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Sample records for 158a gev lead

  1. Multifractal moments in heavy ion Pb-Pb collisions at 158 A GeV

    NASA Astrophysics Data System (ADS)

    Dutt, Sunil

    2016-05-01

    In present work, we use the method of scaled factorial moments to search for intermittent behavior in Pb-Pb interactions at 158 A GeV. The analysis is done on photon distributions obtained using preshower photon multiplicity detector. Scaled factorial moments are used to study short range fluctuations in pseudorapidity distributions of photons. Scaled factorial moments are calculated using horizontal corrected and vertical analysis. The results are compared with simulation analysis using VENUS event generator.

  2. Centrality Dependence of Neutral Pion Production in 158A GeV {sup 208}Pb+{sup 208}Pb Collisions

    SciTech Connect

    Aggarwal, M.M.; Bhatia, V.S.; Agnihotri, A.; Bhalla, K.B.; Gupta, S.K.; Raniwala, R.; Raniwala, S.; Ahammed, Z.; Chattopadhyay, S.; Das, A.C.; Dutta Majumdar, M.R.; Ganti, M.S.; Mukhopadhyay, D.S.; Nayak, T.K.; Sinha, B.C.; Trivedi, M.D.; Viyogi, Y.P.; Angelis, A.L.; Donni, P.; Foka, P.; Kalechofsky, H.; Martin, M.; Naef, H.; Rosselet, L.; Rubio, J.M.; Solomey, N.; Voeroes, S.; Antonenko, V.; Cherbatchev, R.; Doubovik, I.; Fokin, S.; Ippolitov, M.; Karadjev, K.; Koutcheryaev, I.; Lebedev, A.; Manko, V.; Mgebrichvili, G.; Nianine, A.; Sibiriak, I.; Tsvetkov, A.; Vinogradov, A.; Arefiev, V.; Astakhov, V.; Avdeitchikov, V.; Baldine, A.; Barabach, L.; Batiounia, B.; Chalyshev, V.; Djordjadze, V.; Frolov, V.; Gavrishchuk, O.; Guskov, B.; Kosarev, I.; Kuzmin, N.; Maximov, A.; Mehdiyev, R.; Mikhalev, D.; Myalkovski, V.; Nikitine, V.; Nikolaev, S.; Nomokonov, P.; Parfenov, A.; Pavliouk, S.; Roufanov, I.; Shabratova, G.; Slavine, N.; Vodopianov, A.; Awes, T.C.; Kim, H.; Plasil, F.; Stankus, P.; Young, G.R.; Baba, P.V.; Badyal, S.K.; Rao, N.K.; Sambyal, S.S.; Barlag, C.; Bathe, S.; Blume, C.; Bohne, E.; Boeroecz, Z.K.; Bucher, D.; Buesching, H.; Claussen, A.; Glasow, R.; Kampert, K.; Kees, S.; Kruempel, T.; Pietzmann, T.; Reygers, K.; Santo, R.; Schlagheck, H.; Stueken, D.; Bernier, T.; Gutbrod, H.H.; Luquin, L.; Nayak, S.K.; Pinanaud, W.; Retiere, F.; Roy, C.; Bock, R.; Kolb, B.W.; Langbein, I.; Lee, Y.Y.; Neumaier, S.; and others

    1998-11-01

    The production of neutral pions in 158A GeV {sup 208}Pb+ {sup 208}Pb collisions has been studied in the WA98 experiment at the CERN Super Proton Synchrotron (SPS). Transverse momentum spectra are studied for the range 0.3{le}m{sub T}{minus}m{sub 0}{le}4.0 GeV /c . The results for central collisions are compared to various models. The centrality dependence of the neutral pion spectral shape and yield is investigated. An invariance of the spectral shape and a simple scaling of the yield with the number of participating nucleons is observed for centralities with greater than about 30thinspthinspparticipating nucleons. This is most naturally explained by assuming an equilibrated system. {copyright} {ital 1998} {ital The American Physical Society }

  3. Localized charged-neutral fluctuations in 158A GeV Pb+Pb collisions

    SciTech Connect

    Aggarwal, M. M.; Agnihotri, A.; Ahammed, Z.; Angelis, A. L. S.; Antonenko, V.; Arefiev, V.; Astakhov, V.; Avdeitchikov, V.; Awes, T. C.; Baba, P. V. K. S.

    2001-07-01

    Localized fluctuations in the multiplicity of charged particles and photons produced in central 158A GeV/c Pb+Pb collisions are studied. The charged versus neutral correlations in common {eta}-{phi} phase space regions of varying azimuthal size are analyzed by two different methods. The analysis provides a model-independent demonstration of nonstatistical fluctuations in both charged particle and photon multiplicities in limited azimuthal regions. However, no correlated charge-neutral fluctuations are observed, contrary to expectations for the production of a disoriented chiral condensate. The result is not explained by the widely used VENUS model.

  4. Critical fluctuations of the proton density in A+A collisions at 158 A GeV

    NASA Astrophysics Data System (ADS)

    Anticic, T.; Baatar, B.; Bartke, J.; Beck, H.; Betev, L.; Białkowska, H.; Blume, C.; Bogusz, M.; Boimska, B.; Book, J.; Botje, M.; Bunčić, P.; Cetner, T.; Christakoglou, P.; Chvala, O.; Cramer, J.; Eckardt, V.; Fodor, Z.; Foka, P.; Friese, V.; Gaździcki, M.; Grebieszkow, K.; Höhne, C.; Kadija, K.; Karev, A.; Kolesnikov, V. I.; Kowalski, M.; Kresan, D.; Laszlo, A.; van Leeuwen, M.; Maćkowiak-Pawłowska, M.; Makariev, M.; Malakhov, A. I.; Mateev, M.; Melkumov, G. L.; Mitrovski, M.; Mrówczyński, St.; Pálla, G.; Panagiotou, A. D.; Peryt, W.; Pluta, J.; Prindle, D.; Pühlhofer, F.; Renfordt, R.; Roland, C.; Roland, G.; Rustamov, A.; Rybczyński, M.; Rybicki, A.; Sandoval, A.; Schmitz, N.; Schuster, T.; Seyboth, P.; Siklér, F.; Skrzypczak, E.; Slodkowski, M.; Stefanek, G.; Stock, R.; Ströbele, H.; Susa, T.; Szuba, M.; Varga, D.; Vassiliou, M.; Veres, G. I.; Vesztergombi, G.; Vranić, D.; Włodarczyk, Z.; Wojtaszek-Szwarć, A.; Antoniou, N. G.; Davis, N.; Diakonos, F. K.

    2015-12-01

    We look for fluctuations expected for the QCD critical point using an intermittency analysis in the transverse momentum phase space of protons produced around midrapidity in the 12.5 % most central C+C, Si+Si and Pb+Pb collisions at the maximum SPS energy of 158 A GeV. We find evidence of power-law fluctuations for the Si+Si data. The fitted power-law exponent φ 2 = 0.96^{+0.38}_{-0.25}{ (stat.)} ± 0.16{ (syst.)} is consistent with the value expected for critical fluctuations. Power-law fluctuations had previously also been observed in low-mass π ^+ π ^- pairs in the same Si+Si collisions.

  5. Observation of Direct Photons in Central 158A GeV {sup 208}Pb+{sup 208}Pb Collisions

    SciTech Connect

    Aggarwal, M. M.; Agnihotri, A.; Ahammed, Z.; Angelis, A. L. S.; Antonenko, V.; Arefiev, V.; Astakhov, V.; Avdeitchikov, V.; Awes, T. C.; Baba, P. V. K. S.

    2000-10-23

    A measurement of direct photon production in {sup 208}Pb+ {sup 208}Pb collisions at 158A GeV has been carried out in the CERN WA98 experiment. The invariant yield of direct photons in central collisions is extracted as a function of transverse momentum in the interval 0.51.5 GeV/c . The result constitutes the first observation of direct photons in ultrarelativistic heavy-ion collisions. It could be significant for diagnosis of quark-gluon-plasma formation.

  6. Calculation of the Coulomb Fission Cross Sections for Pb-Pb and Bi-Pb Interactions at 158 A GeV

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    The Weizsacker-Williams (WW) method of virtual quanta is used to make approximate cross section calculations for peripheral relativistic heavy-ion collisions. We calculated the Coulomb fission cross sections for projectile ions of Pb-208 and Bi-209 with energies of 158 A GeV interacting with a Pb-208 target. We also calculated the electromagnetic absorption cross section for Pb-208 ion interacting as described. For comparison we use both the full WW method and a standard approximate WW method. The approximate WW method in larger cross sections compared to the more accurate full WW method.

  7. Freeze-Out Parameters in Central 158A GeV P{number_sign}208 b+Pb Collision80s

    SciTech Connect

    Aggarwal, M.M.; Bhatia, V.S.; Agnihotri, A.; Bhalla, K.B.; Gupta, S.K.; Raniwala, R.; Raniwala, S.; Ahammed, Z.; Chattopadhyay, S.; Das, A.C.; Dutta Majumdar, M.R.; Ganti, M.S.; Mukhopadhyay, D.S.; Nayak, T.K.; Sinha, B.C.; Trivedi, M.D.; Viyogi, Y.P.; Angelis, A.L.; Donni, P.; Foka, P.; Kalechofsky, H.; Martin, M.; Naef, H.; Rosselet, L.; Rubio, J.M.; Solomey, N.; Voeroes, S.; Antonenko, V.; Cherbatchev, R.; Doubovik, I.; Fokin, S.; Ippolitov, M.; Karadjev, K.; Koutcheryaev, I.; Lebedev, A.; Manko, V.; Mgebrichvili, G.; Nianine, A.; Sibiriak, I.; Tsvetkov, A.; Vinogradov, A.; Arefiev, V.; Astakhov, V.; Avdeitchikov, V.; Baldine, A.; Barabach, L.; Batiounia, B.; Chalyshev, V.; Djordjadze, V.; Frolov, V.; Gavrishchuk, O.; Guskov, B.; Kosarev, I.; Kuzmin, N.; Maximov, A.; Mehdiyev, R.; Mikhalev, D.; Myalkovski, V.; Nikitine, V.; Nikolaev, S.; Nomokonov, P.; Parfenov, A.; Pavliouk, S.; Roufanov, I.; Shabratova, G.; Slavine, N.; Vodopianov, A.; Awes, T.C.; Kim, H.; Plasil, F.; Stankus, P.; Young, G.R.; Baba, P.V.; Badyal, S.K.; Dutt, S.; Mir, M.F.; Rao, N.K.; Sambyal, S.S.; Shah, T.H.; Barlag, C.; Bathe, S.; Blume, C.; Bohne, E.; Boeroecz, Z.K.; Bucher, D.; Buesching, H.; Claussen, A.; Glasow, R.; Kampert, K.; Kees, S.; Kruempel, T.; Peitzmann, T.; Reygers, K.; Santo, R.; Schlagheck, H.; Stueken, D.; Bernier, T.; Delagrange, H.; Gutbrod, H.H.; Luquin, L.; Martinez, G.; Nayak, S.K.; Pinganaud, W.; Retiere, F.; Roy, C.; Schutz, Y. and others

    1999-08-01

    Neutral pion production in central 158A GeV {sup 208}Pb+ {sup 208} Pb collisions has been studied in the WA98 experiment at the CERN Super Proton Synchrotron. The {pi}{sup 0} transverse mass spectrum has been analyzed in terms of a thermal model with hydrodynamic expansion. The high accuracy and large kinematic coverage of the measurement allow one to limit previously noted ambiguities in the extracted freeze-out parameters. The results are shown to be sensitive to the shape of the velocity distribution at freeze-out. {copyright} {ital 1999} {ital The American Physical Society }

  8. Freeze-Out Parameters in Central 158A GeV P[number sign]208 b+Pb Collision80s

    SciTech Connect

    Aggarwal, M.M.; Bhatia, V.S. ); Agnihotri, A.; Bhalla, K.B.; Gupta, S.K.; Raniwala, R.; Raniwala, S. ); Ahammed, Z.; Chattopadhyay, S.; Das, A.C.; Dutta Majumdar, M.R.; Ganti, M.S.; Mukhopadhyay, D.S.; Nayak, T.K.; Sinha, B.C.; Trivedi, M.D.; Viyogi, Y.P. ); Angelis, A.L.; Donni, P.; Foka, P.; Kalechofsky, H.; Martin, M.; Naef, H.; Rosselet, L.; Rubio, J.M.; Solomey, N.; Voeroes, S. ); Antonenko, V.; Cherbatchev, R.; Doubovik, I.; Fokin, S.; Ippolitov, M.; Karadjev, K.; Koutcheryaev, I.; Lebedev, A.; Manko, V.; Mgebrichvili, G.; Nianine, A.; Sibiriak, I.; Tsvetkov, A.; Vinogradov, A. ); Arefiev, V.; Astakhov, V.; Avdeitchikov, V.; Baldine, A.; Barabach, L.; Batiounia, B.; Chalyshev, V.; Djordjadze, V.; Frolov, V.; Ga

    1999-08-01

    Neutral pion production in central 158A GeV [sup 208]Pb+ [sup 208] Pb collisions has been studied in the WA98 experiment at the CERN Super Proton Synchrotron. The [pi][sup 0] transverse mass spectrum has been analyzed in terms of a thermal model with hydrodynamic expansion. The high accuracy and large kinematic coverage of the measurement allow one to limit previously noted ambiguities in the extracted freeze-out parameters. The results are shown to be sensitive to the shape of the velocity distribution at freeze-out. [copyright] [ital 1999] [ital The American Physical Society

  9. Energy dependence of transverse momentum fluctuations in Pb+Pb collisions at the CERN Super Proton Synchrotron (SPS) at 20A to 158A GeV

    SciTech Connect

    NA49 Collaboration; Anticic, T.

    2009-04-15

    Results are presented on event-by-event fluctuations of transverse momenta p{sub T} in central Pb+Pb interactions at 20A, 30A, 40A, 80A, and 158A GeV. The analysis was performed for charged particles at forward center-of-mass rapidity (1.1 < y*{sub {pi}} < 2.6). Three fluctuation measures were studied: the distribution of average transverse momentum M(p{sub T}) in the event, the {phi}{sub p{sub T}} fluctuation measure, and two-particle transverse momentum correlations. Fluctuations of p{sub T} are small and show no significant energy dependence in the energy range of the CERN Super Proton Synchrotron. Results are compared with QCD-inspired predictions for the critical point, and with the UrQMD model. Transverse momentum fluctuations, similar to multiplicity fluctuations, do not show the increase expected for freeze-out near the critical point of QCD.

  10. K*(892)⁰ and K̄*(892)⁰ production in central Pb + Pb, Si + Si, C + C, and inelastic p + p collisions at 158A GeV

    SciTech Connect

    Anticic, T.; Baatar, B.; Barna, D.; Bartke, J.; Beck, H.; Betev, L.; Białkowska, H.; Blume, C.; Bogusz, M.; Boimska, B.; Book, J.; Botje, M.; Bunčić, P.; Cetner, T.; Christakoglou, P.; Chung, P.; Chvala, O.; Cramer, J. G.; Eckardt, V.; Fodor, Z.; Foka, P.; Friese, V.; Gaździcki, M.; Grebieszkow, K.; Höhne, C.; Kadija, K.; Karev, A.; Kolesnikov, V. I.; Kowalski, M.; Kresan, D.; Laszlo, A.; Lacey, R.; van Leeuwen, M.; Mackowiak, M.; Makariev, M.; Malakhov, A. I.; Mateev, M.; Melkumov, G. L.; Mitrovski, M.; Mrówczyński, S.; Nicolic, V.; Pálla, G.; Panagiotou, A. D.; Peryt, W.; Pluta, J.; Prindle, D.; Pühlhofer, F.; Renfordt, R.; Roland, C.; Roland, G.; Rybczyński, M.; Rybicki, A.; Sandoval, A.; Schmitz, N.; Schuster, T.; Seyboth, P.; Siklér, F.; Skrzypczak, E.; Słodkowski, M.; Stefanek, G.; Stock, R.; Ströbele, H.; Susa, T.; Szuba, M.; Utvić, M.; Varga, D.; Vassiliou, M.; Veres, G. I.; Vesztergombi, G.; Vranić, D.; Włodarczyk, Z.; Wojtaszek-Szwarc, A.

    2011-12-13

    Production of the K*(892)0 and K̄*(892)⁰ resonances was studied via their K⁺π⁻ and K⁻π⁺ decay modes in central Pb+Pb, Si+Si, C+C, and inelastic p+p collisions at 158A GeV(√(sNN)=17.3 GeV) with the NA49 detector at the CERN SPS. Transverse momentum and rapidity distributions were measured and total yields were estimated. The yield of K* exceeds that of K̄* by about a factor of two in nucleus-nucleus reactions. The total yield ratios ⟨K*⟩/⟨K+⟩ and ⟨K̄*⟩/⟨K-⟩ are strongly suppressed in central Pb+Pb compared to p+p, C+C, and Si+Si collisions, in agreement with the expected attenuation of these short-lived resonance states in the hadronic phase of the expanding fireball. The UrQMD model, although incorporating such a scenario, does not provide a quantitative description of the experimental results. The statistical hadron gas model assuming the same freeze-out parameters for stable hadrons and resonances overestimates the ⟨K*⟩/⟨K⟩ ratios in central Pb+Pb collisions by about a factor of 2.5.

  11. K*(892)⁰ and K̄*(892)⁰ production in central Pb + Pb, Si + Si, C + C, and inelastic p + p collisions at 158A GeV

    DOE PAGESBeta

    Anticic, T.; Baatar, B.; Barna, D.; Bartke, J.; Beck, H.; Betev, L.; Białkowska, H.; Blume, C.; Bogusz, M.; Boimska, B.; et al

    2011-12-13

    Production of the K*(892)0 and K̄*(892)⁰ resonances was studied via their K⁺π⁻ and K⁻π⁺ decay modes in central Pb+Pb, Si+Si, C+C, and inelastic p+p collisions at 158A GeV(√(sNN)=17.3 GeV) with the NA49 detector at the CERN SPS. Transverse momentum and rapidity distributions were measured and total yields were estimated. The yield of K* exceeds that of K̄* by about a factor of two in nucleus-nucleus reactions. The total yield ratios ⟨K*⟩/⟨K+⟩ and ⟨K̄*⟩/⟨K-⟩ are strongly suppressed in central Pb+Pb compared to p+p, C+C, and Si+Si collisions, in agreement with the expected attenuation of these short-lived resonance states in the hadronicmore » phase of the expanding fireball. The UrQMD model, although incorporating such a scenario, does not provide a quantitative description of the experimental results. The statistical hadron gas model assuming the same freeze-out parameters for stable hadrons and resonances overestimates the ⟨K*⟩/⟨K⟩ ratios in central Pb+Pb collisions by about a factor of 2.5.« less

  12. Peculiarities of secondary particle generation process in Pb-Pb interactions at 158A GeV

    SciTech Connect

    Astafyeva, N. M.; Dobrotin, N. A.; Dremin, I. M.; Feinberg, E. L.; Goncharova, L. A.; Kotelnikov, K. A.; Martynov, A. G.; Polukhina, N. G.

    1997-05-20

    Experimental data on Pb-Pb central collisions were obtained by means of emulsion magnetic chambers containing the lead target irradiated with the Pb beam in the magnetic field of 1.8 Tesla at CERN in December, 1994 and November, 1996. 50 {mu}m thick emulsion layers were placed perpendicular to the beam. Results of data analysis show existence of certain peculiar patterns in several central collisions (e.g. ring-like events, jets, multiple narrow spikes in secondary particle pseudorapidity distributions, etc.) The methods of pattern recognition theory, in particular, wavelet technique (the method of localized spectral analysis), used in target diagram analysis, reveal the detailed features of such structures.

  13. Three-pion interferometry results from central Pb+Pb collisions at 158A GeV/c.

    PubMed

    Aggarwal, M M; Agnihotri, A; Ahammed, Z; Angelis, A L; Antonenko, V; Arefiev, V; Astakhov, V; Avdeitchikov, V; Awes, T C; Baba, P V; Badyal, S K; Barlag, C; Bathe, S; Batiounia, B; Bernier, T; Bhalla, K B; Bhatia, V S; Blume, C; Bock, R; Bohne, E M; Böröcz, Z; Bucher, D; Buijs, A; Büsching, H; Carlen, L; Chalyshev, V; Chattopadhyay, S; Cherbatchev, R; Chujo, T; Claussen, A; Das, A C; Decowski, M P; Delagrange, H; Djordjadze, V; Donni, P; Doubovik, I; Dutt, S; Dutta Majumdar, M R; El Chenawi, K; Eliseev, S; Enosawa, K; Foka, P; Fokin, S; Ganti, M S; Garpman, S; Gavrishchuk, O; Geurts, F J; Ghosh, T K; Glasow, R; Gupta, S K; Guskov, B; Gustafsson, H A; Gutbrod, H H; Higuchi, R; Hrivnacova, I; Ippolitov, M; Kalechofsky, H; Kamermans, R; Kampert, K H; Karadjev, K; Karpio, K; Kato, S; Kees, S; Klein-Bösing, C; Knoche, S; Kolb, B W; Kosarev, I; Koutcheryaev, I; Krümpel, T; Kugler, A; Kulinich, P; Kurata, M; Kurita, K; Kuzmin, N; Langbein, I; Lebedev, A; Lee, Y Y; Löhner, H; Luquin, L; Mahapatra, D P; Manko, V; Martin, M; Martínez, G; Maximov, A; Mgebrichvili, G; Miake, Y; Mir, M F; Mishra, G C; Miyamoto, Y; Mohanty, B; Mora, M J; Morrison, D; Mukhopadhyay, D S; Naef, H; Nandi, B K; Nayak, S K; Nayak, T K; Neumaier, S; Nianine, A; Nikitine, V; Nikolaev, S; Nilsson, P; Nishimura, S; Nomokonov, P; Nystrand, J; Obenshain, F E; Oskarsson, A; Otterlund, I; Pachr, M; Pavliouk, S; Peitzmann, T; Petracek, V; Pinganaud, W; Plasil, F; von Poblotzki, U; Purschke, M L; Rak, J; Raniwala, R; Raniwala, S; Ramamurthy, V S; Rao, N K; Retiere, F; Reygers, K; Roland, G; Rosselet, L; Roufanov, I; Roy, C; Rubio, J M; Sako, H; Sambyal, S S; Santo, R; Sato, S; Schlagheck, H; Schmidt, H R; Schutz, Y; Shabratova, G; Shah, T H; Sibiriak, I; Siemiarczuk, T; Silvermyr, D; Sinha, B C; Slavine, N; Söderström, K; Solomey, N; Sørensen, S P; Stankus, P; Stefanek, G; Steinberg, P; Stenlund, E; Stüken, D; Sumbera, M; Svensson, T; Trivedi, M D; Tsvetkov, A; Tykarski, L; Urbahn, J; Pijll, E C; Eijndhoven, N; Nieuwenhuizen, G J; Vinogradov, A; Viyogi, Y P; Vodopianov, A; Vörös, S; Wysłouch, B; Yagi, K; Yokota, Y; Young, G R

    2000-10-01

    Three-particle correlations have been measured for identified pi(-) from central 158A GeV Pb+Pb collisions by the WA98 experiment at CERN. A substantial contribution of the genuine three-body correlation has been found as expected for a mainly chaotic and symmetric source. PMID:11005962

  14. Three-Pion Interferometry Results from Central Pb+Pb Collisions at 158A GeV/c

    SciTech Connect

    Aggarwal, M. M.; Agnihotri, A.; Ahammed, Z.; Angelis, A. L. S.; Antonenko, V.; Arefiev, V.; Astakhov, V.; Avdeitchikov, V.; Awes, T. C.; Baba, P. V. K. S.

    2000-10-02

    Three-particle correlations have been measured for identified {pi}{sup -} from central 158A GeV Pb+Pb collisions by the WA98 experiment at CERN. A substantial contribution of the genuine three-body correlation has been found as expected for a mainly chaotic and symmetric source.

  15. Di-hadron correlations with identified leading hadrons in 200 GeV Au + Au and d + Au collisions at STAR

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Bai, X.; Bairathi, V.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, T.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jia, J.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, W.; Li, Z. M.; Li, Y.; Li, C.; Li, X.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Ma, R.; Ma, L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Mei, J. C.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, Y.; Sun, Z.; Sun, X. M.; Sun, X.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Tawfik, A.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, J. S.; Wang, F.; Wang, H.; Wang, G.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Wu; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, H.; Xu, Z.; Xu, Q. H.; Xu, Y. F.; Xu, N.; Yang, S.; Yang, Y.; Yang, Q.; Yang, Y.; Yang, C.; Yang, Y.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, Y.; Zhang, Z.; Zhang, J. B.; Zhang, J.; Zhang, X. P.; Zhang, S.; Zhang, J.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.

    2015-12-01

    The STAR Collaboration presents for the first time two-dimensional di-hadron correlations with identified leading hadrons in 200 GeV central Au + Au and minimum-bias d + Au collisions to explore hadronization mechanisms in the quark gluon plasma. The enhancement of the jet-like yield for leading pions in Au + Au data with respect to the d + Au reference and the absence of such an enhancement for leading non-pions (protons and kaons) are discussed within the context of a quark recombination scenario. The correlated yield at large angles, specifically in the ridge region, is found to be significantly higher for leading non-pions than pions. The consistencies of the constituent quark scaling, azimuthal harmonic model and a mini-jet modification model description of the data are tested, providing further constraints on hadronization.

  16. The role of Ile87 of CYP158A2 in oxidative coupling reaction

    SciTech Connect

    Zhao, Bin; Bellamine, Aouatef; Lei, Li; Waterman, Michael R.

    2012-05-15

    Both CYP158A1 and CYP158A2 are able to catalyze an oxidative C-C coupling reaction producing biflaviolin or triflaviolin in Streptomyces coelicolor A3(2). The substrate-bound crystal structures of CYP158A2 and CYP158A1 reveal that the side chain of Ile87 in CYP158A2 points to the active site contacting the distal flaviolin molecule, however, the bulkier side chain of Lys90 in CYP158A1 (corresponding to Ile87 in CYP158A2) is toward the distal surface of the protein. These results suggest that these residues could be important in determining product regiospecificity. In order to explore the role of the two residues in catalysis, the reciprocal mutants, Ile87Lys and Lys90Ile, of CYP158A2 and CYP158A1, respectively, were generated and characterized. The mutant Ile87Lys enzyme forms two isomers of biflaviolin instead of three isomers of biflaviolin in wild-type CYP158A2. CYP158A1 containing the substitution of lysine with isoleucine has the same catalytic activity compared with the wild-type CYP158A1. The crystal structure of Ile87Lys showed that the BC loop in the mutant is in a very different orientation compared with the BC loop in both CYP158A1/A2 structures. These results shed light on the mechanism of the oxidative coupling reaction catalyzed by cytochrome P450.

  17. The Role of Ile87 of CYP158A2 in Oxidative Coupling Reaction

    PubMed Central

    Zhao, Bin; Bellamine, Aouatef; Lei, Li; Waterman, Michael R.

    2012-01-01

    Both CYP158A1 and CYP158A2 are able to catalyze an oxidative C-C coupling reaction producing biflaviolin or triflaviolin in Streptomyces coelicolor A3(2). The substrate-bound crystal structures of CYP158A2 and CYP158A1 reveal that the side chain of Ile87 in CYP158A2 points to the active site contacting the distal flaviolin molecule, however, the bulkier side chain of Lys90 in CYP158A1 (corresponding to Ile87 in CYP158A2) is toward the distal surface of the protein. These results suggest that these residues could be important in determining product regiospecificity. In order to explore the role of the two residues in catalysis, the reciprocal mutants, Ile87Lys and Lys90Ile, of CYP158A2 and CYP158A1, respectively, were generated and characterized. The mutant Ile87Lys enzyme forms two isomers of biflaviolin instead of three isomers of biflaviolin in wild-type CYP158A2. CYP158A1 containing the substitution of lysine with isoleucine has the same catalytic activity compared with the wild-type CYP158A1. The crystal structure of Ile87Lys showed that the BC loop in the mutant is in a very different orientation compared with the BC loop in both CYP158A1/A2 structures. These results shed light on the mechanism of the oxidative coupling reaction catalyzed by cytochrome P450. PMID:22203090

  18. Neutron production in collisions between carbon nuclei of energy 2 GeV per nucleon and carbon, aluminum, copper, cadmium, and lead nuclei

    SciTech Connect

    Yurevich, V. I.; Yakovlev, R. M.; Lyapin, V. G.

    2012-02-15

    Double-differential cross sections for neutron production were measured by the time-of-flight method for the interactions between carbon nuclei of energy 2 GeV per nucleon and carbon, aluminum, copper, cadmium, and lead nuclei. These measurements were performed for angles of 30 Degree-Sign , 53 Degree-Sign , and 90 Degree-Sign in the neutron-energy range fromseveral hundred keVunits to 300MeV. The phenomenologicalmodel of four moving sources was used as a basis in analyzing experimental results and in estimating the contribution to neutron emission from various reaction stages. The temperature parameters determined from the slope of the neutron energy spectra proved to be 22 {+-} 2 MeV for a hot source (fireball) and 4.5 {+-} 0.3 MeV for the stage of thermal fragmentation of highly excited heavy nuclear residues. The relative contribution of these two sources to the total neutron yield is independent of the type of the target nucleus and is about 42%, on average.

  19. Lead

    MedlinePlus

    ... Lead Share Facebook Twitter Google+ Pinterest Contact Us Lead Poisoning is Preventable If your home was built before ... of the RRP rule. Read more . Learn about Lead Poisoning Prevention Week . Report Uncertified Contractors and Environmental Violations ...

  20. Transverse momenta of fragments of relativistic sulfur and lead nuclei after their interaction with track-emulsion nuclei at energies of 200 and 160 GeV per nucleon

    SciTech Connect

    Lepekhin, F. G. Tkach, L. N.

    2011-05-15

    Transverse-momentum distributions of doubly charged fragments of sulfur and lead nuclei having energies of 200 and 160 GeV per nucleon and interacting with nuclei in a track emulsion were investigated. No trace of compression or heating of nuclear matter in the interaction of these nuclei with track-emulsion nuclei was revealed experimentally. Transverse momenta of fragments of relativistic nuclei were found to obey a normal distribution that corresponds to a degenerate momentum distribution of nucleons in the ground state of a nucleus before its interaction with a track-emulsion nucleus. There is no piece of evidence that fragments of relativistic nuclei originate from some excited state of an intermediate nucleus. This picture of the fragmentation of relativistic nuclei complies with the naive parton model proposed by Feynman and Gribov. In summary, the fragmentation of relativistic nuclei at energies of 160 and 200 GeV per nucleon is cold and fast.

  1. Lead

    MedlinePlus

    ... obvious symptoms, it frequently goes unrecognized. CDC’s Childhood Lead Poisoning Prevention Program is committed to the Healthy People ... Lead Levels Information for Parents Tips for preventing lead poisoning About Us Overview of CDC’s Childhood Lead Poisoning ...

  2. Comparison of some lead and non-lead based glass systems, standard shielding concretes and commercial window glasses in terms of shielding parameters in the energy region of 1 keV-100 GeV: A comparative study

    NASA Astrophysics Data System (ADS)

    Kurudirek, Murat; Özdemir, Yüksel; Şimşek, Önder; Durak, Rıdvan

    2010-12-01

    The effective atomic numbers, Z eff of some glass systems with and without Pb have been calculated in the energy region of 1 keV-100 GeV including the K absorption edges of high Z elements present in the glass. Also, these glass systems have been compared with some standard shielding concretes and commercial window glasses in terms of mean free paths and total mass attenuation coefficients in the continuous energy range. Comparisons with experiments were also provided wherever possible for glasses. It has been observed that the glass systems without Pb have higher values of Z eff than that of Pb based glasses at some high energy regions even if they have lower mean atomic numbers than Pb based glasses. When compared with some standard shielding concretes and commercial window glasses, generally it has been shown that the given glass systems have superior properties than concretes and window glasses with respect to the radiation-shielding properties, thus confirming the availability of using these glasses as substitutes for some shielding concretes and commercial window glasses to improve radiation-shielding properties in the continuous energy region.

  3. Next-to-Leading-Order QCD Correction to e{sup +}e{sup -}{yields}J/{psi}+{eta}{sub c} at {radical}(s)=10.6 GeV

    SciTech Connect

    Zhang Yujie; Gao Yingjia; Chao, K.-T.

    2006-03-10

    One of the most challenging open problems in heavy quarkonium physics is the double charm production in e{sup +}e{sup -} annihilation at B factories. The measured cross section of e{sup +}e{sup -}{yields}J/{psi}+{eta}{sub c} is much larger than leading order (LO) theoretical predictions. With the nonrelativistic QCD factorization formalism, we calculate the next-to-leading order (NLO) QCD correction to this process. Taking all one-loop self-energy, triangle, box, and pentagon diagrams into account, and factoring the Coulomb-singular term into the cc bound state wave function, we get an ultraviolet and infrared finite correction to the cross section of e{sup +}e{sup -}{yields}J/{psi}+{eta}{sub c} at {radical}(s)=10.6 GeV. We find that the NLO QCD correction can substantially enhance the cross section with a K factor (the ratio of NLO to LO) of about 1.8-2.1; hence, it greatly reduces the large discrepancy between theory and experiment.

  4. Antideuteron production in 158A GeV/c Pb + Pb collisions

    PubMed

    Bearden; Boggild; Boissevain; Christiansen; Conin; Dodd; Erazmus; Esumi; Fabjan; Ferenc; Franz; Gaardhoje; Hansen; Hansen; Hardtke; van Hecke H; Holzer; Humanic; Hummel; Jacak; Kaimi; Kaneta; Kohama; Kopytine; Leltchouk; Ljubicic

    2000-09-25

    The invariant cross section as a function of transverse momentum for antideuterons produced in 158A GeV/c per nucleon Pb+Pb central collisions has been measured by the NA44 experiment at CERN. This measurement, together with a measurement of antiprotons, allows for the determination of the antideuteron coalescence parameter. The extracted coalescence radius is found to agree with the deuteron coalescence radius and radii determined from two particle correlations. PMID:10991207

  5. Study of 232Th(n, γ) and 232Th(n,f) reaction rates in a graphite moderated spallation neutron field produced by 1.6 GeV deuterons on lead target

    NASA Astrophysics Data System (ADS)

    Asquith, N. L.; Hashemi-Nezhad, S. R.; Westmeier, W.; Zhuk, I.; Tyutyunnikov, S.; Adam, J.

    2015-02-01

    The Gamma-3 assembly of the Joint Institute for Nuclear Research (JINR), Dubna, Russia is designed to emulate the neutron spectrum of a thermal Accelerator Driven System (ADS). It consists of a lead spallation target surrounded by reactor grade graphite. The target was irradiated with 1.6 GeV deuterons from the Nuclotron accelerator and the neutron capture and fission rate of 232Th in several locations within the assembly were experimentally measured. 232Th is a proposed fuel for envisaged Accelerator Driven Systems and these two reactions are fundamental to the performance and feasibility of 232Th in an ADS. The irradiation of the Gamma-3 assembly was also simulated using MCNPX 2.7 with the INCL4 intra-nuclear cascade and ABLA fission/evaporation models. Good agreement between the experimentally measured and calculated reaction rates was found. This serves as a good validation for the computational models and cross section data used to simulate neutron production and transport of spallation neutrons within a thermal ADS.

  6. New measurement of the electron flux from 10 GeV to 100 GeV with the bets instrument

    NASA Astrophysics Data System (ADS)

    Torii, S.; Tamura, T.; Tateyama, N.; Yoshida, K.; Yamagami, T.; Kamioka, E.; Saito, Y.; Murakami, H.; Kobayashi, T.; Komori, Y.; Kasahara, K.; Yuda, T.; Nishimura, J.

    The BETS (balloon-borne electron telescope with scintillating fibers) instrument has been developed for high-altitude balloon flights to observe the cosmic ray electrons with energies of 10 GeV to several 100 GeV. The detector is a Lead/SciFi sampling calorimeter consisting of 36 SciFi belts (each 280 mm wide) and 8 lead plates (each 5 mm thick). The electron identification is performed by triggering the electro-magnetic showers on board and by analyzing the three-dimensional shower images by an intensified CCD camera. It is demonstrated in the flight data in 1995 and 1997 that a reliable identification of the electron component against the proton background is achieved up to a few 100 GeV. The performance of detector was tested by the CERN-SPS electron beams in 1996 and with the proton beams in 1997. The obtained energy spectrum is consistent with the recent observation by HEAT, although our result still has a little room for improvement. The energy spectrum from 10 GeV to 1000 GeV which is obtained by combining these data and the emulsion chamber data (Nishimura 1997) suggests that the diffusion constant is about 1 × 10 28 ( E/GeV) 0.3 cm 2/sec in the energy range between 10 GeV and 1000 GeV. A hump in the energy spectrum is observed around several hundred GeV, which is expected from a nearby source.

  7. Phase-space dependence of particle-ratio fluctuations in Pb + Pb collisions from 20A to 158A GeV beam energy

    NASA Astrophysics Data System (ADS)

    Anticic, T.; Baatar, B.; Bartke, J.; Beck, H.; Betev, L.; Białkowska, H.; Blume, C.; Boimska, B.; Book, J.; Botje, M.; Bunčić, P.; Christakoglou, P.; Chung, P.; Chvala, O.; Cramer, J.; Eckardt, V.; Fodor, Z.; Foka, P.; Friese, V.; Gaździcki, M.; Grebieszkow, K.; Höhne, C.; Kadija, K.; Karev, A.; Kolesnikov, V.; Kowalski, M.; Kresan, D.; Laszlo, A.; Lacey, R.; van Leeuwen, M.; Maćkowiak-Pawłowska, M.; Makariev, M.; Malakhov, A.; Melkumov, G.; Mitrovski, M.; Mrówczyński, S.; Pálla, G.; Panagiotou, A.; Peryt, W.; Pluta, J.; Prindle, D.; Pühlhofer, F.; Renfordt, R.; Roland, C.; Roland, G.; Rybczyński, M.; Rybicki, A.; Sandoval, A.; Rustamov, A.; Schmitz, N.; Schuster, T.; Seyboth, P.; Siklér, F.; Skrzypczak, E.; Słodkowski, M.; Stefanek, G.; Stock, R.; Ströbele, H.; Susa, T.; Szuba, M.; Varga, D.; Vassiliou, M.; Veres, G.; Vesztergombi, G.; Vranić, D.; Włodarczyk, Z.; Wojtaszek-Szwarc, A.; NA49 Collaboration

    2014-05-01

    A novel approach, the identity method, was used for particle identification and the study of fluctuations of particle yield ratios in Pb + Pb collisions at the CERN Super Proton Synchrotron (SPS). This procedure allows one to measure the moments of the multiplicity distributions of protons (p), kaons (K), pions (π), and electrons (e) in case of incomplete particle identification. Using these moments the excitation function of the fluctuation measure νdyn[A,B] was measured, with A and B denoting different particle types. The obtained energy dependence of νdyn agrees with previously published NA49 results on the related measure σdyn. However, νdyn[K,p] and νdyn[K,π] were found to depend on the phase-space coverage. This feature most likely explains the reported differences between measurements of NA49 and those of STAR in central Au + Au collisions.

  8. Upgrade of CEBAF from 6 Gev To 12 Gev: Status

    SciTech Connect

    Harwood, Leigh

    2013-04-19

    The CEBAF accelerator is being upgraded from 6 GeV to 12 GeV by the US Department of Energy. The accelerator upgrade is being done within the existing tunnel footprint. The accelerator upgrade includes: 10 new srfbased high-performance cryomodules plus RF systems, doubling the 2K helium plant's capability, upgrading the existing beamlines to operate at nearly double the original performance envelope, and adding a beamline to a new experimental area. Construction is over 75% complete with final completion projected for late FY13. Details of the upgrade and status of the work will be presented.

  9. Characterising the 750 GeV diphoton excess

    NASA Astrophysics Data System (ADS)

    Bernon, Jérémy; Goudelis, Andreas; Kraml, Sabine; Mawatari, Kentarou; Sengupta, Dipan

    2016-05-01

    We study kinematic distributions that may help characterise the recently observed excess in diphoton events at 750 GeV at the LHC Run 2. Several scenarios are considered, including spin-0 and spin-2 750 GeV resonances that decay directly into photon pairs as well as heavier parent resonances that undergo three-body or cascade decays. We find that combinations of the distributions of the diphoton system and the leading photon can distinguish the topology and mass spectra of the different scenarios, while patterns of QCD radiation can help differentiate the production mechanisms. Moreover, missing energy is a powerful discriminator for the heavy parent scenarios if they involve (effectively) invisible particles. While our study concentrates on the current excess at 750 GeV, the analysis is general and can also be useful for characterising other potential diphoton signals in the future.

  10. Ratio of jet cross sections at square root of s = 630 GeV and 1800 GeV.

    PubMed

    Abbott, B; Abolins, M; Abramov, V; Acharya, B S; Adams, D L; Adams, M; Alves, G A; Amos, N; Anderson, E W; Baarmand, M M; Babintsev, V V; Babukhadia, L; Baden, A; Baldin, B; Balm, P W; Banerjee, S; Bantly, J; Barberis, E; Baringer, P; Bartlett, J F; Bassler, U; Bean, A; Begel, M; Belyaev, A; Beri, S B; Bernardi, G; Bertram, I; Besson, A; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Bhattacharjee, M; Blazey, G; Blessing, S; Boehnlein, A; Bojko, N I; Borcherding, F; Brandt, A; Breedon, R; Briskin, G; Brock, R; Brooijmans, G; Bross, A; Buchholz, D; Buehler, M; Buescher, V; Burtovoi, V S; Butler, J M; Canelli, F; Carvalho, W; Casey, D; Casilum, Z; Castilla-Valdez, H; Chakraborty, D; Chan, K M; Chekulaev, S V; Cho, D K; Choi, S; Chopra, S; Christenson, J H; Chung, M; Claes, D; Clark, A R; Cochran, J; Coney, L; Connolly, B; Cooper, W E; Coppage, D; Cummings, M A; Cutts, D; Dahl, O I; Davis, G A; Davis, K; De, K; Del Signore, K; Demarteau, M; Demina, R; Demine, P; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Di Loreto, G; Doulas, S; Draper, P; Ducros, Y; Dudko, L V; Duensing, S; Dugad, S R; Dyshkant, A; Edmunds, D; Ellison, J; Elvira, V D; Engelmann, R; Eno, S; Eppley, G; Ermolov, P; Eroshin, O V; Estrada, J; Evans, H; Evdokimov, V N; Fahland, T; Feher, S; Fein, D; Ferbel, T; Fisk, H E; Fisyak, Y; Flattum, E; Fleuret, F; Fortner, M; Frame, K C; Fuess, S; Gallas, E; Galyaev, A N; Gartung, P; Gavrilov, V; Genik, R J; Genser, K; Gerber, C E; Gershtein, Y; Gibbard, B; Gilmartin, R; Ginther, G; Gómez, B; Gómez, G; Goncharov, P I; González Solís, J L; Gordon, H; Goss, L T; Gounder, K; Goussiou, A; Graf, N; Graham, G; Grannis, P D; Green, J A; Greenlee, H; Grinstein, S; Groer, L; Grudberg, P; Grünendahl, S; Gupta, A; Gurzhiev, S N; Gutierrez, G; Gutierrez, P; Hadley, N J; Haggerty, H; Hagopian, S; Hagopian, V; Hahn, K S; Hall, R E; Hanlet, P; Hansen, S; Hauptman, J M; Hays, C; Hebert, C; Hedin, D; Heinson, A P; Heintz, U; Heuring, T; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoftun, J S; Hou, S; Huang, Y; Ito, A S; Jerger, S A; Jesik, R; Johns, K; Johnson, M; Jonckheere, A; Jones, M; Jöstlein, H; Juste, A; Kahn, S; Kajfasz, E; Karmanov, D; Karmgard, D; Kehoe, R; Kim, S K; Klima, B; Klopfenstein, C; Knuteson, B; Ko, W; Kohli, J M; Kostritskiy, A V; Kotcher, J; Kotwal, A V; Kozelov, A V; Kozlovsky, E A; Krane, J; Krishnaswamy, M R; Krzywdzinski, S; Kubantsev, M; Kuleshov, S; Kulik, Y; Kunori, S; Kuznetsov, V E; Landsberg, G; Leflat, A; Lehner, F; Li, J; Li, Q Z; Lima, J G; Lincoln, D; Linn, S L; Linnemann, J; Lipton, R; Lucotte, A; Lueking, L; Lundstedt, C; Maciel, A K; Madaras, R J; Manankov, V; Mao, H S; Marshall, T; Martin, M I; Martin, R D; Mauritz, K M; May, B; Mayorov, A A; McCarthy, R; McDonald, J; McMahon, T; Melanson, H L; Meng, X C; Merkin, M; Merritt, K W; Miao, C; Miettinen, H; Mihalcea, D; Mincer, A; Mishra, C S; Mokhov, N; Mondal, N K; Montgomery, H E; Moore, R W; Mostafa, M; da Motta, H; Nagy, E; Nang, F; Narain, M; Narasimham, V S; Neal, H A; Negret, J P; Negroni, S; Norman, D; Oesch, L; Oguri, V; Olivier, B; Oshima, N; Padley, P; Pan, L J; Para, A; Parashar, N; Partridge, R; Parua, N; Paterno, M; Patwa, A; Pawlik, B; Perkins, J; Peters, M; Peters, O; Piegaia, R; Piekarz, H; Pope, B G; Popkov, E; Prosper, H B; Protopopescu, S; Qian, J; Quintas, P Z; Raja, R; Rajagopalan, S; Ramberg, E; Rapidis, P A; Reay, N W; Reucroft, S; Rha, J; Rijssenbeek, M; Rockwell, T; Roco, M; Rubinov, P; Ruchti, R; Rutherfoord, J; Santoro, A; Sawyer, L; Schamberger, R D; Schellman, H; Schwartzman, A; Sculli, J; Sen, N; Shabalina, E; Shankar, H C; Shivpuri, R K; Shpakov, D; Shupe, M; Sidwell, R A; Simak, V; Singh, H; Singh, J B; Sirotenko, V; Slattery, P; Smith, E; Smith, R P; Snihur, R; Snow, G R; Snow, J; Snyder, S; Solomon, J; Sorín, V; Sosebee, M; Sotnikova, N; Soustruznik, K; Souza, M; Stanton, N R; Steinbrück, G; Stephens, R W; Stevenson, M L; Stichelbaut, F; Stoker, D; Stolin, V; Stoyanova, D A; Strauss, M; Streets, K; Strovink, M; Stutte, L; Sznajder, A; Taylor, W; Tentindo-Repond, S; Thompson, J; Toback, D; Tripathi, S M; Trippe, T G; Turcot, A S; Tuts, P M; van Gemmeren, P; Vaniev, V; Van Kooten, R; Varelas, N; Volkov, A A; Vorobiev, A P; Wahl, H D; Wang, H; Wang, Z M; Warchol, J; Watts, G; Wayne, M; Weerts, H; White, A; White, J T; Whiteson, D; Wightman, J A; Wijngaarden, D A; Willis, S; Wimpenny, S J; Wirjawan, J V; Womersley, J; Wood, D R; Yamada, R; Yamin, P; Yasuda, T; Yip, K; Youssef, S; Yu, J; Yu, Z; Zanabria, M; Zheng, H; Zhou, Z; Zhu, Z H; Zielinski, M; Zieminska, D; Zieminski, A; Zutshi, V; Zverev, E G; Zylberstejn, A

    2001-03-19

    The D0 Collaboration has measured the inclusive jet cross section in barpp collisions at square root of s = 630 GeV. The results for pseudorapidities (eta)<0.5 are combined with our previous results at square root of s = 1800 GeV to form a ratio of cross sections with smaller uncertainties than either individual measurement. Next-to-leading-order QCD predictions show excellent agreement with the measurement at 630 GeV; agreement is also satisfactory for the ratio. Specifically, despite a 10% to 15% difference in the absolute magnitude, the dependence of the ratio on jet transverse momentum is very similar for data and theory. PMID:11289971

  11. ACCELERATING POLARIZED PROTONS TO 250 GEV

    SciTech Connect

    BAI,M.; AHRENS, L.; ALEKSEEV, I.G.; ALESSI, J.; BEEBE-WANG, J.; ET AL.

    2007-06-25

    The Relativistic Heavy Ion Collider (RHIC) as the first high energy polarized proton collider was designed t o provide polarized proton collisions a t a maximum beam energy of 250 GeV. I t has been providing collisions a t a beam energy of 100 Gel' since 2001. Equipped with two full Siberian snakes in each ring, polarization is preserved during the acceleration from injection to 100 GeV with careful control of the betatron tunes and the vertical orbit distortions. However, the intrinsic spin resonances beyond 100 GeV are about a factor of two stronger than those below 100 GeV? making it important t o examine the impact of these strong intrinsic spin resonances on polarization survival and the tolerance for vertical orbit distortions. Polarized protons were accelerated t o the record energy of 250 GeV in RHIC with a polarization of 46% measured a t top energy in 2006. The polarization measurement as a function of beam energy also shows some polarization loss around 136 GeV, the first strong intrinsic resonance above 100 GeV. This paper presents the results and discusses the sensitivity of the polarization survival t o orbit distortions.

  12. Beyond the MSSM Higgs bosons at 125 GeV

    NASA Astrophysics Data System (ADS)

    Boudjema, F.; Drieu La Rochelle, G.

    2012-07-01

    Beyond the MSSM framework is an effective theory approach that encapsulates a variety of extensions beyond the MSSM with which it shares the same field content. The lightest Higgs mass can be much heavier than in the MSSM without creating a tension with naturalness or requiring superheavy stops. The phenomenology of the Higgs sector is at the same time much richer. We critically review the properties of a Higgs with mass around 125 GeV in this model. In particular, we investigate how the rates in the important inclusive 2γ channel, the 2γ+2 jets and the ZZ→4l (and/or WW) can be enhanced or reduced compared to the standard model and what kind of correlations between these rates are possible. We consider both a vanilla model where stops have moderate masses with no trilinear stop mixing term and a model having a large stop mixing with a light stop. We show that in both cases there are scenarios that lead to enhancements in these rates at a mass of 125 GeV corresponding to either the lightest Higgs or the heaviest CP-even Higgs of the model. In all of these scenarios we study the prospects of finding other signatures of either the 125 GeV Higgs or those of the heavier Higgses. In most cases the τ¯τ channels are the most promising. Exclusion limits from the recent LHC Higgs searches are folded in our analyses while the tantalizing hints for a Higgs signal at 125 GeV are used as an example of how to constrain beyond the MSSM and/or direct future searches.

  13. ON THE EXTERNAL SHOCK SYNCHROTRON MODEL FOR GAMMA-RAY BURSTS' GeV EMISSION

    SciTech Connect

    Piran, Tsvi; Nakar, Ehud E-mail: udini@wise.tau.ac.i

    2010-08-01

    The dominant component of the GeV gamma-ray burst emission detected by the Large Area Telescope begins after the prompt soft (sub-MeV) gamma rays and lasts longer. This has led to the intriguing suggestion that the GeV emission is generated via synchrotron emission of the external shock. Moreover, the limits on the MeV afterglow emission lead to the suggestion that at least in bright GeV bursts the field is not amplified beyond compression in the shock. We show here that considerations of confinement (within the decelerating shock), efficiency, and cooling of the emitting electrons constrain, within this model, the magnetic fields that arise in both the upstream (unshocked circumburst) and downstream (shocked circumburst) regions, allowing us to put direct limits on their values. The well-known limit on the maximal synchrotron emission, when combined with the blast wave evolution, implies that late photons (arriving more than {approx}100 s after the burst) with energies higher than {approx}10 GeV do not arise naturally from an external shock synchrotron and almost certainly have a different origin. Finally, even a modest seed flux (a few mJy) in IR-optical would quench, via Inverse Compton cooling, the GeV emission unless the magnetic field is significantly amplified behind the shock. An observation of a burst with simultaneous IR-optical and GeV emission will rule out this model.

  14. Evaluation of dynamically downscaled extreme temperature using a spatially-aggregated generalized extreme value (GEV) model

    NASA Astrophysics Data System (ADS)

    Wang, Jiali; Han, Yuefeng; Stein, Michael L.; Kotamarthi, Veerabhadra R.; Huang, Whitney K.

    2016-02-01

    The weather research and forecast (WRF) model downscaling skill in extreme maximum daily temperature is evaluated by using the generalized extreme value (GEV) distribution. While the GEV distribution has been used extensively in climatology and meteorology for estimating probabilities of extreme events, accurately estimating GEV parameters based on data from a single pixel can be difficult, even with fairly long data records. This work proposes a simple method assuming that the shape parameter, the most difficult of the three parameters to estimate, does not vary over a relatively large region. This approach is applied to evaluate 31-year WRF-downscaled extreme maximum temperature through comparison with North American regional reanalysis (NARR) data. Uncertainty in GEV parameter estimates and the statistical significance in the differences of estimates between WRF and NARR are accounted for by conducting a novel bootstrap procedure that makes no assumption of temporal or spatial independence within a year, which is especially important for climate data. Despite certain biases over parts of the United States, overall, WRF shows good agreement with NARR in the spatial pattern and magnitudes of GEV parameter estimates. Both WRF and NARR show a significant increase in extreme maximum temperature over the southern Great Plains and southeastern United States in January and over the western United States in July. The GEV model shows clear benefits from the regionally constant shape parameter assumption, for example, leading to estimates of the location and scale parameters of the model that show coherent spatial patterns.

  15. Where Will LEAD Lead?

    ERIC Educational Resources Information Center

    Wildman, Louis

    After setting forth eight assumptions concerning the education of educational administrators, findings about the Leadership in Educational Administration Development (LEAD) program are discussed. The analysis is based on the first-year applications, telephone conversations with staff at a majority of the project sites, and additional material…

  16. LEADING WITH LEADING INDICATORS

    SciTech Connect

    PREVETTE, S.S.

    2005-01-27

    This paper documents Fluor Hanford's use of Leading Indicators, management leadership, and statistical methodology in order to improve safe performance of work. By applying these methods, Fluor Hanford achieved a significant reduction in injury rates in 2003 and 2004, and the improvement continues today. The integration of data, leadership, and teamwork pays off with improved safety performance and credibility with the customer. The use of Statistical Process Control, Pareto Charts, and Systems Thinking and their effect on management decisions and employee involvement are discussed. Included are practical examples of choosing leading indicators. A statistically based color coded dashboard presentation system methodology is provided. These tools, management theories and methods, coupled with involved leadership and employee efforts, directly led to significant improvements in worker safety and health, and environmental protection and restoration at one of the nation's largest nuclear cleanup sites.

  17. Determination of the b-quark production cross section in p{anti p} collisions at 630 GeV

    SciTech Connect

    Abbott, B.

    1997-10-01

    We present a preliminary measurement of the b-quark production cross section in p{anti p} collisions at {radical}s = 630 GeV. The analysis is based on 340 nb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron Collider. We determine the ratio of the b-quark production cross sections at 630 GeV to 1800 GeV and compare our results with the CDF and UA1 measurements, and with the next-to- leading order QCD predictions.

  18. 750 GeV diphoton excess

    NASA Astrophysics Data System (ADS)

    Altmannshofer, Wolfgang; Galloway, Jamison; Gori, Stefania; Kagan, Alexander L.; Martin, Adam; Zupan, Jure

    2016-05-01

    We explore several perturbative scenarios in which the diphoton excess at 750 GeV can potentially be explained: a scalar singlet, a two Higgs doublet model (2HDM), a 2HDM with an extra singlet, and the decays of heavier resonances, both vector and scalar. We draw the following conclusions: (i) due to gauge invariance a 750 GeV scalar singlet can accommodate the observed excess more readily than a scalar S U (2 )L doublet; (ii) scalar singlet production via gluon fusion is one option, however, vector boson fusion can also provide a large enough rate, (iii) 2HDMs with an extra singlet and no extra fermions can only give a signal in a severely tuned region of the parameter space; (iv) decays of heavier resonances can give a large enough diphoton signal at 750 GeV, while simultaneously explaining the absence of a signal at 8 TeV.

  19. JEFFERSON LAB 12 GEV CEBAF UPGRADE

    SciTech Connect

    Rode, C. H.

    2010-04-09

    The existing continuous electron beam accelerator facility (CEBAF) at Thomas Jefferson National Accelerator Facility (TJNAF) is a 5-pass, recirculating cw electron Linac operating at approx6 GeV and is devoted to basic research in nuclear physics. The 12 GeV CEBAF Upgrade is a $310 M project, sponsored by the Department of Energy (DOE) Office of Nuclear Physics, that will expand its research capabilities substantially by doubling the maximum energy and adding major new experimental apparatus. The project received construction approval in September 2008 and has started the major procurement process. The cryogenic aspects of the 12 GeV CEBAF Upgrade includes: doubling the accelerating voltages of the Linacs by adding ten new high-performance, superconducting radiofrequency (SRF) cryomodules (CMs) to the existing 42 1/4 cryomodules; doubling of the 2 K cryogenics plant; and the addition of eight superconducting magnets.

  20. 750 GeV diphotons from a D3-brane

    NASA Astrophysics Data System (ADS)

    Heckman, Jonathan J.

    2016-05-01

    Motivated by the recently reported diphoton excess at 750 GeV observed by both CMS and ATLAS, we study string-based particle physics models which can accommodate this signal. Quite remarkably, although Grand Unified Theories in F-theory tend to impose tight restrictions on candidate extra sectors, the case of a probe D3-brane near an E-type Yukawa point naturally leads to a class of strongly coupled models capable of accommodating the observed signature. In these models, the visible sector is realized by intersecting 7-branes, and the 750 GeV resonance is a scalar modulus associated with motion of the D3-brane in the direction transverse to the Standard Model 7-branes. Integrating out heavy 3-7 string messenger states leads to dimension five operators for gluon fusion production and diphoton decays. Due to the unified structure of interactions, these models also predict that there should be additional decay channels to ZZ and Zγ. We also comment on models with distorted unification, where both the production mechanism and decay channels can differ.

  1. Results from Cu+Au collisions at 200 GeV in PHENIX Experiment

    NASA Astrophysics Data System (ADS)

    Berdnikov, Ya. A.; Ivanishchev, D. A.; Kotov, D. O.; Riabov, V. G.; Riabov, Yu. G.; Samsonov, V. M.; Safonov, A. S.

    2016-01-01

    Collisions of asymmetric nuclei (Cu+Au) differ essentially from the case of symmetric nuclei (Cu+Cu, Au+Au) collisions in the geometry of overlap region. This leads to a number of consequences, which provide more absolute and accurate information about fundamental properties of matter under extreme conditions. Nuclear modification factors for π-mesons in Cu+Au interactions at 200 GeV were measured in PHENIX Experiment at RHIC. New experimental data on measurement of flows of different order (v1, v2) for light hadrons in Cu+Au interactions at 200 GeV will be discussed in this paper.

  2. Lead Poisoning

    MedlinePlus

    ... Experiments Stories Lessons Topics Games Activities Lessons MENU Lead Poisoning Kids Homepage Topics Pollution Lead Poisoning What is ... you can avoid contact with it! Sources of Lead Poisoning HOUSE PAINTS: Before1950, lead-based paint was used ...

  3. Lead Test

    MedlinePlus

    ... to determine lead sources, educating family members about lead poisoning , and instituting follow-up testing to monitor the ... high levels of lead, see the article on Lead Poisoning . The Occupational Safety and Health Administration (OSHA) has ...

  4. Lead Poisoning

    MedlinePlus

    Lead Poisoning What is it and who is affected? Lead is a highly toxic substance, exposure to which ... and children can suffer from the effects of lead poisoning, but childhood lead poisoning is much more frequent. ...

  5. Estimating Shock Spectra: Extensions beyond GEVS

    NASA Technical Reports Server (NTRS)

    Igusa, Takeru; Maahs, Gordon L.

    2008-01-01

    Shock response spectra (SRS) are the standard description of some vibration environments on spacecraft for equipment qualification. For shock events produced by pyrotechnic devices, SRS can have significant frequency content as high as 10 kHz. It is difficult to construct and analyze finite element models that can resolve dynamic behavior at such high frequencies. GEVS provides simple, empirically based methods for approximating the SRS for a wide variety of shock events. It begins with a base SRS according to the type of pyrotechnic device, and then provides attenuation relations to adjust this SRS according to distance from the shock source, the type of structural frame and the properties of any structural joints between the source and equipment. In our paper we extend GEVS to include more detailed information about the spacecraft structure. To retain the general framework of GEVS, we begin with a base SRS and adjust this SRS using attenuation relations. We use modal and traveling wave concepts to derive the attenuation relations for simple canonical structures. Then we show how these concepts can be used to analyze more complex structures using finite element mode shapes to explicitly calculate the attenuation factors. Since the low- to mid-frequency finite element modal information is extrapolated to obtain the low- to high-frequency attenuation relations, the resulting attenuated SRS is formulated as an upper bound rather than as mean predicted values. We illustrate the extended GEVS approach by analyzing the impact response of composite tubes and the shock response of the STEREO spacecraft.

  6. A regional GEV scale-invariant framework for Intensity-Duration-Frequency analysis

    NASA Astrophysics Data System (ADS)

    Blanchet, J.; Ceresetti, D.; Molinié, G.; Creutin, J.-D.

    2016-09-01

    We propose in this paper a regional formulation of Intensity-Duration-Frequency curves of point-rainfall maxima in a scale-invariant Generalized Extreme Value (GEV) framework. The two assumptions we make is that extreme daily rainfall is GEV-distributed - which is justified by Extreme Value Theory (EVT) - and that extremes of aggregated daily rainfall follow simple-scaling relationships. Following these assumptions, we develop in a unified way a GEV simple-scaling model for extremes of aggregated daily rainfall over the range of durations where scaling applies. Then we propose a way of correcting this model for measurement frequency, giving a new GEV-scaling model for extremes of aggregated hourly rainfall. This model deviates from the simple-scaling assumption. This framework is applied to the Mediterranean region of Cévennes-Vivarais, France. A network of about 300 daily raingage stations covering the last 50 years and accumulated to span the range 1 day-1 week is used to fit the scale invariant GEV-model locally. By means of spatial interpolation of the model parameters, and correction for measurement frequency, we are able to build a regional model with good performances down to 1 h duration, even though only one hourly station is used to build the model. Finally we produce mean and return level maps within the region in the range 1 h-1 week and comment on the potential rain storms leading to these maps.

  7. TARGET FRAGMENT ENERGIES AND MOMENTA IN THE REACTION OF 4.8 GeV {sup 12}C AND 5.0 GeV {sup 20}Ne WITH {sup 238}U

    SciTech Connect

    Loveland, W.; Luo, Cheng; McGaughey, P. L.; Morrissey, D. J.; Seaborg, G. T.

    1980-10-01

    Target fragment recoil properties were measured using the thick target-thick catcher technique for the interaction of 4.8 GeV {sup 12}C and 5.0 GeV {sup 20}Ne with {sup 238}U. The target fragment energies and momenta are very similar for the reaction of 4.8 GeV (400 MeV/A) {sup 12}C and 5.0 GeV (250 MeV/A) {sup 20}Ne with {sup 238}U. In the complex variation of fragment momenta with their N/Z ratio, one finds evidence suggesting the existence of several mechanisms leading to the formation of the target fragments. Comparison of these results with the predictions of the intranuclear cascade model of Yariv and Fraenkel and the firestreak model shows that both model predictions grossly overestimate the target fragment momenta.

  8. Lead Poisoning

    MedlinePlus

    Lead is a metal that occurs naturally in the earth's crust. Lead can be found in all parts of our ... from human activities such as mining and manufacturing. Lead used to be in paint; older houses may ...

  9. Lead poisoning

    MedlinePlus

    ... swallows a lead object or breathes in lead dust, some of the poison can stay in the ... a health problem. Lead is everywhere, including dirt, dust, new toys, and old house paint. Unfortunately, you ...

  10. Lead Toxicity

    MedlinePlus

    ... homes. • Most people, especially children, who suffer from lead poisoning are exposed through lead-contaminated household dust or ... and six if they are at risk of lead poisoning (see: ). Who can I call to get more ...

  11. Meson Spectroscopy At Jlab At 12 Gev

    SciTech Connect

    Fegan, Stuart

    2014-12-01

    The 12 GeV upgrade to the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab will enable a new generation of experiments in hadronic nuclear physics, seeking to address fundamental questions in our understanding of QCD. The existence of exotic states, suggested by both quark models and lattice calculations, would allow gluonic degrees of freedom to be explored, and may help explain the role played by gluons in the QCD interaction. This article will review the meson spectroscopy program being planned at the lab following the 12 GeV upgrade, utilising real and quasi-real photon beams in two of the lab's four experimental halls, whose distinct capabilities will enable an extensive set of spectroscopy experiments to be performed at the same facility.

  12. Booster 6-GeV study

    SciTech Connect

    Yang, Xi; Ankenbrandt, Charles M.; Pellico, William A.; Lackey, James; Padilla, Rene; Norem, J.; /Argonne

    2004-12-01

    Since a wider aperture has been obtained along the Booster beam line, this opens the opportunity for Booster running a higher intensity beam than ever before. Sooner or later, the available RF accelerating voltage will become a new limit for the beam intensity. Either by increasing the RFSUM or by reducing the accelerating rate can achieve the similar goal. The motivation for the 6-GeV study is to gain the relative accelerating voltage via a slower acceleration.

  13. Lead Poisoning

    MedlinePlus

    ... our environment. Much of it comes from human activities such as mining and manufacturing. Lead used to be in paint; older houses may still have lead paint. You could be exposed to lead by Eating food or drinking water that contains lead. Water pipes in older homes ...

  14. Lead poisoning

    SciTech Connect

    Rekus, J.F.

    1992-08-01

    Construction workers who weld, cut or blast structural steel coated with lead-based paint are at significant risk of lead poisoning. Although technology to control these exposures may not have existed when the lead standard was promulgated, it is available today. Employers who do not take steps to protect their employees from lead exposure may be cited and fined severely for their failure.

  15. Upgrade of CEBAF from 6-GeV To 12-GeV: Status

    SciTech Connect

    Harwood, Leigh H.

    2013-04-01

    The CEBAF accelerator is being upgraded from 6 GeV to 12 GeV by the US Department of Energy. The accelerator upgrade is being done within the existing tunnel footprint. The accelerator upgrade includes: 10 new srfbased high-performance cryomodules plus RF systems, doubling the 2K helium plants capability, upgrading the existing beamlines to operate at nearly double the original performance envelope, and adding a beamline to a new experimental area. Construction is over 75% complete with final completion projected for late FY13. Details of the upgrade and status of the work will be presented.

  16. Walking from 750 GeV to 950 GeV in the technipion zoo

    NASA Astrophysics Data System (ADS)

    Matsuzaki, Shinya; Yamawaki, Koichi

    2016-06-01

    If the 750-GeV diphoton excess is identified with the color-singlet isosinglet technipion P0 (750) in the one-family walking technicolor model, as in our previous paper, then there should exist another color-singlet technipion-isotriplet one, P±,3, predicted at around 950 GeV independently of the dynamical details. The P±,3(950 ) are produced at the LHC via vector-boson and photon-fusion processes, predominantly decaying to W γ and γ γ , respectively. Those walking technicolor signals can be explored at run 2 or 3, which would further open the door for a plethora of other (colored) technipions.

  17. Lead poisoning

    MedlinePlus

    ... lead is still found in some modern faucets. Soil contaminated by decades of car exhaust or years ... house paint scrapings. Lead is more common in soil near highways and houses. Hobbies involving soldering, stained ...

  18. LASER WAKEFIELD ACCELERATION BEYOND 1 GeV USING IONIZATION INDUCED INJECTION*

    SciTech Connect

    Marsh, K A; Clayton, C E; Joshi, C; Lu, W; Mori, W B; Pak, A; silva, L O; Lemos, N; Fonseca, R A; de Freitas, S; Albert, F; Doeppner, T; Filip, C; Froula, D; Glenzer, S H; Price, D; Ralph, J; Pollock, B B

    2011-03-22

    A series of laser wake field accelerator experiments leading to electron energy exceeding 1 GeV are described. Theoretical concepts and experimental methods developed while conducting experiments using the 10 TW Ti:Sapphire laser at UCLA were implemented and transferred successfully to the 100 TW Callisto Laser System at the Jupiter Laser Facility at LLNL. To reach electron energies greater than 1 GeV with current laser systems, it is necessary to inject and trap electrons into the wake and to guide the laser for more than 1 cm of plasma. Using the 10 TW laser, the physics of self-guiding and the limitations in regards to pump depletion over cm-scale plasmas were demonstrated. Furthermore, a novel injection mechanism was explored which allows injection by ionization at conditions necessary for generating electron energies greater than a GeV. The 10 TW results were followed by self-guiding at the 100 TW scale over cm plasma lengths. The energy of the self-injected electrons, at 3 x 10{sup 18} cm{sup -3} plasma density, was limited by dephasing to 720 MeV. Implementation of ionization injection allowed extending the acceleration well beyond a centimeter and 1.4 GeV electrons were measured.

  19. Commissioning and Operation of 12 GeV CEBAF

    SciTech Connect

    Freyberger, Arne P.

    2015-09-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) located at the Thomas Jefferson National Accelerator Laboratory (JLab) has been recently upgraded to deliver continuous electron beams to the experimental users at a maximum energy of 12 GeV, three times the original design energy of 4 GeV. This paper will present an overview of the upgrade, referred to as the 12GeV upgrade, and highlights from recent beam commissioning results.

  20. Lead Pencils

    NASA Technical Reports Server (NTRS)

    Gray, L. B.

    1971-01-01

    A study, undertaken to determine the lead content of paint on various pencils in the Goddard supply system, is reported. The survey found that lead content varied from .04 mg per pencil for carmine colored pencils to approximately 43 mg per pencil for yellow colored pencils. Results also show that yellow pencils had higher lead content than other colors analyzed. More detailed results are given in tabular form.

  1. Leading Democratically

    ERIC Educational Resources Information Center

    Brookfield, Stephen

    2010-01-01

    Democracy is the most venerated of American ideas, the one for which wars are fought and people die. So most people would probably agree that leaders should be able to lead well in a democratic society. Yet, genuinely democratic leadership is a relative rarity. Leading democratically means viewing leadership as a function or process, rather than…

  2. 3 GeV Injector Design Handbook

    SciTech Connect

    Wiedemann, H.; /SLAC, SSRL

    2009-12-16

    This Design Handbook is intended to be the main reference book for the specifications of the 3 GeV SPEAR booster synchrotron project. It is intended to be a consistent description of the project including design criteria, key technical specifications as well as current design approaches. Since a project is not complete till it's complete changes and modifications of early conceptual designs must be expected during the duration of the construction. Therefore, this Design Handbook is issued as a loose leaf binder so that individual sections can be replaced as needed. Each page will be dated to ease identification with respect to latest revisions. At the end of the project this Design Handbook will have become the 'as built' reference book of the injector for operations and maintenance personnel.

  3. The lead-glass electromagnetic calorimeter for the SELEX experiment

    SciTech Connect

    M. Y. Balatz et al.

    2004-07-19

    A large-acceptance, highly segmented electromagnetic lead glass calorimeter for Experiment E781 (SELEX) at Fermi National Acceleration Laboratory was designed and built. This detector has been used to reconstruct photons and electrons with energies ranging from few GeV up to 500 GeV in the collisions of the 650 GeV {Sigma}{sup -} hyperons and {pi}{sup -} mesons with the target nucleons. The design, calibration and performance of the calorimeter are described. Energy resolution and position resolution are assessed using both calibration electron beams and {pi}{sup 0} mesons reconstructed in 650 GeV hadron-hadron interactions. The performance of the calorimeter in selecting resonant states that involve photons is demonstrated.

  4. Predicted CALET measurements of electron and positron spectra from 3 to 20 GeV using the geomagnetic field

    NASA Astrophysics Data System (ADS)

    Rauch, B. F.

    2014-05-01

    The CALorimetric Electron Telescope (CALET) is an imaging calorimeter under construction for launch to the ISS in 2014 for a planned 5 year mission. CALET consists of a charge detection module (CHD) with two segmented planes of 1 cm thick plastic scintillator, an imaging calorimeter (IMC) with a total of 3 radiation lengths (X∘) of tungsten plates read out with 8 planes of interleaved scintillating fibers, and a total absorption calorimeter (TASC) with 27 X∘ of lead tungstate (PWO) logs. The primary objectives of the experiment are to measure the electron e+e energy spectra from 1 GeV to 20 TeV, to detect gamma-rays above 10 GeV, and to measure the energy spectra of nuclei from protons through iron up to 1000 TeV. In this paper we describe how the geomagnetic field at the 51.6° inclination orbit of the ISS can be used to allow CALET to measure the distinct electron and positron fluxes. The positron fraction has been seen to rise above ˜10 GeV by previous experiments (HEAT, AMS-01), and more recently to continue to increase to higher energies (˜80 GeV for PAMELA, ˜200 GeV for Fermi and ˜350 GeV with the best statistics for AMS-02). Utilizing the geomagnetic cutoff, CALET will be able to distinguish electrons and positrons in the ˜3-20 GeV energy range where the positron fraction turns upward to complement existing high statistics measurements.

  5. Polarized proton collisions at 205 GeV at RHIC.

    PubMed

    Bai, M; Roser, T; Ahrens, L; Alekseev, I G; Alessi, J; Beebe-Wang, J; Blaskiewicz, M; Bravar, A; Brennan, J M; Bruno, D; Bunce, G; Courant, E; Drees, A; Fischer, W; Gardner, C; Gill, R; Glenn, J; Haeberli, W; Huang, H; Jinnouchi, O; Kewisch, J; Luccio, A; Luo, Y; Nakagawa, I; Okada, H; Pilat, F; Mackay, W W; Makdisi, Y; Montag, C; Ptitsyn, V; Satogata, T; Stephenson, E; Svirida, D; Tepikian, S; Trbojevic, D; Tsoupas, N; Wise, T; Zelenski, A; Zeno, K; Zhang, S Y

    2006-05-01

    The Brookhaven Relativistic Heavy Ion Collider (RHIC) has been providing collisions of polarized protons at a beam energy of 100 GeV since 2001. Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to 100 GeV. However, the intrinsic spin resonances beyond 100 GeV are about a factor of 2 stronger than those below 100 GeV making it important to examine the impact of these strong intrinsic spin resonances on polarization survival and the tolerance for vertical orbit distortions. Polarized protons were first accelerated to the record energy of 205 GeV in RHIC with a significant polarization measured at top energy in 2005. This Letter presents the results and discusses the sensitivity of the polarization survival to orbit distortions. PMID:16712305

  6. ON THE ORIGIN OF > 10 GeV PHOTONS IN GAMMA-RAY BURST AFTERGLOWS

    SciTech Connect

    Wang Xiangyu; Liu Ruoyu; Lemoine, Martin

    2013-07-10

    Fermi/LAT has detected long-lasting high-energy photons (>100 MeV) from gamma-ray bursts (GRBs), with the highest energy photons reaching about 100 GeV. One proposed scenario is that they are produced by high-energy electrons accelerated in GRB forward shocks via synchrotron radiation. We study the maximum synchrotron photon energy in this scenario, considering the properties of the microturbulence magnetic fields behind the shock, as revealed by recent particle-in-cell simulations and theoretical analyses of relativistic collisionless shocks. Due to the small-scale nature of the microturbulent magnetic field, the Bohm acceleration approximation, in which the scattering mean free path is equal to the particle Larmor radius, breaks down at such high energies. This effect leads to a typical maximum synchrotron photon of a few GeV at 100 s after the burst and this maximum synchrotron photon energy decreases quickly with time. We show that the fast decrease of the maximum synchrotron photon energy leads to a fast decay of the synchrotron flux. The 10-100 GeV photons detected after the prompt phase cannot be produced by the synchrotron mechanism. They could originate from the synchrotron self-Compton emission of the early afterglow if the circumburst density is sufficiently large, or from the external inverse Compton process in the presence of central X-ray emission, such as X-ray flares and prompt high-latitude X-ray emission.

  7. 750 GeV diphoton excess and a dark matter messenger at the Galactic Center

    NASA Astrophysics Data System (ADS)

    Huang, Xian-Jun; Zhang, Wei-Hong; Zhou, Yu-Feng

    2016-06-01

    The first data from the LHC run 2 have shown a possible excess in diphoton events with invariant mass ˜750 GeV , suggesting the existence of a new resonance which may decay dominantly into dark matter (DM) particles. We show in a simple model that the reported diphoton excess at the LHC is consistent with another photon excess, the 2 GeV excess in cosmic gamma-ray fluxes towards the Galactic Center observed by the Fermi-LAT. Both the excesses can be simultaneously explained by a ˜60 GeV scalar DM particle annihilating dominantly into two gluons with a typical thermal annihilation cross section, which leads to the prediction of a width-to-mass ratio Γ /M ≈O (10-2) of the resonance. The upper limit on the dijet search at LHC run 1 leads to a lower limit on the predicted cross section for DM annihilating into γ γ final states ⟨σ v ⟩γ γ≳O (10-30) cm3 s-1 . Both the predictions can be tested by the LHC, Fermi-LAT, and future experiments.

  8. An extension of two-Higgs-doublet model and the excesses of 750 GeV diphoton, muon g-2 and h → μτ

    NASA Astrophysics Data System (ADS)

    Han, Xiao-Fang; Wang, Lei; Yang, Jin Min

    2016-06-01

    In this paper we simultaneously explain the excesses of the 750 GeV diphoton, muon g-2 and h → μτ in an extension of the two-Higgs-doublet model (2HDM) with additional vector-like fermions and a CP-odd scalar singlet (P) which is identified as the 750 GeV resonance. This 750 GeV resonance has a mixing with the CP-odd scalar (A) from a second scalar doublet, which leads to a coupling between P and the SM particles as well as a coupling between A and the vector-like fermions. Such mixing and couplings are strongly constrained by τ → μγ, muon g-2 and the 750 GeV diphoton data. We scan over the parameter space and find that such an extension can simultaneously account for the observed excesses of 750 GeV diphoton, muon g-2 and h → μτ. The 750 GeV resonance decays in exotic modes, such as P → hA, P → HZ, P → HA and P →W±H∓, and its width can be dozens of GeV and is sensitive to the mixing angle.

  9. Implications of the 750 GeV diphoton excess in gaugino mediation

    NASA Astrophysics Data System (ADS)

    Han, Chengcheng; Yanagida, Tsutomu T.; Yokozaki, Norimi

    2016-03-01

    The 750 GeV diphoton excess reported by ATLAS and CMS indicates the presence of several pairs of the vectorlike matter multiplets around TeV scale. If that is the case, radiative corrections from the S U (3 ) gauge interaction significantly change from those of the minimal supersymmetric standard model, and the infrared-free nature of the gauge interaction leads to characteristic supersymmetry mass spectra: a ratio of a squark mass to the gluino mass, and scalar trilinear couplings are enhanced at the low-energy scale. Consequently, even in gaugino mediation models, the Higgs boson mass of 125 GeV is explained with the fairly light gluino of 2-3 TeV, which can be accessible at the LHC.

  10. 750 GeV diphoton excess from E6 in F-theory GUTs

    NASA Astrophysics Data System (ADS)

    Karozas, Athanasios; King, Stephen F.; Leontaris, George K.; Meadowcroft, Andrew K.

    2016-06-01

    We interpret the 750-760 GeV diphoton resonance as one or more of the spinless components of a singlet superfield arising from the three 27-dimensional representations of E6 in F-theory, which also contain three copies of colour-triplet charge ∓ 1 / 3 vector-like fermions Di ,Dbari and inert Higgs doublets to which the singlets may couple. For definiteness we consider (without change) a model that was proposed some time ago which contains such states, as well as bulk exotics, leading to gauge coupling unification. The smoking gun prediction of the model is the existence of other similar spinless resonances, possibly close in mass to 750-760 GeV, decaying into diphotons, as well as the three families of vector-like fermions Di ,Dbari.

  11. Diffractive dijet production at sqrt[s] = 630 and 1800 GeV at the Fermilab Tevatron.

    PubMed

    Acosta, D; Affolder, T; Akimoto, H; Albrow, M G; Amaral, P; Ambrose, D; Amidei, D; Anikeev, K; Antos, J; Apollinari, G; Arisawa, T; Artikov, A; Asakawa, T; Ashmanskas, W; Azfar, F; Azzi-Bacchetta, P; Bacchetta, N; Bachacou, H; Bailey, S; de Barbaro, P; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Barone, M; Bauer, G; Bedeschi, F; Belforte, S; Bell, W H; Bellettini, G; Bellinger, J; Benjamin, D; Bensinger, J; Beretvas, A; Berge, J P; Berryhill, J; Bhatti, A; Binkley, M; Bisello, D; Bishai, M; Blair, R E; Blocker, C; Bloom, K; Blumenfeld, B; Blusk, S R; Bocci, A; Bodek, A; Bolla, G; Bonushkin, Y; Borras, K; Bortoletto, D; Boudreau, J; Brandl, A; van den Brink, S; Bromberg, C; Brozovic, M; Brubaker, E; Bruner, N; Buckley-Geer, E; Budagov, J; Budd, H S; Burkett, K; Busetto, G; Byon-Wagner, A; Byrum, K L; Cabrera, S; Calafiura, P; Campbell, M; Carithers, W; Carlson, J; Carlsmith, D; Caskey, W; Castro, A; Cauz, D; Cerri, A; Chan, A W; Chang, P S; Chang, P T; Chapman, J; Chen, C; Chen, Y C; Cheng, M-T; Chertok, M; Chiarelli, G; Chirikov-Zorin, I; Chlachidze, G; Chlebana, F; Christofek, L; Chu, M L; Chung, J Y; Chung, Y S; Ciobanu, C I; Clark, A G; Colijn, A P; Connolly, A; Convery, M E; Conway, J; Cordelli, M; Cranshaw, J; Cropp, R; Culbertson, R; Dagenhart, D; D'Auria, S; DeJongh, F; Dell'Agnello, S; Dell'Orso, M; Demers, S; Demortier, L; Deninno, M; Derwent, P F; Devlin, T; Dittmann, J R; Dominguez, A; Donati, S; Done, J; D'Onofrio, M; Dorigo, T; Eddy, N; Einsweiler, K; Elias, J E; Engels, E; Erbacher, R; Errede, D; Errede, S; Fan, Q; Fang, H-C; Feild, R G; Fernandez, J P; Ferretti, C; Field, R D; Fiori, I; Flaugher, B; Foster, G W; Franklin, M; Freeman, J; Friedman, J; Fukui, Y; Furic, I; Galeotti, S; Gallas, A; Gallinaro, M; Gao, T; Garcia-Sciveres, M; Garfinkel, A F; Gatti, P; Gay, C; Gerdes, D W; Giannetti, P; Glagolev, V; Glenzinski, D; Gold, M; Goldstein, J; Gorelov, I; Goshaw, A T; Gotra, Y; Goulianos, K; Green, C; Grim, G; Gris, P; Grosso-Pilcher, C; Guenther, M; Guillian, G; Guimaraes da Costa, J; Haas, R M; Haber, C; Hahn, S R; Hall, C; Handa, T; Handler, R; Hao, W; Happacher, F; Hara, K; Hardman, A D; Harris, R M; Hartmann, F; Hatakeyama, K; Hauser, J; Heinrich, J; Heiss, A; Herndon, M; Hill, C; Hocker, A; Hoffman, K D; Hollebeek, R; Holloway, L; Huffman, B T; Hughes, R; Huston, J; Huth, J; Ikeda, H; Incandela, J; Introzzi, G; Ivanov, A; Iwai, J; Iwata, Y; James, E; Jones, M; Joshi, U; Kambara, H; Kamon, T; Kaneko, T; Karr, K; Kartal, S; Kasha, H; Kato, Y; Keaffaber, T A; Kelley, K; Kelly, M; Khazins, D; Kikuchi, T; Kilminster, B; Kim, B J; Kim, D H; Kim, H S; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kirby, M; Kirk, M; Kirsch, L; Klimenko, S; Koehn, P; Kondo, K; Konigsberg, J; Korn, A; Korytov, A; Kovacs, E; Kroll, J; Kruse, M; Kuhlmann, S E; Kurino, K; Kuwabara, T; Laasanen, A T; Lai, N; Lami, S; Lammel, S; Lancaster, J; Lancaster, M; Lander, R; Lath, A; Latino, G; LeCompte, T; Lee, A M; Lee, K; Leone, S; Lewis, J D; Lindgren, M; Liss, T M; Liu, J B; Liu, Y C; Litvintsev, D O; Lobban, O; Lockyer, N S; Loken, J; Loreti, M; Lucchesi, D; Lukens, P; Lusin, S; Lyons, L; Lys, J; Madrak, R; Maeshima, K; Maksimovic, P; Malferrari, L; Mangano, M; Mariotti, M; Martignon, G; Martin, A; Matthews, J A J; Mayer, J; Mazzanti, P; McFarland, K S; McIntyre, P; Menguzzato, M; Menzione, A; Merkel, P; Mesropian, C; Meyer, A; Miao, T; Miller, R; Miller, J S; Minato, H; Miscetti, S; Mishina, M; Mitselmakher, G; Miyazaki, Y; Moggi, N; Moore, C; Moore, E; Moore, R; Morita, Y; Moulik, T; Mulhearn, M; Mukherjee, A; Muller, T; Munar, A; Murat, P; Murgia, S; Nachtman, J; Nagaslaev, V; Nahn, S; Nakada, H; Nakano, I; Nelson, C; Nelson, T; Neu, C; Neuberger, D; Newman-Holmes, C; Ngan, C-Y P; Niu, H; Nodulman, L; Nomerotski, A; Oh, S H; Oh, Y D; Ohmoto, T; Ohsugi, T; Oishi, R; Okusawa, T; Olsen, J; Orejudos, W; Pagliarone, C; Palmonari, F; Paoletti, R; Papadimitriou, V; Partos, D; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D; Pescara, L; Phillips, T J; Piacentino, G; Pitts, K T; Pompos, A; Pondrom, L; Pope, G; Popovic, M; Prokoshin, F; Proudfoot, J; Ptohos, F; Pukhov, O; Punzi, G; Rakitine, A; Ratnikov, F; Reher, D; Reichold, A; Renton, P; Ribon, A; Riegler, W; Rimondi, F; Ristori, L; Riveline, M; Robertson, W J; Robinson, A; Rodrigo, T; Rolli, S; Rosenson, L; Roser, R; Rossin, R; Rott, C; Roy, A; Ruiz, A; Safonov, A; St Denis, R; Sakumoto, W K; Saltzberg, D; Sanchez, C; Sansoni, A; Santi, L; Sato, H; Savard, P; Savoy-Navarro, A; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Scodellaro, L; Scott, A; Scribano, A; Sedov, A; Segler, S; Seidel, S; Seiya, Y; Semenov, A; Semeria, F; Shah, T; Shapiro, M D; Shepard, P F; Shibayama, T; Shimojima, M; Shochet, M; Sidoti, A; Siegrist, J; Sill, A; Sinervo, P; Singh, P; Slaughter, A J; Sliwa, K; Smith, C; Snider, F D; Solodsky, A; Spalding, J; Speer, T; Sphicas, P

    2002-04-15

    We report a measurement of the diffractive structure function F(D)(jj) of the antiproton obtained from a study of dijet events produced in association with a leading antiproton in pp collisions at sqrt[s] = 630 GeV at the Fermilab Tevatron. The ratio of F(D)(jj) at sqrt[s] = 630 GeV to F(D)(jj) obtained from a similar measurement at sqrt[s] = 1800 GeV is compared with expectations from QCD factorization and other theoretical predictions. We also report a measurement of the xi ( x-Pomeron) and beta ( x of parton in Pomeron) dependence of F(D)(jj) at sqrt[s] = 1800 GeV. In the region 0.035GeV2, and beta<0.5, F(D)(jj)(beta,xi) is found to be of the form beta(-1.0+/-0.1)xi(-0.9+/-0.1), which obeys beta-xi factorization. PMID:11955190

  12. Ecotoxicology: Lead

    USGS Publications Warehouse

    Scheuhammer, A.M.; Beyer, W.N.; Schmitt, C.J.

    2008-01-01

    Lead (Pb) is a naturally occurring metallic element; trace concentrations are found in all environmental media and in all living things. However, certain human activities, especially base metal mining and smelting; combustion of leaded gasoline; the use of Pb in hunting, target shooting, and recreational angling; the use of Pb-based paints; and the uncontrolled disposal of Pb-containing products such as old vehicle batteries and electronic devices have resulted in increased environmental levels of Pb, and have created risks for Pb exposure and toxicity in invertebrates, fish, and wildlife in some ecosystems.

  13. Tetraethyl lead

    Integrated Risk Information System (IRIS)

    Tetraethyl lead ; CASRN 78 - 00 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  14. Ratio of isolated photon cross sections in pp macro collisions at square root of s = 630 and 1800 GeV.

    PubMed

    Abazov, V M; Abbott, B; Abdesselam, A; Abolins, M; Abramov, V; Acharya, B S; Adams, D L; Adams, M; Ahmed, S N; Alexeev, G D; Alton, A; Alves, G A; Amos, N; Anderson, E W; Arnoud, Y; Avila, C; Baarmand, M M; Babintsev, V V; Babukhadia, L; Bacon, T C; Baden, A; Baldin, B; Balm, P W; Banerjee, S; Barberis, E; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Bean, A; Beaudette, F; Begel, M; Belyaev, A; Beri, S B; Bernardi, G; Bertram, I; Besson, A; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Bhattacharjee, M; Blazey, G; Blekman, F; Blessing, S; Boehnlein, A; Bojko, N I; Borcherding, F; Bos, K; Bose, T; Brandt, A; Breedon, R; Briskin, G; Brock, R; Brooijmans, G; Bross, A; Buchholz, D; Buehler, M; Buescher, V; Burtovoi, V S; Butler, J M; Canelli, F; Carvalho, W; Casey, D; Casilum, Z; Castilla-Valdez, H; Chakraborty, D; Chan, K M; Chekulaev, S V; Cho, D K; Choi, S; Chopra, S; Christenson, J H; Chung, M; Claes, D; Clark, A R; Cochran, J; Coney, L; Connolly, B; Cooper, W E; Coppage, D; Crépé-Renaudin, S; Cummings, M A; Cutts, D; Davis, G A; Davis, K; De, K; de Jong, S J; Del Signore, K; Demarteau, M; Demina, R; Demine, P; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Doulas, S; Ducros, Y; Dudko, L V; Duensing, S; Duflot, L; Dugad, S R; Duperrin, A; Dyshkant, A; Edmunds, D; Ellison, J; Elvira, V D; Engelmann, R; Eno, S; Eppley, G; Ermolov, P; Eroshin, O V; Estrada, J; Evans, H; Evdokimov, V N; Fahland, T; Feher, S; Fein, D; Ferbel, T; Filthaut, F; Fisk, H E; Fisyak, Y; Flattum, E; Fleuret, F; Fortner, M; Fox, H; Frame, K C; Fu, S; Fuess, S; Gallas, E; Galyaev, A N; Gao, M; Gavrilov, V; Genik, R J; Genser, K; Gerber, C E; Gershtein, Y; Gilmartin, R; Ginther, G; Gómez, B; Gómez, G; Goncharov, P I; González Solís, J L; Gordon, H; Goss, L T; Gounder, K; Goussiou, A; Graf, N; Graham, G; Grannis, P D; Green, J A; Greenlee, H; Greenwood, Z D; Grinstein, S; Groer, L; Grünendahl, S; Gupta, A; Gurzhiev, S N; Gutierrez, G; Gutierrez, P; Hadley, N J; Haggerty, H; Hagopian, S; Hagopian, V; Hall, R E; Hanlet, P; Hansen, S; Hauptman, J M; Hays, C; Hebert, C; Hedin, D; Heinmiller, J M; Heinson, A P; Heintz, U; Heuring, T; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Huang, Y; Illingworth, R; Ito, A S; Jaffré, M; Jain, S; Jesik, R; Johns, K; Johnson, M; Jonckheere, A; Jöstlein, H; Juste, A; Kahl, W; Kahn, S; Kajfasz, E; Kalinin, A M; Karmanov, D; Karmgard, D; Kehoe, R; Khanov, A; Kharchilava, A; Kim, S K; Klima, B; Knuteson, B; Ko, W; Kohli, J M; Kostritskiy, A V; Kotcher, J; Kothari, B; Kotwal, A V; Kozelov, A V; Kozlovsky, E A; Krane, J; Krishnaswamy, M R; Krivkova, P; Krzywdzinski, S; Kubantsev, M; Kuleshov, S; Kulik, Y; Kunori, S; Kupco, A; Kuznetsov, V E; Landsberg, G; Lee, W M; Leflat, A; Leggett, C; Lehner, F; Li, J; Li, Q Z; Li, X; Lima, J G; Lincoln, D; Linn, S L; Linnemann, J; Lipton, R; Lucotte, A; Lueking, L; Lundstedt, C; Luo, C; Maciel, A K; Madaras, R J; Malyshev, V L; Manankov, V; Mao, H S; Marshall, T; Martin, M I; Mauritz, K M; May, B; Mayorov, A A; McCarthy, R; McMahon, T; Melanson, H L; Merkin, M; Merritt, K W; Miao, C; Miettinen, H; Mihalcea, D; Mishra, C S; Mokhov, N; Mondal, N K; Montgomery, H E; Moore, R W; Mostafa, M; da Motta, H; Nagy, E; Nang, F; Narain, M; Narasimham, V S; Naumann, N A; Neal, H A; Negret, J P; Negroni, S; Nunnemann, T; O'Neil, D; Oguri, V; Olivier, B; Oshima, N; Padley, P; Pan, L J; Papageorgiou, K; Para, A; Parashar, N; Partridge, R; Parua, N; Paterno, M; Patwa, A; Pawlik, B; Perkins, J; Peters, O; Pétroff, P; Piegaia, R; Pope, B G; Popkov, E; Prosper, H B; Protopopescu, S; Przybycien, M B; Qian, J; Raja, R; Rajagopalan, S; Ramberg, E; Rapidis, P A; Reay, N W; Reucroft, S; Ridel, M; Rijssenbeek, M; Rizatdinova, F; Rockwell, T; Roco, M; Royon, C; Rubinov, P; Ruchti, R; Rutherfoord, J; Sabirov, B M; Sajot, G; Santoro, A; Sawyer, L; Schamberger, R D; Schellman, H; Schwartzman, A; Sen, N; Shabalina, E; Shivpuri, R K; Shpakov, D; Shupe, M; Sidwell, R A; Simak, V; Singh, H; Singh, J B; Sirotenko, V; Slattery, P; Smith, E; Smith, R P; Snihur, R; Snow, G R; Snow, J; Snyder, S; Solomon, J; Song, Y; Sorín, V; Sosebee, M; Sotnikova, N; Soustruznik, K; Souza, M; Stanton, N R; Steinbrück, G; Stephens, R W; Stichelbaut, F; Stoker, D; Stolin, V; Stone, A; Stoyanova, D A; Strang, M A; Strauss, M; Strovink, M; Stutte, L; Sznajder, A; Talby, M; Taylor, W; Tentindo-Repond, S; Tripathi, S M; Trippe, T G; Turcot, A S; Tuts, P M; Vaniev, V; Van Kooten, R; Varelas, N; Vertogradov, L S; Villeneuve-Seguier, F; Volkov, A A; Vorobiev, A P; Wahl, H D; Wang, H; Wang, Z M; Warchol, J; Watts, G; Wayne, M; Weerts, H; White, A; White, J T; Whiteson, D; Wightman, J A; Wijngaarden, D A; Willis, S; Wimpenny, S J; Womersley, J; Wood, D R; Xu, Q; Yamada, R; Yamin, P; Yasuda, T; Yatsunenko, Y A; Yip, K; Youssef, S; Yu, J; Yu, Z; Zanabria, M; Zhang, X; Zheng, H; Zhou, B; Zhou, Z; Zielinski, M; Zieminska, D; Zieminski, A; Zutshi, V; Zverev, E G; Zylberstejn, A

    2001-12-17

    The inclusive cross section for production of isolated photons has been measured in pp macro collisions at square root of s = 630 GeV with the D0 detector at the Fermilab Tevatron Collider. The photons span a transverse energy (E(T)) range from 7-49 GeV and have pseudorapidity absolute value of eta < 2.5. This measurement is combined with the previous D0 result at square root of s = 1800 GeV to form a ratio of the cross sections. Comparison of next-to-leading-order QCD with the measured cross section at 630 GeV and the ratio of cross sections show satisfactory agreement in most of the E(T) range. PMID:11736564

  15. Interpreting 750 GeV diphoton excess in plain NMSSM

    NASA Astrophysics Data System (ADS)

    Badziak, Marcin; Olechowski, Marek; Pokorski, Stefan; Sakurai, Kazuki

    2016-09-01

    NMSSM has enough ingredients to explain the diphoton excess at 750 GeV: singlet-like (pseudo) scalar (a) s and higgsinos as heavy vector-like fermions. We consider the production of the 750 GeV singlet-like pseudo scalar a from a decay of the doublet-like pseudo scalar A, and the subsequent decay of a into two photons via higgsino loop. We demonstrate that this cascade decay of the NMSSM Higgs bosons can explain the diphoton excess at 750 GeV.

  16. Blazar Astronomy above 50 GeV

    NASA Astrophysics Data System (ADS)

    Smith, D. A.

    This contribution is dedicated to the memory of Chaman L. Bhat, an atmospheric Cherenkov pioneer and a leader of the Indian gamma-ray community, who died in a road accident on Mt. Abu on December 17, just after the workshop. While few blazars have been detected beyond EGRET energies, these extreme cases may be the ones that 'make or break' some models describing blazars in particular, and therefore AGNs in general. This paper first reviews the status of the various atmospheric Cherenkov gamma-ray telescopes. We then describe the most recent results from these instruments, paying particular attention to the recent detection of 1ES 1426+428 by the Whipple, CAT, and HEGRA imagers. We illustrate the dilemma of target selection using the example of W Com. We then discuss the consequences of the first measurements of Mrk 421 below 100 GeV by the solar heliostat arrays CELESTE and STACEE. This first foray into the energy range linking EGRET with the current imagers requires us to start using functional forms for the spectral energy distributions that are more physical than the simple power laws (or parabolas) used up to now to describe the imager or satellite results. We can hope that HESS, followed by MAGIC and VERITAS, as well as CELESTE and STACEE, will make this a recurring problem in 2002 and 2003.

  17. Evidence for the 125 GeV Higgs boson decaying to a pair of $$\\tau$$ leptons

    DOE PAGESBeta

    Chatrchyan, Serguei

    2014-01-20

    A search for a standard model Higgs boson decaying into a pair of tau leptons is performed using events recorded by the CMS experiment at the LHC in 2011 and 2012. The dataset corresponds to an integrated luminosity of 4.9 inverse femtobarns at a centre-of-mass energy of 7 TeV and 19.7 inverse femtobarns at 8 TeV. Each tau lepton decays hadronically or leptonically to an electron or a muon, leading to six different final states for the tau-lepton pair, all considered in this analysis. An excess of events is observed over the expected background contributions, with a local significance largermore » than 3 standard deviations for m[H] values between 115 and 130 GeV. The best fit of the observed H to tau tau signal cross section for m[H] = 125 GeV is 0.78 +- 0.27 times the standard model expectation. These observations constitute evidence for the 125 GeV Higgs boson decaying to a pair of tau leptons.« less

  18. Evidence for the 125 GeV Higgs boson decaying to a pair of $\\tau$ leptons

    SciTech Connect

    Chatrchyan, Serguei

    2014-01-20

    A search for a standard model Higgs boson decaying into a pair of tau leptons is performed using events recorded by the CMS experiment at the LHC in 2011 and 2012. The dataset corresponds to an integrated luminosity of 4.9 inverse femtobarns at a centre-of-mass energy of 7 TeV and 19.7 inverse femtobarns at 8 TeV. Each tau lepton decays hadronically or leptonically to an electron or a muon, leading to six different final states for the tau-lepton pair, all considered in this analysis. An excess of events is observed over the expected background contributions, with a local significance larger than 3 standard deviations for m[H] values between 115 and 130 GeV. The best fit of the observed H to tau tau signal cross section for m[H] = 125 GeV is 0.78 +- 0.27 times the standard model expectation. These observations constitute evidence for the 125 GeV Higgs boson decaying to a pair of tau leptons.

  19. Natural islands for a 125 GeV Higgs in the scale-invariant NMSSM

    NASA Astrophysics Data System (ADS)

    Agashe, Kaustubh; Cui, Yanou; Franceschini, Roberto

    2013-02-01

    We study whether a 125 GeV standard model-like Higgs boson can be accommodated within the scale-invariant NMSSM in a way that is natural in all respects, i.e., not only is the stop mass and hence its loop contribution to Higgs mass of natural size, but we do not allow significant tuning of NMSSM parameters as well. We pursue as much as possible an analytic approach which gives clear insights on various ways to accommodate such a Higgs mass, while conducting complementary numerical analyses. We consider both scenarios with singlet-like state being heavier and lighter than SM-like Higgs. With A-terms being small, we find for the NMSSM to be perturbative up to GUT scale, it is not possible to get 125 GeV Higgs mass, which is true even if we tune parameters of NMSSM. If we allow some of the couplings to become non-perturbative below the GUT scale, then the non-tuned option implies that the singlet self-coupling, κ, is larger than the singlet-Higgs coupling, λ, which itself is order 1. This leads to a Landau pole for these couplings close to the weak scale, in particular below ~ 104 TeV. In both the perturbative and non-perturbative NMSSM, allowing large A λ , A κ gives "more room" to accommodate a 125 GeV Higgs, but a tuning of these A-terms may be needed. In our analysis we also conduct a careful study of the constraints on the parameter space from requiring global stability of the desired vacuum fitting a 125 GeV Higgs, which is complementary to existing literature. In particular, as the singlet-higgs coupling λ increases, vacuum stability becomes more serious of an issue.

  20. 750 GeV Diphoton Excess May Not Imply a 750 GeV Resonance

    NASA Astrophysics Data System (ADS)

    Cho, Won Sang; Kim, Doojin; Kong, Kyoungchul; Lim, Sung Hak; Matchev, Konstantin T.; Park, Jong-Chul; Park, Myeonghun

    2016-04-01

    We discuss nonstandard interpretations of the 750 GeV diphoton excess recently reported by the ATLAS and CMS Collaborations which do not involve a new, relatively broad resonance with a mass near 750 GeV. Instead, we consider the sequential cascade decay of a much heavier, possibly quite narrow, resonance into two photons along with one or more additional particles. The resulting diphoton invariant mass signal is generically rather broad, as suggested by the data. We examine three specific event topologies—the "antler," the "sandwich," and the two-step cascade decay—and show that they all can provide a good fit to the observed published data. In each case, we delineate the preferred mass parameter space selected by the best fit. In spite of the presence of extra particles in the final state, the measured diphoton pT spectrum is moderate due to its anticorrelation with the diphoton invariant mass. We comment on the future prospects of discriminating with higher statistics between our scenarios, as well as from more conventional interpretations.

  1. Test of lead glass shower counters

    SciTech Connect

    Kawabata, S.; Ogawa, K.; Sugahara, R.; Sumiyoshi, T.; Takahashi, K.; Awaji, N.; Hayashii, H.; Iwata, S.; Gearhart, R.A.; Miyamoto, A.

    1983-10-01

    Lead glass counters made of wedge shaped blocks of SF6 were tested with positrons at SLAC. The beam energy ranged from 2 to 17.5 GeV. Energy dependence and beam position dependence of pulse height and energy resolution were studied with lead glass blocks of various lengths. The effect of a BK-7 light guide on pulse height was clearly observed. Degradation of the energy resolution due to aluminum absorbers of various lengths was investigated. A mesh type photomultiplier was also tested.

  2. Characterization of Lead Tungstate for Neutral Particle Spectrometer at 12 GeV JLab

    NASA Astrophysics Data System (ADS)

    Runyon, Christian

    2015-10-01

    Precision measurements of the deeply-virtual Compton scattering cross section at different beam energies to extract the real part of the Compton form factor, measurements to push the energy scale of real Compton scattering, and measurements of the basic semi-inclusive neutral-pion cross section in a kinematical region where the QCD factorization scheme is expected to hold all have something in common: the need for detecting neutral particles with high precision and high luminosity. The Neutral Particle Spectrometer (NPS) is a crystal electromagnetic calorimeter preceded by a sweeping magnet to sweep away charged particles. In this presentation I will show the results of PbWO4 crystal quality studies for the NPS. PbWO4 is optimal for the NPS due to its small Moliere radius and radiation hardness. The critical aspect for crystal quality, and thus resolution/precision, is the combination of high light output and radiation hardness, which depend strongly on the manufacturing process. We have tested the performance of PbWO4 crystals, and in particular, measured their light yield, optical transmission, and uniformity and radiation hardness. The homogeneity of the crystal was investigated based on the variation of the transverse optical transmission. Supported in part by NSF-PHY-1306227.

  3. SPIN Effects, QCD, and Jefferson Laboratory with 12 GeV electrons

    SciTech Connect

    Prokudin, Alexey

    2013-11-01

    QCD and Spin physics are playing important role in our understanding of hadron structure. I will give a short overview of origin of hadron structure in QCD and highlight modern understanding of the subject. Jefferson Laboratory is undergoing an upgrade that will increase the energy of electron beam up to 12 GeV. JLab is one of the leading facilities in nuclear physics studies and once operational in 2015 JLab 12 will be crucial for future of nuclear physics. I will briefly discuss future studies in four experimental halls of Jefferson Lab.

  4. The ETFDH c.158A>G variation disrupts the balanced interplay of ESE- and ESS-binding proteins thereby causing missplicing and multiple Acyl-CoA dehydrogenation deficiency.

    PubMed

    Olsen, Rikke K J; Brøner, Sabrina; Sabaratnam, Rugivan; Doktor, Thomas K; Andersen, Henriette S; Bruun, Gitte H; Gahrn, Birthe; Stenbroen, Vibeke; Olpin, Simon E; Dobbie, Angus; Gregersen, Niels; Andresen, Brage S

    2014-01-01

    Multiple acyl-CoA dehydrogenation deficiency is a disorder of fatty acid and amino acid oxidation caused by defects of electron transfer flavoprotein (ETF) or its dehydrogenase (ETFDH). A clear relationship between genotype and phenotype makes genotyping of patients important not only diagnostically but also for prognosis and for assessment of treatment. In the present study, we show that a predicted benign ETFDH missense variation (c.158A>G/p.Lys53Arg) in exon 2 causes exon skipping and degradation of ETFDH protein in patient samples. Using splicing reporter minigenes and RNA pull-down of nuclear proteins, we show that the c.158A>G variation increases the strength of a preexisting exonic splicing silencer (ESS) motif UAGGGA. This ESS motif binds splice inhibitory hnRNP A1, hnRNP A2/B1, and hnRNP H proteins. Binding of these inhibitory proteins prevents binding of the positive splicing regulatory SRSF1 and SRSF5 proteins to nearby and overlapping exonic splicing enhancer elements and this causes exon skipping. We further suggest that binding of hnRNP proteins to UAGGGA is increased by triggering synergistic hnRNP H binding to GGG triplets located upstream and downsteam of the UAGGGA motif. A number of disease-causing exonic elements that induce exon skipping in other genes have a similar architecture as the one in ETFDH exon 2. PMID:24123825

  5. Interpreting a 750 GeV diphoton resonance

    NASA Astrophysics Data System (ADS)

    Gupta, Rick S.; Jäger, Sebastian; Kats, Yevgeny; Perez, Gilad; Stamou, Emmanuel

    2016-07-01

    We discuss the implications of the significant excesses in the diphoton final state observed by the LHC experiments ATLAS and CMS around a diphoton invariant mass of 750 GeV. The interpretation of the excess as a spin-zero s-channel resonance implies model-independent lower bounds on both its branching ratio and its coupling to photons, which stringently constrain dynamical models. We consider both the case where the excess is described by a narrow and a broad resonance. We also obtain model-independent constraints on the allowed couplings and branching fractions to final states other than diphotons, by including the interplay with 8 TeV searches. These results can guide attempts to construct viable dynamical models of the resonance. Turning to specific models, our findings suggest that the anomaly cannot be accounted for by the presence of only an additional singlet or doublet spin-zero field and the Standard Model degrees of freedom; this includes all two-Higgs-doublet models. Likewise, heavy scalars in the MSSM cannot explain the excess if stability of the electroweak vacuum is required, at least in a leading-order analysis. If we assume that the resonance is broad we find that it is challenging to find a weakly coupled explanation. However, we provide an existence proof in the form of a model with vectorlike quarks with large electric charge that is perturbative up to the 100 TeV scale. For the narrow-resonance case a similar model can be perturbative up to high scales also with smaller charges. We also find that, in their simplest form, dilaton models cannot explain the size of the excess. Some implications for flavor physics are briefly discussed.

  6. Centrality dependence of direct photon production in (square root)S(NN) = 200 GeV Au + Au collisions.

    PubMed

    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; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Devismes, A; 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; Perdekamp, M Grosse; Guryn, W; Gustafsson, H-A; Hachiya, T; Haggerty, J S; Hamagaki, H; Hansen, A G; Hartouni, E P; Harvey, M; Hayano, R; Hayashi, N; 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, 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 T; Pantuev, V; 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 K; 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; Veszprémi, V; 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; Zhou, S J; Zolin, L

    2005-06-17

    The first measurement of direct photons in Au + Au collisions at (square root)S(NN) = 200 GeV is presented. The direct photon signal is extracted as a function of the Au + Au collision centrality and compared to next-to-leading order perturbative quantum chromodynamics calculations. The direct photon yield is shown to scale with the number of nucleon-nucleon collisions for all centralities. PMID:16090462

  7. Diffractive dijet production with a leading proton in ep collisions at HERA

    NASA Astrophysics Data System (ADS)

    Andreev, V.; Baghdasaryan, A.; Begzsuren, K.; Belousov, A.; Belov, P.; Boudry, V.; Brandt, G.; Brinkmann, M.; Brisson, V.; Britzger, D.; Buniatyan, A.; Bylinkin, A.; Bystritskaya, L.; Campbell, A. J.; Cantun Avila, K. B.; Ceccopieri, F.; Cerny, K.; Chekelian, V.; Contreras, J. G.; Cvach, J.; Dainton, J. B.; Daum, K.; Diaconu, C.; Dobre, M.; Dodonov, V.; Dossanov, A.; Eckerlin, G.; Egli, S.; Elsen, E.; Favart, L.; Fedotov, A.; Feltesse, J.; Ferencei, J.; Fleischer, M.; Fomenko, A.; Gabathuler, E.; Gayler, J.; Ghazaryan, S.; Glazov, A.; Goerlich, L.; Gogitidze, N.; Gouzevitch, M.; Grab, C.; Grebenyuk, A.; Greenshaw, T.; Grindhammer, G.; Haidt, D.; Henderson, R. C. W.; Herbst, M.; Hladky, J.; Hoffmann, D.; Horisberger, R.; Hreus, T.; Huber, F.; Jacquet, M.; Janssen, X.; Jung, H.; Kapichine, M.; Kiesling, C.; Klein, M.; Kleinwort, C.; Kogler, R.; Kostka, P.; Kretzschmar, J.; Krüger, K.; Landon, M. P. J.; Lange, W.; Laycock, P.; Lebedev, A.; Levonian, S.; Lipka, K.; List, B.; List, J.; Lobodzinski, B.; Malinovski, E.; Martyn, H.-U.; Maxfield, S. J.; Mehta, A.; Meyer, A. B.; Meyer, H.; Meyer, J.; Mikocki, S.; Morozov, A.; Müller, K.; Naumann, Th.; Newman, P. R.; Niebuhr, C.; Nowak, G.; Olsson, J. E.; Ozerov, D.; Pahl, P.; Pascaud, C.; Patel, G. D.; Perez, E.; Petrukhin, A.; Picuric, I.; Pirumov, H.; Pitzl, D.; Plačakytė, R.; Pokorny, B.; Polifka, R.; Radescu, V.; Raicevic, N.; Ravdandorj, T.; Reimer, P.; Rizvi, E.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Rotaru, M.; Rusakov, S.; Šálek, D.; Sankey, D. P. C.; Sauter, M.; Sauvan, E.; Schmitt, S.; Schoeffel, L.; Schöning, A.; Schultz-Coulon, H.-C.; Sefkow, F.; Shushkevich, S.; Soloviev, Y.; Sopicki, P.; South, D.; Spaskov, V.; Specka, A.; Steder, M.; Stella, B.; Straumann, U.; Sykora, T.; Thompson, P. D.; Traynor, D.; Truöl, P.; Tsakov, I.; Tseepeldorj, B.; Turnau, J.; Valkárová, A.; Vallée, C.; Van Mechelen, P.; Vazdik, Y.; Wegener, D.; Wünsch, E.; Žáček, J.; Zhang, Z.; Žlebčík, R.; Zohrabyan, H.; Zomer, F.

    2015-05-01

    The cross section of the diffractive process e + p → e + Xp is measured at a centre-of-mass energy of 318 GeV, where the system X contains at least two jets and the leading final state proton p is detected in the H1 Very Forward Proton Spectrometer. The measurement is performed in photoproduction with photon virtualities Q 2 < 2 GeV2 and in deep-inelastic scattering with 4 GeV2 < Q 2 < 80 GeV2. The results are compared to next- to-leading order QCD calculations based on diffractive parton distribution functions as extracted from measurements of inclusive cross sections in diffractive deep-inelastic scattering.

  8. CEBAF SRF Performance during Initial 12 GeV Commissioning

    SciTech Connect

    Bachimanchi, Ramakrishna; Allison, Trent; Daly, Edward; Drury, Michael; Hovater, J; Lahti, George; Mounts, Clyde; Nelson, Richard; Plawski, Tomasz

    2015-09-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) energy upgrade from 6 GeV to 12 GeV includes the installation of eleven new 100 MV cryomodules (88 cavities). The superconducting RF cavities are designed to operate CW at an accelerating gradient of 19.3 MV/m with a QL of 3×107. Not all the cavities were operated at the minimum gradient of 19.3 MV/m with the beam. Though the initial 12 GeV milestones were achieved during the initial commissioning of CEBAF, there are still some issues to be addressed for long term reliable operation of these modules. This paper reports the operational experiences during the initial commissioning and the path forward to improve the performance of C100 (100 MV) modules.

  9. Spin Structure with JLab 6 and 12 GeV

    SciTech Connect

    Jian-Ping Chen

    2012-02-01

    Highlights of JLab 6 GeV results on spin structure study and plan for 12 GeV program. Spin structure study is full of surprises and puzzles. A decade of experiments from JLab yield these exciting results: (1) valence spin structure; (2) precision measurements of g{sub 2}/d{sub 2} - high-twist; (3) spin sum rules and polarizabilities; and (4) first neutron transversity. There is a bright future as the 12 GeV Upgrade will greatly enhance our capability: (1) Precision determination of the valence quark spin structure flavor separation; (2) Precision measurements of g{sub 2}/d{sub 2}; and (3) Precision extraction of transversity/tensor charge.

  10. GeV flares observations with GLAST LAT

    SciTech Connect

    Galli, A.; Omodei, N.; Piro, L.

    2007-07-12

    Early X-ray afterglow observations show that X-ray flares are very common features in GRB light curves. X-ray flares may reflect long duration central engine activity. The delayed flare photons are expected to interact with relativistic electrons by Inverse Compton giving delayed high energy counterparts that potentially will be detected by GLAST LAT, which could observe GRB from 20 MeV to more than 300 GeV. The nature oh high energy spectral components from GRB detected by EGRET is still debated. Observations with GLAST LAT will give useful information to constrain the origin of X-ray flares. In this work we simulate a set of possible GeV emitting flares in the context of External Shock model to study the capability of GLAST LAT to detect GeV flares at different intensities and durations.

  11. RHIC 100 GeV Polarized Proton Luminosity

    SciTech Connect

    Zhang, S. Y.

    2014-01-17

    A big problem in RHIC 100 GeV proton run 2009 was the significantly lower luminosity lifetime than all previous runs. It is shown in this note that the beam intensity decay in run 2009 is caused by the RF voltage ramping in store. It is also shown that the beam decay is not clearly related to the beam momentum spread, therefore, not directly due to the 0.7m. β* Furthermore, the most important factor regarding the low luminosity lifetime is the faster transverse emittance growth in store, which is also much worse than the previous runs, and is also related to the RF ramping. In 100 GeV proton run 2012a, the RF ramping was abandoned, but the β* was increased to 0.85m, with more than 20% loss of luminosity, which is not necessary. It is strongly suggested to use smaller β* in 100 GeV polarized proton run 2015/2016

  12. The Jefferson Lab 12 GeV Upgrade

    SciTech Connect

    R.D. McKeown

    2010-09-01

    Construction of the 12 GeV upgrade to the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Facility is presently underway. This upgrade includes doubling the energy of the electron beam to 12 GeV, the addition of a new fourth experimental hall, and the construction of upgraded detector hardware. An overview of this upgrade project is presented, along with highlights of the anticipated experimental program. The 12 GeV upgrade project at Jefferson Lab will enable a powerful new experimental program that will advance our understanding of the quark/gluon structure of hadronic matter, the nature of Quantum Chromodynamics, and the properties of a new extended standard model of particle interactions. Commissioning of the upgraded beam will be begin in 2013, and the full complement of upgraded experimental equipment will be completed in 2015. This unique facility will provide many opportunities for exploration and discovery for a large international community of nuclear scientists.

  13. Jefferson Lab 12 GeV CEBAF Upgrade

    SciTech Connect

    Claus Rode

    2010-04-01

    The existing continuous electron beam accelerator facility (CEBAF) at Thomas Jefferson National Accelerator Facility (TJNAF) is a 5-pass, recirculating cw electron Linac operating at ~6 GeV and is devoted to basic research in nuclear physics. The 12 GeV CEBAF Upgrade is a $310 M project, sponsored by the Department of Energy (DOE) Office of Nuclear Physics, that will expand its research capabilities substantially by doubling the maximum energy and adding major new experimental apparatus. The project received construction approval in September 2008 and has started the major procurement process. The cryogenic aspects of the 12 GeV CEBAF Upgrade includes: doubling the accelerating voltages of the Linacs by adding ten new high-performance, superconducting radiofrequency (SRF) cryomodules (CMs) to the existing 42 1/4 cryomodules; doubling of the 2 K cryogenics plant; and the addition of eight superconducting magnets.

  14. The 6 GeV TMD Program at Jefferson Lab

    SciTech Connect

    Puckett, Andrew J.

    2015-01-01

    The study of the transverse momentum dependent parton distributions (TMDs) of the nucleon in semi-inclusive deep-inelastic scattering (SIDIS) has emerged as one of the major physics motivations driving the experimental program using the upgraded 11 GeV electron beam at Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF). The accelerator construction phase of the CEBAF upgrade is essentially complete and commissioning of the accelerator has begun as of April, 2014. As the new era of CEBAF operations begins, it is appropriate to review the body of published and forthcoming results on TMDs from the 6 GeV era of CEBAF operations, discuss what has been learned, and discuss the key challenges and opportunities for the 11 GeV SIDIS program of CEBAF.

  15. Resonances from QCD bound states and the 750 GeV diphoton excess

    NASA Astrophysics Data System (ADS)

    Kats, Yevgeny; Strassler, Matthew J.

    2016-05-01

    Pair production of colored particles is in general accompanied by production of QCD bound states (onia) slightly below the pair-production threshold. Bound state annihilation leads to resonant signals, which in some cases are easier to see than the decays of the pair-produced constituents. In a previous paper ( arXiv:1204.1119 ) we estimated the bound state signals, at leading order and in the Coulomb approximation, for particles with various spins, color representations and electric charges, and used 7 TeV ATLAS and CMS resonance searches to set rough limits. Here we update our results to include 8 and 13 TeV data. We find that the recently reported diphoton excesses near 750 GeV could indeed be due to a bound state of this kind. A narrow resonance of the correct size could be obtained for a color-triplet scalar with electric charge -4/3 and mass near 375GeV, if (as a recent lattice computation suggests) the wave function at the origin is somewhat larger than anticipated. Pair production of this particle could have evaded detection up to now. Other candidates may include a triplet scalar of charge 5/3, a triplet fermion of charge -4/3, and perhaps a sextet scalar of charge -2/3.

  16. Reconstruction of GeV Neutrino Events in LENA

    SciTech Connect

    Moellenberg, R.; Feilitzsch, F. von; Goeger-Neff, M.; Hellgartner, D.; Lewke, T.; Meindl, Q.; Oberauer, L.; Potzel, W.; Tippmann, M.; Winter, J.; Wurm, M.; Peltoniemi, J.

    2011-10-06

    LENA (Low Energy Neutrino Astronomy) is a proposed next generation liquid-scintillator detector with about 50 kt target mass. Besides the detection of solar neutrinos, geoneutrinos, supernova neutrinos and the search for the proton decay, LENA could also be used as the far detector of a next generation neutrino beam. The present contribution outlines the status of the Monte Carlo studies towards the reconstruction of GeV neutrinos in LENA. Both the tracking capabilities at a few hundred MeV, most interesting for a beta beam, and above 1 GeV for a superbeam experiment are presented.

  17. Estimating changes in temperature extremes from millennial-scale climate simulations using generalized extreme value (GEV) distributions

    NASA Astrophysics Data System (ADS)

    Huang, Whitney K.; Stein, Michael L.; McInerney, David J.; Sun, Shanshan; Moyer, Elisabeth J.

    2016-07-01

    Changes in extreme weather may produce some of the largest societal impacts of anthropogenic climate change. However, it is intrinsically difficult to estimate changes in extreme events from the short observational record. In this work we use millennial runs from the Community Climate System Model version 3 (CCSM3) in equilibrated pre-industrial and possible future (700 and 1400 ppm CO2) conditions to examine both how extremes change in this model and how well these changes can be estimated as a function of run length. We estimate changes to distributions of future temperature extremes (annual minima and annual maxima) in the contiguous United States by fitting generalized extreme value (GEV) distributions. Using 1000-year pre-industrial and future time series, we show that warm extremes largely change in accordance with mean shifts in the distribution of summertime temperatures. Cold extremes warm more than mean shifts in the distribution of wintertime temperatures, but changes in GEV location parameters are generally well explained by the combination of mean shifts and reduced wintertime temperature variability. For cold extremes at inland locations, return levels at long recurrence intervals show additional effects related to changes in the spread and shape of GEV distributions. We then examine uncertainties that result from using shorter model runs. In theory, the GEV distribution can allow prediction of infrequent events using time series shorter than the recurrence interval of those events. To investigate how well this approach works in practice, we estimate 20-, 50-, and 100-year extreme events using segments of varying lengths. We find that even using GEV distributions, time series of comparable or shorter length than the return period of interest can lead to very poor estimates. These results suggest caution when attempting to use short observational time series or model runs to infer infrequent extremes.

  18. Balloon measurements of the energy spectrum of cosmic electrons between 1 GeV and 25 GeV

    NASA Technical Reports Server (NTRS)

    Earl, J. A.; Neely, D. E.; Rygg, T. A.

    1971-01-01

    During three balloon flights made in 1966 and 1967, cosmic electrons were investigated with the aid of a hodoscope detector which provided extensive and detailed information on each cosmic ray event triggering the apparatus. Similar information obtained during calibration exposures to protons and pions as well as to electrons was used to provide identification of cosmic electrons and to determine their energies. Differential primary electron intensities measured in the range from 1 GeV to 25 GeV were substantially larger than some earlier measurements. Taken in conjunction with existing measurements at energies above 100 GeV, this indicates that the energy spectrum of cosmic electrons is steeper than that of cosmic-ray nuclei and, consequently, suggests that Compton/synchrotron energy loss plays a significant role in shaping the electron spectrum.

  19. E6 inspired SUSY benchmarks, dark matter relic density and a 125 GeV Higgs

    NASA Astrophysics Data System (ADS)

    Athron, Peter; Harries, Dylan; Nevzorov, Roman; Williams, Anthony G.

    2016-09-01

    We explore the relic density of dark matter and the particle spectrum within a constrained version of an E6 inspired SUSY model with an extra U(1)N gauge symmetry. In this model a single exact custodial symmetry forbids tree-level flavor-changing transitions and the most dangerous baryon and lepton number violating operators. We present a set of benchmark points showing scenarios that have a SM-like Higgs mass of 125 GeV and sparticle masses above the LHC limits. They lead to striking new physics signatures which may be observed during run II of the LHC and can distinguish this model from the simplest SUSY extensions of the SM. At the same time these benchmark scenarios are consistent with the measured dark matter abundance and necessarily lead to large dark matter direct detection cross sections close to current limits and observable soon at the XENON1T experiment.

  20. Shielding Design Aspects of SR Beamlines for 3-GeV And 8-GeV Class Synchrotron Radiation Facilities

    SciTech Connect

    Asano, Yoshihiro; Liu, James C.; Rokni, Sayed; /SLAC

    2007-09-24

    Differences in synchrotron radiation beamline shielding design between the facilities of 3 GeV class and 8 GeV class are discussed with regard to SLAC SSRL and SPring-8 beamlines. Requirements of beamline shielding as well as the accelerator shielding depend on the stored electron energy, and here some factors in beamline shielding depending on the stored energy in particular, are clarified, namely the effect of build up, the effect of double scattering of photons at branch beamlines, and the spread of gas bremsstrahlung.

  1. Pion form factor in the range -10 GeV2 ≤ s ≤ 1 GeV2

    NASA Astrophysics Data System (ADS)

    Achasov, N. N.; Kozhevnikov, A. A.

    2013-01-01

    Based on the field-theory-inspired approach, a new expression for the pion form factor F π is proposed. It takes into account the pseudoscalar meson loops π+π- and Kbar K and the mixing of ρ(770) with heavier ρ(1450) and ρ(1700) resonances. The expression ensures correct analytical properties and describes the data in the wide range of the energy squared -10 GeV2 ≤ s ≤ 1 GeV2 without introducing the phenomenological Blatt-Weisskopf range parameter R π.

  2. Nucleon Form Factors experiments with 12 GeV CEBAF

    SciTech Connect

    Wojtsekhowski, B.

    2008-10-13

    A number of precision form factor experiments at high momentum transfer will be performed with the 11 GeV electron beam of CEBAF. We review the approved proposals and the conceptual schemes of several new suggestions. Form factor data will serve as a major input for the construction of a tomographic image of the nucleon.

  3. Promising interpretation of diphoton resonance at 750 GeV

    NASA Astrophysics Data System (ADS)

    Bi, Xiao-Jun; Ding, Ran; Fan, Yizhou; Huang, Li; Li, Chuang; Li, Tianjun; Raza, Shabbar; Wang, Xiao-Chuan; Zhu, Bin

    2016-07-01

    Recently, an excess of events in diphoton channel with invariant mass of about 750 GeV has been reported by the ATLAS and CMS Collaborations. Considering it as a tantalizing hint for new physics beyond the Standard Model (SM), we propose a simple extension of the SM with an additional doublet Higgs H' and a singlet s . We consider the neutral component H0' of H' as the 750 GeV resonance and assume that s is lighter than 2.6 GeV. In particular, H0' can be produced at tree level via q q ¯ production and decay into a pair of s at tree level. Then s can decay into a pair of collimated photons, which cannot be distinguished at the LHC. We show that the diphoton production cross section can be from 3 to 13 fb, the decay width of H0' can be from 30 to 60 GeV, and all the current experimental constraints including dijet constraint can be satisfied.

  4. 7-GeV Advanced Photon Source Conceptual Design Report

    SciTech Connect

    Not Available

    1987-04-01

    During the past decade, synchrotron radiation emitted by circulating electron beams has come into wide use as a powerful, versatile source of x-rays for probing the structure of matter and for studying various physical processes. Several synchrotron radiation facilities with different designs and characteristics are now in regular operation throughout the world, with recent additions in this country being the 0.8-GeV and 2.5-GeV rings of NSLS at Brookhaven National Laboratory. However, none of the operating facilities has been designed to use a low-emittance, high-energy stored beam, together with modern undulator devices, to produce a large number of hard x-ray beams of extremely high brilliance. This document is a proposal to the Department of Energy to construct and operate high-energy synchrotron radiation facility at Argonne National Laboratory. We have now chosen to set the design energy of this facility at 7.0 GeV, with the capability to operate at up to 7.5 GeV.

  5. 12 GeV detector technology at Jefferson Lab

    SciTech Connect

    Leckey, John P.; Collaboration: GlueX Collaboration

    2013-04-19

    The Thomas Jefferson National Accelerator Facility (JLab) is presently in the middle of an upgrade to increase the energy of its CW electron beam from 6 GeV to 12 GeV along with the addition of a fourth experimental hall. Driven both by necessity and availability, novel detectors and electronics modules have been used in the upgrade. One such sensor is the Silicon Photomultiplier (SiPM), specifically a Multi-Pixel Photon Counter (MPPC), which is an array of avalanche photodiode pixels operating in Geiger mode that are used to sense photons. The SiPMs replace conventional photomultiplier tubes and have several distinct advantages including the safe operation in a magnetic field and the lack of need for high voltage. Another key to 12 GeV success is advanced fast electronics. Jlab will use custom 250 MHz and 125 MHz 12-bit analog to digital converters (ADCs) and time to digital converters (TDCs) all of which take advantage of VME Switched Serial (VXS) bus with its GB/s high bandwidth readout capability. These new technologies will be used to readout drift chambers, calorimeters, spectrometers and other particle detectors at Jlab once the 12 GeV upgrade is complete. The largest experiment at Jlab utilizing these components is GlueX - an experiment in the newly constructed Hall D that will study the photoproduction of light mesons in the search for hybrid mesons. The performance of these components and their respective detectors will be presented.

  6. 750 GeV diphoton resonance and electric dipole moments

    NASA Astrophysics Data System (ADS)

    Choi, Kiwoon; Im, Sang Hui; Kim, Hyungjin; Mo, Doh Young

    2016-09-01

    We examine the implication of the recently observed 750 GeV diphoton excess for the electric dipole moments of the neutron and electron. If the excess is due to a spin zero resonance which couples to photons and gluons through the loops of massive vector-like fermions, the resulting neutron electric dipole moment can be comparable to the present experimental bound if the CP-violating angle α in the underlying new physics is of O (10-1). An electron EDM comparable to the present bound can be achieved through a mixing between the 750 GeV resonance and the Standard Model Higgs boson, if the mixing angle itself for an approximately pseudoscalar resonance, or the mixing angle times the CP-violating angle α for an approximately scalar resonance, is of O (10-3). For the case that the 750 GeV resonance corresponds to a composite pseudo-Nambu-Goldstone boson formed by a QCD-like hypercolor dynamics confining at ΛHC, the resulting neutron EDM can be estimated with α ∼(750 GeV /ΛHC) 2θHC, where θHC is the hypercolor vacuum angle.

  7. GeV C. W. electron microtron design report

    SciTech Connect

    Not Available

    1982-05-01

    Rising interest in the nuclear physics community in a GeV C.W. electron accelerator reflects the growing importance of high-resolution short-range nuclear physics to future advances in the field. In this report major current problems are reviewed and the details of prospective measurements which could be made with a GeV C.W. electron facility are discussed, together with their impact on an understanding of nuclear forces and the structure of nuclear matter. The microtron accelerator has been chosen as the technology to generate the electron beams required for the research discussed because of the advantages of superior beam quality, low capital and operating cost and capability of furnishing beams of several energies and intensities simultaneously. A complete technical description of the conceptual design for a 2 GeV double-sided C.W. electron microtron is presented. The accelerator can furnish three beams with independently controlled energy and intensity. The maximum current per beam is 100 ..mu..amps. Although the precise objective for maximum beam energy is still a subject of debate, the design developed in this study provides the base technology for microtron accelerators at higher energies (2 to 6 GeV) using multi-sided geometries.

  8. 12 GeV detector technology at Jefferson Lab

    SciTech Connect

    Leckey, John P.

    2013-04-01

    The Thomas Jefferson National Accelerator Facility (JLab) is presently in the middle of an upgrade to increase the energy of its CW electron beam from 6 GeV to 12 GeV along with the addition of a fourth experimental hall. Driven both by necessity and availability, novel detectors and electronics modules have been used in the upgrade. One such sensor is the Silicon Photomultiplier (SiPM), specifically a Multi-Pixel Photon Counter (MPPC), which is an array of avalanche photodiode pixels operating in Geiger mode that are used to sense photons. The SiPMs replace conventional photomultiplier tubes and have several distinct advantages including the safe operation in a magnetic field and the lack of need for high voltage. Another key to 12 GeV success is advanced fast electronics. Jlab will use custom 250 MHz and 125 MHz 12-bit analog to digital converters (ADCs) and time to digital converters (TDCs) all of which take advantage of VME Switched Serial (VXS) bus with its GB/s high bandwidth readout capability. These new technologies will be used to readout drift chambers, calorimeters, spectrometers and other particle detectors at Jlab once the 12 GeV upgrade is complete. The largest experiment at Jlab utilizing these components is GlueX - an experiment in the newly constructed Hall D that will study the photoproduction of light mesons in the search for hybrid mesons. The performance of these components and their respective detectors will be presented.

  9. The JLAB 12 GeV Energy Upgrade of CEBAF

    SciTech Connect

    Harwood, Leigh H.

    2013-12-01

    This presentation should describe the progress of the 12GeV Upgrade of CEBAF at Jefferson Lab. The status of the upgrade should be presented as well as details on the construction, procurement, installation and commissioning of the magnet and SRF components of the upgrade.

  10. Jet fragmentation functions for identified particles in p+p collisions at 200 GeV in the STAR experiment

    NASA Astrophysics Data System (ADS)

    Bruna, Elena

    2008-10-01

    According to theoretical predictions, jet quenching in heavy-ion collisions modifies the jet energy and multiplicity distributions, as well as the jet hadrochemical composition. The measurement of jet fragmentation functions in p+p collisions at 200 GeV provides a baseline to study jet modifications in Au+Au collisions at RHIC. A cone algorithm is used to reconstruct jets in the STAR Time Projection Chamber and Electromagnetic Calorimeter; a study of the jet energy resolution based on PYTHIA+GEANT simulations is reported. We present the results on distributions of jet fragments in p+p collisions at 200 GeV in STAR for charged hadrons and identified particles at different jet energies and cone radii. The results are compared to MLLA (modified leading logarithmic approximation) calculations which provide a good description of the data at higher jet energies.

  11. Multiwavelength Observations of GRB 110731A: GeV Emission from Onset to Afterglow

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Asano, K.; Baldini, L.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Bellazzini, R.; Blandford, R. D.; Bonamente, E.; Borgland, A. W.; Bottacini, E.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Cecchi, C.; Charles, E.; Chaves, R. C. G.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Dermer, C. D.; Silva, E. do Couto e.; Drell, P. S.; Drlica-Wagner, A.; Favuzzi, C.; Fegan, S. J.; Focke, W. B.; Franckowiak, A.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Granot, J.; Greiner, J.; Grenier, I. A.; Grove, J. E.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Hayashida, M.; Hays, E.; Hughes, R. E.; Jackson, M. S.; Jogler, T.; Jóhannesson, G.; Johnson, A. S.; Knödlseder, J.; Kocevski, D.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Mazziotta, M. N.; McEnery, J. E.; Mehault, J.; Mészáros, P.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monte, C.; Monzani, M. E.; Moretti, E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naumann-Godo, M.; Norris, J. P.; Nuss, E.; Nymark, T.; Ohno, M.; Ohsugi, T.; Omodei, N.; Orienti, M.; Orlando, E.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Racusin, J. L.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Romoli, C.; Roth, M.; Ryde, F.; Sanchez, D. A.; Sgrò, C.; Siskind, E. J.; Sonbas, E.; Spinelli, P.; Stamatikos, M.; Takahashi, H.; Tanaka, T.; Thayer, J. G.; Thayer, J. B.; Tibaldo, L.; Tinivella, M.; Tosti, G.; Troja, E.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Waite, A. P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Gruber, D.; Bhat, P. N.; Bissaldi, E.; Briggs, M. S.; Burgess, J. M.; Connaughton, V.; Foley, S.; Kippen, R. M.; Kouveliotou, C.; McBreen, S.; McGlynn, S.; Paciesas, W. S.; Pelassa, V.; Preece, R.; Rau, A.; van der Horst, A. J.; von Kienlin, A.; Kann, D. A.; Filgas, R.; Klose, S.; Krühler, T.; Fukui, A.; Sako, T.; Tristram, P. J.; Oates, S. R.; Ukwatta, T. N.; Littlejohns, O.

    2013-02-01

    We report on the multiwavelength observations of the bright, long gamma-ray burst GRB 110731A, by the Fermi and Swift observatories, and by the MOA and GROND optical telescopes. The analysis of the prompt phase reveals that GRB 110731A shares many features with bright Large Area Telescope bursts observed by Fermi during the first three years on-orbit: a light curve with short time variability across the whole energy range during the prompt phase, delayed onset of the emission above 100 MeV, extra power-law component and temporally extended high-energy emission. In addition, this is the first GRB for which simultaneous GeV, X-ray, and optical data are available over multiple epochs beginning just after the trigger time and extending for more than 800 s, allowing temporal and spectral analysis in different epochs that favor emission from the forward shock in a wind-type medium. The observed temporally extended GeV emission is most likely part of the high-energy end of the afterglow emission. Both the single-zone pair transparency constraint for the prompt signal and the spectral and temporal analysis of the forward-shock afterglow emission independently lead to an estimate of the bulk Lorentz factor of the jet Γ ~ 500-550.

  12. MULTIWAVELENGTH OBSERVATIONS OF GRB 110731A: GeV EMISSION FROM ONSET TO AFTERGLOW

    SciTech Connect

    Ackermann, M.; Ajello, M.; Blandford, R. D.; Borgland, A. W.; Bottacini, E.; Buehler, R.; Cameron, R. A.; Asano, K.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Buson, S.; Bonamente, E.; Brigida, M.; Bruel, P.; Caraveo, P. A. E-mail: giacomov@slac.stanford.edu E-mail: srazzaque@ssd5.nrl.navy.mil E-mail: dgruber@mpe.mpg.de; and others

    2013-02-15

    We report on the multiwavelength observations of the bright, long gamma-ray burst GRB 110731A, by the Fermi and Swift observatories, and by the MOA and GROND optical telescopes. The analysis of the prompt phase reveals that GRB 110731A shares many features with bright Large Area Telescope bursts observed by Fermi during the first three years on-orbit: a light curve with short time variability across the whole energy range during the prompt phase, delayed onset of the emission above 100 MeV, extra power-law component and temporally extended high-energy emission. In addition, this is the first GRB for which simultaneous GeV, X-ray, and optical data are available over multiple epochs beginning just after the trigger time and extending for more than 800 s, allowing temporal and spectral analysis in different epochs that favor emission from the forward shock in a wind-type medium. The observed temporally extended GeV emission is most likely part of the high-energy end of the afterglow emission. Both the single-zone pair transparency constraint for the prompt signal and the spectral and temporal analysis of the forward-shock afterglow emission independently lead to an estimate of the bulk Lorentz factor of the jet {Gamma} {approx} 500-550.

  13. Why is GeV physics relevant in the age of the LHC?

    SciTech Connect

    Pennington, Michael R.

    2014-02-01

    The contribution that Jefferson Lab has made, with its 6 GeV electron beam, and will make, with its 12 GeV upgrade, to our understanding of the way the fundamental interactions work, particularly strong coupling QCD, is outlined. The physics at the GeV scale is essential even in TeV collisions.

  14. The multiplicity and the spectra of secondaries correlated with the leading particle energy

    NASA Technical Reports Server (NTRS)

    Kruglov, N. A.; Proskuryakov, A. S.; Sarycheva, L. I.; Smirnova, L. N.

    1985-01-01

    The spectra of leading particles of different nature in pp-collisions at E sub 0 = 33 GeV are obtained. The multiplicities and the spectra of secondaries, mesons, gamma-quanta, lambda and lambda-hyperons and protons for different leading particle energy ranges are determined.

  15. Dynamic aperture calculation for 100 GeV Au-Au and 250 GeV pp lattices with near third order resonance working point

    SciTech Connect

    Gu, X.; Luo, Y.; Fischer, W.

    2010-08-01

    In the preparation for the 2011 RHIC 250 GeV polarized proton (pp) run, both experiment and simulation were carried out to investigate the possibility to accelerate the proton beam with a vertical tune near 2/3. It had been found experimentally in Run-9 that accelerating the proton beam with a vertical tune close to 2/3 will greatly benefit the transmission of the proton polarization. In this note, we report the calculated dynamic apertures with the 100 GeV Au run and 250 GeV proton run lattices with vertical tunes close to the third order resonance. We will compare the third order resonance band width between the beam experiment and the simulation with the 100 GeV Au lattices. And we also will compare the calculated resonance band width between the 100 GeV Au and 250 GeV proton run lattices.

  16. Meson Spectroscopy at JLab@12 GeV

    SciTech Connect

    Celentano, Andrea

    2013-03-01

    Meson, being the simplest hadronic bound system, is the ideal "laboratory" to study the interaction between quarks, to understand the role of the gluons inside hadrons and to investigate the origin of color confinement. To perform such studies it is important to measure the meson spectrum, with precise determination of resonance masses and properties, looking for rare qbar q states and for unconventional mesons with exotic quantum numbers (i.e. mesons with quantum numbers that are not compatible with a qbar q structure). With the imminent advent of the 12 GeV upgrade of Jefferson Lab a new generation of meson spectroscopy experiments will start: "Meson-Ex" in Hall B and "GLUEX" in Hall D. Both will use photo-production to explore the spectrum of mesons in the light-quark sector, in the energy range of few GeVs.

  17. Scaled simulations of a 10 GeV accelerator

    SciTech Connect

    Cormier-Michel, Estelle; Geddes, C.G.R; Esarey, E.; Schroeder, C.B.; Bruhwiler, D.L.; Paul, K.; Cowan, B.; Leemans, W.P.

    2008-09-08

    Laser plasma accelerators are able to produce high quality electron beams from 1 MeV to 1 GeV. The next generation of plasma accelerator experiments will likely use a multi-stage approach where a high quality electron bunch is first produced and then injected into an accelerating structure. In this paper we present scaled particle-in-cell simulations of a 10 GeV stage in the quasi-linear regime. We show that physical parameters can be scaled to be able to perform these simulations at reasonable computational cost. Beam loading properties and electron bunch energy gain are calculated. A range of parameter regimes are studied to optimize the quality of the electron bunch at the output of the stage.

  18. GeV plasma accelerators driven in waveguides

    SciTech Connect

    Hooker, S.M.; Brunetti, E.; Esarey, E.; Gallacher, J.G.; Geddes,C.G.R.; Gonsalves, A.J.; Jaroszynski, D.A.; Kamperidis, C.; Kneip, S.; Krushelnick, K.; Leemans, W.P.; Mangles, S.P.D.; Murphy, C.D.; Nagler,B.; Najmudin, Z.; Nakamura, K.; Norreys, P.A.; Panasenko, D.; Rowlands-Rees, T.P.; Schroeder, C.B.; Toth, Cs.; Trines, R.

    2007-11-01

    During the last few years laser-driven plasma acceleratorshave been shown to generate quasi-monoenergetic electron beams withenergies up to several hundred MeV. Extending the output energy oflaser-driven plasma accelerators to the GeV range requires operation atplasma densities an order of magnitude lower, i.e. 1018 cm-3, andincreasing the distance over which acceleration is maintained from a fewmillimetres to a few tens of millimetres. One approach for achieving thisis to guide the driving laser pulse in the plasma channel formed in agas-filled capillary discharge waveguide. We present transverseinterferometric measurements of the evolution of the plasma channelformed and compare these measurements with models of the capillarydischarge. We describe in detail experiments performed at LawrenceBerkeley National Laboratory and at Rutherford Appleton Laboratory inwhich plasma accelerators were driven within this type of waveguide togenerate quasimonoenergetic electron beams with energies up to 1GeV.

  19. The 12 GeV Energy Upgrade at Jefferson Laboratory

    SciTech Connect

    Pilat, Fulvia C.

    2012-09-01

    Two new cryomodules and an extensive upgrade of the bending magnets at Jefferson Lab has been recently completed in preparation for the full energy upgrade in about one year. Jefferson Laboratory has undertaken a major upgrade of its flagship facility, the CW re-circulating CEBAF linac, with the goal of doubling the linac energy to 12 GeV. I will discuss here the main scope and timeline of the upgrade and report on recent accomplishments and the present status. I will then discuss in more detail the core of the upgrade, the new additional C100 cryomodules, their production, tests and recent successful performance. I will then conclude by looking at the future plans of Jefferson Laboratory, from the commissioning and operations of the 12 GeV CEBAF to the design of the MEIC electron ion collider.

  20. Scaled simulations of a 10 GeV accelerator

    SciTech Connect

    Cormier-Michel, Estelle; Geddes, C. G. R.; Schroeder, C. B.; Esarey, E.; Leemans, W. P.; Bruhwiler, D. L.; Paul, K.; Cowan, B.

    2009-01-22

    Laser plasma accelerators are able to produce high quality electron beams from 1 MeV to 1 GeV. The next generation of plasma accelerator experiments will likely use a multi-stage approach where a high quality electron bunch is first produced and then injected into an accelerating structure. In this paper we present scaled particle-in-cell simulations of a 10 GeV stage in the quasi-linear regime. We show that physical parameters can be scaled to be able to perform these simulations at reasonable computational cost. Beam loading properties and electron bunch energy gain are calculated. A range of parameter regimes are studied to optimize the quality of the electron bunch at the output of the stage.

  1. Nucleon spin physics using CEBAF at 11 GeV

    SciTech Connect

    Zein-Eddine Meziani

    2003-03-01

    We discuss key experiments that address some of the nucleon spin physics questions as part of the 12 GeV planning for the energy upgrade of the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. These experiments take advantage of a highly polarized beam and the availability of polarized target namely {sup 3}He combined with a Medium Acceptance Spectrometer (MAD) in Hall A.

  2. Lead-acid cell

    SciTech Connect

    Hradcovsky, R.J.; Kozak, O.R.

    1980-12-09

    A lead-acid storage battery is described that has a lead negative electrode, a lead dioxide positive electrode and a sulfuric acid electrolyte having an organic catalyst dissolved therein which prevents dissolution of the electrodes into lead sulfate whereby in the course of discharge, the lead dioxide is reduced to lead oxide and the lead is oxidized.

  3. Jet production in deep-inelastic muon scattering at 490 GeV

    SciTech Connect

    Melanson, H.L.; E665 Collaboration

    1993-06-01

    Measurements of jet rates in deep-inelastic muon scattering are presented. The JADE algorithm is used to define jets in the kinematic region 9 < W < 33 GeV. Data taken on a proton target are analyzed within the QCD framework, with the goal of extracting {alpha}{sub s}. Results on the Q{sup 2} dependence of the average transverse momentum of jets are used to demonstrate the running of the strong coupling constant {alpha}{sub s}. In addition, first measurements of the production of jets from heavy nuclei in the region x{sub B{sub j}} > 0.001 are discussed. Initial results indicate a suppression in the rate of two forward jets in carbon, calcium and lead as compared to deuterium. All results presented are preliminary.

  4. Lead Poisoning Prevention Tips

    MedlinePlus

    ... CDC.gov . Lead Home Calendar of Events National Lead Poisoning Prevention Week Archived Materials CDC's Childhood Lead Poisoning Prevention Program Advisory Committee (ACCLPP) Current Activities Blood ...

  5. Multiple collision effects on the antiproton production by high energy proton (100 GeV - 1000 GeV)

    SciTech Connect

    Takahashi, Hiroshi; Powell, J.

    1987-01-01

    Antiproton production rates which take into account multiple collision are calculated using a simple model. Methods to reduce capture of the produced antiprotons by the target are discussed, including geometry of target and the use of a high intensity laser. Antiproton production increases substantially above 150 GeV proton incident energy. The yield increases almost linearly with incident energy, alleviating space charge problems in the high current accelerator that produces large amounts of antiprotons.

  6. Exploring hadron structure through exclusive kaon electroproduction from JLab 6GeV to 12GeV

    NASA Astrophysics Data System (ADS)

    Carmignotto, Marco; Horn, Tanja; Sapkota, Indra; Mkrtchyan, Arthur

    2015-10-01

    Exclusive reactions have been successfully used to probe hadrons at long and short distance scales, allowing us to study the interaction of elementary particles and their dynamics on the basis of Quantum Chromodynamics (QCD). The electroproduction of mesons has shown to be a powerful tool for these studies. High precision data for the pion taken at the 6 GeV Jefferson Lab provided important information about the pion form factor and brought us puzzles regarding the applicability of hard-soft QCD factorization. The kaon provides an interesting way to expand these studies, opening the possibility to access the production mechanism involving strangeness physics and also search for the onset of factorization on systems containing heavier quarks. Most of the precision cross section measurements at the 6 GeV Jefferson Lab were primarily designed for pions, but some of these experiments also captured kaons in their acceptance. In this talk, I will show preliminary kaon cross section results from such experiments. I will also discuss plans to explore the extended Q2 range capability with dedicated kaon experiments at the 12 GeV Jefferson Lab to study the onset of factorization for mesons including strangeness and the meson electroproduction mechanism in general. JSA Graduate Fellowship.

  7. Midrapidity neutral-pion production in proton-proton collisions at square root s = 200 GeV.

    PubMed

    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; Drees, K 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, M; Guryn, W; Gustafsson, H-A; 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, 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 T; 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 K; 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

    2003-12-12

    The invariant differential cross section for inclusive neutral-pion production in p+p collisions at sqrt[s]=200 GeV has been measured at midrapidity (|eta|<0.35) over the range 1leading order perturbative QCD calculations are consistent with these measurements. The precision of our result is sufficient to differentiate between prevailing gluon-to-pion fragmentation functions. PMID:14683109

  8. Strange magnetic form factor of the proton at $Q^2 = 0.23$ GeV$^2$

    SciTech Connect

    Wang, Ping; Leinweber, Derek; Thomas, Anthony; Young, Ross

    2009-06-01

    We determine the $u$ and $d$ quark contributions to the proton magnetic form factor at finite momentum transfer by applying chiral corrections to quenched lattice data. Heavy baryon chiral perturbation theory is applied at next to leading order in the quenched, and full QCD cases for the valence sector using finite range regularization. Under the assumption of charge symmetry these values can be combined with the experimental values of the proton and neutron magnetic form factors to deduce a relatively accurate value for the strange magnetic form factor at $Q^2=0.23$ GeV$^2$, namely $G_M^s=-0.034 \\pm 0.021$ $\\mu_N$.

  9. Where Will LEAD Lead? An Update on My LEAD Research.

    ERIC Educational Resources Information Center

    Wildman, Louis

    Issues in the future of a federal collaborative program, Leadership in Educational Administration Development (LEAD), are discussed in this paper. Problems attributed to LEAD are its antagonistic posture to educational administration programs in higher education and political conflicts of interest. Methodology involved analysis of successful LEAD…

  10. Lead in petrol. The isotopic lead experiment

    SciTech Connect

    Facchetti, S. )

    1989-10-01

    Many studies were dedicated to the evaluation of the impact of automotive lead on the environment and to the assessment of its absorption in the human population. They can be subdivided into two groups, those based on changes of air and blood lead concentrations and those based on changes of air and blood lead isotopic compositions. According to various authors, 50-66% of the lead added to petrol is mobilized in the atmosphere, while most of the remainder adheres to the walls of the exhaust system from which it is expelled by mechanical and thermal shocks in the forms of easily sedimented particles. The fraction directly emitted by engine exhaust fumes is found in the form of fine particles, which can be transferred a long way from the emitting sources. However important the contribution of petrol lead to the total airborne lead may be, our knowledge does not permit a straightforward calculation of the percentage of petrol lead in total blood lead, which of course can also originate from other sources (e.g., industrial, natural). To evaluate this percentage in 1973, the idea of the Isotopic Lead Experiment (ILE project) was conceived to label, on a regional scale, petrol with a nonradioactive lead of an isotopic composition sufficiently different from that of background lead and sufficiently stable in time. This Account summarizes the main results obtained by the ILE project.

  11. Background model systematics for the Fermi GeV excess

    NASA Astrophysics Data System (ADS)

    Calore, Francesca; Cholis, Ilias; Weniger, Christoph

    2015-03-01

    The possible gamma-ray excess in the inner Galaxy and the Galactic center (GC) suggested by Fermi-LAT observations has triggered a large number of studies. It has been interpreted as a variety of different phenomena such as a signal from WIMP dark matter annihilation, gamma-ray emission from a population of millisecond pulsars, or emission from cosmic rays injected in a sequence of burst-like events or continuously at the GC. We present the first comprehensive study of model systematics coming from the Galactic diffuse emission in the inner part of our Galaxy and their impact on the inferred properties of the excess emission at Galactic latitudes 2° < |b| < 20° and 300 MeV to 500 GeV. We study both theoretical and empirical model systematics, which we deduce from a large range of Galactic diffuse emission models and a principal component analysis of residuals in numerous test regions along the Galactic plane. We show that the hypothesis of an extended spherical excess emission with a uniform energy spectrum is compatible with the Fermi-LAT data in our region of interest at 95% CL. Assuming that this excess is the extended counterpart of the one seen in the inner few degrees of the Galaxy, we derive a lower limit of 10.0° (95% CL) on its extension away from the GC. We show that, in light of the large correlated uncertainties that affect the subtraction of the Galactic diffuse emission in the relevant regions, the energy spectrum of the excess is equally compatible with both a simple broken power-law of break energy Ebreak = 2.1 ± 0.2 GeV, and with spectra predicted by the self-annihilation of dark matter, implying in the case of bar bb final states a dark matter mass of mχ=49+6.4-5.4 GeV.

  12. Charmed Meson Production in 800 GEV Proton-Proton Interactions.

    NASA Astrophysics Data System (ADS)

    Senko, Mark Frederick

    The purpose of this dissertation is to present the results of a study concerning the energy dependence of charmed meson production properties as a test of Quantum Chromodynamics (QCD). This experiment was performed at Fermi National Accelerator Laboratory, using a rapid cycling bubble chamber (LEBC) as a hydrogen target and high resolution vertex detector, in combination with the Fermilab Multiparticle Spectrometer (FMPS). The multiplicity trigger was unbiased, and spectrometer acceptance was good at x_ {F} >=q 0. A comparison of the results from previous experiments at center of mass energies sqrt{s} <=q 27 GeV and sqrt {s} >=q 53 GeV implies a total charm particle production cross section which rises rapidly as a function of sqrt{s} . The result of our experiment, sigma (D/| D) = 42.7 +/- 7.8 mub at sqrt{s} = 38 GeV, indicates a slower rise, in agreement with QCD predictions. A maximum likelihood fit to the parameterization of the differential cross section as d^2sigma/dx_{F}dp _sp{|}{2} ~ (1 - | x_{F }|)^{n}e^{-bp _sp{|}{2}} gives the results n = 8.4_sp {-1.9}{+2.2}, b = 0.78_sp{-0.16}{+0.19} (GeV/c)^{-2}, and < pbot > = 1.1_sp{-0.1}{+0.2} GeV/c. When compared with results from the lower energy experiments, these values indicate charm production becoming more central and < pbot > being consistent with the charmed quark mass. These results are once again consistent with QCD predictions. Lastly, analysis has shown that sigma(D ^*^+/-)/sigma(D^0) is governed primarily by spin statistics, displaying no energy dependence. The resulting cross section for D^*^+/- production is sigma(D^*^+/-) = 13.31 +/- 5.74 mub.

  13. Inclusive cross section and double helicity asymmetry for {pi}{sup 0} production in p+p collisions at {radical}(s)=62.4 GeV

    SciTech Connect

    Adare, A.; Bickley, A. A.; Ellinghaus, F.; Glenn, A.; Kinney, E.; Kiriluk, K.; Nagle, J. L.; Seele, J.; Wysocki, M.; Afanasiev, S.; Isupov, A.; Litvinenko, A.; Malakhov, A.; Peresedov, V.; Rukoyatkin, P.; Zolin, L.; Aidala, C.; Ajitanand, N. N.; Alexander, J.; Chung, P.

    2009-01-01

    The PHENIX experiment presents results from the RHIC 2006 run with polarized p+p collisions at {radical}(s)=62.4 GeV, for inclusive {pi}{sup 0} production at midrapidity. Unpolarized cross section results are measured for transverse momenta p{sub T}=0.5 to 7 GeV/c. Next-to-leading order perturbative quantum chromodynamics calculations are compared with the data, and while the calculations are consistent with the measurements, next-to-leading logarithmic corrections improve the agreement. Double helicity asymmetries A{sub LL} are presented for p{sub T}=1 to 4 GeV/c and probe the higher range of Bjorken x of the gluon (x{sub g}) with better statistical precision than our previous measurements at {radical}(s)=200 GeV. These measurements are sensitive to the gluon polarization in the proton for 0.06

  14. GEM: ANL 4-GeV CW electron microtron design

    SciTech Connect

    Kustom, R.L.

    1983-01-01

    A six-sided hexagonal microtron has been chosen as the accelerator to generate the beams required to pursue a national research program at a CW 4 GeV electron laboratory. This option has the advantage of superior beam quality, low capital and operating cost, and promise of furnishing beams of several electron energies simultaneously. Only moderate rf power is required because of the basic feature of all microtron designs, recirculation of the electron beam through the same rf accelerating section many times. The hexatron design has the additional feature of compatibility with an existing accelerator complex at Argonne which is currently unoccupied and available.

  15. An 8-GeV Synchrotron-Based Proton Driver

    SciTech Connect

    Weiren Chou

    2003-06-04

    In January 2002, the Fermilab Director initiated a design study for a high average power, modest energy proton facility. Such a facility is a possible candidate for a construction project in the U.S. starting in the middle of this decade. The key technical element is a new machine, dubbed the ''Proton Driver,'' as a replacement of the present Booster. The study of an 8-GeV synchrotron-based proton driver has been completed and published. This paper will give a summary report, including machine layout and performance, optics, beam dynamics issues, technical systems design, civil construction, cost estimate and schedule.

  16. Nonintrusive emittance measurement of 1 GeV H- beam

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Aleksandrov, A.; Long, C.; Menshov, A.; Pogge, J.; Webster, A.; Zhukov, A.

    2012-05-01

    A laser wire based transverse phase space measurement system has been developed at the Spallation Neutron Source (SNS). The system enables a direct measurement of the transverse emittance in both directions on a 1 GeV hydrogen ion (H-) beam at the high energy beam transport (HEBT) beam line. The measurement is non-destructive and has been conducted on a neutron production H- beam. This paper describes the design, implementation, and measurement performance of the system. The experience on the installation and commissioning of the laser emittance measurement system will also be discussed.

  17. Parity-violating DIS at 12 GeV

    SciTech Connect

    Souder, Paul

    2007-06-01

    The advent of the 12-GeV upgrade at JLab will present an excellent opportunity to study parity violation in deep inelastic scattering at high values of x. The physics issues in this domain include charge symmetry violation, quark-quark correlations in the nucleon, and tests of the Standard Model. This program will require a high-luminosity detector with high acceptance for scattering angles up to about 35°. A possible design for a solenoidal spectrometer that meets this requirement is suggested.

  18. The Jefferson Lab 12 GeV Upgrade

    SciTech Connect

    R.D. McKeown

    2011-10-01

    A major upgrade of the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Facility is in progress. Construction began in 2008 and the project should be completed in 2015. The upgrade includes doubling the energy of the electron beam to 12 GeV, the addition of a new fourth experimental hall, and new experimental equipment in three of the experimental halls. A brief overview of this upgrade project is presented along with some highlights of the anticipated experimental program.

  19. 8 GeV H- ions: Transport and injection

    SciTech Connect

    Chou, W.; Bryant, H.; Drozhdin, A.; Hill, C.; Kostin, M.; Macek, R.; Ostiguy, J.-F.; Rees, G.H.; Tang, Z.; Yoon, P.; /Fermilab /New Mexico U. /Los Alamos /Rutherford /Rochester U.

    2005-05-01

    Fermilab is working on the design of an 8 GeV superconducting RF H{sup -} linac called the Proton Driver. The energy of H{sup -} beam will be an order of magnitude higher than the existing ones. This brings up a number of technical challenges to transport and injection of H{sup -} ions. This paper will focus on the subjects of stripping losses (including stripping by blackbody radiation, field and residual gas) and carbon foil stripping efficiency, along with a brief discussion on other issues such as Stark states lifetime of hydrogen atoms, single and multiple Coulomb scattering, foil heating and stress, radiation activation, collimation and jitter correction, etc.

  20. High energy electrons beyond 100 GEV observed by emulsion chamber

    NASA Technical Reports Server (NTRS)

    Nishimura, J.; Fujii, M.; Yoshida, A.; Taira, T.; Aizu, H.; Nomura, Y.; Kobayashi, T.; Kazuno, M.; Nishio, A.; Golden, R. L.

    1986-01-01

    Much efforts have been expended to observe the spectrum of electrons in the high energy region with large area emulsion chambers exposed at balloon altitudes, and now 15 electrons beyond 1 TeV have been observed. The observed integral flux at 1 TeV is (3.24 + or - 0.87)x10(-5)/sq m sec sr. The statistics of the data around a few hundred GeV are also improving by using new shower detecting films of high sensitivity. The astrophysical significance of the observed spectrum are discussed for the propagation of electrons based on the leaky box and the nested leaky box model.

  1. The 12 GeV JLab Upgrade Project

    SciTech Connect

    Smith, Elton

    2009-01-01

    The upgrade of the CEBAF Accelerator at Jefferson Lab to 12 GeV will deliver high luminosity and high quality beams, which will open unique opportunities for studies of the quark and gluon structure of hadrons in the valence region. Such physics will be made accessible by substantial additions to the experimental equipment in combination with the increased energy reach of the upgraded machine. The emphasis of the talk will be on the program in a new experimental Hall D designed to search for gluonic excitations.

  2. Lead and the Romans

    ERIC Educational Resources Information Center

    Reddy, Aravind; Braun, Charles L.

    2010-01-01

    Lead poisoning has been a problem since early history and continues into modern times. An appealing characteristic of lead is that many lead salts are sweet. In the absence of cane and beet sugars, early Romans used "sugar of lead" (lead acetate) to sweeten desserts, fruits, and sour wine. People most at risk would have been those who consumed the…

  3. Lead levels - blood

    MedlinePlus

    ... is used to screen people at risk for lead poisoning. This may include industrial workers and children who ... also used to measure how well treatment for lead poisoning is working. Lead is common in the environment, ...

  4. GeV excess and phenomenological astrophysics modeling

    NASA Astrophysics Data System (ADS)

    Huang, Xiaoyuan; Enßlin, Torsten; Selig, Marco

    2016-05-01

    Predefined spatial templates to describe the background of γ-ray emission from astrophysical processes, like cosmic ray interactions, are used in previous searches for the γ-ray signatures of annihilating galactic dark matter. In this proceeding, we investigate the GeV excess in the inner Galaxy using an alternative approach, in which the astrophysical components are identified solely by their spectral and morphological properties. We confirm the reported GeV excess and derive related parameters for dark matter interpretation, which are consistent with previous results. We investigate the morphology of this spectral excess as preferred by the data only. This emission component exhibits a central Galaxy cusp as expected for a dark matter annihilation signal. However, Galactic disk regions with a morphology of that of the hot interstellar medium also host such a spectral component. This points to a possible astrophysical origin of the excess and requests a more detailed understanding of astrophysical γ-ray emitting processes in the galactic center region before definite claims about a dark matter annihilation signal can be made.

  5. Radiation microscope for SEE testing using GeV ions.

    SciTech Connect

    Doyle, Barney Lee; Knapp, James Arthur; Rossi, Paolo; Hattar, Khalid M.; Vizkelethy, Gyorgy; Brice, David Kenneth; Branson, Janelle V.

    2009-09-01

    Radiation Effects Microscopy is an extremely useful technique in failure analysis of electronic parts used in radiation environment. It also provides much needed support for development of radiation hard components used in spacecraft and nuclear weapons. As the IC manufacturing technology progresses, more and more overlayers are used; therefore, the sensitive region of the part is getting farther and farther from the surface. The thickness of these overlayers is so large today that the traditional microbeams, which are used for REM are unable to reach the sensitive regions. As a result, higher ion beam energies have to be used (> GeV), which are available only at cyclotrons. Since it is extremely complicated to focus these GeV ion beams, a new method has to be developed to perform REM at cyclotrons. We developed a new technique, Ion Photon Emission Microscopy, where instead of focusing the ion beam we use secondary photons emitted from a fluorescence layer on top of the devices being tested to determine the position of the ion hit. By recording this position information in coincidence with an SEE signal we will be able to indentify radiation sensitive regions of modern electronic parts, which will increase the efficiency of radiation hard circuits.

  6. Galactic Diffuse Gamma Ray Emission Is Greater than 10 Gev

    NASA Technical Reports Server (NTRS)

    Hunter, Stanley D.; White, Nicholas E. (Technical Monitor)

    2000-01-01

    AGILE and Gamma-ray Large Area Telescope (GLAST) are the next high-energy gamma-ray telescopes to be flown in space. These instruments will have angular resolution about 5 times better than Energetic Gamma-Ray Experiment Telescope (EGRET) above 10 GeV and much larger field of view. The on-axis effective area of AGILE will be about half that of EGRET, whereas GLAST will have about 6 times greater effective area than EGRET. The capabilities of ground based very high-energy telescopes are also improving, e.g. Whipple, and new telescopes, e.g. Solar Tower Atmospheric Cerenkov Effect Experiment (STACEE), Cerenkov Low Energy Sampling and Timing Experiment (CELESTE), and Mars Advanced Greenhouse Integrated Complex (MAGIC) are expected to have low-energy thresholds and sensitivities that will overlap the GLAST sensitivity above approximately 10 GeV. In anticipation of the results from these new telescopes, our current understanding of the galactic diffuse gamma-ray emission, including the matter and cosmic ray distributions is reviewed. The outstanding questions are discussed and the potential of future observations with these new instruments to resolve these questions is examined.

  7. Search for GeV GRBs at Chacaltaya

    SciTech Connect

    Castellina, A.; Ghia, P. L.; Morello, C.; Trinchero, G.; Vallania, P.; Vernetto, S.; Navarra, G.; Saavedra, O.; Yoshii, H.; Kaneko, T.; Kakimoto, K.; Nishi, K.; Cabrera, R.; Urzagasti, D.; Velarde, A.; Barthelmy, S. D.; Butterworth, P.; Cline, T. L.; Gehrels, N.; Fishman, G. J.

    1998-05-16

    In this paper we present the results of a search for GeV Gamma Ray Bursts made by the INCA experiment during the first 9 months of operation. INCA, an air shower array located at Mount Chacaltaya (Bolivia) at 5200 m a.s.l., has been searching for GRBs since December 1996. Up to August, 1997, 34 GRBs detected by BATSE occurred in the field of view of the experiment. For any burst, the counting rate of the array in the 2 hours interval around the burst trigger time has been studied. No significant excess has been observed. Assuming for the bursts a power low energy spectrum extending up to 1 TeV with a slope {alpha}=-2 and a duration of 10 s, the obtained 1 GeV-1 TeV energy fluence upper limits range from 7.9 10{sup -5} erg cm{sup -2} to 3.5 10{sup -3} erg cm{sup -2} depending on the event zenith angles.

  8. Detector development for Jefferson Lab's 12 GeV Upgrade

    NASA Astrophysics Data System (ADS)

    Qiang, Yi

    2015-05-01

    Jefferson Lab will soon finish its highly anticipated 12 GeV Upgrade. With doubled maximum energy, Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) will enable a new experimental program with substantial discovery potential, addressing important topics in nuclear, hadronic and electroweak physics. In order to take full advantage of the high energy, high luminosity beam, new detectors are being developed, designed and constructed to fit the needs of different physics topics. The paper will give an overview of various new detector technologies to be used for 12 GeV experiments. It will then focus on the development of two solenoid-based spectrometers, the GlueX and SoLID spectrometers. The GlueX experiment in Hall D will study the complex properties of gluons through exotic hybrid meson spectroscopy. The GlueX spectrometer, a hermetic detector package designed for spectroscopy and the associated partial wave analysis, is currently in the final stage of construction. Hall A, on the other hand, is developing the SoLID spectrometer to capture the 3D image of the nucleon from semi-inclusive processes and to study the intrinsic properties of quarks through mirror symmetry breaking. Such a spectrometer will have the capability to handle very high event rates while still maintaining a large acceptance in the forward region.

  9. Estimation procedures for the GEV distribution for the minima

    NASA Astrophysics Data System (ADS)

    Raynal-Villasenor, Jose A.; Raynal-Gutierrez, M. Elena

    2014-11-01

    The biased and unbiased moments (MOM1 and MOM2), maximum likelihood (ML), sextiles (SEX1 and SEX2) and probability weighted moments (PWM) methods for the estimation the parameters and quantiles of the General Extreme Value (GEV) Distribution for the minima were analyzed and compared by using data generation techniques of the type of distribution sampling experiments. Considering bias, variance and mean square error criteria of estimates of parameters and quantiles, it is concluded that in general for the values of the shape parameter considered: -0.1, -0.3, and -0.5 and 0.1, 0.3 and 0.5, the sample sizes analyzed: 9 ⩽ N ⩽ 99 and non-exceedance probabilities: 0.01 ⩽ Π(x) ⩽ 0.10, the ML method performed better than the other five. However, for sample sizes bigger than 49, most of the methods, with the exception of SEX1, produced similar results. As a general conclusion of the study reported here, it can be stated that the ML method resulted to be better to the other five when estimating the parameters and quantiles of the GEV distribution for the minima, for the cases analyzed in this study.

  10. STANDARDIZATION OF CEBAF 12 GEV UPGRADE CAVITY TESTING

    SciTech Connect

    Tiffany Bass, G. Davis, Christiana Wilson, Mircea Stirbet

    2012-07-01

    CEBAF 12GeV upgrade project includes 80 new 7-cell cavities to form 10 cryomodules. Each cavity underwent RF qualification at 2.07K using a high power accelerating gradient test and an HOM survey in Jefferson Lab's Vertical Testing Area (VTA) before cavity string assembly. In order to ensure consistently high quality data, updated cavity testing procedures and analysis were implemented and used by a group of VTA operators. For high power tests, a cavity testing procedure was developed and used in conjunction with a LabVIEW program to collect the test data. Additionally while the cavity was at 2.07K, an HOM survey was performed using a network analyzer and a combination of Excel and Mathematica programs. Data analysis was standardized and an online logbook, Pansophy, was used for data storage and mining. The Pansophy system allowed test results to be easily summarized and searchable across all cavity tests. In this presentation, the CEBAF 12GeV upgrade cavity testing procedure, method for data analysis, and results reporting results will be discussed.

  11. Detector development for Jefferson Lab's 12GeV Upgrade

    SciTech Connect

    Qiang, Yi

    2015-05-01

    Jefferson Lab will soon finish its highly anticipated 12 GeV Upgrade. With doubled maximum energy, Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF) will enable a new experimental program with substantial discovery potential, addressing important topics in nuclear, hadronic and electroweak physics. In order to take full advantage of the high energy, high luminosity beam, new detectors are being developed, designed and constructed to fit the needs of different physics topics. The paper will give an overview of various new detector technologies to be used for 12 GeV experiments. It will then focus on the development of two solenoid-based spectrometers, the GlueX and SoLID spectrometers. The GlueX experiment in Hall D will study the complex properties of gluons through exotic hybrid meson spectroscopy. The GlueX spectrometer, a hermetic detector package designed for spectroscopy and the associated partial wave analysis, is currently in the final stage of construction. Hall A, on the other hand, is developing the SoLID spectrometer to capture the 3D image of the nucleon from semi-inclusive processes and to study the intrinsic properties of quarks through mirror symmetry breaking. Such a spectrometer will have the capability to handle very high event rates while still maintaining a large acceptance in the forward region.

  12. Detector development for Jefferson Lab's 12GeV Upgrade

    DOE PAGESBeta

    Qiang, Yi

    2015-05-01

    Jefferson Lab will soon finish its highly anticipated 12 GeV Upgrade. With doubled maximum energy, Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF) will enable a new experimental program with substantial discovery potential, addressing important topics in nuclear, hadronic and electroweak physics. In order to take full advantage of the high energy, high luminosity beam, new detectors are being developed, designed and constructed to fit the needs of different physics topics. The paper will give an overview of various new detector technologies to be used for 12 GeV experiments. It will then focus on the development of two solenoid-based spectrometers,more » the GlueX and SoLID spectrometers. The GlueX experiment in Hall D will study the complex properties of gluons through exotic hybrid meson spectroscopy. The GlueX spectrometer, a hermetic detector package designed for spectroscopy and the associated partial wave analysis, is currently in the final stage of construction. Hall A, on the other hand, is developing the SoLID spectrometer to capture the 3D image of the nucleon from semi-inclusive processes and to study the intrinsic properties of quarks through mirror symmetry breaking. Such a spectrometer will have the capability to handle very high event rates while still maintaining a large acceptance in the forward region.« less

  13. 12 GeV Upgrade Project - Cryomodule Production

    SciTech Connect

    J. Hogan, A. Burrill, G.K. Davis, M.A. Drury, M. Wiseman

    2012-07-01

    The Thomas Jefferson National Accelerator Facility (Jefferson Lab) is producing ten 100+MV SRF cryomodules (C100) as part of the CEBAF 12 GeV Upgrade Project. Once installed, these cryomodules will become part of an integrated accelerator system upgrade that will result in doubling the energy of the CEBAF machine from 6 to 12 GeV. This paper will present a complete overview of the C100 cryomodule production process. The C100 cryomodule was designed to have the major components procured from private industry and assembled together at Jefferson Lab. In addition to measuring the integrated component performance, the performance of the individual components is verified prior to being released for production and assembly into a cryomodule. Following a comprehensive cold acceptance test of all subsystems, the completed C100 cryomodules are installed and commissioned in the CEBAF machine in preparation of accelerator operations. This overview of the cryomodule production process will include all principal performance measurements, acceptance criterion and up to date status of current activities.

  14. 750 GeV diphotons from supersymmetry with Dirac gauginos

    NASA Astrophysics Data System (ADS)

    Cohen, Timothy; Kribs, Graham D.; Nelson, Ann E.; Ostdiek, Bryan

    2016-07-01

    Motivated by the recent excess in the diphoton invariant mass near 750 GeV, we explore a supersymmetric extension of the Standard Model that includes the minimal set of superpartners as well as additional Dirac partner chiral superfields in the adjoint representation for each gauge group. The bino partner pseudoscalar is identified as the 750 GeV resonance, while superpotential interactions between it and the gluino (wino) partners yield production via gluon fusion (decay to photon pairs) at one-loop. The gauginos and these additional adjoint superpartners are married by a Dirac mass and must also have Majorana masses. While a large wino partner Majorana mass is necessary to explain the excess, the gluino can be approximately Dirac-like, providing benefits consistent with being both "supersoft" (loop corrections to the scalar masses from Dirac gauginos are free of logarithmic enhancements) and "supersafe" (the experimental limits on the squark/gluino masses can be relaxed due to the reduced production rate). Consistency with the measured Standard Model-like Higgs boson mass is imposed, and a numerical exploration of the parameter space is provided. Models that can account for the diphoton excess are additionally characterized by having couplings that can remain perturbative up to very high scales, while remaining consistent with experimental constraints, the Higgs boson mass, and an electroweak scale which is not excessively fine-tuned.

  15. Commissioning of the 123 MeV injector for 12 GeV CEBAF

    SciTech Connect

    Wang, Yan; Hofler, Alicia S.; Kazimi, Reza

    2015-09-01

    The upgrade of CEBAF to 12GeV included modifications to the injector portion of the accelerator. These changes included the doubling of the injection energy and relocation of the final transport elements to accommodate changes in the CEBAF recirculation arcs. This paper will describe the design changes and the modelling of the new 12GeV CEBAF injector. Stray magnetic fields have been a known issue for the 6 GeV CEBAF injector, the results of modelling the new 12GeV injector and the resulting changes implemented to mitigate this issue are described in this paper. The results of beam commissioning of the injector are also presented.

  16. Galactic antiprotons of 0.2-2 GeV energy

    NASA Technical Reports Server (NTRS)

    Shulakova, M. S.; Bogomolov, E. A.; Vasilyev, G. I.; Iodko, M. G.; Krutkov, S. Y.; Lubyanaya, N. D.; Romanov, V. A.; Stepanov, S. V.

    1985-01-01

    Balloon measurements of the galactic antiproton flux in the energy range 0.2 GeV to 2 GeV are presented. The experiments were carried out in the summer of 1984 with magnet spectrometers flown at a residual pressure of approximately 10 g sq cm and cut off rigidity of approximately 0.6 GV. An upper limit for the antiproton to proton flux ratio has been obtained of antiproton/proton (0.2 GeV to 2 GeV) less than 5 x .0001.

  17. The AMS-02 lead-scintillating fibres Electromagnetic Calorimeter

    NASA Astrophysics Data System (ADS)

    Adloff, C.; Basara, L.; Bigongiari, G.; Bosi, F.; Brun, P.; Cadoux, F.; Cervelli, F.; Chambert, V.; Chen, G.; Chen, G. M.; Chen, H. S.; Coignet, G.; Cougoulat, G.; Di Falco, S.; Dubois, J. M.; Elles, S.; Falchini, E.; Fiasson, A.; Fougeron, D.; Fouque, N.; Galeotti, S.; Gallucci, G.; Gherarducci, F.; Girard, L.; Giuseppe, F.; Goy, C.; Hermel, R.; Incagli, M.; Jacquemier, J.; Journet, L.; Kossakowski, R.; Lepareur, V.; Li, Z. H.; Lieunard, B.; Lomtadze, T.; Lu, Y. S.; Maestro, P.; Magazzù, C.; Maire, M.; Orsini, A.; Paniccia, M.; Pedreschi, E.; Peltier, F.; Piendibene, M.; Pilo, F.; Pochon, J.; Rambure, T.; Rosier-Lees, S.; Spinella, F.; Tang, X. W.; Tassan-Viol, J.; Tazzioli, A.; Vannini, C.; Vialle, J. P.; Zhuang, H. L.

    2013-06-01

    The Electromagnetic Calorimeter (ECAL) of the AMS-02 experiment is a fine grained lead-scintillating fibres sampling calorimeter that allows for a precise three-dimensional imaging of the longitudinal and lateral shower development. It provides a high (≥106) electron/hadron discrimination with the other AMS-02 detectors [1] and good energy resolution. The calorimeter also provides a standalone photon trigger capability to AMS-02. The mechanical assembly was realized to ensure minimum weight, still supporting the intrinsically heavy calorimeter during launch. ECAL light collection system and electronics are designed to measure electromagnetic particles over a wide energy range, from GeV up to TeV. A full-scale flight-like model was tested using electrons and proton beams with energies ranging from 6 to 250 GeV.

  18. Strange particle production in p+p collisions at {radical}(s)=200 GeV

    SciTech Connect

    Abelev, B. I.; Bielcik, J.; Bielcikova, J.; Caines, H.; Catu, O.; Chikanian, A.; Du, F.; Finch, E.; Harris, J. W.; Heinz, M.; Lamont, M. A. C.; Lin, G.; Majka, R.; Nattrass, C.; Salur, S.; Sandweiss, J.; Smirnov, N.; Witt, R.; Adams, J.; Barnby, L. S.

    2007-06-15

    We present strange particle spectra and yields measured at midrapidity in {radical}(s)=200 GeV proton-proton (p+p) collisions at the BNL Relativistic Heavy Ion Collider (RHIC). We find that the previously observed universal transverse mass (m{sub T}{identical_to}{radical}(p{sub T}{sup 2}+m{sup 2})) scaling of hadron production in p+p collisions seems to break down at higher m{sub T} and that there is a difference in the shape of the m{sub T} spectrum between baryons and mesons. We observe midrapidity antibaryon to baryon ratios near unity for {lambda} and {xi} baryons and no dependence of the ratio on transverse momentum, indicating that our data do not yet reach the quark-jet dominated region. We show the dependence of the mean transverse momentum on measured charged particle multiplicity and on particle mass and infer that these trends are consistent with gluon-jet dominated particle production. The data are compared with previous measurements made at the CERN Super Proton Synchrotron and Intersecting Storage Rings and in Fermilab experiments and with leading-order and next-to-leading-order string fragmentation model predictions. We infer from these comparisons that the spectral shapes and particle yields from p+p collisions at RHIC energies have large contributions from gluon jets rather than from quark jets.

  19. Strange Particle Production in $p+p$ Collisions at $\\sqrt{s}$= 200GeV

    SciTech Connect

    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.; Calderon de la Barca Sanchez, M.; 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.; de Moura, M.M.; 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.; Dutta Mazumdar, M.R.; 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.S.; 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.; et al.

    2006-07-31

    We present strange particle spectra and yields measured atmid-rapidity in sqrt text s=200 GeV proton-proton (p+p) collisions atRHIC. We find that the previously observed universal transverse mass(mathrm mT \\equiv\\sqrt mathrm p_T 2+\\mathrm m2) scaling of hadronproduction in p+p collisions seems to break down at higher \\mt and thatthere is a difference in the shape of the \\mt spectrum between baryonsand mesons. We observe mid-rapidity anti-baryon to baryon ratios nearunity for Lambda and Xi baryons and no dependence of the ratio ontransverse momentum, indicating that our data do not yet reach thequark-jet dominated region. We show the dependence of the mean transversemomentum (\\mpt) on measured charged particle multiplicity and on particlemass and infer that these trends are consistent with gluon-jet dominatedparticle production. The data are compared to previous measurements fromCERN-SPS, ISR and FNAL experiments and to Leading Order (LO) and Next toLeading order (NLO) string fragmentation model predictions. We infer fromthese comparisons that the spectral shapes and particle yields from $p+p$collisions at RHIC energies have large contributions from gluon jetsrather than quark jets.

  20. Demonstration of self-truncated ionization injection for GeV electron beams

    PubMed Central

    Mirzaie, M.; Li, S.; Zeng, M.; Hafz, N. A. M.; Chen, M.; Li, G. Y.; Zhu, Q. J.; Liao, H.; Sokollik, T.; Liu, F.; Ma, Y. Y.; Chen, L.M.; Sheng, Z. M.; Zhang, J.

    2015-01-01

    Ionization-induced injection mechanism was introduced in 2010 to reduce the laser intensity threshold for controllable electron trapping in laser wakefield accelerators (LWFA). However, usually it generates electron beams with continuous energy spectra. Subsequently, a dual-stage target separating the injection and acceleration processes was regarded as essential to achieve narrow energy-spread electron beams by ionization injection. Recently, we numerically proposed a self-truncation scenario of the ionization injection process based upon overshooting of the laser-focusing in plasma which can reduce the electron injection length down to a few hundred micrometers, leading to accelerated beams with extremely low energy-spread in a single-stage. Here, using 100 TW-class laser pulses we report experimental observations of this injection scenario in centimeter-long plasma leading to the generation of narrow energy-spread GeV electron beams, demonstrating its robustness and scalability. Compared with the self-injection and dual-stage schemes, the self-truncated ionization injection generates higher-quality electron beams at lower intensities and densities, and is therefore promising for practical applications. PMID:26423136

  1. Demonstration of self-truncated ionization injection for GeV electron beams.

    PubMed

    Mirzaie, M; Li, S; Zeng, M; Hafz, N A M; Chen, M; Li, G Y; Zhu, Q J; Liao, H; Sokollik, T; Liu, F; Ma, Y Y; Chen, L M; Sheng, Z M; Zhang, J

    2015-01-01

    Ionization-induced injection mechanism was introduced in 2010 to reduce the laser intensity threshold for controllable electron trapping in laser wakefield accelerators (LWFA). However, usually it generates electron beams with continuous energy spectra. Subsequently, a dual-stage target separating the injection and acceleration processes was regarded as essential to achieve narrow energy-spread electron beams by ionization injection. Recently, we numerically proposed a self-truncation scenario of the ionization injection process based upon overshooting of the laser-focusing in plasma which can reduce the electron injection length down to a few hundred micrometers, leading to accelerated beams with extremely low energy-spread in a single-stage. Here, using 100 TW-class laser pulses we report experimental observations of this injection scenario in centimeter-long plasma leading to the generation of narrow energy-spread GeV electron beams, demonstrating its robustness and scalability. Compared with the self-injection and dual-stage schemes, the self-truncated ionization injection generates higher-quality electron beams at lower intensities and densities, and is therefore promising for practical applications. PMID:26423136

  2. Strange particle production in p+p collisions at s=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.; Burton, T. P.; 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.; Dash, 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.; Gupta, A.; 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.; 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.; 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.; 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, V. 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.

    2007-06-01

    We present strange particle spectra and yields measured at midrapidity in s=200 GeV proton-proton (p+p) collisions at the BNL Relativistic Heavy Ion Collider (RHIC). We find that the previously observed universal transverse mass (mT≡pT2+m2) scaling of hadron production in p+p collisions seems to break down at higher mT and that there is a difference in the shape of the mT spectrum between baryons and mesons. We observe midrapidity antibaryon to baryon ratios near unity for Λ and Ξ baryons and no dependence of the ratio on transverse momentum, indicating that our data do not yet reach the quark-jet dominated region. We show the dependence of the mean transverse momentum on measured charged particle multiplicity and on particle mass and infer that these trends are consistent with gluon-jet dominated particle production. The data are compared with previous measurements made at the CERN Super Proton Synchrotron and Intersecting Storage Rings and in Fermilab experiments and with leading-order and next-to-leading-order string fragmentation model predictions. We infer from these comparisons that the spectral shapes and particle yields from p+p collisions at RHIC energies have large contributions from gluon jets rather than from quark jets.

  3. Lead Surveillance Program

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Background on lead exposure is presented including forms of lead, sources, hematologic effects, neurologic effects, endocrine effects, renal effects, and reproductive and developmental effects. The purpose of the Lead Surveillance Program at LeRC is outlined, and the specifics of the Medical Surveillance Program for Lead Exposure at LeRC are discussed.

  4. GeV γ-ray Emission Detected by Fermi-LAT Probably Associated with the Thermal Composite Supernova Remnant Kesteven 41 in a Molecular Environment

    NASA Astrophysics Data System (ADS)

    Liu, Bing; Chen, Yang; Zhang, Xiao; Zhang, Gao-Yuan; Xing, Yi; Pannuti, Thomas G.

    2015-08-01

    Hadronic emission from supernova remnant (SNR)-molecular cloud (MC) association systems has been widely regarded as a probe of shock-accelerated cosmic-ray protons. Here, we report on the detection of a γ-ray emission source with a significance of 24σ in 0.2-300 GeV, projected to lie to the northwest of the thermal composite SNR Kesteven 41, using 5.6 years of Fermi-Large Area Telescope (LAT) observation data. No significant long-term variability in the energy range 0.2-300 GeV is detected around this source. The 3σ error circle, 0\\buildrel{\\circ}\\over{.} 09 in radius, covers the 1720 MHz OH maser and is essentially consistent with the location of the {V}{LSR}˜ -50 {km} {{{s}}}-1 MC with which the SNR interacts. The source emission has an exponential cutoff power-law spectrum with a photon index of 1.9 ± 0.1 and a cutoff energy of 4.0+/- 0.9 {GeV}, and the corresponding 0.2-300 GeV luminosity is ˜ 1.3× {10}36 {{erg}} {{{s}}}-1 at a distance of 12 kpc. There is no radio pulsar in the 3σ circle responsible for the high γ-ray luminosity. While the inverse Compton scattering scenario would lead to difficulty in the electron energy budget, the source emission can naturally be explained by the hadronic interaction between the relativistic protons accelerated by the shock of SNR Kesteven 41 and the adjacent northwestern MC. In this paper, we present a list of Galactic thermal composite SNRs detected at GeV γ-ray energies by Fermi-LAT.

  5. Shower development of particles with momenta from 15 GeV to 150 GeV in the CALICE scintillator-tungsten hadronic calorimeter

    NASA Astrophysics Data System (ADS)

    Chefdeville, M.; Karyotakis, Y.; Repond, J.; Schlereth, J.; Xia, L.; Eigen, G.; Marshall, J. S.; Thomson, M. A.; Ward, D. R.; Alipour Tehrani, N.; Apostolakis, J.; Dannheim, D.; Elsener, K.; Folger, G.; Grefe, C.; Ivantchenko, V.; Killenberg, M.; Klempt, W.; van der Kraaij, E.; Linssen, L.; Lucaci-Timoce, A.-I.; Münnich, A.; Poss, S.; Ribon, A.; Roloff, P.; Sailer, A.; Schlatter, D.; Sicking, E.; Strube, J.; Uzhinskiy, V.; Chang, S.; Khan, A.; Kim, D. H.; Kong, D. J.; Oh, Y. D.; Blazey, G. C.; Dyshkant, A.; Francis, K.; Zutshi, V.; Giraud, J.; Grondin, D.; Hostachy, J.-Y.; Brianne, E.; Cornett, U.; David, D.; Falley, G.; Gadow, K.; Göttlicher, P.; Günter, C.; Hartbrich, O.; Hermberg, B.; Irles, A.; Karstensen, S.; Krivan, F.; Krüger, K.; Kvasnicka, J.; Lu, S.; Lutz, B.; Morozov, S.; Morgunov, V.; Neubüser, C.; Provenza, A.; Reinecke, M.; Sefkow, F.; Smirnov, P.; Terwort, M.; Tran, H. L.; Vargas-Trevino, A.; Garutti, E.; Laurien, S.; Matysek, M.; Ramilli, M.; Schröder, S.; Briggl, K.; Eckert, P.; Harion, T.; Munwes, Y.; Schultz-Coulon, H.-Ch.; Shen, W.; Stamen, R.; Bilki, B.; Onel, Y.; Kawagoe, K.; Hirai, H.; Sudo, Y.; Suehara, T.; Sumida, H.; Takada, S.; Tomita, T.; Yoshioka, T.; Wing, M.; Calvo Alamillo, E.; Fouz, M.-C.; Marin, J.; Puerta-Pelayo, J.; Verdugo, A.; Bobchenko, B.; Chadeeva, M.; Danilov, M.; Markin, O.; Mizuk, R.; Novikov, E.; Rusinov, V.; Tarkovsky, E.; Kirikova, N.; Kozlov, V.; Smirnov, P.; Soloviev, Y.; Besson, D.; Buzhan, P.; Popova, E.; Gabriel, M.; Kiesling, C.; van der Kolk, N.; Seidel, K.; Simon, F.; Soldner, C.; Szalay, M.; Tesar, M.; Weuste, L.; Amjad, M. S.; Bonis, J.; Cornebise, P.; Richard, F.; Pöschl, R.; Rouëné, J.; Thiebault, A.; Anduze, M.; Balagura, V.; Boudry, V.; Brient, J.-C.; Cizel, J.-B.; Cornat, R.; Frotin, M.; Gastaldi, F.; Haddad, Y.; Magniette, F.; Nanni, J.; Pavy, S.; Rubio-Roy, M.; Shpak, K.; Tran, T. H.; Videau, H.; Yu, D.; Callier, S.; Conforti di Lorenzo, S.; Dulucq, F.; Fleury, J.; Martin-Chassard, G.; de la Taille, Ch.; Raux, L.; Seguin-Moreau, N.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kovalcuk, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Ruzicka, P.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Ieki, S.; Kamiya, Y.; Ootani, W.; Shibata, N.; Chen, S.; Jeans, D.; Komamiya, S.; Kozakai, C.; Nakanishi, H.; Götze, M.; Sauer, J.; Weber, S.; Zeitnitz, C.

    2015-12-01

    We present a study of showers initiated by electrons, pions, kaons, and protons with momenta from 15 GeV to 150 GeV in the highly granular CALICE scintillator-tungsten analogue hadronic calorimeter. The data were recorded at the CERN Super Proton Synchrotron in 2011. The analysis includes measurements of the calorimeter response to each particle type as well as measurements of the energy resolution and studies of the longitudinal and radial shower development for selected particles. The results are compared to Geant4 simulations (version 9.6.p02). In the study of the energy resolution we include previously published data with beam momenta from 1 GeV to 10 GeV recorded at the CERN Proton Synchrotron in 2010.

  6. 750 GeV diphoton resonance, 125 GeV Higgs and muon g - 2 anomaly in deflected anomaly mediation SUSY breaking scenarios

    NASA Astrophysics Data System (ADS)

    Wang, Fei; Wu, Lei; Yang, Jin Min; Zhang, Mengchao

    2016-08-01

    We propose to interpret the 750 GeV diphoton excess in deflected anomaly mediation supersymmetry breaking scenarios, which can naturally predict couplings between a singlet field and vector-like messengers. The CP-even scalar component (S) of the singlet field can serve as the 750 GeV resonance. The messenger scale, which is of order the gravitino scale, can be as light as Fϕ ∼ O (10) TeV when the messenger species NF and the deflection parameter d are moderately large. Such messengers can induce the large loop decay process S → γγ. Our results show that such a scenario can successfully accommodate the 125 GeV Higgs boson, the 750 GeV diphoton excess and the muon g - 2 without conflicting with the LHC constraints. We also comment on the possible explanations in the gauge mediation supersymmetry breaking scenario.

  7. Injection Options for 12 GeV CEBAF Upgrade

    SciTech Connect

    Reza Kazimi; Jay Benesch; Yu-Chiu Chao; Joseph Grames; Geoffrey Krafft; Michael Tiefenback; Byung Yunn; Yuhong Zhang

    2005-05-01

    Jefferson Lab is planning a major upgrade of CEBAF accelerator from 6 to 12 GeV. The injection energy needs to be increased accordingly from 67 MeV to 123 MeV. While the present 100 keV electron gun and beam formation up to 5 MeV would remain unchanged, the accelerating SRF modules in the current injector cannot provide the desired energy increase. Two options for attaining the energy increase have been considered: (1) replacing the present injector SRF modules with new, higher gradient modules, or (2) re-circulating the electron beam through the existing cryomodules to achieve the necessary energy gain in two passes. In this paper we present computer simulation studies for these two options of the injector upgrade and list their advantages and disadvantages.

  8. Laser guiding for GeV laser-plasma accelerators.

    PubMed

    Leemans, Wim; Esarey, Eric; Geddes, Cameron; Schroeder, Carl; Tóth, Csaba

    2006-03-15

    Guiding of relativistically intense laser beams in preformed plasma channels is discussed for development of GeV-class laser accelerators. Experiments using a channel guided laser wakefield accelerator at Lawrence Berkeley National Laboratory (LBNL) have demonstrated that near mono-energetic 100 MeV-class electron beams can be produced with a 10 TW laser system. Analysis, aided by particle-in-cell simulations, as well as experiments with various plasma lengths and densities, indicate that tailoring the length of the accelerator, together with loading of the accelerating structure with beam, is the key to production of mono-energetic electron beams. Increasing the energy towards a GeV and beyond will require reducing the plasma density and design criteria are discussed for an optimized accelerator module. The current progress and future directions are summarized through comparison with conventional accelerators, highlighting the unique short-term prospects for intense radiation sources based on laser-driven plasma accelerators. PMID:16483950

  9. LHC future prospects of the 750 GeV resonance

    NASA Astrophysics Data System (ADS)

    Sato, Ryosuke; Tobioka, Kohsaku

    2016-09-01

    A quantitative discussion on the future prospects of the 750 GeV resonance at the LHC experiment is given using a simple effective field theory analysis. The relative size of two effective operators relevant to diphoton decays can be probed by ratios of diboson signals in a robust way. We obtain the future sensitivities of Zγ, ZZ and WW resonance searches at the high luminosity LHC, rescaling from the current sensitivities at √{ s} = 13 TeV. Then, we show that a large fraction of parameter space in the effective field theory will be covered with 300 fb-1 and almost the whole parameter space will be tested with 3000 fb-1. This discussion is independent of production processes, other decay modes and total decay width.

  10. 1-GeV Linac Upgrade Study at Fermilab

    SciTech Connect

    Popovic, M., Moretti, A., Noble, R., Schmidt, C. W., FNAL

    1998-09-01

    A linac injector for a new proton source complex at Fermilab is assumed to have a kinetic energy of 1 GeV. This linac would be sized to accelerate 100 mA of H{sup -} beam in a 200 microsecond pulse at a 15 Hz repetition rate. This would be adequate to produce {approximately}10{sup 14} protons per pulse allowing for future improvements of the new proton source complex. An alternate proposal is to add 600 MeV of side coupled cavity linac at 805 MHz to the existing 400 MeV Linac. This addition may either be in a new location or use the present Booster tunnel. A discussion of these possibilities will be given.

  11. Open and hidden charm muoproduction. [209 GeV

    SciTech Connect

    Clark, A.R.; Johnson, K.J.; Kerth, L.T.

    1980-09-01

    New results are presented on open and hidden charm and bottom production by 209-GeV muons interacting in a magnetized steel calorimeter. The upper limit on the production of T states by muons is sigma(..mu..N ..-->.. ..mu..UPSILONX)B(UPSILON ..-->.. ..mu mu..) < 22 x 10/sup -39/ cm/sup 2/ (90% confidence level). The distributions of elastically produced psi's are consistent with s-channel helicity conservation (SCHC) and disagree with psi dominance. From analysis of dimuon final states the cross section for diffractive charm muoproduction is 6.9/sub -1.4/sup +1.9/ nb. The structure function F/sub 2/(c anti c) for diffractive charmed-quark pair production is presented. 5 figures, 2 tables.

  12. GeV dark matter searches with the NEWS detector

    NASA Astrophysics Data System (ADS)

    Profumo, Stefano

    2016-03-01

    The proposed NEWS apparatus, a spherical detector with a small central electrode sensor operating as a proportional counter, promises to explore new swaths of the direct detection parameter space in the GeV and sub-GeV dark matter particle mass range by employing very light nuclear targets, such as H and He, and by taking advantage of a very low (sub-keV) energy threshold. Here we discuss and study two example classes of dark matter models that will be tested with NEWS: GeV-scale millicharged dark matter, and a GeV-Dirac Fermion dark matter model with a light (MeV-GeV) scalar or vector mediator, and indicate the physical regions of parameter space the experiment can probe.

  13. Laser Guiding for GeV Laser-Plasma Accelerators

    SciTech Connect

    Leemans, Wim; Esarey, Eric; Geddes, Cameron; Schroeder, C.B.; Toth, Csaba

    2005-06-06

    Guiding of relativistically intense laser beams in preformed plasma channels is discussed for development of GeV-class laser accelerators. Experiments using a channel guided laser wakefield accelerator (LWFA) at LBNL have demonstrated that near mono-energetic 100 MeV-class electron beams can be produced with a 10 TW laser system. Analysis, aided by particle-in-cell simulations, as well as experiments with various plasma lengths and densities, indicate that tailoring the length of the accelerator, together with loading of the accelerating structure with beam, is the key to production of mono-energetic electron beams. Increasing the energy towards a GeV and beyond will require reducing the plasma density and design criteria are discussed for an optimized accelerator module. The current progress and future directions are summarized through comparison with conventional accelerators, highlighting the unique short term prospects for intense radiation sources based on laser-driven plasma accelerators.

  14. GLAST: GeV astronomy in a multiwavelength context

    NASA Astrophysics Data System (ADS)

    Thompson, David J.

    2004-04-01

    The GLAST Large Area Telescope (LAT), successor to Energetic Gamma-ray Experiment Telescope (EGRET) on the Compton Observatory, will play an important role in multiwavelength studies during the second half of this decade. Operating at energies between 20 MeV and greater than 300 GeV with sensitivity 30 or more times greater than that of EGRET, the LAT will offer good spatial and time resolution over a large (>2 sr) field of view. The LAT will bring insight to the whole range of high-energy γ-ray phenomena, including bursts, active galactic nuclei, pulsars, supernova remnants, diffuse emission and unidentified sources. In essentially all cases, the maximum scientific return will come from coordinated (although not necessarily simultaneous) multiwavelength observations. Particularly with its planned scanning mode of operation, GLAST will have full sky coverage on relatively short time scales. The LAT team looks forward to cooperating with observers at other wavelengths.

  15. Higgs stability and the 750 GeV diphoton excess

    NASA Astrophysics Data System (ADS)

    Salvio, Alberto; Mazumdar, Anupam

    2016-04-01

    We study the implications of a possible unstable particle with mass MX GeV, suggested by recent results of ATLAS and CMS on diphoton final states, and work within the minimal model: we add to the Standard Model field content a pseudoscalar and a vector-like fermion carrying both color and electric charge. This can stabilize the electroweak vacuum without invoking new physics at very high energies, which would give an unnaturally large contribution to the Higgs mass. We also show that inflation can be obtained via a UV modification of General Relativity.

  16. 750 GeV diphotons from closed string states

    NASA Astrophysics Data System (ADS)

    Anchordoqui, Luis A.; Antoniadis, Ignatios; Goldberg, Haim; Huang, Xing; Lüst, Dieter; Taylor, Tomasz R.

    2016-04-01

    We show that low-mass-scale string compactifications, with a generic D-brane configuration that realizes the standard model by open strings, can explain the relatively broad peak in the diphoton invariant mass spectrum at 750 GeV recently reported by the ATLAS and CMS Collaborations. Under reasonable assumptions, we demonstrate that the excess could originate from a closed string (possibly axionic) excitation φ that has a coupling with gauge kinetic terms. We estimate the φ production rate from photon-photon fusion in elastic pp scattering, using the effective photon and narrow width approximations. For string scales above today's lower limit Ms ≈ 7 TeV, we can accommodate the diphoton rate observed at Run II while maintaining consistency with Run I data.

  17. Pressure Safety of JLAB 12GeV Upgrade Cryomodule

    SciTech Connect

    Cheng, Gary; Wiseman, Mark A.; Daly, Ed

    2009-11-01

    This paper reviews pressure safety considerations, per the US Department of Energy (DOE) 10CFR851 Final Rule [1], which are being implemented during construction of the 100 Megavolt Cryomodule (C100 CM) for Jefferson Lab’s 12 GeV Upgrade Project. The C100 CM contains several essential subsystems that require pressure safety measures: piping in the supply and return end cans, piping in the thermal shield and the helium headers, the helium vessel assembly which includes high RRR niobium cavities, the end cans, and the vacuum vessel. Due to the vessel sizes and pressure ranges, applicable national consensus code rules are applied. When national consensus codes are not applicable, equivalent design and fabrication approaches are identified and implemented. Considerations for design, material qualification, fabrication, inspection and examination are summarized. In addition, JLAB’s methodologies for implementation of the 10 CFR 851 requirements are described.

  18. Towards GeV laser-driven ion acceleration

    NASA Astrophysics Data System (ADS)

    Hegelich, B. M.; Yin, L.; Albright, B. J.; Flippo, K. A.; Gautier, D. C.; Johnson, R. P.; Letzring, S.; Shah, R. C.; Shimada, T.; Fernandez, J. C.; Henig, A.; Kiefer, D.; Liechtenstein, V.; Schreiber, J.; Habs, D.; Meyer-Ter-Vehn, J.; Rykovanov, S.; Wu, H. C.

    2008-11-01

    Applications like ion-driven fast ignition (IFI) with heavy ions or laser-based hadron therapy require efficient laser-driven ion acceleration to ˜ 0.1 -- 1 GeV. The Break-Out Afterburner (BOA) [1] regime and the Phase-Stable Acceleration (PSA) [2] regime, also reported as Radiation Pressure Acceleration (RPA) [3], promise quasi-monoenergetic beams at such energies, with ˜ 10% efficiency,. This talk summarizes our joint exploratory research program in this new and exciting area, emphasizing the realization of these mechanisms with today's lasers. The laser requirements are discussed, especially pulse contrast. The first experimental results are reported. [1] L. Yin et al., Laser & Part. Beams 24, 1-8 (2006) [2] X. Zhang et al., Phys. Plasmas 14, 123108 (2007) [3] A. P. L. Robinson et al., New J. Phys. 10, 013021 (2008)

  19. Nucleon Form Factors above 6 GeV

    DOE R&D Accomplishments Database

    Taylor, R. E.

    1967-09-01

    This report describes the results from a preliminary analysis of an elastic electron-proton scattering experiment... . We have measured cross sections for e-p scattering in the range of q{sup 2} from 0.7 to 25.0 (GeV/c){sup 2}, providing a large region of overlap with previous measurements. In this experiment we measure the cross section by observing electrons scattered from a beam passing through a liquid hydrogen target. The scattered particles are momentum analyzed by a magnetic spectrometer and identified as electrons in a total absorption shower counter. Data have been obtained with primary electron energies from 4.0 to 17.9 GeV and at scattering angles from 12.5 to 35.0 degrees. In general, only one measurement of a cross section has been made at each momentum transfer.

  20. Leptogenesis via the 750 GeV pseudoscalar

    NASA Astrophysics Data System (ADS)

    Kusenko, Alexander; Pearce, Lauren; Yang, Louis

    2016-06-01

    Recently the ATLAS and CMS Collaborations have reported evidence of a diphoton excess which may be interpreted as a pseudoscalar boson S with a mass around 750 GeV. To explain the diphoton excess, such a boson is coupled to the Standard Model gauge fields via S F F ˜ operators. In this work, we consider the implications of this state for early universe cosmology; in particular, the S field can acquire a large vacuum expectation value due to quantum fluctuations during inflation. During reheating, it then relaxes to its equilibrium value, during which time the same operators introduced to explain the diphoton excess induce a nonzero chemical potential for baryon and lepton number. Interactions such as those involving right-handed neutrinos allow the system to develop a nonzero lepton number and, therefore, this state may also be responsible for the observed cosmological matter-antimatter asymmetry.

  1. 750 GeV diphoton resonance and inflation

    NASA Astrophysics Data System (ADS)

    Hamada, Yuta; Noumi, Toshifumi; Shiu, Gary; Sun, Sichun

    2016-06-01

    We study the possibility of a heavy scalar or pseudoscalar in TeV-scale beyond the Standard Model scenarios being the inflaton of the early universe in light of the recent O (750 ) GeV diphoton excess at the LHC. We consider a scenario in which the new scalar or pseudoscalar couples to the Standard Model gauge bosons at the loop level through new massive Standard Model charged vectorlike fermions with or without dark fermions. We calculate the renormalization group running of both the Standard Model and the new scalar couplings, and present two different models that are perturbative, with a stabilized vacuum up to near the Planck scale. Thus, the Standard Model Higgs and this possible new resonance may still preserve the minimalist features of Higgs inflation.

  2. Lambda Baryon a Production in 91 GEV Positron - Collisions

    NASA Astrophysics Data System (ADS)

    Routenburg, Paul

    1992-01-01

    An analysis of Lambda + | Lambda production in the data collected with the OPAL detector during 1990 is presented. A total inclusive rate is determined and checked through detailed systematic studies. This rate is found to be 0.356 +/- 0.011 (stat.) +/- 0.028 (syst.) per multihadron event. The inclusive cross sections as a function of the fractional Lambda energy (x _{E}) and xi (xi = ln(1/x_{p }), where x_{p} is the fractional Lambda momentum) are determined and compared to the predictions of the HERWIG 5.0 and JETSET 7.2 Monte Carlos as tuned to agree with global event shapes at an average centre-of-mass energy of 91 GeV. The overall Lambda rate is in agreement with the JETSET prediction but less than that predicted by HERWIG. The fragmentation function observed is softer than predicted by either Monte Carlo. Scaling violations are observed in the x_{E } distribution compared to the observations between 29 and 35 GeV. This is attributed to increased gluon radiation. A study is then made of the Lambda decay length distribution, and of the production and decay angles. Reasonable agreement is found between the data and the expectations. There is some indication that the Lambda rate increases faster with event sphericity than does the charged multiplicity. This effect is thought to be due to increased baryon production in gluon fragmentation. Finally, an investigation into Lambda - | Lambda, Lambda - Lambda and | Lambda - | Lambda production in the same event is presented. The results support local baryon number conservation and agree with the JETSET prediction. It is also shown that an additional meson is produced between the baryon and the antibaryon a significant fraction of the time.

  3. The Upgrade of CEBAF to 12 GeV: Physics Motivations and Technical Aspects

    SciTech Connect

    Bernhard Mecking; Larry Cardman

    2002-08-01

    The Continuous Electron Beam Accelerator Facility, CEBAF, makes use of electron and photon beams with an energy up to 6 GeV to investigate the electromagnetic structure of mesons, nucleons, and nuclei. We discuss the physics motivation for upgrading the facility to a maximum energy of 12 GeV and some of the key technological aspects of the upgrade.

  4. Toxicokinetics of bone lead.

    PubMed Central

    Rabinowitz, M B

    1991-01-01

    This article discusses bone as a source of lead to the rest of the body and as a record of past lead exposure. Bone lead levels generally increase with age at rates dependent on the skeletal site and lead exposure. After occupational exposure, the slow decline in blood lead, a 5- to 19-year half-life, reflects the long skeletal half-life. Repeated measurements of bone lead demonstrate the slow elimination of lead from bone. Stable isotope ratios have revealed many details of skeletal uptake and subsequent release. The bulk turnover rates for compact bone are about 2% per year and 8% for spine. Turnover activity varies with age and health. Even though lead approximates calcium, radium, strontium, barium, fluorine, and other bone seekers, the rates for each are different. A simple, two-pool (bone and blood) kinetic model is presented with proposed numerical values for the changes in blood lead levels that occur with changes in turnover rates. Two approaches are offered to further quantify lead turnover. One involves a study of subjects with known past exposure. Changes in the ratio of blood lead to bone lead with time would reflect the course of bone lead availability. Also, stable isotopes and subjects who move from one geographical area to another offer opportunities. Sequential isotope measurements would indicate how much of the lead in blood is from current exposure or bone stores, distinct from changes in absorption or excretion. PMID:2040248

  5. INC Model interpretation of the proton induced residual nuclide production cross sections below 2 GeV

    SciTech Connect

    Divadeenam, M.; Ward, T.E.; Spergel, M.S.; Lakatos, S.; Manche, E.P.

    1991-12-31

    For the purposes of interpreting the abundances of various isotopes in meteorites or on lunar and planetary surfaces exposed to fragmentation by cosmic rays, Webber et al. recently reported the measured total elemental and isotopic cross sections with heavy ions as projectiles on H, He, and C targets with beam energies of 0.33 - 1.7 GeV/nucleon. We employ the INC model to predict the fragmentation of the heavy ions in a hydrogen target with the inverse reaction process: proton bombardment of a heavy-ion nucleus leading to spallation products. Charge-changing and mass-changing cross sections are calculated for proton bombardment of an {sup 56}Fe target with beam energies ranging from 0.33 to 1.88 GeV. Total Z-changing and A-changing cross sections in the energy range 0.6 to 1.88 GeV are in excellent agreement with the corresponding experimental data of Webber et al. and Westfall at al., while the agreement below 0.6 GeV proton energy is not as good. The general trend of the Z-changing cross sections are reproduced by the model calculations at each proton incident energy. The interaction of 200-MeV protons with synthetic Stony Meteorite samples was undertaken to explain radionuclide production in a cosmic-ray environment. The BNL Linac 200-MeV-proton beam was used to irradiate synthetic Stony Meteorites to simulate cosmic-ray exposures corresponding to 6.4 and 16.4 million years. Each irradiated sample was analyzed with the help of a high-resolution gamma-ray spectrometer for long-lived radioisotopes. The intranuclear cascade code HETC was employed to simulate the 200-MeV proton bombardment on the meteorite samples to predict the radionuclides {sup 7}Be, {sup 22}Na, {sup 46}Mn, and {sup 56}Co produced in the experimental investigation.

  6. Studies of beam halo formation in the 12GeV CEBAF design

    SciTech Connect

    Yves Roblin; Arne Freyberger

    2007-06-01

    Beam halo formation in the beam transport design for the Jefferson Lab 12GeV upgrade was investigated using 12GeV beam transport models as well as data from 6GeV CEBAF operations. Various halo sources were considered; these covered both nuclear interactions with beam gas as well as optics-related effects such as non linearities in the magnetic fields of the transport elements. Halo due to beam gas scattering was found to be less of a problem at 12GeV compared to the 6GeV machine. Halo due to non linear effects of magnetic elements was characterized as a function of beam orbit and functional forms of the distribution were derived. These functional forms were used as inputs in subsequent detector optimizations studies.

  7. Coronary Sinus Lead Extraction.

    PubMed

    Cronin, Edmond M; Wilkoff, Bruce L

    2015-12-01

    Expanded indications for cardiac resynchronization therapy and the increasing incidence of cardiac implantable electronic device infection have led to an increased need for coronary sinus (CS) lead extraction. The CS presents unique anatomical obstacles to successful lead extraction. Training and facility requirements for CS lead extraction should mirror those for other leads. Here we review the indications, technique, and results of CS lead extraction. Published success rates and complications are similar to those reported for other leads, although multiple techniques may be required. Re-implantation options may be limited, which should be incorporated into pre-procedural decision making. PMID:26596810

  8. Parity Violation Inelastic Scattering Experiments at 6 GeV and 12 GeV Jefferson Lab

    SciTech Connect

    Sulkosky, Vincent A.; et. al.,

    2015-03-01

    We report on the measurement of parity-violating asymmetries in the deep inelastic scattering and nucleon resonance regions using inclusive scattering of longitudinally polarized electrons from an unpolarized deuterium target. The effective weak couplings C$_{2q}$ are accessible through the deep-inelastic scattering measurements. Here we report a measurement of the parity-violating asymmetry, which yields a determination of 2C$_{2u}$ - C$_{2d}$ with an improved precision of a factor of five relative to the previous result. This result indicates evidence with 95% confidence that the 2C$_{2u}$ - C$_{2d}$ is non-zero. This experiment also provides the first parity-violation data covering the whole resonance region, which provide constraints on nucleon resonance models. Finally, the program to extend these measurements at Jefferson Lab in the 12 GeV era using the Solenoidal Large Intensity Device was also discussed.

  9. Lead - nutritional considerations

    MedlinePlus

    ... lead soldered cans goes into effect. If imported wine containers have a lead foil wrapper, wipe the ... a towel moistened with lemon juice, vinegar, or wine before using. DO NOT store wine, spirits, or ...

  10. Lead - nutritional considerations

    MedlinePlus

    ... found in some containers and cooking utensils . Old paint poses the greatest danger for lead poisoning , especially ... leach out into the liquid. Other important recommendations: Paint over old leaded paint if it is in ...

  11. Lead and tap water

    MedlinePlus

    Water contaminated with lead ... The Environmental Protection Agency (EPA) monitors drinking water and requires water suppliers to produce annual water quality reports. These reports, which include information about lead amounts, are available to consumers. For ...

  12. Lead and tap water

    MedlinePlus

    Water contaminated with lead ... The Environmental Protection Agency (EPA) monitors drinking water in the United States. It requires water suppliers to produce annual water quality reports. These reports include information about lead amounts, and they ...

  13. VOLUMETRIC LEAD ASSAY

    SciTech Connect

    M.A. Ebadian, Ph.D.; S.K. Dua; David Roelant; Sachin Kumar

    2001-01-01

    This report describes a system for handling and radioassay of lead, consisting of a robot, a conveyor, and a gamma spectrometer. The report also presents a cost-benefit analysis of options: radioassay and recycling lead vs. disposal as waste.

  14. Solving the lead dilemma

    SciTech Connect

    Pollack, S. )

    1989-10-01

    This paper discusses the widespread problem of lead poisoning among children. The perils of deleading are addressed and several methods of deleading currently in use are detailed and analyzed. These include the traditional method of burning or sanding off leaded paint, the Baltimore Model involving extensive refabrication of infected dwellings, and encapsulation by which leaded surfaces in the home are covered to prevent the escape of lead dust.

  15. Transplacental transport of lead

    SciTech Connect

    Goyer, R.A. )

    1990-11-01

    Neurotoxicity is the major health effect from exposure to lead for infants and young children, and there is current concern regarding possible toxic effects of lead on the child while in utero. there is no placental-fetal barrier to lead transport. Maternal and fetal blood lead levels are nearly identical, so lead passes through the placenta unencumbered. Lead has been measured in the fetal brain as early as the end of the first trimester (13 weeks). There is a similar rate of increase in brain size and lead content throughout pregnancy in the fetus of mothers in the general population, so concentration of lead probably does not differ greatly during gestation unless exposure of the mother changes. Cell-specific sensitivity to the toxic effects of lead, however, may be greater the younger the fetus. Lead toxicity to the nervous system is characterized by edema or swelling of the brain due to altered permeability of capillary endothelial cells. Experimental studies suggest that immature endothelial cells forming the capillaries of the developing brain are less resistant to the effects of lead, permitting fluid and cations including lead to reach newly formed components of the brain, particularly astrocytes and neurons. Also, the ability of astrocytes and neurons to sequester lead in the form of lead protein complexes occurs only in the later stages of fetal development, permitting lead in maturing brain cells to interact with vital subcellular organelles, particularly mitochondria, which are the major cellular energy source. Intracellular lead also affects binding sites for calcium which, in turn, may affect numerous cell functions including neurotransmitter release.

  16. PHOTOEMISSION PROPERTIES OF LEAD.

    SciTech Connect

    SMEDLEY,J.; RAO,T.; WARREN,J.; SEKUTOWICZ,J.; LEFFERTS,R.; LIPSKI,A.

    2004-07-05

    In this paper we present a study of the photoemission properties of lead at several UV wavelengths, including a study of the damage threshold of electroplated lead under laser cleaning. A quantum efficiency in excess of 0.1% has been achieved for a laser cleaned, electroplated lead sample with a laser wavelength of 193 nm. Niobium cathodes have been measured for comparison, and lead is found to be a superior photoemitter for all measured wavelengths.

  17. Lead and children

    PubMed Central

    Abelsohn, Alan R.; Sanborn, Margaret

    2010-01-01

    Abstract OBJECTIVE To provide family physicians with a practical, evidence-based approach to screening for and preventing children’s exposure to lead. SOURCES OF INFORMATION MEDLINE was searched using terms relevant to lead exposure and poisoning. We reviewed English-language articles published in 2003 to 2008. Most cited studies provide level 2 or 3 evidence. MAIN MESSAGE Lead is a developmental neurotoxin. Children are most commonly exposed and they are most vulnerable. Lead exposure has been associated with many cognitive and motor deficits, as well as distractibility and other characteristics of attention deficit hyperactivity disorder. Although children’s blood lead levels have declined considerably over the past 3 decades with removal of lead from gasoline and paint, children can still be exposed to lead from lead paint in older homes, toys, and other sources. Because post-exposure treatment cannot reverse the cognitive effects of lead exposure, preventing lead exposure is essential. CONCLUSION Family physicians have an important role in screening for children at high risk of lead exposure, and in educating families to prevent the exposure of children to lead. PMID:20547517

  18. Lead Poisoning in Childhood.

    ERIC Educational Resources Information Center

    Pueschel, Siegfried M., Ed.; Linakis, James G., Ed.; Anderson, Angela C., Ed.

    The magnitude of childhood lead poisoning has been inexplicably neglected by modern medicine and by legislators. However, since the 1970s, increased attention has been focused on lead poisoning, and advances have been made in several areas, including understanding of the neurodevelopmental and behavioral ramifications of lead poisoning, and…

  19. Lead Poisoning (For Parents)

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy Lead Poisoning KidsHealth > For Parents > Lead Poisoning Print A A ... Family en español La intoxicación por plomo About Lead Poisoning If you have young kids, it's important to ...

  20. Lead Poisoning in Children.

    ERIC Educational Resources Information Center

    Boeckx, Roger L.

    1986-01-01

    Urban children are exposed to lead through the air they breathe, the water they drink, and the food and nonfood substances they ingest. The history, diagnosis, and treatment of lead poisoning in these children are discussed. Includes information on the toxicology of lead and the various risk classes. (JN)

  1. Lead Poisoning in Children.

    ERIC Educational Resources Information Center

    Drummond, A. H., Jr.

    1981-01-01

    Early symptoms of lead poisoning in children are often overlooked. Lead poisoning has its greatest effects on the brain and nervous system. The obvious long-term solution to the lead poisoning problem is removal of harmful forms of the metal from the environment. (JN)

  2. Learn about Lead

    MedlinePlus

    ... Determine if your family is at risk for lead poisoning with the Lead Poisoning Home Checklist (PDF) . Top of page What do I do if I think my child or I have been exposed to lead? Talk to your pediatrician, general physician, or local ...

  3. Lead Poisoning in Schools.

    ERIC Educational Resources Information Center

    Guyaux, Susan

    1990-01-01

    Overexposure to lead can permanently impair a child's mental and physical development. This article discusses sources of lead paint, survey and testing methods, management and abatement plans, drinking water contamination, and associated federal standards. Although lead is present in soil and in art, theater, and vocational programs, no federal…

  4. Lead poisoning: An overview

    NASA Technical Reports Server (NTRS)

    Gendel, Neil

    1993-01-01

    A problem that should be of great concern to all of us is the lead poisoning of children. First, I would like to present a short overview concerning the reasons everyone should care about lead poisoning, then discuss the history of lead poisoning, what is happening today across the country, and the future.

  5. Conceptual design of the Project-X 1.3 GHz 3-8 GeV pulsed linac

    SciTech Connect

    Solyak, N.; Eidelman, Y.; Nagaitsev, S.; Ostiguy, J.-F.; Vostrikov, A.; Yakovlev, V.; /Fermilab

    2011-03-01

    Project-X, a multi-MW proton source, is under development at Fermilab. It enables a Long Baseline Neutrino Experiment via a new beam line pointed to DUSEL in Lead, South Dakota, and a broad suite of rare decay experiments. The initial acceleration is provided by a 3-GeV 1-mA CW superconducting linac. In a second stage, about 5% of the H{sup -} beam is accelerated up to 8 GeV in a 1.3 GHz SRF pulsed linac and injected into the Recycler/Main Injector complex. In order to mitigate problems with stripping foil heating during injection, higher current pulses are accelerated in the CW linac in conjunction with the 1 mA beam which is separated and further accelerated in the pulsed linac. The optimal current in the pulsed linac is discussed as well as the constraints that led to its selection. A conceptual design which covers optics and RF stability analysis is presented. Finally, the need for HOM damping is discussed.

  6. Lead in the environment

    USGS Publications Warehouse

    Pattee, O.H.; Pain, D.J.

    2003-01-01

    Anthropogenic uses of lead have probably altered its availability and environmental distribution more than any other toxic element. Consequently, lead concentrations in many living organisms may be approaching thresholds of toxicity for the adverse effects of lead. Such thresholds are difficult to define, as they vary with the chemical and physical form of lead, exposure regime, other elements present and also vary both within and between species. The technological capability to accurately quantify low lead concentrations has increased over the last decade, and physiological and behavioral effects have been measured in wildlife with tissue lead concentrations below those previously considered safe for humans.s.236 Consequently. lead criteria for the protection of wildlife and human health are frequently under review, and 'thresholds' of lead toxicity are being reconsidered. Proposed lead criteria for the protection of natural resources have been reviewed by Eisler. Uptake of lead by plants is limited by its generally low availability in soils and sediments, and toxicity may be limited by storage mechanisms and its apparently limited translocation within most plants. Lead does not generally accumulate within the foliar parts of plants, which limits its transfer to higher trophic levels. Although lead may concentrate in plant and animal tissues, no evidence of biomagnification exists. Acid deposition onto surface waters and soils with low buffering capacity may influence the availability of lead for uptake by plants and animals, and this may merit investigation at susceptible sites. The biological significance of chronic low-level lead exposure to wildlife is sometimes difficult to quantify. Animals living in urban environments or near point sources of lead emission are inevitably subject to greater exposure to lead and enhanced risk of lead poisoning. Increasingly strict controls on lead emissions in many countries have reduced exposure to lead from some sources

  7. Background model systematics for the Fermi GeV excess

    SciTech Connect

    Calore, Francesca; Cholis, Ilias; Weniger, Christoph

    2015-03-01

    The possible gamma-ray excess in the inner Galaxy and the Galactic center (GC) suggested by Fermi-LAT observations has triggered a large number of studies. It has been interpreted as a variety of different phenomena such as a signal from WIMP dark matter annihilation, gamma-ray emission from a population of millisecond pulsars, or emission from cosmic rays injected in a sequence of burst-like events or continuously at the GC. We present the first comprehensive study of model systematics coming from the Galactic diffuse emission in the inner part of our Galaxy and their impact on the inferred properties of the excess emission at Galactic latitudes 2° < |b| < 20° and 300 MeV to 500 GeV. We study both theoretical and empirical model systematics, which we deduce from a large range of Galactic diffuse emission models and a principal component analysis of residuals in numerous test regions along the Galactic plane. We show that the hypothesis of an extended spherical excess emission with a uniform energy spectrum is compatible with the Fermi-LAT data in our region of interest at 95% CL. Assuming that this excess is the extended counterpart of the one seen in the inner few degrees of the Galaxy, we derive a lower limit of 10.0° (95% CL) on its extension away from the GC. We show that, in light of the large correlated uncertainties that affect the subtraction of the Galactic diffuse emission in the relevant regions, the energy spectrum of the excess is equally compatible with both a simple broken power-law of break energy E(break) = 2.1 ± 0.2 GeV, and with spectra predicted by the self-annihilation of dark matter, implying in the case of bar bb final states a dark matter mass of m(χ)=49(+6.4)(-)(5.4)  GeV.

  8. Composite magnetic dark matter and the 130 GeV line

    NASA Astrophysics Data System (ADS)

    Cline, James M.; Moore, Guy D.; Frey, Andrew R.

    2012-12-01

    We propose an economical model to explain the apparent 130 GeV gamma ray peak, found in the Fermi/LAT data, in terms of dark matter (DM) annihilation through a dipole moment interaction. The annihilating dark matter particles represent a subdominant component, with mass density 7-17% of the total DM density; and they only annihilate into γγ, γZ, and ZZ, through a magnetic (or electric) dipole moment. Annihilation into other standard model particles is suppressed, due to a DM mass splitting in the magnetic dipole case, or to p-wave scattering in the electric dipole case. In either case, the observed signal requires a dipole moment of strength μ˜2/TeV. We argue that composite models are the preferred means of generating such a large dipole moment, and that the magnetic case is more natural than the electric one. We present a simple model involving a scalar and fermionic techniquark of a confining SU(2) gauge symmetry. We point out some generic challenges for getting such a model to work. The new physics leading to a sufficiently large dipole moment is below the TeV scale, indicating that the magnetic moment is not a valid effective operator for LHC physics, and that production of the strongly interacting constituents, followed by techni-hadronization, is a more likely signature than monophoton events. In particular, four-photon events from the decays of bound state pairs are predicted.

  9. Higgs-like boson at 750 GeV and genesis of baryons

    NASA Astrophysics Data System (ADS)

    Davoudiasl, Hooman; Giardino, Pier Paolo; Zhang, Cen

    2016-07-01

    We propose that the diphoton excess at 750 GeV reported by ATLAS and CMS is due to the decay of an exo-Higgs scalar η associated with the breaking of a new S U (2 )e symmetry, dubbed exo-spin. New fermions, exo-quarks and exo-leptons, get TeV-scale masses through Yukawa couplings with η and generate its couplings to gluons and photons at one loop. The matter content of our model yields a B -L anomaly under S U (2 )e, whose breaking we assume entails a first-order phase transition. A nontrivial B -L asymmetry may therefore be generated in the early Universe, potentially providing a baryogenesis mechanism through the Standard Model (SM) sphaleron processes. The spontaneous breaking of S U (2 )e can, in principle, directly lead to electroweak symmetry breaking, thereby accounting for the proximity of the mass scales of the SM Higgs and the exo-Higgs. Our model can be distinguished from those comprising a singlet scalar and vector fermions by the discovery of TeV scale exo-vector bosons, corresponding to the broken S U (2 )e generators, at the LHC.

  10. Search for excited leptons at 130-140 GeV

    NASA Astrophysics Data System (ADS)

    Buskulic, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Lucotte, A.; Minard, M.-N.; Nief, J.-Y.; Odier, P.; Pietrzyk, B.; Casado, M. P.; Chmeissani, M.; Crespo, J. M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, Ll.; Juste, A.; Martinez, M.; Orteu, S.; Padilla, C.; Park, I. C.; Pascual, A.; Perlas, J. A.; Riu, I.; Sanchez, F.; Teubert, F.; Colaleo, A.; Creanza, D.; de Palma, M.; Gelao, G.; Girone, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Marinelli, N.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Alemany, R.; Bazarko, A. O.; Cattaneo, M.; Comas, P.; Coyle, P.; Drevermann, H.; Forty, R. W.; Frank, M.; Hagelberg, R.; Harvey, J.; Janot, P.; Jost, B.; Kneringer, E.; Knobloch, J.; Lehraus, I.; Lutters, G.; Martin, E. B.; Mato, P.; Minten, A.; Miquel, R.; Mir, Ll. M.; Moneta, L.; Oest, T.; Pacheco, A.; Pusztaszeri, J.-F.; Ranjard, F.; Rensing, P.; Rolandi, L.; Schlatter, D.; Schmelling, M.; Schmitt, M.; Schneider, O.; Tejessy, W.; Tomalin, I. R.; Venturi, A.; Wachsmuth, H.; Wagner, A.; Ajaltouni, Z.; Barrès, A.; Boyer, C.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Rosnet, P.; Rossignol, J.-M.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Nilsson, B. S.; Rensch, B.; Wäänänen, A.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Brient, J. C.; Rougé, A.; Rumpf, M.; Valassi, A.; Videau, H.; Focardi, E.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Jaffe, D. E.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Casper, D.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Dorris, S. J.; Halley, A. W.; Knowles, I. G.; Lynch, J. G.; O'Shea, V.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Teixeira-Dias, P.; Thompson, A. S.; Thomson, F.; Thorn, S.; Turnbull, R. M.; Becker, U.; Geweniger, C.; Graefe, G.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E. E.; Putzer, A.; Schmidt, M.; Sommer, J.; Stenzel, H.; Tittel, K.; Werner, S.; Wunsch, M.; Abbaneo, D.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Dornan, P. J.; Morawitz, P.; Moutoussi, A.; Nash, J.; Sedgbeer, J. K.; Stacey, A. M.; Williams, M. D.; Dissertori, G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Betteridge, A. P.; Bowdery, C. K.; Colrain, P.; Crawford, G.; Finch, A. J.; Foster, F.; Hughes, G.; Sloan, T.; Whelan, E. P.; Williams, M. I.; Galla, A.; Greene, A. M.; Hoffmann, C.; Jacobs, K.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H.-G.; van Gemmeren, P.; Zeitnitz, C.; Aubert, J. J.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Bujosa, G.; Calvet, D.; Carr, J.; Diaconu, C.; Konstantinidis, N.; Payre, P.; Rousseau, D.; Talby, M.; Sadouki, A.; Thulasidas, M.; Tilquin, A.; Trabelsi, K.; Aleppo, M.; Ragusa, F.; Bauer, C.; Berlich, R.; Blum, W.; Büscher, V.; Dietl, H.; Dydak, F.; Ganis, G.; Gotzhein, C.; Kroha, H.; Lütjens, G.; Lutz, G.; Männer, W.; Moser, H.-G.; Richter, R.; Rosado-Schlosser, A.; Schael, S.; Settles, R.; Seywerd, H.; Denis, R. St.; Stenzel, H.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Höcker, A.; Jacholkowska, A.; Jacquet, M.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Nikolic, I.; Park, H. J.; Schune, M.-H.; Simion, S.; Veillet, J.-J.; Videau, I.; Zerwas, D.; Azzurri, P.; Bagliesi, G.; Batignani, G.; Bettarini, S.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Fantechi, R.; Ferrante, I.; Giassi, A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Sciabà, A.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Vannini, C.; Verdini, P. G.; Walsh, J.; Blair, G. A.; Bryant, L. M.; Cerutti, F.; Chambers, J. T.; Gao, Y.; Green, M. G.; Medcalf, T.; Perrodo, P.; Strong, J. A.; von Wimmersperg-Toeller, J. H.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Maley, P.; Norton, P. R.; Thompson, J. C.; Wright, A. E.; Bloch-Devaux, B.; Colas, P.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Black, S. N.; Dann, J. H.; Johnson, R. P.; Kim, H. Y.; Litke, A. M.; McNeil, M. A.; Taylor, G.; Booth, C. N.; Boswell, R.; Brew, C. A. J.; Cartwright, S.; Combley, F.; Koksal, A.; Letho, M.; Newton, W. M.; Reeve, J.; Thompson, L. F.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Saraiva, P.; Smolik, L.; Stephan, F.; Apollonio, M.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Musolino, G.; Putz, J.; Rothberg, J.; Wasserbaech, S.; Williams, R. W.; Armstrong, S. R.; Elmer, P.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; González, S.; Grahl, J.; Greening, T. C.; Hayes, O. J.; Hu, H.; McNamara, P. A.; Nachtman, J. M.; Orejudos, W.; Pan, Y. B.; Saadi, Y.; Scott, I. J.; Walsh, A. M.; Wu, Sau Lan; Wu, X.; Yamartino, J. M.; Zheng, M.; Zobernig, G.; Aleph Collaboration

    1996-02-01

    A search for the radiative decay of excited charged leptons, ℓ ∗, and for radiative and weak decays of excited electron neutrinos, ν e∗, is performed, using the 5.8 pb -1 of data collected by ALEPH at 130-140 GeV. No evidence for a signal is found in single or pair production. Excluded mass limits from pair production are close to 65 GeV/ c2 for all excited lepton species. Limits on the couplings, {λ}/{m ℓ ∗}, of excited leptons are derived from single production. For an excited lepton mass of 130 GeV/ c2, these limits are 0.04 GeV -1 for μ ∗ and τ ∗, and 0.0007 GeV -1 for e ∗. For ν e∗, the limit is at the level of 0.03 GeV -1 for a mass of 120 GeV/ c2, independent of the decay branching ratios.

  11. Measurements of Compton Scattering on the Proton at 2 - 6 GeV

    SciTech Connect

    Danagoulian, Areg

    2006-05-01

    Similar to elastic electron scattering, Compton Scattering on the proton at high momentum transfers(and high p⊥) can be an effective method to study its short-distance structure. An experiment has been carried out to measure the cross sections for Real Compton Scattering (RCS) on the proton for 2.3-5.7 GeV electron beam energies and a wide distribution of large scattering angles. The 25 kinematic settings sampled a domain of s = 5-11(GeV/c)2,-t = -7(GeV/c)2 and -u = 0.5-6.5(GeV/c)2. In addition, a measurement of longitudinal and transverse polarization transfer asymmetries was made at a 3.48 GeV beam energy and a scattering angle of θcm = 120o. These measurements were performed to test the existing theoretical mechanisms for this process as well as to determine RCS form factors. At the heart of the scientific motivation is the desire to understand the manner in which a nucleon interacts with external excitations at the above listed energies, by comparing and contrasting the two existing models – Leading Twist Mechanism and Soft Overlap “Handbag” Mechanism – and identify the dominant mechanism. Furthermore, the Handbag Mechanism allows one to calculate reaction observables in the framework of Generalized Parton Distributions (GPD), which have the function of bridging the wide gap between the exclusive(form factors) and inclusive(parton distribution functions) description of the proton. The experiment was conducted in Hall A of Thomas Jefferson National Accelerator Facility(Jefferson Lab). It used a polarized and unpolarized electron beam, a 6% copper radiator with the thickness of 6.1% radiation lengths (to produce a bremsstrahlung photon beam), the Hall A liquid hydrogen target, a high resolution spectrometer with a focal plane polarimeter, and a photon hodoscope calorimeter. Results of the differential cross sections are presented, and discussed in the general context of the scientific motivation.

  12. Inclusive charm cross sections in 800 GeV/ c p-p interactions

    NASA Astrophysics Data System (ADS)

    Ammar, R.; Banerjee, S.; Baland, J. F.; Ball, S.; Ball, R. C.; Bhat, P. C.; Bromberg, C.; Brun, R.; Canough, G. E.; Coffin, T.; Commichau, V.; Davis, R.; Dershem, T. O.; Dixon, R. L.; Fenker, H. C.; Ganguli, S. N.; Gensch, U.; Giokaris, N.; Girtler, P.; Goshaw, A. T.; Gress, J.; Gurtu, A.; Henri, V. P.; Hernandez, J. J.; Hrubec, J.; Iori, M.; Jones, L. W.; Knauss, D.; Kuhn, D.; Kwak, N.; Leedom, I. D.; Legros, P.; Lemonne, J.; Leutz, H.; Liu, X.; Malhotra, P. K.; Marraffino, J. M.; Mendez, G. E.; Mikocki, S.; Miller, R.; Naumann, T.; Neuhofer, G.; Nguyen, A.; Nikolic, M.; Nowak, H.; Pilette, P.; Poppleton, A.; Poirier, J.; Raghavan, R.; Rasner, K.; Reucroft, S.; Robertson, W. J.; Roe, B. P.; Roos, C. E.; Roth, A.; Senko, M.; Struczinski, W.; Subramanian, A.; Touboul, M. C.; Vonck, B.; Voyvodic, L.; Walker, W. D.; Waters, J. W.; Weber, M. F.; Webster, M. S.; Wickens, J.; Wild, C. F.; Youtsey, S.; LEBC-MPS Collaboration

    1987-01-01

    We report a measurement of the inclusive D/D¯ production cross section in 800 GeV/ c proton-proton interactions. The experiment used the high resolution bubble chamber LEBC exposed to an 800 GeV/ c proton beam at the Fermilab MPS. We obtain σ( D/ D¯)=59 -15+22μ b (statistical errors), having analysed 25% of the total data sample. Comparison with 400 GeV/ c pp dat a obtained with LEBC at CERN shows a D/D¯ cross section increase by a factor of 1.7 -0.5+0.7. This is in good agreement with fusion model calculations.

  13. Research Perspectives at Jefferson Lab: 12 GeV and Beyond

    SciTech Connect

    Kees de Jager

    2002-09-01

    The plans for upgrading the CEBAF accelerator at Jefferson Lab to 12 GeV are presented. The research program supporting that upgrade are illustrated with a few selected examples. The instrumentation under design to carry out that research program is discussed. Finally, a conceptual design of a future upgrade which combines a 25 GeV fixed-target facility and an electron-ion collider facility at a luminosity of up to 10{sup 35}cm{sup -2}s{sup -1} and a CM energy of over 40 GeV.

  14. MSSM with GeV in high-scale gauge mediation

    NASA Astrophysics Data System (ADS)

    Zheng, Sibo

    2014-02-01

    After the discovery of an SM-like Higgs with GeV, it is increasingly urgent to explore a solution to the hierarchy problem. In the context of MSSM from gauge-mediated SUSY breaking, the lower bound on the gluino mass suggests that the messenger scale is probably large if the magnitude of TeV. In this paper, we study the model with GeV and TeV. For moderate Higgs-messenger coupling, a viable model will be shown with moderate fine tuning. In this model, GeV, and nearly vanishes at the input scale, which can be constructed in a microscopic model.

  15. Variable gamma-ray sky at 1 GeV

    NASA Astrophysics Data System (ADS)

    Pshirkov, M. S.; Rubtsov, G. I.

    2013-01-01

    We search for the long-term variability of the gamma-ray sky in the energy range E > 1 GeV with 168 weeks of the gamma-ray telescope Fermi-LAT data. We perform a full sky blind search for regions with variable flux looking for deviations from uniformity. We bin the sky into 12288 pixels using the HEALPix package and use the Kolmogorov-Smirnov test to compare weekly photon counts in each pixel with the constant flux hypothesis. The weekly exposure of Fermi-LAT for each pixel is calculated with the Fermi-LAT tools. We consider flux variations in a pixel significant if the statistical probability of uniformity is less than 4 × 10-6, which corresponds to 0.05 false detections in the whole set. We identified 117 variable sources, 27 of which have not been reported variable before. The sources with previously unidentified variability contain 25 active galactic nuclei (AGN) belonging to the blazar class (11 BL Lacs and 14 FSRQs), one AGN of an uncertain type, and one pulsar PSR J0633+1746 (Geminga).

  16. Gev Gamma-ray Astronomy in the Era of GLAST

    NASA Technical Reports Server (NTRS)

    Gehrels, Neil; White, Nicholas E. (Technical Monitor)

    2000-01-01

    The Gamma Ray Large Area Space Telescope (GLAST) is a high energy astronomy mission planned for launch in 2005. GLAST features two instruments; the Large Area Telescope (LAT) operating from 20 MeV - 300 GeV and the Gamma-ray Burst Monitor (GBM) operating from 10 keV - 25 MeV. GLAST observations will contribute to our understanding of active galactic nuclei and their jets, gamma-ray bursts, extragalactic and galactic diffuse emissions, dark matter, supernova remnants, pulsars, and the unidentified high energy gamma-ray sources. The LAT sensitivity is 4 x 10(exp -9) photons per square centimeter per second (greater than 100 MeV) for a one year all-sky survey, which is a factor of greater than 20 better than CGRO/EGRET. GLAST spectral observations of gamma-ray bursts cover over 6 orders of magnitude in energy thanks to the context observations of the GBM. The upper end of the LAT energy range merges with the low energy end of ground-based observatories to provide a remarkable new perspective on particle acceleration in the Universe.

  17. Exclusive processes at JLab at 6 GeV

    SciTech Connect

    Kim, Andrey

    2015-01-01

    Deeply virtual exclusive reactions provide a unique opportunity to probe the complex internal structure of the nucleon. They allow to access information about the correlations between parton transverse spatial and longitudinal momentum distributions from experimental observables. Dedicated experiments to study Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP) have been carried out at Jefferson Lab using continuous electron beam with energies up to 6 GeV. Unpolarized cross sections, beam, target and double spin asymmetries have been measured for DVCS as well as for π0 exclusive electroproduction. The data from Hall B provide a wide kinematic coverage with Q2=1-4.5 GeV2, xB=0.1-0.5, and -t up to 2 GeV2. Hall A data have limited kinematic range partially overlapping with Hall B kinematics but provide a high accuracy measurements. Scaling tests of the DVCS cross sections provide solid evidence of twist-2 dominance, which makes chiral-even GPDs accessible even at modest Q2. We will discuss the interpretation of these data in terms of Generalized Parton Distributions (GPDs) model. Successful description of the recent CLAS π0 exclusive production data within the framework of the GPD-based model provides a unique opportunity to access the chiral-odd GPDs.

  18. Variable gamma-ray sky at 1 GeV

    SciTech Connect

    Pshirkov, M. S.; Rubtsov, G. I.

    2013-01-15

    We search for the long-term variability of the gamma-ray sky in the energy range E > 1 GeV with 168 weeks of the gamma-ray telescope Fermi-LAT data. We perform a full sky blind search for regions with variable flux looking for deviations from uniformity. We bin the sky into 12288 pixels using the HEALPix package and use the Kolmogorov-Smirnov test to compare weekly photon counts in each pixel with the constant flux hypothesis. The weekly exposure of Fermi-LAT for each pixel is calculated with the Fermi-LAT tools. We consider flux variations in a pixel significant if the statistical probability of uniformity is less than 4 Multiplication-Sign 10{sup -6}, which corresponds to 0.05 false detections in the whole set. We identified 117 variable sources, 27 of which have not been reported variable before. The sources with previously unidentified variability contain 25 active galactic nuclei (AGN) belonging to the blazar class (11 BL Lacs and 14 FSRQs), one AGN of an uncertain type, and one pulsar PSR J0633+1746 (Geminga).

  19. Symmetries behind the 750 GeV diphoton excess

    NASA Astrophysics Data System (ADS)

    Chao, Wei

    2016-06-01

    A 750 GeV resonance has been observed at the run 2 LHC in the diphoton channel. In this paper, we explain this resonance as a C P -even scalar S that triggers the spontaneous breaking of local U (1 )B or U (1 )B+L gauge symmetries. S couples to gluon and photon pairs at the one-loop level, where particles running in the loop are introduced to cancel anomalies, and the gluon fusion is the dominate production channel of S at the LHC. The model contains a scalar dark matter candidate stabilized by the new gauge symmetry. Our study shows that both the observed production cross section at the LHC and the best fit decay width of S can be explained in this model without conflicting with any other experimental data. Constraints on couplings associated with S are studied, which show that S has a negligible mixing with the standard model Higgs boson but sizable coupling with the dark matter.

  20. Nuclear interactions of 340-GeV pions in emulsion

    SciTech Connect

    Tufail, A.; Ahmad, S.; Khan, A.R.; Zafar, M.; Shafi, M. )

    1990-10-01

    Some results on heavy- and shower-particle multiplicities produced in interactions of 340-GeV pions in nuclear emulsion are presented and compared with similar results in proton-nucleus interactions at different energies. Values of {l angle}{ital N}{sub {ital g}}{r angle} in {pi}{sup {minus}}{ital A} interactions are found to be less than its value in {ital pA} interactions at similar energies. This is understood in terms of additive quark model. The result on mean normalized multiplicity reveals that the values of {ital R}{sub {ital A}1} are almost constant in the forward direction for all values of {l angle}{nu}({ital N}{sub {ital g}}){r angle} and {ital R}{sub {ital A}1} increases with {l angle}{nu}({ital N}{sub {ital g}}){r angle} in the intervals 1.2{lt}{eta}{le}2.0 and {eta}{le}1.2.

  1. Spin Light Polarimeter at 12 GeV

    NASA Astrophysics Data System (ADS)

    Mohanmurthy, Prajwal; Dutta, Dipangkar

    2012-03-01

    We plan to develop a realistic design for a novel polarimeter which will go a long way in satisfying the requirements of the precision experiments planned for the 12GeV era at Jefferson National Accelerator Facility (JLAB). A polarimeter based on the asymmetry in the spacial distribution of the spin light component of synchrotron radiation will make for a fine addition to the existing Möller and Compton polarimeters. The spin light polarimeter consists of a set of wriggler magnet along the beam that generate synchrotron radiation. The spacial distribution of synchrotron radiation will be measured by an ionization chamber after being collimated. As a part of the design process, simulation of the effects of fringe field of the 3-pole wriggler magnet that forms the primary component of the polarimeter is underway. The fringe field was simulated using LANL Poisson Superfish mesh EM solver. The results from the simulation, the preliminary design parameters of the polarimeter and its impact will be discussed.

  2. Hydrodynamical assessment of 200[ital A] GeV collisions

    SciTech Connect

    Schnedermann, E.; Heinz, U. Institut fuer Theoretische Physik, Universitaet Regensburg, D-93040 Regensburg )

    1994-09-01

    We are analyzing the hydrodynamics of 200[ital A] GeV S+S collisions using a new approach which tries to quantify the uncertainties arising from the specific implementation of the hydrodynamical model. Based on a previous phenomenological analysis we use the global hydrodynamics model to show that the amount of initial flow, or initial energy density, cannot be determined from the hadronic momentum spectra. We additionally find that almost always a sizable transverse flow develops, which causes the system to freeze out, thereby limiting the flow velocity in itself. This freeze-out dominance in turn makes a distinction between a plasma and a hadron resonance gas equation of state very difficult, whereas a pure pion gas can easily be ruled out from present data. To complete the picture we also analyze particle multiplicity data, which suggest that chemical equilibrium is not reached with respect to the strange particles. However, the overpopulation of pions seems to be at most moderate, with a pion chemical potential far away from the Bose divergence.

  3. Investigation of GEV Proton-Induced Spallation Reactions

    NASA Astrophysics Data System (ADS)

    Hilscher, D.; Herbach, C.-M.; Jahnke, U.; Tishchenko, V. G.; Galin, J.; Lott, B.; Letourneau, A.; Peghaire, A.; Filges, D.; Goldenbaum, F.; Nünighoff, K.; Schaal, H.; Sterzenbach, G.; Wohlmuther, M.; Pienkowski, L.; Schröder, W. U.; Toke, J.

    2004-09-01

    A reliable modeling of GeV proton-induced spallation reactions is indispensable for the design of the spallation module and the target station of future accelerator driven hybrid reactors (ADS) or spallation neutron sources (ESS), in particular, to provide precise predictions for the neutron production, the radiation damage of materials (window), and the production of radioactivity (3H, 7Be etc.) in the target medium. Detailed experimental nuclear data are needed for sensitive validations and improvements of the models, whose predictive power is strongly dependent on the correct physical description of the three main stages of a spallation reaction: (i) the Intra-Nuclear-Cascade (INC) with the fast heating of the target nucleus, (ii) the de-excitation due to pre-equilibrium emission including the possibility of multi-fragmentation, and (iii) the statistical decay of thermally excited nuclei by evaporation of light particles and fission in the case of heavy nuclei. Key experimental data for this endeavor are absolute production cross sections and energy spectra for neutrons and light charged-particles (LCPs), emission of composite particles prior and post to the attainment of an equilibrated system, distribution of excitation energies deposited in the nuclei after the INC, and fission probabilities. Systematic measurements of such data are furthermore needed over large ranges of target nuclei and incident proton energies. Such data has been measured with the NESSI detector. An overview of new and previous results will be given.

  4. 750 GeV Diphoton Excess from the Goldstino Superpartner

    NASA Astrophysics Data System (ADS)

    Petersson, Christoffer; Torre, Riccardo

    2016-04-01

    We interpret the diphoton excess recently reported by the ATLAS and CMS Collaborations as a new resonance arising from the sgoldstino scalar, which is the superpartner of the Goldstone mode of spontaneous supersymmetry breaking, the goldstino. The sgoldstino is produced at the LHC via gluon fusion and decays to photons, with interaction strengths proportional to the corresponding gaugino masses over the supersymmetry breaking scale. Fitting the excess, while evading bounds from searches in the dijet, Z γ , Z Z , and W W final states, selects the supersymmetry breaking scale to be a few TeV and particular ranges for the gaugino masses. The two real scalars, corresponding to the C P -even and C P -odd parts of the complex sgoldstino, both have narrow widths, but their masses can be split of the order of 10-30 GeV by electroweak mixing corrections, which could account for the preference of a wider resonance width in the current low-statistics data. In the parameter space under consideration, tree level F -term contributions to the Higgs mass arise, in addition to the standard D -term contribution proportional to the Z -boson mass, which can significantly enhance the tree level Higgs mass.

  5. Lead Poison Detection

    NASA Technical Reports Server (NTRS)

    1976-01-01

    With NASA contracts, Whittaker Corporations Space Science division has developed an electro-optical instrument to mass screen for lead poisoning. Device is portable and detects protoporphyrin in whole blood. Free corpuscular porphyrins occur as an early effect of lead ingestion. Also detects lead in urine used to confirm blood tests. Test is inexpensive and can be applied by relatively unskilled personnel. Similar Whittaker fluorometry device called "drug screen" can measure morphine and quinine in urine much faster and cheaper than other methods.

  6. Lead poisoning: case studies.

    PubMed

    Gordon, J N; Taylor, A; Bennett, P N

    2002-05-01

    Early clinical features of lead toxicity are non-specific and an occupational history is particularly valuable. Lead in the body comprises 2% in the blood (t1/2 35 days) and 95% in bone and dentine (t1/2 20-30 years). Blood lead may remain elevated for years after cessation from long exposure, due to redistribution from bone. Blood lead concentration is the most widely used marker for inorganic lead exposure. Zinc protoporphyrin (ZPP) concentration in blood usefully reflects lead exposure over the prior 3 months. Symptomatic patients with blood lead concentration >2.4 micromol l-1 (50 microg dl-1) or in any event >3.8 micromol l-1 (80 microg dl-1) should receive sodium calciumedetate i.v., followed by succimer by mouth for 19 days. Asymptomatic patients with blood lead concentration >2.4 micromol l-1 (50 microg dl-1) may be treated with succimer alone. Sodium calciumedetate should be given with dimercaprol to treat lead encephalopathy. PMID:11994050

  7. Early Commissioning Experience and Future Plans for the 12 GeV Continuous Electron Beam Accelerator Facility

    SciTech Connect

    Spata, Michael F.

    2014-12-01

    Jefferson Lab has recently completed the accelerator portion of the 12 GeV Upgrade for the Continuous Electron Beam Accelerator Facility. All 52 SRF cryomodules have been commissioned and operated with beam. The initial beam transport goals of demonstrating 2.2 GeV per pass, greater than 6 GeV in 3 passes to an existing experimental facility and greater than 10 GeV in 5-1/2 passes have all been accomplished. These results along with future plans to commission the remaining beamlines and to increase the performance of the accelerator to achieve reliable, robust and efficient operations at 12 GeV are presented.

  8. Revisiting the pion leading-twist distribution amplitude within the QCD background field theory

    NASA Astrophysics Data System (ADS)

    Zhong, Tao; Wu, Xing-Gang; Wang, Zhi-Gang; Huang, Tao; Fu, Hai-Bing; Han, Hua-Yong

    2014-07-01

    We study the pion leading-twist distribution amplitude (DA) within the framework of Shifman-Vainshtein-Zakharov sum rules under the background field theory. To improve the accuracy of the sum rules, we expand both the quark propagator and the vertex (z.D↔)n of the correlator up to dimension-six operators in the background field theory. The sum rules for the pion DA moments are obtained, in which all condensates up to dimension-six have been taken into consideration. Using the sum rules, we obtain ⟨ξ2⟩|1 GeV=0.338±0.032, ⟨ξ4⟩|1GeV=0.211±0.030 and ⟨ξ6⟩|1GeV=0.163±0.030. It is shown that the dimension-six condensates shall provide sizable contributions to the pion DA moments. We show that the first Gegenbauer moment of the pion leading-twist DA is a2π|1 GeV=0.403±0.093, which is consistent with those obtained in the literature within errors but prefers a larger central value as indicated by lattice QCD predictions.

  9. The dijet cross section measurement in proton-proton collisions at a center of mass energy of 500 GeV at STAR

    NASA Astrophysics Data System (ADS)

    Webb, Grant

    Polarized deep inelastic scattering experiments play a vital role in the exploration of the spin structure of the proton. The polarized proton-proton collider at RHIC provides direct access to the gluon spin distribution through longitudinal double spin asymmetry measurements of inclusive jets, pions, and dijets. This thesis presents the measurement of the dijet double differential cross-section in proton-proton collisions at center of mass energies of [sq rt]s = 500 GeV. The data represent an integrated luminosity of 8.7 pb--1 recorded by the STAR detector during the 2009 RHIC run. A comprehensive jet analysis was performed to determine the ideal jet algorithm and jet parameters used in [sq rt]s = 500 GeV collisions at the STAR detector. The cross-section is measured as a function of the dijet invariant mass (30 ≤ Mij ≤ 152 GeV) in the mid rapidity region with a maximum rapidity range of | ymax| ≤ 0.8. This result shows agreement with theoretical next-to-leading order pQCD calculations, motivating the use of dijet asymmetries at STAR to further constrain the shape of Deltag( x). KEYWORDS: Dijet Cross Section, Gluon Spin, STAR Detector, Jetography, Embedding.

  10. Leading Education Reference Sources.

    ERIC Educational Resources Information Center

    Spencer, Michael D.

    This annotated bibliography focuses on, but is not limited to, reference sources on education found in the library at St. Bonaventure University, New York. The ERIC database leads the list of leading education reference sources. Also mentioned are the "Thesaurus of ERIC Descriptors" and the Academic Index (InfoTrak) computer system. Other…

  11. Leading Educational Change Wisely

    ERIC Educational Resources Information Center

    Forrester, Gillian

    2011-01-01

    In this article, the author reviews Christopher Branson's book entitled "Leading Educational Change Wisely". The book provides an alternative and engaging perspective on leading educational change. Branson utilises "wisdom" as its central conceptual device to present a thought-provoking and philosophical account on how leaders are able to build a…

  12. Supersonic Leading Edge Receptivity

    NASA Technical Reports Server (NTRS)

    Maslov, Anatoly A.

    1998-01-01

    This paper describes experimental studies of leading edge boundary layer receptivity for imposed stream disturbances. Studies were conducted in the supersonic T-325 facility at ITAM and include data for both sharp and blunt leading edges. The data are in agreement with existing theory and should provide guidance for the development of more complete theories and numerical computations of this phenomena.

  13. Lead carbonate scintillator materials

    DOEpatents

    Derenzo, Stephen E.; Moses, William W.

    1991-01-01

    Improved radiation detectors containing lead carbonate or basic lead carbonate as the scintillator element are disclosed. Both of these scintillators have been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to other known scintillator materials. The radiation detectors disclosed are favorably suited for use in general purpose detection and in medical uses.

  14. LEAD IN CANDLE EMISSIONS

    EPA Science Inventory

    The candle-using public should be made aware that the core of candle wicks may contain lead. Used as a stiffening agent to keep the wick out of the molten wax, lead can be emitted as particulate to the air and then deposited on indoor surfaces. To define the problem, 100 sets of ...

  15. Lead Poisoning in Children.

    ERIC Educational Resources Information Center

    Lin-Fu, Jane S.

    This publication is a guide to help social and health workers plan a preventive campaign against lead poisoning, a cause of mental retardation other neurological handicaps, and death among children. The main victims are 1- to 6-year-olds living in areas where deteriorating housing prevails. Among the causes of lead poisoning are: ingestion of…

  16. Rapid Lead Screening Test

    MedlinePlus

    ... and treated earlier before the damaging effects of lead poisoning occur. U.S. Department of Health and Human Services ... exceed 10μg/dL, the threshold used to indicate lead poisoning. The American Academy of Pediatrics (AAP) estimates one ...

  17. Recovering lead from batteries

    NASA Astrophysics Data System (ADS)

    David Prengaman, R.

    1995-01-01

    Over the past 20 years, a significant number of processes have been developed to recover lead from scrap batteries. These processes recover lead via hydrometallurgical processing of the paste component of the battery followed by electrowinning. A number of pilot plant operations have been conducted, but thus far none of the processes have become operational.

  18. Lead toxicity: a review

    PubMed Central

    Ara, Anjum; Usmani, Jawed Ahmad

    2015-01-01

    Lead toxicity is an important environmental disease and its effects on the human body are devastating. There is almost no function in the human body which is not affected by lead toxicity. Though in countries like US and Canada the use of lead has been controlled up to a certain extent, it is still used vehemently in the developing countries. This is primarily because lead bears unique physical and chemical properties that make it suitable for a large number of applications for which humans have exploited its benefits from historical times and thus it has become a common environmental pollutant. Lead is highly persistent in the environment and because of its continuous use its levels rise in almost every country, posing serious threats. This article reviews the works listed in the literature with recent updates regarding the toxicity of lead. Focus is also on toxic effects of lead on the renal, reproductive and nervous system. Finally the techniques available for treating lead toxicity are presented with some recent updates. PMID:27486361

  19. Reconciling the muon g -2 , a 125 GeV Higgs boson, and dark matter in gauge mediation models

    NASA Astrophysics Data System (ADS)

    Gogoladze, Ilia; Shafi, Qaisar; Ün, Cem Salih

    2015-12-01

    We present a class of models in the framework of gauge mediation supersymmetry breaking where the standard model is supplemented by additional U (1 ) symmetry which acts only on the third generation fermions. The messenger fields carry a nontrivial U (1 ) charge and are vectorlike particles under this symmetry. This leads to additional contributions to the soft supersymmetry breaking mass terms for the third-generation squarks and sleptons. In this framework we show that the muon g -2 anomaly, the observed 125 GeV Higgs boson mass and the detected relic dark matter abundance (gravitino in our case) can be simultaneously accommodated. The resolution of the muon g -2 anomaly, in particular, yields the result that masses of squarks in the first two families, as well the gluino mass, should be ≲2.5 TeV , which will be tested at LHC14.

  20. Lead polluters get punished

    SciTech Connect

    Not Available

    1991-08-09

    The Environmental Protection Agency (EPA) and the Department of Justice last week cracked down on 36 US companies for polluting the environment with lead. EPA slapped fines totaling more than $10 million on 12 of the offending companies, and Justice filed 24 civil complaints. Hank Habicht, deputy administrator of the EPA, said that his agency's initiative comes after 8 months of intense - and presumably successful - efforts at locating and documenting lead pollution in the soil, air, and water supply. Most feared has been lead's ability to damage the intellectual development of children. This caused the agency, Habicht said, to look beyond the usual suspect - lead in the water supply - to lead-laced dirt in residential areas. Meanwhile, the Department of Justice is using the EPA contamination data as well. Twenty US attorneys have been assigned to pore over the federal environmental statutes, including the Clean Water Act and the Superfund Law, in order to file civil complaints.

  1. The Science and Experimental Equipment for the 12 GeV Upgrade of CEBAF

    SciTech Connect

    Arrington, John; Bernstein, Aron; Brooks, William; Burker, Volker; Cardman, Lawrence; Carlson, Carl; Cates, Gordon; Chen, Jian-Ping; Dzierba, Alex; Ent, Rolf; Elouadrhiri, Latifa; Fenker, Howard; Gao, Haiyan; Gasparian, Ashot; Goity, Jose; Higinbotham, Douglas; Holt, Roy; Hyde, Charles; De Jager, Cornelis; Jeschonnek, Sabine; Ji, Xiangdong; Jiang, Xiangdong; Jones, Mark; Keppel, Cynthia; Kuhn, Sebastian; Kumar, Krishna; Laget, Jean; Mack, David; Meyer, Curtis; Melnitchouk, Wolodymyr; Meziani, Zein-Eddine; Radyushkin, Anatoly; Ramsey-Musolf, Mike; Reimer, Paul; Richards, David; Rondon-Aramayo, Oscar; Salgado, Carlos; Smith, Elton; Schiavilla, Rocco; Souder, Paul; Stoler, Paul; Thomas, Anthony; Ulmer, Paul; Weinstein, Lawrence; Weiss, Christian

    2005-01-10

    This Conceptual Design Report (CDR) presents the compelling scientific case for upgrading the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab to 12 GeV. Such a facility will make profound contributions to the study of hadronic matter.

  2. Radiation shielding of the beam absorber in the MI 8-GeV beam line

    SciTech Connect

    Rakhno, I.; /Fermilab

    2006-01-01

    Results of Monte Carlo radiation shielding calculations performed for the beam absorber of the MI 8 GeV beam line are presented and discussed. The possibility to reach the level of 10{sup 19} protons per year is investigated.

  3. 750 GeV diphoton excess explained by a resonant sneutrino in R -parity violating supersymmetry

    NASA Astrophysics Data System (ADS)

    Allanach, B. C.; Dev, P. S. Bhupal; Renner, S. A.; Sakurai, Kazuki

    2016-06-01

    We explain the recent excess seen by ATLAS and CMS experiments at around 750 GeV in the diphoton invariant mass as a narrow-width sneutrino decaying to diphotons via a stau loop in R -parity violating supersymmetry. The stau mass is predicted to be somewhere between half the resonant sneutrino mass and half the sneutrino mass plus 14 GeV. The scenario also predicts further signal channels at an invariant mass of 750 GeV, the most promising being into dijets and W W . We also predict a left-handed charged slepton decaying into W Z and W γ at a mass 750-754 GeV.

  4. A Catalog of Fermi-LAT Sources Detected above 50 GeV

    NASA Astrophysics Data System (ADS)

    Dominguez, Alberto; Ajello, Marco; Gasparrini, Dario; Cutini, Sara; Fermi-LAT Collaboration

    2015-01-01

    The Fermi Large Area Telescope (LAT) has been routinely gathering science data since August 2008, surveying the full sky every three hours. The first Fermi-LAT catalog of sources detected above 10 GeV (1FHL) relied on three years of data to characterize the >10 GeV sky. The improved acceptance and point-spread function of the new Pass 8 event reconstruction and classification together with six years of observations now available allow the detection and characterization of sources directly above 50 GeV. This closes the gap between ground-based Cherenkov telescopes, which have excellent sensitivity but small fields of view and duty cycles, and all-sky observations at GeV energies from orbit. In this contribution we will present the resulting catalog and discuss the properties of the Galactic and extragalactic source populations.

  5. Lead toxicity: Current concerns

    SciTech Connect

    Goyer, R.A. )

    1993-04-01

    Over the 20-year period since the first issue of Environmental Health Perspectives was published, there has been considerable progress in the understanding of the potential toxicity of exposure to lead. Many of these advances have been reviewed in published symposia, conferences, and review papers in EHP. This brief review identifies major advances as well as a number of current concerns that present opportunities for prevention and intervention strategies. The major scientific advance has been the demonstration that blood lead (PbB) levels of 10-15 micrograms/dL in newborn and very young infants result in cognitive and behavioral deficits. Further support for this observation is being obtained by prospective or longitudinal studies presently in progress. The mechanism(s) for the central nervous system effects of lead is unclear but involve lead interactions within calcium-mediated intracellular messenger systems and neurotransmission. Effects of low-level lead exposure on blood pressure, particularly in adult men, may be related to the effect of lead on calcium-mediated control of vascular smooth muscle contraction and on the renin-angiotensin system. Reproductive effects of lead have long been suspected, but low-level effects have not been well studied. Whether lead is a carcinogen or its association with renal adenocarcinoma is a consequence of cystic nephropathy is uncertain. Major risk factors for lead toxicity in children in the United States include nutrition, particularly deficiencies of essential metals, calcium, iron, and zinc, and housing and socioeconomic status. A goal for the year 2000 is to reduce prevalence of blood lead levels exceeding 15 micrograms/dL. 97 refs.

  6. Lead-free piezoceramics

    NASA Astrophysics Data System (ADS)

    Saito, Yasuyoshi; Takao, Hisaaki; Tani, Toshihiko; Nonoyama, Tatsuhiko; Takatori, Kazumasa; Homma, Takahiko; Nagaya, Toshiatsu; Nakamura, Masaya

    2004-11-01

    Lead has recently been expelled from many commercial applications and materials (for example, from solder, glass and pottery glaze) owing to concerns regarding its toxicity. Lead zirconium titanate (PZT) ceramics are high-performance piezoelectric materials, which are widely used in sensors, actuators and other electronic devices; they contain more than 60 weight per cent lead. Although there has been a concerted effort to develop lead-free piezoelectric ceramics, no effective alternative to PZT has yet been found. Here we report a lead-free piezoelectric ceramic with an electric-field-induced strain comparable to typical actuator-grade PZT. We achieved this through the combination of the discovery of a morphotropic phase boundary in an alkaline niobate-based perovskite solid solution, and the development of a processing route leading to highly <001> textured polycrystals. The ceramic exhibits a piezoelectric constant d33 (the induced charge per unit force applied in the same direction) of above 300picocoulombs per newton (pCN-1), and texturing the material leads to a peak d33 of 416pCN-1. The textured material also exhibits temperature-independent field-induced strain characteristics.

  7. Lead in calcium supplements.

    PubMed

    Scelfo, G M; Flegal, A R

    2000-04-01

    Intercalibrated measurements of lead in calcium supplements indicate the importance of rigorous analytical techniques to accurately quantify contaminant exposures in complex matrices. Without such techniques, measurements of lead concentrations in calcium supplements may be either erroneously low, by as much as 50%, or below the detection limit needed for new public health criteria. In this study, we determined the lead content of 136 brands of supplements that were purchased in 1996. The calcium in the products was derived from natural sources (bonemeal, dolomite, or oyster shell) or was synthesized and/or refined (chelated and nonchelated calcium). The dried products were acid digested and analyzed for lead by high resolution-inductively coupled plasma-mass spectrometry. The method's limit of quantitation averaged 0.06 microg/g, with a coefficient of variation of 1.7% and a 90-100% lead recovery of a bonemeal standard reference material. Two-thirds of those calcium supplements failed to meet the 1999 California criteria for acceptable lead levels (1.5 microg/daily dose of calcium) in consumer products. The nonchelated synthesized and/or refined calcium products, specifically antacids and infant formulas, had the lowest lead concentrations, ranging from nondetectable to 2.9 microg Pb/g calcium, and had the largest proportion of brands meeting the new criteria (85% of the antacids and 100% of the infant formulas). PMID:10753088

  8. Lead in calcium supplements.

    PubMed Central

    Scelfo, G M; Flegal, A R

    2000-01-01

    Intercalibrated measurements of lead in calcium supplements indicate the importance of rigorous analytical techniques to accurately quantify contaminant exposures in complex matrices. Without such techniques, measurements of lead concentrations in calcium supplements may be either erroneously low, by as much as 50%, or below the detection limit needed for new public health criteria. In this study, we determined the lead content of 136 brands of supplements that were purchased in 1996. The calcium in the products was derived from natural sources (bonemeal, dolomite, or oyster shell) or was synthesized and/or refined (chelated and nonchelated calcium). The dried products were acid digested and analyzed for lead by high resolution-inductively coupled plasma-mass spectrometry. The method's limit of quantitation averaged 0.06 microg/g, with a coefficient of variation of 1.7% and a 90-100% lead recovery of a bonemeal standard reference material. Two-thirds of those calcium supplements failed to meet the 1999 California criteria for acceptable lead levels (1.5 microg/daily dose of calcium) in consumer products. The nonchelated synthesized and/or refined calcium products, specifically antacids and infant formulas, had the lowest lead concentrations, ranging from nondetectable to 2.9 microg Pb/g calcium, and had the largest proportion of brands meeting the new criteria (85% of the antacids and 100% of the infant formulas). Images Figure 1 Figure 2 PMID:10753088

  9. Energies of GRB blast waves and prompt efficiencies as implied by modelling of X-ray and GeV afterglows

    NASA Astrophysics Data System (ADS)

    Beniamini, Paz; Nava, Lara; Duran, Rodolfo Barniol; Piran, Tsvi

    2015-11-01

    We consider a sample of 10 gamma-ray bursts with long-lasting ( ≳ 102 s) emission detected by Fermi/Large Area Telescope and for which X-ray data around 1 d are also available. We assume that both the X-rays and the GeV emission are produced by electrons accelerated at the external forward shock, and show that the X-ray and the GeV fluxes lead to very different estimates of the initial kinetic energy of the blast wave. The energy estimated from GeV is on average ˜50 times larger than the one estimated from X-rays. We model the data (accounting also for optical detections around 1 d, if available) to unveil the reason for this discrepancy and find that good modelling within the forward shock model is always possible and leads to two possibilities: (i) either the X-ray emitting electrons (unlike the GeV emitting electrons) are in the slow-cooling regime or (ii) the X-ray synchrotron flux is strongly suppressed by Compton cooling, whereas, due to the Klein-Nishina suppression, this effect is much smaller at GeV energies. In both cases the X-ray flux is no longer a robust proxy for the blast wave kinetic energy. On average, both cases require weak magnetic fields (10-6 ≲ ɛB ≲ 10-3) and relatively large isotropic kinetic blast wave energies 10^{53} erg<{E}_{0,kin}<10^{55} erg corresponding to large lower limits on the collimated energies, in the range 10^{52} erg<{E}_{θ ,kin}<5× 10^{52} erg for an ISM (interstellar medium) environment with n ˜ 1 cm-3 and 10^{52} erg<{E}_{θ ,kin}<10^{53} erg for a wind environment with A* ˜ 1. These energies are larger than those estimated from the X-ray flux alone, and imply smaller inferred values of the prompt efficiency mechanism, reducing the efficiency requirements on the still uncertain mechanism responsible for prompt emission.

  10. The First Fermi-LAT Catalog of Sources Above 10 GeV

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Allafort, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Moiseev, Alexander A.

    2013-01-01

    We present a catalog of gamma-ray sources at energies above 10 GeV based on data from the Large Area Telescope (LAT) accumulated during the first 3 yr of the Fermi Gamma-ray Space Telescope mission. The first Fermi-LAT catalog of >10 GeV sources (1FHL) has 514 sources. For each source we present location, spectrum, a measure of variability, and associations with cataloged sources at other wavelengths. We found that 449 (87%) could be associated with known sources, of which 393 (76% of the 1FHL sources) are active galactic nuclei. Of the 27 sources associated with known pulsars, we find 20 (12) to have significant pulsations in the range >10 GeV (>25 GeV). In this work we also report that, at energies above 10 GeV, unresolved sources account for 27% +/- 8% of the isotropic ? -ray background, while the unresolved Galactic population contributes only at the few percent level to the Galactic diffuse background. We also highlight the subset of the 1FHL sources that are best candidates for detection at energies above 50-100 GeV with current and future ground-based ? -ray observatories.