC in proton therapy . The second technology...the contract included three development agreements directly related to the work supported by this grant to develop technology for proton therapy .

Active Proton Interrogation for Homeland Security

NASA Astrophysics Data System (ADS)

Greene, Steven; Morris, Christopher; Canavan, Gregory; Chung, Kiwhan; Elson, Jay; Hogan, Gary; Makela, Mark; Mariam, Fesseha; Murray, Matthew; Saunders, Alexander; Spaulding, Randy; Wang, Zhehui; Waters, Laurie; Wysocki, Frederick

2010-02-01

Energetic proton beams may provide an attractive technology for active interrogation of nuclear threats because: they have large fission cross sections, long mean free paths and high penetration, and proton beams can be manipulated with magnetic optics. We have measured time-dependent cross sections for delayed neutrons and gamma rays using 800 MeV protons from the Los Alamos Neutron Science Center and 4 GeV protons from the Brookhaven Alternating Gradient Synchrotron for a set of bare and shielded targets. The results show significant signals from both unshielded and shielded nuclear materials. Results will be presented. )

1000-fold enhancement in proton conductivity of a MOF using post-synthetically anchored proton transporters

PubMed Central

Shalini, Sorout; Dhavale, Vishal M.; Eldho, Kavalakal M.; Kurungot, Sreekumar; Ajithkumar, Thallaseril G.; Vaidhyanathan, Ramanathan

2016-01-01

Pyridinol, a coordinating zwitter-ionic species serves as stoichiometrically loadable and non-leachable proton carrier. The partial replacement of the pyridinol by stronger hydrogen bonding, coordinating guest, ethylene glycol (EG), offers 1000-fold enhancement in conductivity (10−6 to 10−3 Scm−1) with record low activation energy (0.11 eV). Atomic modeling coupled with 13C-SSNMR provides insights into the potential proton conduction pathway functionalized with post-synthetically anchored dynamic proton transporting EG moieties. PMID:27577681

Water at hydrophobic interfaces delays proton surface-to-bulk transfer and provides a pathway for lateral proton diffusion

PubMed Central

Zhang, Chao; Knyazev, Denis G.; Vereshaga, Yana A.; Ippoliti, Emiliano; Nguyen, Trung Hai; Carloni, Paolo; Pohl, Peter

2012-01-01

Fast lateral proton migration along membranes is of vital importance for cellular energy homeostasis and various proton-coupled transport processes. It can only occur if attractive forces keep the proton at the interface. How to reconcile this high affinity to the membrane surface with high proton mobility is unclear. Here, we tested whether a minimalistic model interface between an apolar hydrophobic phase (n-decane) and an aqueous phase mimics the biological pathway for lateral proton migration. The observed diffusion span, on the order of tens of micrometers, and the high proton mobility were both similar to the values previously reported for lipid bilayers. Extensive ab initio simulations on the same water/n-decane interface reproduced the experimentally derived free energy barrier for the excess proton. The free energy profile GH+ adopts the shape of a well at the interface, having a width of two water molecules and a depth of 6 ± 2RT. The hydroniums in direct contact with n-decane have a reduced mobility. However, the hydroniums in the second layer of water molecules are mobile. Their in silico diffusion coefficient matches that derived from our in vitro experiments, (5.7 ± 0.7) × 10-5 cm2 s-1. Conceivably, these are the protons that allow for fast diffusion along biological membranes. PMID:22675120

Characterizing the proton loading site in cytochrome c oxidase.

PubMed

Lu, Jianxun; Gunner, M R

2014-08-26

Cytochrome c oxidase (CcO) uses the energy released by reduction of O2 to H2O to drive eight charges from the high pH to low pH side of the membrane, increasing the electrochemical gradient. Four electrons and protons are used for chemistry, while four more protons are pumped. Proton pumping requires that residues on a pathway change proton affinity through the reaction cycle to load and then release protons. The protonation states of all residues in CcO are determined in MultiConformational Continuum Electrostatics simulations with the protonation and redox states of heme a, a3, Cu(B), Y288, and E286 used to define the catalytic cycle. One proton is found to be loaded and released from residues identified as the proton loading site (PLS) on the P-side of the protein in each of the four CcO redox states. Thus, the same proton pumping mechanism can be used each time CcO is reduced. Calculations with structures of Rhodobacter sphaeroides, Paracoccus denitrificans, and bovine CcO derived by crystallography and molecular dynamics show the PLS functions similarly in different CcO species. The PLS is a cluster rather than a single residue, as different structures show 1-4 residues load and release protons. However, the proton affinity of the heme a3 propionic acids primarily determines the number of protons loaded into the PLS; if their proton affinity is too low, less than one proton is loaded.

Proton affinity of methyl nitrate - Less than proton affinity of nitric acid

NASA Technical Reports Server (NTRS)

Lee, Timothy J.; Rice, Julia E.

1992-01-01

Several state-of-the-art ab initio quantum mechanical methods were used to investigate the equilibrium structure, dipole moments, harmonic vibrational frequencies, and IR intensities of methyl nitrate, methanol, and several structures of protonated methyl nitrate, using the same theoretical methods as in an earlier study (Lee and Rice, 1992) of nitric acid. The ab initio results for methyl nitrate and methanol were found to be in good agreement with available experimental data. The proton affinity (PA) of methyl nitrate was calculated to be 176.9 +/-5 kcal/mol, in excellent agreement with the experimental value 176 kcal/mol obtained by Attina et al. (1987) and less than the PA value of nitric acid. An explanation of the discrepancy of the present results with those of an earlier study on protonated nitric acid is proposed.

Timing Comparisons for GLEs and High-energy Proton Events using GPS Proton Measurements

NASA Astrophysics Data System (ADS)

Bernstein, V.; Winter, L. M.; Carver, M.; Morley, S.

2017-12-01

The newly released LANL GPS particle sensor data offers a unique snapshot of access of relativistic particles into the geomagnetic field. Currently, 23 of the 31 operational GPS satellites host energetic particle detectors which can detect the arrival of high-energy solar protons associated with Ground Level Enhancements (GLEs). We compare the timing profiles of solar energetic proton detections from GPS satellites as well as from ground-based Neutron Monitors and GOES spacecraft at geostationary orbit in order to understand how high-energy protons from the Sun enter the geomagnetic field and investigate potential differences in arrival time of energetic protons at GPS satellites as a function of location. Previous studies could only use one or two spacecraft at a similar altitude to track the arrival of energetic particles. With GPS data, we can now test whether the particles arrive isotropically, as assumed, or whether there exist differences in the timing and energetics viewed by each of the individual satellites. Extensions of this work could lead to improvements in space weather forecasting that predict more localized risk estimates for space-based technology.

Proton dynamics in cancer.

PubMed

Huber, Veronica; De Milito, Angelo; Harguindey, Salvador; Reshkin, Stephan J; Wahl, Miriam L; Rauch, Cyril; Chiesi, Antonio; Pouysségur, Jacques; Gatenby, Robert A; Rivoltini, Licia; Fais, Stefano

2010-06-15

Cancer remains a leading cause of death in the world today. Despite decades of research to identify novel therapeutic approaches, durable regressions of metastatic disease are still scanty and survival benefits often negligible. While the current strategy is mostly converging on target-therapies aimed at selectively affecting altered molecular pathways in tumor cells, evidences are in parallel pointing to cell metabolism as a potential Achilles' heel of cancer, to be disrupted for achieving therapeutic benefit. Critical differences in the metabolism of tumor versus normal cells, which include abnormal glycolysis, high lactic acid production, protons accumulation and reversed intra-extracellular pH gradients, make tumor site a hostile microenvironment where only cancer cells can proliferate and survive. Inhibiting these pathways by blocking proton pumps and transporters may deprive cancer cells of a key mechanism of detoxification and thus represent a novel strategy for a pleiotropic and multifaceted suppression of cancer cell growth.Research groups scattered all over the world have recently started to investigate various aspects of proton dynamics in cancer cells with quite encouraging preliminary results. The intent of unifying investigators involved in this research line led to the formation of the "International Society for Proton Dynamics in Cancer" (ISPDC) in January 2010. This is the manifesto of the newly formed society where both basic and clinical investigators are called to foster translational research and stimulate interdisciplinary collaboration for the development of more specific and less toxic therapeutic strategies based on proton dynamics in tumor cell biology.

Multiscale simulation reveals a multifaceted mechanism of proton permeation through the influenza A M2 proton channel

PubMed Central

Liang, Ruibin; Li, Hui; Swanson, Jessica M. J.; Voth, Gregory A.

2014-01-01

The influenza A virus M2 channel (AM2) is crucial in the viral life cycle. Despite many previous experimental and computational studies, the mechanism of the activating process in which proton permeation acidifies the virion to release the viral RNA and core proteins is not well understood. Herein the AM2 proton permeation process has been systematically characterized using multiscale computer simulations, including quantum, classical, and reactive molecular dynamics methods. We report, to our knowledge, the first complete free-energy profiles for proton transport through the entire AM2 transmembrane domain at various pH values, including explicit treatment of excess proton charge delocalization and shuttling through the His37 tetrad. The free-energy profiles reveal that the excess proton must overcome a large free-energy barrier to diffuse to the His37 tetrad, where it is stabilized in a deep minimum reflecting the delocalization of the excess charge among the histidines and the cost of shuttling the proton past them. At lower pH values the His37 tetrad has a larger total charge that increases the channel width, hydration, and solvent dynamics, in agreement with recent 2D-IR spectroscopic studies. The proton transport barrier becomes smaller, despite the increased charge repulsion, due to backbone expansion and the more dynamic pore water molecules. The calculated conductances are in quantitative agreement with recent experimental measurements. In addition, the free-energy profiles and conductances for proton transport in several mutants provide insights for explaining our findings and those of previous experimental mutagenesis studies. PMID:24979779

Multiscale simulation reveals a multifaceted mechanism of proton permeation through the influenza A M2 proton channel.

PubMed

Liang, Ruibin; Li, Hui; Swanson, Jessica M J; Voth, Gregory A

2014-07-01

The influenza A virus M2 channel (AM2) is crucial in the viral life cycle. Despite many previous experimental and computational studies, the mechanism of the activating process in which proton permeation acidifies the virion to release the viral RNA and core proteins is not well understood. Herein the AM2 proton permeation process has been systematically characterized using multiscale computer simulations, including quantum, classical, and reactive molecular dynamics methods. We report, to our knowledge, the first complete free-energy profiles for proton transport through the entire AM2 transmembrane domain at various pH values, including explicit treatment of excess proton charge delocalization and shuttling through the His37 tetrad. The free-energy profiles reveal that the excess proton must overcome a large free-energy barrier to diffuse to the His37 tetrad, where it is stabilized in a deep minimum reflecting the delocalization of the excess charge among the histidines and the cost of shuttling the proton past them. At lower pH values the His37 tetrad has a larger total charge that increases the channel width, hydration, and solvent dynamics, in agreement with recent 2D-IR spectroscopic studies. The proton transport barrier becomes smaller, despite the increased charge repulsion, due to backbone expansion and the more dynamic pore water molecules. The calculated conductances are in quantitative agreement with recent experimental measurements. In addition, the free-energy profiles and conductances for proton transport in several mutants provide insights for explaining our findings and those of previous experimental mutagenesis studies.

[Proton beam therapy].

PubMed

Ogino, Takashi

2006-04-01

Proton beam therapy (PBT) has made it possible to deliver a higher concentration of radiation to the tumor by its Bragg-peak, and is easy to utilize due to the fact that its biological characteristics are identical with X-rays. PBT has a half-century history, and more than 40,000 patients have been reported as having had treatments with proton beams worldwide. The historic change to this therapy occurred in the 1990s, when the Loma Linda University Medical Center began its clinical activity as the first hospital in the world to utilize a medically dedicated proton therapy facility. Since then, similar hospital-based medically dedicated facilities have been constructed. Results from around the world have shown the therapeutic superiority of PBT over alternative treatment options for ocular melanoma, skull base sarcoma, head & neck cancer, lung cancer,esophageal cancer, hepatocellular carcinoma, and prostate cancer. PBT is expected to achieve further advancement both clinically and technologically.

Self-proton/ion radiography of laser-produced proton/ion beam from thin foil targets

NASA Astrophysics Data System (ADS)

Paudel, Y.; Renard-Le Galloudec, N.; Nicolai, Ph.; d'Humieres, E.; Ya. Faenov, A.; Kantsyrev, V. L.; Safronova, A. S.; Shrestha, I.; Osborne, G. C.; Shlyaptseva, V. V.; Sentoku, Y.

2012-12-01

Protons and multicharged ions generated from high-intensity laser interactions with thin foil targets have been studied with a 100 TW laser system. Protons/ions with energies up to 10 MeV are accelerated either from the front or the rear surface of the target material. We have observed for the first time that the protons/ions accelerated from the front surface of the target, in a direction opposite to the laser propagation direction, are turned around and pulled back to the rear surface, in the laser propagation direction. This proton/ion beam is able to create a self-radiograph of the target and glass stalk holding the target itself recorded through the radiochromic film stack. This unique result indicates strong long-living (ns time scale) magnetic fields present in the laser-produced plasma, which are extremely important in energy transport during the intense laser irradiation. The magnetic field from laser main pulse expands rapidly in the preformed plasma to rotate the laser produced protons. Radiation hydrodynamic simulations and ray tracing found that the magnetic field created by the amplified spontaneous emission prepulse is not sufficient to explain the particle trajectories, but the additional field created by the main pulse interaction estimated from particle-in-cell simulation is able to change the particle trajectories.

Correlated proton-electron hole dynamics in protonated water clusters upon extreme ultraviolet photoionization

PubMed Central

Li, Zheng; Vendrell, Oriol

2016-01-01

The ultrafast nuclear and electronic dynamics of protonated water clusters H+(H2O)n after extreme ultraviolet photoionization is investigated. In particular, we focus on cluster cations with n = 3, 6, and 21. Upon ionization, two positive charges are present in the cluster related to the excess proton and the missing electron, respectively. A correlation is found between the cluster's geometrical conformation and initial electronic energy with the size of the final fragments produced. For situations in which the electron hole and proton are initially spatially close, the two entities become correlated and separate in a time-scale of 20 to 40 fs driven by strong non-adiabatic effects. PMID:26798842

Correlated proton-electron hole dynamics in protonated water clusters upon extreme ultraviolet photoionization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Zheng; Vendrell, Oriol

2016-01-13

The ultrafast nuclear and electronic dynamics of protonated water clusters H+(H2O)n after extreme ultraviolet photoionization is investigated. In particular, we focus on cluster cations with n = 3, 6, and 21. Upon ionization, two positive charges are present in the cluster related to the excess proton and the missing electron, respectively. A correlation is found between the cluster's geometrical conformation and initial electronic energy with the size of the final fragments produced. As a result, for situations in which the electron hole and proton are initially spatially close, the two entities become correlated and separate in a time-scale of 20more » to 40 fs driven by strong non-adiabatic effects.« less

Origins of Protons in C-H Bond Insertion Products of Phenols: Proton-Self-Sufficient Function via Water Molecules.

PubMed

Luo, Zhoujie; Gao, Ya; Zhu, Tong; Zhang, John Zenghui; Xia, Fei

2017-08-31

Water molecules can serve as proton shuttles for proton transfer in the C-H bond insertion reactions catalyzed by transition metal complexes. Recently, the control experiments performed for C-H bond insertion of phenol and anisol by gold carbenes show that large discrepancy exists in the yields of hydrogenated and deuterated products. Thus, we conducted a detailed theoretical analysis on the function of water molecules in the C-H bond insertion reactions. The comparison of calculated results and control experiments indicates that the solution water molecules play a crucial role of proton shuttle in C-H bond insertion. In particular, it was found that the hydroxyl groups in phenols were capable of donating protons via water shuttles for the production of C-H products, which had a substantial influence on the yields of inserted products. The hydroxyl groups instead of C-H bonds in phenols function like "proton reservoirs" in the C-H bond insertion, which we call the "proton self-sufficient" (PSS) function of phenol. The PSS function of phenol indicates that the substrates with and without proton reservoirs will lead to different C-H bond insertion products.

Proton Testing: Opportunities, Pitfalls and Puzzles

NASA Technical Reports Server (NTRS)

Ladbury, Raymond

2017-01-01

Although proton SEE testing can place constraints on some heavy-ion SEE susceptibilities, it is important to quantify residual risk that protons may not reveal all SEE susceptibilities in a system. We examine the relative strengths and limitations of proton and heavy-ion SEE testing and how these may be affected by technology scaling and high-Z materials in the device.

Asymmetric protonation of EmrE

PubMed Central

Morrison, Emma A.; Robinson, Anne E.; Liu, Yongjia

2015-01-01

The small multidrug resistance transporter EmrE is a homodimer that uses energy provided by the proton motive force to drive the efflux of drug substrates. The pKa values of its “active-site” residues—glutamate 14 (Glu14) from each subunit—must be poised around physiological pH values to efficiently couple proton import to drug export in vivo. To assess the protonation of EmrE, pH titrations were conducted with 1H-15N TROSY-HSQC nuclear magnetic resonance (NMR) spectra. Analysis of these spectra indicates that the Glu14 residues have asymmetric pKa values of 7.0 ± 0.1 and 8.2 ± 0.3 at 45°C and 6.8 ± 0.1 and 8.5 ± 0.2 at 25°C. These pKa values are substantially increased compared with typical pKa values for solvent-exposed glutamates but are within the range of published Glu14 pKa values inferred from the pH dependence of substrate binding and transport assays. The active-site mutant, E14D-EmrE, has pKa values below the physiological pH range, consistent with its impaired transport activity. The NMR spectra demonstrate that the protonation states of the active-site Glu14 residues determine both the global structure and the rate of conformational exchange between inward- and outward-facing EmrE. Thus, the pKa values of the asymmetric active-site Glu14 residues are key for proper coupling of proton import to multidrug efflux. However, the results raise new questions regarding the coupling mechanism because they show that EmrE exists in a mixture of protonation states near neutral pH and can interconvert between inward- and outward-facing forms in multiple different protonation states. PMID:26573622

The Search for Proton Decay.

ERIC Educational Resources Information Center

Marshak, Marvin L.

1984-01-01

Provides the rationale for and examples of experiments designed to test the stability of protons and bound neutrons. Also considers the unification question, cosmological implications, current and future detectors, and current status of knowledge on proton decay. (JN)

The clinical case for proton beam therapy

PubMed Central

2012-01-01

Abstract Over the past 20 years, several proton beam treatment programs have been implemented throughout the United States. Increasingly, the number of new programs under development is growing. Proton beam therapy has the potential for improving tumor control and survival through dose escalation. It also has potential for reducing harm to normal organs through dose reduction. However, proton beam therapy is more costly than conventional x-ray therapy. This increased cost may be offset by improved function, improved quality of life, and reduced costs related to treating the late effects of therapy. Clinical research opportunities are abundant to determine which patients will gain the most benefit from proton beam therapy. We review the clinical case for proton beam therapy. Summary sentence Proton beam therapy is a technically advanced and promising form of radiation therapy. PMID:23083010

A 6 kV arbitrary waveform generator for the Tevatron Electron Lens

DOE PAGES

Pfeffer, H.; Saewert, G.

2011-11-09

This paper reports on a 6 kV modulator built and installed at Fermilab to drive the electron gun anode for the Tevatron Electron Lens (TEL). The TEL was built with the intention of shifting the individual (anti)proton bunch tunes to even out the tune spread among all 36 bunches with the desire of improving Tevatron integrated luminosity. This modulator is essentially a 6 kV arbitrary waveform generator that enables the TEL to define the electron beam intensity on a bunch-by-bunch basis. A voltage waveform is constructed having a 7 μs duration that corresponds to the tune shift requirements of amore » 12-bunch (anti)proton beam pulse train. This waveform is played out for any one or all three bunch trains in the Tevatron. The programmed waveform voltages transition to different levels at time intervals corresponding to the 395 ns bunch spacing. In addition, complex voltage waveforms can be played out at a sustained rate of 143 kHz over the full 6 kV output range. This paper describes the novel design of the inductive adder topology employing five transformers. It describes the design aspects that minimize switching losses for this multi-kilovolt, high repetition rate and high duty factor application.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pfeffer, H.; Saewert, G.

This paper reports on a 6 kV modulator built and installed at Fermilab to drive the electron gun anode for the Tevatron Electron Lens (TEL). The TEL was built with the intention of shifting the individual (anti)proton bunch tunes to even out the tune spread among all 36 bunches with the desire of improving Tevatron integrated luminosity. This modulator is essentially a 6 kV arbitrary waveform generator that enables the TEL to define the electron beam intensity on a bunch-by-bunch basis. A voltage waveform is constructed having a 7 μs duration that corresponds to the tune shift requirements of amore » 12-bunch (anti)proton beam pulse train. This waveform is played out for any one or all three bunch trains in the Tevatron. The programmed waveform voltages transition to different levels at time intervals corresponding to the 395 ns bunch spacing. In addition, complex voltage waveforms can be played out at a sustained rate of 143 kHz over the full 6 kV output range. This paper describes the novel design of the inductive adder topology employing five transformers. It describes the design aspects that minimize switching losses for this multi-kilovolt, high repetition rate and high duty factor application.« less

Rapidity and species dependence of particle production at large transverse momentum for d+Au collisions at sNN=200 GeV

NASA Astrophysics Data System (ADS)

Abelev, B. I.; Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Anderson, M.; Arkhipkin, D.; Averichev, G. S.; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Bekele, S.; Belaga, V. V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Benedosso, F.; Bhardwaj, S.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Blyth, S.-L.; Bonner, B. E.; Botje, M.; Bouchet, J.; Brandin, A. V.; Bravar, A.; Bystersky, M.; Cadman, R. V.; Cai, X. Z.; Caines, H.; Sánchez, M. Calderón De La Barca; Castillo, J.; Catu, O.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, J. P.; Cormier, T. M.; Cosentino, M. R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Das, S.; Daugherity, M.; Moura, M. M. De; Dedovich, T. G.; Dephillips, M.; Derevschikov, A. A.; Didenko, L.; Dietel, T.; Djawotho, P.; Dogra, S. M.; Dong, W. J.; Dong, X.; Draper, J. E.; Du, F.; Dunin, V. B.; Dunlop, J. C.; Mazumdar, M. R. Dutta; Eckardt, V.; Edwards, W. R.; Efimov, L. G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filimonov, K.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Fu, J.; Gagliardi, C. A.; Gaillard, L.; Ganti, M. S.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J. E.; Gorbunov, Y. G.; Gos, H.; Grebenyuk, O.; Grosnick, D.; Guertin, S. M.; Guimaraes, K. S. F. F.; Guo, Y.; Gupta, N.; Gutierrez, T. D.; Haag, B.; Hallman, T. J.; Hamed, A.; Harris, J. W.; He, W.; Heinz, M.; Henry, T. W.; Hepplemann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffman, A. M.; Hoffmann, G. W.; Horner, M. J.; Huang, H. Z.; Huang, S. L.; Hughes, E. W.; Humanic, T. J.; Igo, G.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jia, F.; Jiang, H.; Jones, P. G.; Judd, E. G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Khodyrev, V. Yu.; Kim, B. C.; Kiryluk, J.; Kisiel, A.; Kislov, E. M.; Klein, S. R.; Kocoloski, A.; Koetke, D. D.; Kollegger, T.; Kopytine, M.; Kotchenda, L.; Kouchpil, V.; Kowalik, K. L.; Kramer, M.; Kravtsov, P.; Kravtsov, V. I.; Krueger, K.; Kuhn, C.; Kulikov, A. I.; Kumar, A.; Kuznetsov, A. A.; Lamont, M. A. C.; Landgraf, J. M.; Lange, S.; Lapointe, S.; Laue, F.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Lehocka, S.; Levine, M. J.; Li, C.; Li, Q.; Li, Y.; Lin, G.; Lin, X.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Liu, Z.; Ljubicic, T.; Llope, W. J.; Long, H.; Longacre, R. S.; Lopez-Noriega, M.; Love, W. A.; Lu, Y.; Ludlam, T.; Lynn, D.; Ma, G. L.; Ma, J. G.; Ma, Y. G.; Magestro, D.; Mahapatra, D. P.; Majka, R.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Martin, L.; Matis, H. S.; Matulenko, Yu. A.; McClain, C. J.; McShane, T. S.; Melnick, Yu.; Meschanin, A.; Millane, J.; Miller, M. L.; Minaev, N. G.; Mioduszewski, S.; Mironov, C.; Mischke, A.; Mishra, D. K.; Mitchell, J.; Mohanty, B.; Molnar, L.; Moore, C. F.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Netrakanti, P. K.; Nikitin, V. A.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldenburg, M.; Olson, D.; Pachr, M.; Pal, S. K.; Panebratsev, Y.; Panitkin, S. Y.; Pavlinov, A. I.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Petrov, V. A.; Phatak, S. C.; Picha, R.; Planinic, M.; Pluta, J.; Poljak, N.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potekhin, M.; Potrebenikova, E.; Potukuchi, B. V. K. S.; Prindle, D.; Pruneau, C.; Putschke, J.; Rakness, G.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Razin, S. V.; Reinnarth, J.; Relyea, D.; Retiere, F.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Sahoo, R.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sarsour, M.; Sazhin, P. S.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schweda, K.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shen, W. Q.; Shimanskiy, S. S.; Sichtermann, E.; Simon, F.; Singaraju, R. N.; Smirnov, N.; Snellings, R.; Sood, G.; Sorensen, P.; Sowinski, J.; Speltz, J.; Spinka, H. M.; Srivastava, B.; Stadnik, A.; Stanislaus, T. D. S.; Stock, R.; Stolpovsky, A.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Sugarbaker, E.; Sumbera, M.; Sun, Z.; Surrow, B.; Swanger, M.; Symons, T. J. M.; Toledo, A. Szanto De; Tai, A.; Takahashi, J.; Tang, A. H.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Timmins, A. R.; Timoshenko, S.; Tokarev, M.; Trainor, T. A.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; Buren, G. Van; Kolk, N. Van Der; Leeuwen, M. Van; Molen, A. M. Vander; Varma, R.; Vasilevski, I. M.; Vasiliev, A. N.; Vernet, R.; Vigdor, S. E.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Waggoner, W. T.; Wang, F.; Wang, G.; Wang, J. S.; Wang, X. L.; Wang, Y.; Watson, J. W.; Webb, J. C.; Westfall, G. D.; Wetzler, A.; , C. Whitten, Jr.; Wieman, H.; Wissink, S. W.; Witt, R.; Wood, J.; Wu, J.; Xu, N.; Xu, Q. H.; Xu, Z.; Yepes, P.; Yoo, I.-K.; Yurevich, V. I.; Zhan, W.; Zhang, H.; Zhang, W. M.; Zhang, Y.; Zhang, Z. P.; Zhao, Y.; Zhong, C.; Zoulkarneev, R.; Zoulkarneeva, Y.; Zubarev, A. N.; Zuo, J. X.

2007-11-01

We determine rapidity asymmetry in the production of charged pions, protons, and antiprotons for large transverse momentum (pT) for d+Au collisions at sNN=200 GeV. The rapidity asymmetry is defined as the ratio of particle yields at backward rapidity (Au beam direction) to those at forward rapidity (d beam direction). The identified hadrons are measured in the rapidity regions |y|<0.5 and 0.5<|y|<1.0 for the pT range 2.5proton+antiproton production in both the rapidity regions. The asymmetry is larger for 0.5<|y|<1.0 than for |y|<0.5 and is almost independent of particle type. The measurements are compared to various model predictions employing multiple scattering, energy loss, nuclear shadowing, saturation effects, and recombination and also to a phenomenological parton model. We find that asymmetries are sensitive to model parameters and show model preference. The rapidity dependence of π-/π+ and p¯/p ratios in peripheral d+Au and forward neutron-tagged events are used to study the contributions of valence quarks and gluons to particle production at high pT.

What is LAMPF II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thiessen, H.A.

1982-08-01

The present conception of LAMPF II is a high-intensity 16-GeV synchrotron injected by the LAMPF 800-MeV H/sup -/ beam. The proton beam will be used to make secondary beams of neutrinos, muons, pions, kaons, antiprotons, and hyperons more intense than those of any existing or proposed accelerator. For example, by taking maximum advantage of a thick target, modern beam optics, and the LAMPF II proton beam, it will be possible to make a negative muon beam with nearly 100% duty factor and nearly 100 times the flux of the existing Stopped Muon Channel (SMC). Because the unique features of themore » proposed machine are most applicable to beams of the same momentum as LAMPF (that is, < 2 GeV/c), it may be possible to use most of the experimental areas and some of the auxiliary equipment, including spectrometers, with the new accelerator. The complete facility will provide improved technology for many areas of physics already available at LAMPF and will allow expansion of medium-energy physics to include kaons, antiprotons, and hyperons. When LAMPF II comes on line in 1990 LAMPF will have been operational for 18 years and a major upgrade such as this proposal will be reasonable and prudent.« less

Characterizing the proton loading site in cytochrome c oxidase

PubMed Central

Lu, Jianxun; Gunner, M. R.

2014-01-01

Cytochrome c oxidase (CcO) uses the energy released by reduction of O2 to H2O to drive eight charges from the high pH to low pH side of the membrane, increasing the electrochemical gradient. Four electrons and protons are used for chemistry, while four more protons are pumped. Proton pumping requires that residues on a pathway change proton affinity through the reaction cycle to load and then release protons. The protonation states of all residues in CcO are determined in MultiConformational Continuum Electrostatics simulations with the protonation and redox states of heme a, a3, CuB, Y288, and E286 used to define the catalytic cycle. One proton is found to be loaded and released from residues identified as the proton loading site (PLS) on the P-side of the protein in each of the four CcO redox states. Thus, the same proton pumping mechanism can be used each time CcO is reduced. Calculations with structures of Rhodobacter sphaeroides, Paracoccus denitrificans, and bovine CcO derived by crystallography and molecular dynamics show the PLS functions similarly in different CcO species. The PLS is a cluster rather than a single residue, as different structures show 1–4 residues load and release protons. However, the proton affinity of the heme a3 propionic acids primarily determines the number of protons loaded into the PLS; if their proton affinity is too low, less than one proton is loaded. PMID:25114210

The mechanism of proton conduction in phosphoric acid

NASA Astrophysics Data System (ADS)

Vilčiauskas, Linas; Tuckerman, Mark E.; Bester, Gabriel; Paddison, Stephen J.; Kreuer, Klaus-Dieter

2012-06-01

Neat liquid phosphoric acid (H3PO4) has the highest intrinsic proton conductivity of any known substance and is a useful model for understanding proton transport in other phosphate-based systems in biology and clean energy technologies. Here, we present an ab initio molecular dynamics study that reveals, for the first time, the microscopic mechanism of this high proton conductivity. Anomalously fast proton transport in hydrogen-bonded systems involves a structural diffusion mechanism in which intramolecular proton transfer is driven by specific hydrogen bond rearrangements in the surrounding environment. Aqueous media transport excess charge defects through local hydrogen bond rearrangements that drive individual proton transfer reactions. In contrast, strong, polarizable hydrogen bonds in phosphoric acid produce coupled proton motion and a pronounced protic dielectric response of the medium, leading to the formation of extended, polarized hydrogen-bonded chains. The interplay between these chains and a frustrated hydrogen-bond network gives rise to the high proton conductivity.

The optimal balance between quality and efficiency in proton radiography imaging technique at various proton beam energies: A Monte Carlo study.

PubMed

Biegun, A K; van Goethem, M-J; van der Graaf, E R; van Beuzekom, M; Koffeman, E N; Nakaji, T; Takatsu, J; Visser, J; Brandenburg, S

2017-09-01

Proton radiography is a novel imaging modality that allows direct measurement of the proton energy loss in various tissues. Currently, due to the conversion of so-called Hounsfield units from X-ray Computed Tomography (CT) into relative proton stopping powers (RPSP), the uncertainties of RPSP are 3-5% or higher, which need to be minimized down to 1% to make the proton treatment plans more accurate. In this work, we simulated a proton radiography system, with position-sensitive detectors (PSDs) and a residual energy detector (RED). The simulations were built using Geant4, a Monte Carlo simulation toolkit. A phantom, consisting of several materials was placed between the PSDs of various Water Equivalent Thicknesses (WET), corresponding to an ideal detector, a gaseous detector, silicon and plastic scintillator detectors. The energy loss radiograph and the scattering angle distributions of the protons were studied for proton beam energies of 150MeV, 190MeV and 230MeV. To improve the image quality deteriorated by the multiple Coulomb scattering (MCS), protons with small angles were selected. Two ways of calculating a scattering angle were considered using the proton's direction and position. A scattering angle cut of 8.7mrad was applied giving an optimal balance between quality and efficiency of the radiographic image. For the three proton beam energies, the number of protons used in image reconstruction with the direction method was half the number of protons kept using the position method. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Regional-Scale Surface Magnetic Fields and Proton Fluxes to Mercury's Surface from Proton-Reflection Magnetometry

NASA Astrophysics Data System (ADS)

Winslow, R. M.; Johnson, C. L.; Anderson, B. J.; Gershman, D. J.; Raines, J. M.; Lillis, R. J.; Korth, H.; Slavin, J. A.; Solomon, S. C.; Zurbuchen, T.

2014-12-01

The application of a recently developed proton-reflection magnetometry technique to MESSENGER spacecraft observations at Mercury has yielded two significant findings. First, loss-cone observations directly confirm particle precipitation to Mercury's surface and indicate that solar wind plasma persistently bombards the planet not only in the magnetic cusp regions but over a large fraction of the southern hemisphere. Second, the inferred surface field strengths independently confirm the north-south asymmetry in Mercury's global magnetic field structure first documented from observations of magnetic equator crossings. Here we extend this work with 1.5 additional years of observations (i.e., to 2.5 years in all) to further probe Mercury's surface magnetic field and better resolve proton flux precipitation to the planet's surface. We map regions where proton loss cones are observed; these maps indicate regions where protons precipitate directly onto the surface. The augmentation of our data set over that used in our original study allows us to examine the proton loss cones in cells of dimension 10° latitude by 20° longitude in Mercury body-fixed coordinates. We observe a transition from double-sided to single-sided loss cones in the pitch-angle distributions; this transition marks the boundary between open and closed field lines. At the surface this boundary lies between 60° and 70°N. Our observations allow the estimation of surface magnetic field strengths in the northern cusp region and the calculation of incident proton fluxes to both hemispheres. In the northern cusp, our regional-scale observations are consistent with an offset dipole field and a dipole moment of 190 nT RM3, where RM is Mercury's radius, implying that any regional-scale variations in surface magnetic field strengths are either weak relative to the dipole field or occur at length scales smaller than the resolution of our observations (~300 km). From the global proton flux map (north of 40° S

Proton-Coupled Electron Transfer in Artificial Photosynthetic Systems.

PubMed

Mora, S Jimena; Odella, Emmanuel; Moore, Gary F; Gust, Devens; Moore, Thomas A; Moore, Ana L

2018-02-20

Artificial photosynthetic constructs can in principle operate more efficiently than natural photosynthesis because they can be rationally designed to optimize solar energy conversion for meeting human demands rather than the multiple needs of an organism competing for growth and reproduction in a complex ecosystem. The artificial photosynthetic constructs described in this Account consist primarily of covalently linked synthetic chromophores, electron donors and acceptors, and proton donors and acceptors that carry out the light absorption, electron transfer, and proton-coupled electron transfer (PCET) processes characteristic of photosynthetic cells. PCET is the movement of an electron from one site to another accompanied by proton transfer. PCET and the transport of protons over tens of angstroms are important in all living cells because they are a fundamental link between redox processes and the establishment of transmembrane gradients of proton electrochemical potential, known as proton-motive force (PMF), which is the unifying concept in bioenergetics. We have chosen a benzimidazole phenol (BIP) system as a platform for the study of PCET because with appropriate substitutions it is possible to design assemblies in which one or multiple proton transfers can accompany oxidation of the phenol. In BIP, oxidation of the phenol increases its acidity by more than ten pK a units; thus, electrochemical oxidation of the phenol is associated with a proton transfer to the imidazole. This is an example of a PCET process involving transfer of one electron and one proton, known as electron-proton transfer (EPT). When the benzimidazole moiety of BIP is substituted at the 4-position with good proton acceptor groups such as aliphatic amines, experimental and theoretical results indicate that two proton transfers occur upon one-electron oxidation of the phenol. This phenomenon is described as a one-electron-two-proton transfer (E2PT) process and results in translocation of