Tritium β decay in chiral effective field theory

DOE PAGES

Baroni, A.; Girlanda, L.; Kievsky, A.; ...

2016-08-18

We evaluate the Fermi and Gamow-Teller (GT) matrix elements in tritiummore » $$\\beta$$-decay by including in the charge-changing weak current the corrections up to one loop recently derived in nuclear chiral effective field theory ($$\\chi$$ EFT). The trinucleon wave functions are obtained from hyperspherical-harmonics solutions of the Schroedinger equation with two- and three-nucleon potentials corresponding to either $$\\chi$$ EFT (the N3LO/N2LO combination) or meson-exchange phenomenology (the AV18/UIX combination). We find that contributions due to loop corrections in the axial current are, in relative terms, as large as (and in some cases, dominate) those from one-pion exchange, which nominally occur at lower order in the power counting. Furthermore, we also provide values for the low-energy constants multiplying the contact axial current and three-nucleon potential, required to reproduce the experimental GT matrix element and trinucleon binding energies in the N3LO/N2LO and AV18/UIX calculations.« less

A percent-level determination of the nucleon axial coupling from Quantum Chromodynamics

DOE PAGES

Chang, Chia C.; Rinaldi, Enrico; Nicholson, A. N.; ...

2018-06-15

Here, the axial coupling of the nucleon, g A, is the strength of its coupling to the weak axial current of the Standard Model, much as the electric charge is the strength of the coupling to the electromagnetic current. This axial coupling dictates, for example, the rate of β-decay of neutrons to protons and the strength of the attractive long-range force between nucleons. Precision tests of the Standard Model in nuclear environments require a quantitative understanding of nuclear physics rooted in Quantum Chromodynamics, a pillar of this theory. The prominence of g A makes it a benchmark quantity to determinemore » from theory, a difficult task as the theory is non-perturbative. Lattice QCD provides a rigorous, non-perturbative definition of the theory which can be numerically implemented. In order to determine g A, the lattice QCD community has identified two challenges that must be overcome to achieve a 2% precision by 2020: the excited state contamination must be controlled, and the statistical precision must be markedly improved. Here we report a calculation of g A QCD =1.271 ± 0.013, using an unconventional method11 that overcomes these challenges.« less

A percent-level determination of the nucleon axial coupling from Quantum Chromodynamics

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

Chang, Chia C.; Rinaldi, Enrico; Nicholson, A. N.

Here, the axial coupling of the nucleon, g A, is the strength of its coupling to the weak axial current of the Standard Model, much as the electric charge is the strength of the coupling to the electromagnetic current. This axial coupling dictates, for example, the rate of β-decay of neutrons to protons and the strength of the attractive long-range force between nucleons. Precision tests of the Standard Model in nuclear environments require a quantitative understanding of nuclear physics rooted in Quantum Chromodynamics, a pillar of this theory. The prominence of g A makes it a benchmark quantity to determinemore » from theory, a difficult task as the theory is non-perturbative. Lattice QCD provides a rigorous, non-perturbative definition of the theory which can be numerically implemented. In order to determine g A, the lattice QCD community has identified two challenges that must be overcome to achieve a 2% precision by 2020: the excited state contamination must be controlled, and the statistical precision must be markedly improved. Here we report a calculation of g A QCD =1.271 ± 0.013, using an unconventional method11 that overcomes these challenges.« less

Neutrino-driven Explosion of a 20 Solar-mass Star in Three Dimensions Enabled by Strange-quark Contributions to Neutrino-Nucleon Scattering

NASA Astrophysics Data System (ADS)

Melson, Tobias; Janka, Hans-Thomas; Bollig, Robert; Hanke, Florian; Marek, Andreas; Müller, Bernhard

2015-08-01

Interactions with neutrons and protons play a crucial role for the neutrino opacity of matter in the supernova core. Their current implementation in many simulation codes, however, is rather schematic and ignores not only modifications for the correlated nuclear medium of the nascent neutron star, but also free-space corrections from nucleon recoil, weak magnetism, or strange quarks, which can easily add up to changes of several 10% for neutrino energies in the spectral peak. In the Garching supernova simulations with the Prometheus-Vertex code, such sophistications have been included for a long time except for the strange-quark contributions to the nucleon spin, which affect neutral-current neutrino scattering. We demonstrate on the basis of a 20 {M}⊙ progenitor star that a moderate strangeness-dependent contribution of {g}{{a}}{{s}}=-0.2 to the axial-vector coupling constant {g}{{a}}≈ 1.26 can turn an unsuccessful three-dimensional (3D) model into a successful explosion. Such a modification is in the direction of current experimental results and reduces the neutral-current scattering opacity of neutrons, which dominate in the medium around and above the neutrinosphere. This leads to increased luminosities and mean energies of all neutrino species and strengthens the neutrino-energy deposition in the heating layer. Higher nonradial kinetic energy in the gain layer signals enhanced buoyancy activity that enables the onset of the explosion at ˜300 ms after bounce, in contrast to the model with vanishing strangeness contributions to neutrino-nucleon scattering. Our results demonstrate the close proximity to explosion of the previously published, unsuccessful 3D models of the Garching group.

Observation of shadowing of neutrino- and antineutrino-nucleus interactions and comparison with PCAC predictions

NASA Astrophysics Data System (ADS)

Allport, P. P.; Erriquez, O.; Guy, J.; Venus, W.; Aderholz, M.; Berggren, M.; Bullock, F. W.; Calicchio, M.; Coghen, T.; Cooper-Sarkar, A. M.; Jones, G. T.; Marage, P.; Mobayyen, M.; Morrison, D. R. O.; Neveu, M.; Parker, M. A.; Radojicic, D.; Sansum, R. A.; Saitta, B.; Schmitz, N.; Simopoulou, E.; O'neale, S.; Van Apeldoorn, G.; Varvell, K.; Vayaki, A.; Wachsmuth, H.; Wittek, W.; BEBC WA59 Collaboration

1989-12-01

Comparing the kinematical distributions of events obtained on neon and deuterium targets in similar experimental conditions reveals a reduction of the neutrino and antineutrino charged current cross section per nucleon in neon at low Q2. The effect, interpreted as due to geometric shadowing of the weak propagator in interactions of neutrinos and antineutrinos with nuclei, agrees well with predictions derived from PCAC.

A per-cent-level determination of the nucleon axial coupling from quantum chromodynamics.

PubMed

Chang, C C; Nicholson, A N; Rinaldi, E; Berkowitz, E; Garron, N; Brantley, D A; Monge-Camacho, H; Monahan, C J; Bouchard, C; Clark, M A; Joó, B; Kurth, T; Orginos, K; Vranas, P; Walker-Loud, A

2018-06-01

The axial coupling of the nucleon, g A , is the strength of its coupling to the weak axial current of the standard model of particle physics, in much the same way as the electric charge is the strength of the coupling to the electromagnetic current. This axial coupling dictates the rate at which neutrons decay to protons, the strength of the attractive long-range force between nucleons and other features of nuclear physics. Precision tests of the standard model in nuclear environments require a quantitative understanding of nuclear physics that is rooted in quantum chromodynamics, a pillar of the standard model. The importance of g A makes it a benchmark quantity to determine theoretically-a difficult task because quantum chromodynamics is non-perturbative, precluding known analytical methods. Lattice quantum chromodynamics provides a rigorous, non-perturbative definition of quantum chromodynamics that can be implemented numerically. It has been estimated that a precision of two per cent would be possible by 2020 if two challenges are overcome 1,2 : contamination of g A from excited states must be controlled in the calculations and statistical precision must be improved markedly 2-10 . Here we use an unconventional method 11 inspired by the Feynman-Hellmann theorem that overcomes these challenges. We calculate a g A value of 1.271 ± 0.013, which has a precision of about one per cent.

Quantum Monte Carlo calculations of weak transitions in A = 6 – 10 nuclei

DOE PAGES

Pastore, S.; Baroni, A.; Carlson, J.; ...

2018-02-26

{\\it Ab initio} calculations of the Gamow-Teller (GT) matrix elements in themore » $$\\beta$$ decays of $^6$He and $$^{10}$$C and electron captures in $^7$Be are carried out using both variational and Green's function Monte Carlo wave functions obtained from the Argonne $$v_{18}$$ two-nucleon and Illinois-7 three-nucleon interactions, and axial many-body currents derived from either meson-exchange phenomenology or chiral effective field theory. The agreement with experimental data is excellent for the electron captures in $^7$Be, while theory overestimates the $^6$He and $$^{10}$$C data by $$\\sim 2\\%$$ and $$\\sim 10\\%$$, respectively. We show that for these systems correlations in the nuclear wave functions are crucial to explain the data, while many-body currents increase by $$\\sim 2$$--$$3\\%$$ the one-body GT contributions. These findings suggest that the longstanding $$g_A$$-problem, {\\it i.e.}, the systematic overprediction ($$\\sim 20 \\%$$ in $$A\\le 18$$ nuclei) of GT matrix elements in shell-model calculations, may be resolved, at least partially, by correlation effects.« less

New limit on possible long-range parity-odd interactions of the neutron from neutron-spin rotation in liquid 4He.

PubMed

Yan, H; Snow, W M

2013-02-22

Various theories beyond the standard model predict new particles with masses in the sub-eV range with very weak couplings to ordinary matter. A parity-odd interaction between polarized nucleons and unpolarized matter proportional to g(V)g(A)s · p is one such possibility, where s[over →] and p[over →] are the spin and the momentum of the polarized nucleon, and g(V) and g(A) are the vector and axial vector couplings of an interaction induced by the exchange of a new light vector boson. We report a new experimental upper bound on such possible long-range parity-odd interactions of the neutron with nucleons and electrons from a recent search for parity violation in neutron spin rotation in liquid ^{4}He. Our constraint on the product of vector and axial vector couplings of a possible new light vector boson is g(V) g(A)(n) ≤ 10(-32) for an interaction range of 1 m. This upper bound is more than 7 orders of magnitude more stringent than the existing laboratory constraints for interaction ranges below 1 m, corresponding to a broad range of vector boson masses above 10(-6) eV. More sensitive searches for a g(V) g(A)(n) coupling could be performed using neutron spin rotation measurements in heavy nuclei or through analysis of experiments conducted to search for nucleon-nucleon weak interactions and nuclear anapole moments.

Proton-Proton Fusion and Tritium β Decay from Lattice Quantum Chromodynamics

NASA Astrophysics Data System (ADS)

Savage, Martin J.; Shanahan, Phiala E.; Tiburzi, Brian C.; Wagman, Michael L.; Winter, Frank; Beane, Silas R.; Chang, Emmanuel; Davoudi, Zohreh; Detmold, William; Orginos, Kostas; Nplqcd Collaboration

2017-08-01

The nuclear matrix element determining the p p →d e+ν fusion cross section and the Gamow-Teller matrix element contributing to tritium β decay are calculated with lattice quantum chromodynamics for the first time. Using a new implementation of the background field method, these quantities are calculated at the SU(3) flavor-symmetric value of the quark masses, corresponding to a pion mass of mπ˜806 MeV . The Gamow-Teller matrix element in tritium is found to be 0.979(03)(10) at these quark masses, which is within 2 σ of the experimental value. Assuming that the short-distance correlated two-nucleon contributions to the matrix element (meson-exchange currents) depend only mildly on the quark masses, as seen for the analogous magnetic interactions, the calculated p p →d e+ν transition matrix element leads to a fusion cross section at the physical quark masses that is consistent with its currently accepted value. Moreover, the leading two-nucleon axial counterterm of pionless effective field theory is determined to be L1 ,A=3.9 (0.2 )(1.0 )(0.4 )(0.9 ) fm3 at a renormalization scale set by the physical pion mass, also agreeing within the accepted phenomenological range. This work concretely demonstrates that weak transition amplitudes in few-nucleon systems can be studied directly from the fundamental quark and gluon degrees of freedom and opens the way for subsequent investigations of many important quantities in nuclear physics.

Properties of nucleon resonances by means of a genetic algorithm

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

Fernandez-Ramirez, C.; Moya de Guerra, E.; Instituto de Estructura de la Materia, CSIC, Serrano 123, E-28006 Madrid

2008-06-15

We present an optimization scheme that employs a genetic algorithm (GA) to determine the properties of low-lying nucleon excitations within a realistic photo-pion production model based upon an effective Lagrangian. We show that with this modern optimization technique it is possible to reliably assess the parameters of the resonances and the associated error bars as well as to identify weaknesses in the models. To illustrate the problems the optimization process may encounter, we provide results obtained for the nucleon resonances {delta}(1230) and {delta}(1700). The former can be easily isolated and thus has been studied in depth, while the latter ismore » not as well known experimentally.« less

STATISTICAL CHARACTERISTICS OF ELEMENTAL ABUNDANCE RATIOS: OBSERVATIONS FROM THE ACE SPACECRAFT

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

Zhao, L.-L.; Zhang, H.

We statistically analyze the elemental galactic cosmic ray (GCR) composition measurements of elements 5 ≤ Z ≤ 28 within the energy range 30–500 MeV/nucleon from the CRIS instrument on board the ACE spacecraft in orbit about the L1 Lagrange point during the period from 1997 to 2014. Similarly to the last unusual solar minimum, the elevated elemental intensities of all heavy nuclei during the current weak solar maximum in 2014 are ∼40% higher than that of the previous solar maximum in 2002, which has been attributed to the weak modulation associated with low solar activity levels during the ongoing weakestmore » solar maximum since the dawn of space age. In addition, the abundance ratios of heavy nuclei with respect to elemental oxygen are generally independent of kinetic energy per nucleon in the energy region 60–200 MeV/nuc, in good agreement with previous experiments. Furthermore, the abundance ratios of most relatively abundant species, except carbon, exhibit considerable solar-cycle variation, which are obviously positively correlated with the sunspot numbers with about one-year time lag. We also find that the percentage variation of abundance ratios for most elements are approximately identical. These preliminary results provide valuable insights into the characteristics of elemental heavy nuclei composition and place new and significant constraints on future GCR heavy nuclei propagation and modulation models.« less

Is There Really a Spin Crisis?

NASA Astrophysics Data System (ADS)

Qing, Di; Chen, XiangSong; Su, WeiNing; Wang, Fan

1999-10-01

The matrix element of quark axial vector current is shown to be different from the nonrelativistic quark spin sum for a nucleon at rest. The nucleon spin content discovered in polarized deep inelastic scattering is shown to be accommodated in a constituent quark model with 15% sea quark component mixing. The relativistic correction and sea quark pair excitation inherently related to quark axial vector current reduce the nucleon axial charge and this reduction is compensated by the relativistic quark orbital angular momentum exactly and in turn keeps the nucleon spin 1/2 untouched. Nucleon tensor charge has similar but smaller relativistic and sea quark pair excitation reduction. The project supported in part by the NSF (19675018), SED and SSTD of China

Results on the Spin-Dependent Scattering of Weakly Interacting Massive Particles on Nucleons from the Run 3 Data of the LUX Experiment

NASA Astrophysics Data System (ADS)

Akerib, D. S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Bradley, A.; Bramante, R.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Chapman, J. J.; Chiller, A. A.; Chiller, C.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; de Viveiros, L.; Dobi, A.; Dobson, J. E. Y.; Druszkiewicz, E.; Edwards, B. N.; Faham, C. H.; Fiorucci, S.; Gaitskell, R. J.; Gehman, V. M.; Ghag, C.; Gibson, K. R.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Ihm, M.; Jacobsen, R. G.; Ji, W.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lee, C.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Malling, D. C.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Ott, R. A.; Palladino, K. J.; Pangilinan, M.; Pease, E. K.; Phelps, P.; Reichhart, L.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solovov, V. N.; Sorensen, P.; Stephenson, S.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Yazdani, K.; Young, S. K.; Zhang, C.; LUX Collaboration

2016-04-01

We present experimental constraints on the spin-dependent WIMP (weakly interacting massive particle)-nucleon elastic cross sections from LUX data acquired in 2013. LUX is a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility (Lead, South Dakota), which is designed to observe the recoil signature of galactic WIMPs scattering from xenon nuclei. A profile likelihood ratio analysis of 1.4 ×104 kg day of fiducial exposure allows 90% C.L. upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of σn=9.4 ×10-41 cm2 (σp=2.9 ×10-39 cm2 ) at 33 GeV /c2 . The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.

Quark-mass dependence of two-nucleon observables

NASA Astrophysics Data System (ADS)

Chen, Jiunn-Wei; Lee, Tze-Kei; Liu, C.-P.; Liu, Yu-Sheng

2012-11-01

We study the potential implications of lattice QCD determinations of the S-wave nucleon-nucleon scattering lengths with unphysical light quark masses. If the light quark masses are small enough such that nuclear effective field theory (NEFT) can be used to perform quark-mass extrapolations, then the leading quark-mass dependence of not only the effective range and the two-body current, but also all the low-energy deuteron matrix elements up to next-to-leading-order in NEFT can be obtained. As a proof of principle, we compute the quark-mass dependence of the deuteron charge radius, magnetic moment, polarizability, and the deuteron photodisintegration cross section using the lattice calculation of the scattering lengths at 354 MeV pion mass by the ``Nuclear Physics with Lattice QCD'' (NPLQCD) collaboration and the NEFT power counting scheme of Beane, Kaplan, and Vuorinen (BKV), even though it is not yet established that the 354 MeV pion mass is within the radius of convergence of the BKV scheme. Once the lattice result with quark mass within the NEFT radius of convergence is obtained, our observation can be used to constrain the time variation of isoscalar combination of u and d quark mass mq, to help the anthropic principle study to find the mq range that allows the existence of life, and to provide a weak test of the multiverse conjecture.

The quest for novel modes of excitation in exotic nuclei

NASA Astrophysics Data System (ADS)

Paar, N.

2010-06-01

This paper provides an insight into several open problems in the quest for novel modes of excitation in nuclei with isospin asymmetry, deformation and finite-temperature characteristics in stellar environments. Major unsolved problems include the nature of pygmy dipole resonances, the quest for various multipole and spin-isospin excitations both in neutron-rich and proton drip-line nuclei mainly driven by loosely bound nucleons, excitations in unstable deformed nuclei and evolution of their properties with the shape phase transition. Exotic modes of excitation in nuclei at finite temperatures characteristic of supernova evolution present open problems with a possible impact in modeling astrophysically relevant weak interaction rates. All these issues challenge self-consistent many-body theory frameworks at the frontiers of on-going research, including nuclear energy density functionals, both phenomenological and constrained by the strong interaction physics of QCD, models based on low-momentum two-nucleon interaction Vlow-k and correlated realistic nucleon-nucleon interaction VUCOM, supplemented by three-body force, as well as two-nucleon and three-nucleon interactions derived from the chiral effective field theory. Joined theoretical and experimental efforts, including research with radioactive isotope beams, are needed to provide insight into dynamical properties of nuclei away from the valley of stability, involving the interplay of isospin asymmetry, deformation and finite temperature.

Results on the Spin-Dependent Scattering of Weakly Interacting Massive Particles on Nucleons from the Run 3 Data of the LUX Experiment.

PubMed

Akerib, D S; Araújo, H M; Bai, X; Bailey, A J; Balajthy, J; Beltrame, P; Bernard, E P; Bernstein, A; Biesiadzinski, T P; Boulton, E M; Bradley, A; Bramante, R; Cahn, S B; Carmona-Benitez, M C; Chan, C; Chapman, J J; Chiller, A A; Chiller, C; Currie, A; Cutter, J E; Davison, T J R; de Viveiros, L; Dobi, A; Dobson, J E Y; Druszkiewicz, E; Edwards, B N; Faham, C H; Fiorucci, S; Gaitskell, R J; Gehman, V M; Ghag, C; Gibson, K R; Gilchriese, M G D; Hall, C R; Hanhardt, M; Haselschwardt, S J; Hertel, S A; Hogan, D P; Horn, M; Huang, D Q; Ignarra, C M; Ihm, M; Jacobsen, R G; Ji, W; Kazkaz, K; Khaitan, D; Knoche, R; Larsen, N A; Lee, C; Lenardo, B G; Lesko, K T; Lindote, A; Lopes, M I; Malling, D C; Manalaysay, A; Mannino, R L; Marzioni, M F; McKinsey, D N; Mei, D-M; Mock, J; Moongweluwan, M; Morad, J A; Murphy, A St J; Nehrkorn, C; Nelson, H N; Neves, F; O'Sullivan, K; Oliver-Mallory, K C; Ott, R A; Palladino, K J; Pangilinan, M; Pease, E K; Phelps, P; Reichhart, L; Rhyne, C; Shaw, S; Shutt, T A; Silva, C; Solovov, V N; Sorensen, P; Stephenson, S; Sumner, T J; Szydagis, M; Taylor, D J; Taylor, W; Tennyson, B P; Terman, P A; Tiedt, D R; To, W H; Tripathi, M; Tvrznikova, L; Uvarov, S; Verbus, J R; Webb, R C; White, J T; Whitis, T J; Witherell, M S; Wolfs, F L H; Yazdani, K; Young, S K; Zhang, C

2016-04-22

We present experimental constraints on the spin-dependent WIMP (weakly interacting massive particle)-nucleon elastic cross sections from LUX data acquired in 2013. LUX is a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility (Lead, South Dakota), which is designed to observe the recoil signature of galactic WIMPs scattering from xenon nuclei. A profile likelihood ratio analysis of 1.4×10^{4}  kg day of fiducial exposure allows 90% C.L. upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of σ_{n}=9.4×10^{-41}  cm^{2} (σ_{p}=2.9×10^{-39}  cm^{2}) at 33  GeV/c^{2}. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.

Results on the spin-dependent scattering of weakly interacting massive particles on nucleons from the Run 3 Data of the LUX Experiment

DOE PAGES

Akerib, D. S.

2016-04-20

Here, we present experimental constraints on the spin-dependent WIMP (weakly interacting massive particle)-nucleon elastic cross sections from LUX data acquired in 2013. LUX is a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility (Lead, South Dakota), which is designed to observe the recoil signature of galactic WIMPs scattering from xenon nuclei. A profile likelihood ratio analysis of 1.4 × 10 4 kg day of fiducial exposure allows 90% C.L. upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of σ n = 9.4 × 10 –41 cm 2 (σ p = 2.9 × 10more » –39 cm 2) at 33 GeV/c 2. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.« less

Novel Soft-Pion Theorem for Long-Range Nuclear Parity Violation.

PubMed

Feng, Xu; Guo, Feng-Kun; Seng, Chien-Yeah

2018-05-04

The parity-odd effect in the standard model weak neutral current reveals itself in the long-range parity-violating nuclear potential generated by the pion exchanges in the ΔI=1 channel with the parity-odd pion-nucleon coupling constant h_{π}^{1}. Despite decades of experimental and theoretical efforts, the size of this coupling constant is still not well understood. In this Letter, we derive a soft-pion theorem relating h_{π}^{1} and the neutron-proton mass splitting induced by an artificial parity-even counterpart of the ΔI=1 weak Lagrangian and demonstrate that the theorem still holds exact at the next-to-leading order in the chiral perturbation theory. A considerable amount of simplification is expected in the study of h_{π}^{1} by using either lattice or other QCD models following its reduction from a parity-odd proton-neutron-pion matrix element to a simpler spectroscopic quantity. The theorem paves the way to much more precise calculations of h_{π}^{1}, and thus a quantitative test of the strangeness-conserving neutral current interaction of the standard model is foreseen.

Novel Soft-Pion Theorem for Long-Range Nuclear Parity Violation

NASA Astrophysics Data System (ADS)

Feng, Xu; Guo, Feng-Kun; Seng, Chien-Yeah

2018-05-01

The parity-odd effect in the standard model weak neutral current reveals itself in the long-range parity-violating nuclear potential generated by the pion exchanges in the Δ I =1 channel with the parity-odd pion-nucleon coupling constant hπ1 . Despite decades of experimental and theoretical efforts, the size of this coupling constant is still not well understood. In this Letter, we derive a soft-pion theorem relating hπ1 and the neutron-proton mass splitting induced by an artificial parity-even counterpart of the Δ I =1 weak Lagrangian and demonstrate that the theorem still holds exact at the next-to-leading order in the chiral perturbation theory. A considerable amount of simplification is expected in the study of hπ1 by using either lattice or other QCD models following its reduction from a parity-odd proton-neutron-pion matrix element to a simpler spectroscopic quantity. The theorem paves the way to much more precise calculations of hπ1, and thus a quantitative test of the strangeness-conserving neutral current interaction of the standard model is foreseen.

Vector and Axial Form Factors Applied to Neutrino Quasielastic Scattering

NASA Astrophysics Data System (ADS)

Budd, H.; Bodek, A.; Arrington, J.

2005-02-01

We calculate the quasielastic cross sections for neutrino scattering on nucleons using up to date fits to the nucleon elastic electromagnetic form factors GEp, GEn, GMp, GMn, and weak form factors. We show the extraction of F(q). We show the that F(q) has a different contribution to the anti-neutrino cross section, and how the anti-neutrino data can be used to check F(q) extracted from neutrino scattering. (Presented by Howard Budd at NuInt04, Mar. 2004, Laboratori Nazionali del Gran Sasso - INFN - Assergi, Italy [ http://nuint04.lngs.infn.it/])

Search for Dark Matter Interactions using Ionization Yield in Liquid Xenon

NASA Astrophysics Data System (ADS)

Uvarov, Sergey

Cosmological observations overwhelmingly support the existence of dark matter which constitutes 87% of the universe's total mass. Weakly Interacting Massive Particles (WIMPs) are a prime candidate for dark matter, and the Large Underground Xenon (LUX) experiment aims to a direct-detection of a WIMP-nucleon interaction. The LUX detector is a dual-phase xenon time-projection chamber housed 4,850 feet underground at Sanford Underground Research Facility in Lead, South Dakota. We present the ionization-only analysis of the LUX 2013 WIMP search data. In the 1.04 x 104 kg-days exposure, thirty events were observed out of the 24.8 expected from radioactive backgrounds. We employ a cut-and-count method to set a 1-sided 90% C.L. upper limit for spin-independent WIMP-nucleon cross-sections. A zero charge yield for nuclear-recoils below 0.7 keV is included upper limit calculation. This ionization-only analysis excludes an unexplored region of WIMP-nucleon cross-section for low-mass WIMPs achieving 1.56 x 10-43 cm2 WIMP-nucleon cross-section exclusion for a 5.1 GeV/ c2 WIMP.

Probing Low-Mass Vector Bosons with Parity Nonconservation and Nuclear Anapole Moment Measurements in Atoms and Molecules

NASA Astrophysics Data System (ADS)

Dzuba, V. A.; Flambaum, V. V.; Stadnik, Y. V.

2017-12-01

In the presence of P -violating interactions, the exchange of vector bosons between electrons and nucleons induces parity-nonconserving (PNC) effects in atoms and molecules, while the exchange of vector bosons between nucleons induces anapole moments of nuclei. We perform calculations of such vector-mediated PNC effects in Cs, Ba+ , Yb, Tl, Fr, and Ra+ using the same relativistic many-body approaches as in earlier calculations of standard-model PNC effects, but with the long-range operator of the weak interaction. We calculate nuclear anapole moments due to vector-boson exchange using a simple nuclear model. From measured and predicted (within the standard model) values for the PNC amplitudes in Cs, Yb, and Tl, as well as the nuclear anapole moment of 133Cs, we constrain the P -violating vector-pseudovector nucleon-electron and nucleon-proton interactions mediated by a generic vector boson of arbitrary mass. Our limits improve on existing bounds from other experiments by many orders of magnitude over a very large range of vector-boson masses.

Systematics of intermediate-energy single-nucleon removal cross sections

NASA Astrophysics Data System (ADS)

Tostevin, J. A.; Gade, A.

2014-11-01

There is now a large and increasing body of experimental data and theoretical analyses for reactions that remove a single nucleon from an intermediate-energy beam of neutron- or proton-rich nuclei. In each such measurement, one obtains the inclusive cross section for the population of all bound final states of the mass A -1 reaction residue. These data, from different regions of the nuclear chart, and that involve weakly and strongly bound nucleons, are compared with theoretical expectations. These calculations include an approximate treatment of the reaction dynamics and shell-model descriptions of the projectile initial state, the bound final states of the residues, and the single-particle strengths computed from their overlap functions. The results are discussed in the light of recent data, more exclusive tests of the eikonal dynamical description, and calculations that take input from more microscopic nuclear structure models.

Roy-Steiner-equation analysis of pion-nucleon scattering

NASA Astrophysics Data System (ADS)

Meißner, U.-G.; Ruiz de Elvira, J.; Hoferichter, M.; Kubis, B.

2017-03-01

Low-energy pion-nucleon scattering is relevant for many areas in nuclear and hadronic physics, ranging from the scalar couplings of the nucleon to the long-range part of two-pion-exchange potentials and three-nucleon forces in Chiral Effective Field Theory. In this talk, we show how the fruitful combination of dispersion-theoretical methods, in particular in the form of Roy-Steiner equations, with modern high-precision data on hadronic atoms allows one to determine the pion-nucleon scattering amplitudes at low energies with unprecedented accuracy. Special attention will be paid to the extraction of the pion-nucleon σ-term, and we discuss in detail the current tension with recent lattice results, as well as the determination of the low-energy constants of chiral perturbation theory.

Nucleon-Nucleon Total Cross Section

NASA Technical Reports Server (NTRS)

Norbury, John W.

2008-01-01

The total proton-proton and neutron-proton cross sections currently used in the transport code HZETRN show significant disagreement with experiment in the GeV and EeV energy ranges. The GeV range is near the region of maximum cosmic ray intensity. It is therefore important to correct these cross sections, so that predictions of space radiation environments will be accurate. Parameterizations of nucleon-nucleon total cross sections are developed which are accurate over the entire energy range of the cosmic ray spectrum.

On the Relativistic Separable Functions for the Breakup Reactions

NASA Astrophysics Data System (ADS)

Bondarenko, Serge G.; Burov, Valery V.; Rogochaya, Elena P.

2018-02-01

In the paper the so-called modified Yamaguchi function for the Bethe-Salpeter equation with a separable kernel is discussed. The type of the functions is defined by the analytic stucture of the hadron current with breakup - the reactions with interacting nucleon-nucleon pair in the final state (electro-, photo-, and nucleon-disintegration of the deuteron).

Polarized lepton-nucleon elastic scattering and a search for a light scalar boson

NASA Astrophysics Data System (ADS)

Liu, Yu-Sheng; Miller, Gerald A.

2015-09-01

Lepton-nucleon elastic scattering, using the one-photon and one-scalar-boson exchange mechanisms considering all possible polarizations, is used to study searches for a new scalar boson and suggest new measurements of the nucleon form factors. A new light scalar boson, which feebly couples to leptons and nucleons, may account for the proton radius and muon g -2 puzzles. We show that the scalar boson produces relatively large effects in a certain kinematic region when using sufficient control of lepton and nucleon spin polarization. We generalize current techniques to measure the ratio GE:GM and present a new method to separately measure GM2 and GE2 using polarized incoming and outgoing muons.

The Ultimate Structure of Matter: The High Energy Physics Program from the 1950s through the 1980s

DOE R&D Accomplishments Database

1990-02-01

This discusses the following topics in High Energy Physics: The Particle Zoo; The Strong and the Weak; The Particle Explosion; Deep Inside the Nucleon; The Search for Unity; Physics in Collision; The Standard Model; Particles and the Cosmos; and Practical Benefits.

Occurrence and Characteristics of {sup 18}O-exchange Reactions Catalyzed By Sodium- and Potassium-dependent Adenosine Triphosphatases

DOE R&D Accomplishments Database

Dahms, A. S.; Boyer, P. D.

This discusses the following topics in High Energy Physics: The Particle Zoo; The Strong and the Weak; The Particle Explosion; Deep Inside the Nucleon; The Search for Unity; Physics in Collision; The Standard Model; Particles and the Cosmos; and Practical Benefits.

Study of the charge dependence of the pion–nucleon coupling constant on the basis of data on low-energy nucleon–nucleon interactions

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

Babenko, V. A.; Petrov, N. M., E-mail: pet2@ukr.net

2016-01-15

The relation between quantities that characterize the pion–nucleon and nucleon–nucleon interactions is studied with allowance for the fact that, at low energies, nuclear forces in nucleon–nucleon systems are mediated predominantly by one-pion exchange. On the basis of the values currently recommended for the low-energy parameters of the proton–proton interaction, the charged pion–nucleon coupling constant is evaluated at g{sub π}{sup 2}±/4π = 14.55(13). This value is in perfect agreement with the experimental value of g{sub π}{sup 2}±/4π = 14.52(26) found by the Uppsala Neutron Research Group. At the same time, the value obtained for the charged pion–nucleon coupling constant differs sizablymore » from the value of the pion–nucleon coupling constant for neutral pions, which is g{sub π}{sup 2} 0/4π = 13.55(13). This is indicative of a substantial charge dependence of the coupling constant.« less

Axions from 1987A

NASA Technical Reports Server (NTRS)

Turner, Michael S.

1988-01-01

The process of axion emission from SN 1987A by nucleon-nucleon axion bremsstrahlung is investigated based on neutrino observations. The results indicate that the axion luminosity must be less than about 10 to the 53rd erg/s if: (1) axions couple very weakly (with an axion mass of less than about 0.75 x 10 to the -3rd); or (2) axions couple strongly enough to be trapped and radiated from an axion sphere with T sub a of less than about 8 MeV (with an axion mass of greater than about 2.2 eV). Axion trapping is found to occur for axion masses of greater than about 0.016 eV.

New formula of Nuclear Force

NASA Astrophysics Data System (ADS)

Uddin, Kamal

2011-04-01

It is well established that the forces between nucleons are transmitted by meson. The quantitative explanation of nuclear forces in terms of meson theory was extremely tentative & in complete but this theory supplies a valuable point of view . it is fairly certain now that the nucleons within nuclear matter are in a state made rather different from their free condition by the proximity of other nucleons charge independence of nuclear forces demand the existence of neutral meson as amongst the same type of nucleolus (P-P) or (N-N). this force demand the same spin & orbital angular momentum. The exchange interaction in produced by only a neutral meson. The involving mesons without electric charge, that it gives exchanges forces between proton & Neutron & also therefore maintains charge in dependence character. It is evident for the nature of the products that neutral mesons decay by strong & weak interaction both. It means that neutral mesons constituents responsible for the electromagnetic interaction. Dramatically neutral mesons plays important role for electromagnetic & nuclear force both.

The parity-violating asymmetry in the 3He(n,p)3H reaction

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

M. Viviani, R. Schiavilla, L. Girlanda, A. Kievsky, L.E. Marcucci

2010-10-01

The longitudinal asymmetry induced by parity-violating (PV) components in the nucleon-nucleon potential is studied in the charge-exchange reaction 3He(n,p)3H at vanishing incident neutron energies. An expression for the PV observable is derived in terms of T-matrix elements for transitions from the {2S+1}L_J=1S_0 and 3S_1 states in the incoming n-3He channel to states with J=0 and 1 in the outgoing p-3H channel. The T-matrix elements involving PV transitions are obtained in first-order perturbation theory in the hadronic weak-interaction potential, while those connecting states of the same parity are derived from solutions of the strong-interaction Hamiltonian with the hyperspherical-harmonics method. The coupled-channelmore » nature of the scattering problem is fully accounted for. Results are obtained corresponding to realistic or chiral two- and three-nucleon strong-interaction potentials in combination with either the DDH or pionless EFT model for the weak-interaction potential. The asymmetries, predicted with PV pion and vector-meson coupling constants corresponding (essentially) to the DDH "best values" set, range from -9.44 to -2.48 in units of 10^{-8}, depending on the input strong-interaction Hamiltonian. This large model dependence is a consequence of cancellations between long-range (pion) and short-range (vector-meson) contributions, and is of course sensitive to the assumed values for the PV coupling constants.« less

CORE-COLLAPSE SUPERNOVA EQUATIONS OF STATE BASED ON NEUTRON STAR OBSERVATIONS

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

Steiner, A. W.; Hempel, M.; Fischer, T.

2013-09-01

Many of the currently available equations of state for core-collapse supernova simulations give large neutron star radii and do not provide large enough neutron star masses, both of which are inconsistent with some recent neutron star observations. In addition, one of the critical uncertainties in the nucleon-nucleon interaction, the nuclear symmetry energy, is not fully explored by the currently available equations of state. In this article, we construct two new equations of state which match recent neutron star observations and provide more flexibility in studying the dependence on nuclear matter properties. The equations of state are also provided in tabularmore » form, covering a wide range in density, temperature, and asymmetry, suitable for astrophysical simulations. These new equations of state are implemented into our spherically symmetric core-collapse supernova model, which is based on general relativistic radiation hydrodynamics with three-flavor Boltzmann neutrino transport. The results are compared with commonly used equations of state in supernova simulations of 11.2 and 40 M{sub Sun} progenitors. We consider only equations of state which are fitted to nuclear binding energies and other experimental and observational constraints. We find that central densities at bounce are weakly correlated with L and that there is a moderate influence of the symmetry energy on the evolution of the electron fraction. The new models also obey the previously observed correlation between the time to black hole formation and the maximum mass of an s = 4 neutron star.« less

Nucleon QCD sum rules in the instanton medium

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

Ryskin, M. G.; Drukarev, E. G., E-mail: drukarev@pnpi.spb.ru; Sadovnikova, V. A.

2015-09-15

We try to find grounds for the standard nucleon QCD sum rules, based on a more detailed description of the QCD vacuum. We calculate the polarization operator of the nucleon current in the instanton medium. The medium (QCD vacuum) is assumed to be a composition of the small-size instantons and some long-wave gluon fluctuations. We solve the corresponding QCD sum rule equations and demonstrate that there is a solution with the value of the nucleon mass close to the physical one if the fraction of the small-size instantons contribution is w{sub s} ≈ 2/3.

Evaluating nuclear physics inputs in core-collapse supernova models

NASA Astrophysics Data System (ADS)

Lentz, E.; Hix, W. R.; Baird, M. L.; Messer, O. E. B.; Mezzacappa, A.

Core-collapse supernova models depend on the details of the nuclear and weak interaction physics inputs just as they depend on the details of the macroscopic physics (transport, hydrodynamics, etc.), numerical methods, and progenitors. We present preliminary results from our ongoing comparison studies of nuclear and weak interaction physics inputs to core collapse supernova models using the spherically-symmetric, general relativistic, neutrino radiation hydrodynamics code Agile-Boltztran. We focus on comparisons of the effects of the nuclear EoS and the effects of improving the opacities, particularly neutrino--nucleon interactions.

Determination of the axial-vector weak coupling constant with ultracold neutrons.

PubMed

Liu, J; Mendenhall, M P; Holley, A T; Back, H O; Bowles, T J; Broussard, L J; Carr, R; Clayton, S; Currie, S; Filippone, B W; García, A; Geltenbort, P; Hickerson, K P; Hoagland, J; Hogan, G E; Hona, B; Ito, T M; Liu, C-Y; Makela, M; Mammei, R R; Martin, J W; Melconian, D; Morris, C L; Pattie, R W; Pérez Galván, A; Pitt, M L; Plaster, B; Ramsey, J C; Rios, R; Russell, R; Saunders, A; Seestrom, S J; Sondheim, W E; Tatar, E; Vogelaar, R B; VornDick, B; Wrede, C; Yan, H; Young, A R

2010-10-29

A precise measurement of the neutron decay β asymmetry A₀ has been carried out using polarized ultracold neutrons from the pulsed spallation ultracold neutron source at the Los Alamos Neutron Science Center. Combining data obtained in 2008 and 2009, we report A₀ = -0.119 66±0.000 89{-0.001 40}{+0.001 23}, from which we determine the ratio of the axial-vector to vector weak coupling of the nucleon g{A}/g{V}=-1.275 90{-0.004 45}{+0.004 09}.

How strange is pion electroproduction?

DOE PAGES

Gorchtein, Mikhail; Spiesberger, Hubert; Zhang, Xilin

2015-11-18

We consider pion production in parity-violating electron scattering (PVES) in the presence of nucleon strangeness in the framework of partial wave analysis with unitarity. Using the experimental bounds on the strange form factors obtained in elastic PVES, we study the sensitivity of the parity-violating asymmetry to strange nucleon form factors. For forward kinematics and electron energies above 1 GeV, we observe that this sensitivity may reach about 20% in the threshold region. With parity-violating asymmetries being as large as tens p.p.m., this study suggests that threshold pion production in PVES can be used as a promising way to better constrainmore » strangeness contributions. Using this model for the neutral current pion production, we update the estimate for the dispersive γZ-box correction to the weak charge of the proton. In the kinematics of the Qweak experiment, our new prediction reads Re V γZ(E = 1.165 GeV) = (5.58 ±1.41) ×10 –3, an improvement over the previous uncertainty estimate of ±2.0 ×10 –3. Our new prediction in the kinematics of the upcoming MESA/P2 experiment reads Re V γZ(E = 0.155 GeV) = (1.1 ±0.2) ×10 –3.« less

Recent QCD Results from NuTeV/CCFR Collaboration

NASA Astrophysics Data System (ADS)

Adams, T.; Alton, A.; Arroyo, C. G.; Avvakumov, S.; de Barbaro, L.; de Barbaro, P.; Bazarko, A. O.; Bernstein, R. H.; Bodek, A.; Bolton, T.; Brau, J.; Buchholz, D.; Budd, H.; Bugel, L.; Conrad, J. M.; Drucker, R. B.; Formaggio, J. A.; Frey, R.; Goldman, J.; Goncharov, M.; Harris, D. A.; Johnson, R. A.; Kim, J. H.; King, B. J.; Kinnel, T.; Koutsoliotas, S.; Lamm, M. J.; Marsh, W.; Mason, D.; McFarland, K. S.; McNulty, C.; Mishra, S. R.; Naples, D.; Nienaber, P.; Romosan, A.; Sakumoto, W. K.; Schellman, H. M.; Sculli, F. J.; Seligman, W. G.; Shaevitz, M. H.; Smith, W. H.; Spentzouris, P.; Stern, E. G.; Tamminga, B. M.; Vakili, M.; Vaitaitis, A.; Wu, V.; Yang, U. K.; Yu, J.; Zeller, G. P.

2000-06-01

Fermilab experiments CCFR and its successor NuTeV study nucleon structure through deep inelastic scattering of neutrino beams off an iron target. We report on the most recent CCFR measurement of the νN differential cross section and resulting structure functions ΔxF 3 = xF ν3 - xF overlineν3, and R long = {σ L}/{σ T}, in the framework of massive charm quark. ΔxF3 in sensitive to strange and charm content of the nucleon. NuTeV's preliminary direct measurement of the strange sea, from dimuon charged-current production, and nucleon charm content probed by neutral-current νN interaction, are also presented.

Weak production of strange particles and η mesons off the nucleon

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

Alam, M. Rafi; Athar, M. Sajjad; Simo, I. Ruiz

2015-10-15

The strange particle production induced by (anti)neutrino off nucleon has been studied for |ΔS| = 0 and |ΔS| = 1 channels. The reactions those we have considered are for the production of single kaon/antikaon, eta and associated particle production processes. We have developed a microscopical model based on the SU(3) chiral Lagrangian. The basic parameters of the model are f{sub π}, the pion decay constant, Cabibbo angle, the proton and neutron magnetic moments and the axial vector coupling constants for the baryons octet. For antikaon production we have also included Σ*(1385) resonance and for eta production S{sub 11}(1535) and S{submore » 11}(1650) resonances are included.« less

Study of the Hyperon-Nucleon Interaction in Exclusive Λ Photoproduction off the Deuteron

NASA Astrophysics Data System (ADS)

Zachariou, Nicholas; CLAS Collaboration

2014-09-01

Understanding the nature of the nuclear force in terms of the fundamental degrees of freedom of the theory of strong interaction, Quantum Chromodynamics (QCD), is one of the primary goals of modern nuclear physics. While the nucleon-nucleon (NN) interaction has been studied for decades, a systematic description of the NN potential has been achieved only recently with the development of low-energy Effective Field Theories (EFT). To obtain a comprehensive understanding of the strong interaction, dynamics involving strange baryons must be studied. Currently, little is known about the properties of the hyperon-nucleon (YN) and the hyperon-hyperon (YY) interactions. In this talk I will describe our current research of the Λn interaction using the E06-103 experiment performed with the CLAS detector in Hall B at Jefferson Lab. The large kinematic coverage of the CLAS combined with the exceptionally high quality of the experimental data allows to identify and select final-state interaction events in the reaction γd -->K+ Λn and to establish their kinematical dependencies. The large set of observables we aim to obtain will provide tight constraints on modern YN potentials. I will present the current status of the project and will discuss future incentives. Understanding the nature of the nuclear force in terms of the fundamental degrees of freedom of the theory of strong interaction, Quantum Chromodynamics (QCD), is one of the primary goals of modern nuclear physics. While the nucleon-nucleon (NN) interaction has been studied for decades, a systematic description of the NN potential has been achieved only recently with the development of low-energy Effective Field Theories (EFT). To obtain a comprehensive understanding of the strong interaction, dynamics involving strange baryons must be studied. Currently, little is known about the properties of the hyperon-nucleon (YN) and the hyperon-hyperon (YY) interactions. In this talk I will describe our current research of the Λn interaction using the E06-103 experiment performed with the CLAS detector in Hall B at Jefferson Lab. The large kinematic coverage of the CLAS combined with the exceptionally high quality of the experimental data allows to identify and select final-state interaction events in the reaction γd -->K+ Λn and to establish their kinematical dependencies. The large set of observables we aim to obtain will provide tight constraints on modern YN potentials. I will present the current status of the project and will discuss future incentives. for the CLAS Collaboration.

Direct dark matter detection with the DarkSide-50 experiment

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

Pagani, Luca

2017-01-01

The existence of dark matter is known because of its gravitational effects, and although its nature remains undisclosed, there is a growing indication that the galactic halo could be permeated by weakly interacting massive particles (WIMPs) with mass of the order ofmore » $100$$\\,GeV/c$$^2$ and coupling with ordinary matter at or below the weak scale. In this context, DarkSide-50 aims to direct observe WIMP-nucleon collisions in a liquid argon dual phase time-projection chamber located deep underground at Gran Sasso National Laboratory, in Italy. In this work a re-analysis of the data that led to the best limit on WIMP-nucleon cross section with an argon target is done. As starting point of the new approach, the energy reconstruction of events is considered: a new energy variable is developed where anti-correlation between ionization and scintillation produced by an interaction is taken into account. As first result, a better energy resolution is achieved. In this new energy framewor k, access is granted to micro-physics parameters fundamental to argon scintillation such as the recombination and quenching as a function of the energy. The improved knowledge of recombination and quenching allows to develop a new model for distinguish between events possibly due to WIMPs and backgrounds. In light of the new model, the final result of this work is a more stringent limit on spin independent WIMP-nucleon cross section with an argon target. This work was supervised by Marco Pallavicini and was completed in collaboration with members of the DarkSide collaboration.« less

Measurement of the neutrino neutral-current elastic differential cross section on mineral oil at Eν˜1GeV

NASA Astrophysics Data System (ADS)

Aguilar-Arevalo, A. A.; Anderson, C. E.; Bazarko, A. O.; Brice, S. J.; Brown, B. C.; Bugel, L.; Cao, J.; Coney, L.; Conrad, J. M.; Cox, D. C.; Curioni, A.; Dharmapalan, R.; Djurcic, Z.; Finley, D. A.; Fleming, B. T.; Ford, R.; Garcia, F. G.; Garvey, G. T.; Grange, J.; Green, C.; Green, J. A.; Hart, T. L.; Hawker, E.; Imlay, R.; Johnson, R. A.; Karagiorgi, G.; Kasper, P.; Katori, T.; Kobilarcik, T.; Kourbanis, I.; Koutsoliotas, S.; Laird, E. M.; Linden, S. K.; Link, J. M.; Liu, Y.; Liu, Y.; Louis, W. C.; Mahn, K. B. M.; Marsh, W.; Mauger, C.; McGary, V. T.; McGregor, G.; Metcalf, W.; Meyers, P. D.; Mills, F.; Mills, G. B.; Monroe, J.; Moore, C. D.; Mousseau, J.; Nelson, R. H.; Nienaber, P.; Nowak, J. A.; Osmanov, B.; Ouedraogo, S.; Patterson, R. B.; Pavlovic, Z.; Perevalov, D.; Polly, C. C.; Prebys, E.; Raaf, J. L.; Ray, H.; Roe, B. P.; Russell, A. D.; Sandberg, V.; Schirato, R.; Schmitz, D.; Shaevitz, M. H.; Shoemaker, F. C.; Smith, D.; Soderberg, M.; Sorel, M.; Spentzouris, P.; Spitz, J.; Stancu, I.; Stefanski, R. J.; Sung, M.; Tanaka, H. A.; Tayloe, R.; Tzanov, M.; van de Water, R. G.; Wascko, M. O.; White, D. H.; Wilking, M. J.; Yang, H. J.; Zeller, G. P.; Zimmerman, E. D.

2010-11-01

We report a measurement of the flux-averaged neutral-current elastic differential cross section for neutrinos scattering on mineral oil (CH2) as a function of four-momentum transferred squared, Q2. It is obtained by measuring the kinematics of recoiling nucleons with kinetic energy greater than 50 MeV which are readily detected in MiniBooNE. This differential cross-section distribution is fit with fixed nucleon form factors apart from an axial mass MA that provides a best fit for MA=1.39±0.11GeV. Using the data from the charged-current neutrino interaction sample, a ratio of neutral-current to charged-current quasielastic cross sections as a function of Q2 has been measured. Additionally, single protons with kinetic energies above 350 MeV can be distinguished from neutrons and multiple nucleon events. Using this marker, the strange quark contribution to the neutral-current axial vector form factor at Q2=0, Δs, is found to be Δs=0.08±0.26.

Electromagnetic Structure of A=2 and 3 Nuclei and the Nuclear Current Operator

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

Rocco Schiavilla

Different models for conserved two- and three-body electromagnetic currents are constructed from two- and three-nucleon interactions, using either meson-exchange mechanisms or minimal substitution in the momentum dependence of these interactions. The connection between these two different schemes is elucidated. A number of low-energy electronuclear observables, including (i) np radiative capture at thermal neutron energies and deuteron photodisintegration at low energies, (ii) nd and pd radiative capture reactions, and (iii) isoscalar and isovector magnetic form factors of {sup 3}H and {sup 3}He, are calculated in order to make a comparative study of these models for the current operator. The realistic Argonnemore » v{sub 18} two-nucleon and Urbana IX or Tucson-Melbourne three-nucleon interactions are taken as a case study. For A=3 processes, the bound and continuum wave functions, both below and above deuteron breakup threshold, are obtained with the correlated hyperspherical-harmonics method. Three-body currents give small but significant contributions to some of the polarization observables in the {sup 2}H(p,{gamma}){sup 3}He process and the {sup 2}H(n,{gamma}){sup 3}H cross section at thermal neutron energies. It is shown that the use of a current which did not exactly satisfy current conservation with the two- and three-nucleon interactions in the Hamiltonian was responsible for some of the discrepancies reported in previous studies between the experimental and theoretical polarization observables in pd radiative capture.« less

Studies of the nucleon structure in back-to-back SIDIS

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

Avakian, Harut

2016-03-01

The Deep Inelastic Scattering (DIS) proved to be a great tool in testing of the theory of strong interactions, which was a major focus in last decades. Semi-Inclusive DIS (SIDIS), with detection of an additional hadron allowed first studies of 3D structure of the nucleon, moving the main focus from testing the QCD to understanding of strong interactions and quark gluon dynamics to address a number of puzzles accumulated in recent years. Detection of two hadrons in SIDIS, which is even more complicated, provides access to details of quark gluon interactions inaccessible in single-hadron SIDIS, providing a new avenue tomore » study the complex nucleon structure. Large acceptance of the Electron Ion Collider, allowing detection of two hadrons, produced back-to-back in the current and target fragmentation regions, combined with clear separation of two regions, would provide a unique possibility to study the nucleon structure in target fragmentation region, and correlations of target and current fragmentation regions.« less

Global limits and interference patterns in dark matter direct detection

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

Catena, Riccardo; Gondolo, Paolo

2015-08-13

We compare the general effective theory of one-body dark matter nucleon interactions to current direct detection experiments in a global multidimensional statistical analysis. We derive exclusion limits on the 28 isoscalar and isovector coupling constants of the theory, and show that current data place interesting constraints on dark matter-nucleon interaction operators usually neglected in this context. We characterize the interference patterns that can arise in dark matter direct detection from pairs of dark matter-nucleon interaction operators, or from isoscalar and isovector components of the same operator. We find that commonly neglected destructive interference effects weaken standard direct detection exclusion limitsmore » by up to one order of magnitude in the coupling constants.« less

Global limits and interference patterns in dark matter direct detection

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

Catena, Riccardo; Gondolo, Paolo, E-mail: riccardo.catena@theorie.physik.uni-goettingen.de, E-mail: paolo.gondolo@utah.edu

2015-08-01

We compare the general effective theory of one-body dark matter nucleon interactions to current direct detection experiments in a global multidimensional statistical analysis. We derive exclusion limits on the 28 isoscalar and isovector coupling constants of the theory, and show that current data place interesting constraints on dark matter-nucleon interaction operators usually neglected in this context. We characterize the interference patterns that can arise in dark matter direct detection from pairs of dark matter-nucleon interaction operators, or from isoscalar and isovector components of the same operator. We find that commonly neglected destructive interference effects weaken standard direct detection exclusion limitsmore » by up to one order of magnitude in the coupling constants.« less

Quiet-time properties of low-energy (less than 10 MeV per nucleon) interplanetary ions during solar maximum and solar minimum

NASA Technical Reports Server (NTRS)

Richardson, I. G.; Reames, D. V.; Wenzel, K.-P.; Rodriguez-Pacheco, J.

1990-01-01

The abundances and spectra of 1-10 MeV per nucleon protons, He-3, He-4, C, O, and Fe have been exmained during solar quiet periods from 1978 to 1987 in an effort to investigate the recent suggestion by Wenzel et al. (1990) that the ions may be of solar origin. It is found that the intensities of the ions, other than O, fall by an order of magnitude between solar maximum and solar minimum, and that the greater than 1 MeV per nucleon ions exhibit weak streaming away from the sun. More significantly, the quiet-time ions during solar maximum have He-3-rich and Fe-rich abundances which are established characteristics of small impulsive solar flares. Thus, it is suggested that small unresolved impulsive flares make a substantial contribution to the 'quiet-time' fluxes. He-4 from these flares may also contribute strongly to the ion spectra that were reported for the 35-1600 keV energy range by Wenzel et al.

Measurement of the Inclusive Electron Neutrino Charged Current Cross Section on Carbon with the T2K Near Detector

NASA Astrophysics Data System (ADS)

Abe, K.; Adam, J.; Aihara, H.; Akiri, T.; Andreopoulos, C.; Aoki, S.; Ariga, A.; Assylbekov, S.; Autiero, D.; Barbi, M.; Barker, G. J.; Barr, G.; Bass, M.; Batkiewicz, M.; Bay, F.; Berardi, V.; Berger, B. E.; Berkman, S.; Bhadra, S.; Blaszczyk, F. d. M.; Blondel, A.; Bojechko, C.; Bordoni, S.; Boyd, S. B.; Brailsford, D.; Bravar, A.; Bronner, C.; Buchanan, N.; Calland, R. G.; Caravaca Rodríguez, J.; Cartwright, S. L.; Castillo, R.; Catanesi, M. G.; Cervera, A.; Cherdack, D.; Christodoulou, G.; Clifton, A.; Coleman, J.; Coleman, S. J.; Collazuol, G.; Connolly, K.; Cremonesi, L.; Dabrowska, A.; Danko, I.; Das, R.; Davis, S.; de Perio, P.; De Rosa, G.; Dealtry, T.; Dennis, S. R.; Densham, C.; Dewhurst, D.; Di Lodovico, F.; Di Luise, S.; Drapier, O.; Duboyski, T.; Duffy, K.; Dumarchez, J.; Dytman, S.; Dziewiecki, M.; Emery-Schrenk, S.; Ereditato, A.; Escudero, L.; Finch, A. J.; Friend, M.; Fujii, Y.; Fukuda, Y.; Furmanski, A. P.; Galymov, V.; Giffin, S.; Giganti, C.; Gilje, K.; Goeldi, D.; Golan, T.; Gonin, M.; Grant, N.; Gudin, D.; Hadley, D. R.; Haesler, A.; Haigh, M. D.; Hamilton, P.; Hansen, D.; Hara, T.; Hartz, M.; Hasegawa, T.; Hastings, N. C.; Hayato, Y.; Hearty, C.; Helmer, R. L.; Hierholzer, M.; Hignight, J.; Hillairet, A.; Himmel, A.; Hiraki, T.; Hirota, S.; Holeczek, J.; Horikawa, S.; Huang, K.; Ichikawa, A. K.; Ieki, K.; Ieva, M.; Ikeda, M.; Imber, J.; Insler, J.; Irvine, T. J.; Ishida, T.; Ishii, T.; Iwai, E.; Iwamoto, K.; Iyogi, K.; Izmaylov, A.; Jacob, A.; Jamieson, B.; Johnson, R. A.; Jo, J. H.; Jonsson, P.; Jung, C. K.; Kabirnezhad, M.; Kaboth, A. C.; Kajita, T.; Kakuno, H.; Kameda, J.; Kanazawa, Y.; Karlen, D.; Karpikov, I.; Katori, T.; Kearns, E.; Khabibullin, M.; Khotjantsev, A.; Kielczewska, D.; Kikawa, T.; Kilinski, A.; Kim, J.; Kisiel, J.; Kitching, P.; Kobayashi, T.; Koch, L.; Kolaceke, A.; Konaka, A.; Kormos, L. L.; Korzenev, A.; Koshio, Y.; Kropp, W.; Kubo, H.; Kudenko, Y.; Kurjata, R.; Kutter, T.; Lagoda, J.; Lamont, I.; Larkin, E.; Laveder, M.; Lawe, M.; Lazos, M.; Lindner, T.; Lister, C.; Litchfield, R. P.; Longhin, A.; Ludovici, L.; Magaletti, L.; Mahn, K.; Malek, M.; Manly, S.; Marino, A. D.; Marteau, J.; Martin, J. F.; Martynenko, S.; Maruyama, T.; Matveev, V.; Mavrokoridis, K.; Mazzucato, E.; McCarthy, M.; McCauley, N.; McFarland, K. S.; McGrew, C.; Metelko, C.; Mijakowski, P.; Miller, C. A.; Minamino, A.; Mineev, O.; Missert, A.; Miura, M.; Moriyama, S.; Mueller, Th. A.; Murakami, A.; Murdoch, M.; Murphy, S.; Myslik, J.; Nakadaira, T.; Nakahata, M.; Nakamura, K.; Nakayama, S.; Nakaya, T.; Nakayoshi, K.; Nielsen, C.; Nirkko, M.; Nishikawa, K.; Nishimura, Y.; O'Keeffe, H. M.; Ohta, R.; Okumura, K.; Okusawa, T.; Oryszczak, W.; Oser, S. M.; Owen, R. A.; Oyama, Y.; Palladino, V.; Palomino, J. L.; Paolone, V.; Payne, D.; Perevozchikov, O.; Perkin, J. D.; Petrov, Y.; Pickard, L.; Pinzon Guerra, E. S.; Pistillo, C.; Plonski, P.; Poplawska, E.; Popov, B.; Posiadala, M.; Poutissou, J.-M.; Poutissou, R.; Przewlocki, P.; Quilain, B.; Radicioni, E.; Ratoff, P. N.; Ravonel, M.; Rayner, M. A. M.; Redij, A.; Reeves, M.; Reinherz-Aronis, E.; Rodrigues, P. A.; Rojas, P.; Rondio, E.; Roth, S.; Rubbia, A.; Ruterbories, D.; Sacco, R.; Sakashita, K.; Sánchez, F.; Sato, F.; Scantamburlo, E.; Scholberg, K.; Schoppmann, S.; Schwehr, J.; Scott, M.; Seiya, Y.; Sekiguchi, T.; Sekiya, H.; Sgalaberna, D.; Shiozawa, M.; Short, S.; Shustrov, Y.; Sinclair, P.; Smith, B.; Smy, M.; Sobczyk, J. T.; Sobel, H.; Sorel, M.; Southwell, L.; Stamoulis, P.; Steinmann, J.; Still, B.; Suda, Y.; Suzuki, A.; Suzuki, K.; Suzuki, S. Y.; Suzuki, Y.; Tacik, R.; Tada, M.; Takahashi, S.; Takeda, A.; Takeuchi, Y.; Tanaka, H. K.; Tanaka, H. A.; Tanaka, M. M.; Terhorst, D.; Terri, R.; Thompson, L. F.; Thorley, A.; Tobayama, S.; Toki, W.; Tomura, T.; Totsuka, Y.; Touramanis, C.; Tsukamoto, T.; Tzanov, M.; Uchida, Y.; Vacheret, A.; Vagins, M.; Vasseur, G.; Wachala, T.; Waldron, A. V.; Walter, C. W.; Wark, D.; Wascko, M. O.; Weber, A.; Wendell, R.; Wilkes, R. J.; Wilking, M. J.; Wilkinson, C.; Williamson, Z.; Wilson, J. R.; Wilson, R. J.; Wongjirad, T.; Yamada, Y.; Yamamoto, K.; Yanagisawa, C.; Yano, T.; Yen, S.; Yershov, N.; Yokoyama, M.; Yuan, T.; Yu, M.; Zalewska, A.; Zalipska, J.; Zambelli, L.; Zaremba, K.; Ziembicki, M.; Zimmerman, E. D.; Zito, M.; Żmuda, J.; T2K Collaboration

2014-12-01

The T2K off-axis near detector ND280 is used to make the first differential cross-section measurements of electron neutrino charged current interactions at energies ˜1 GeV as a function of electron momentum, electron scattering angle, and four-momentum transfer of the interaction. The total flux-averaged νe charged current cross section on carbon is measured to be ⟨σ ⟩ϕ =1.11 ±0.10 (stat)±0.18 (syst)×1 0-38 cm2/nucleon . The differential and total cross-section measurements agree with the predictions of two leading neutrino interaction generators, NEUT and GENIE. The NEUT prediction is 1.23 ×1 0-38 cm2/nucleon and the GENIE prediction is 1.08 ×1 0-38 cm2/nucleon . The total νe charged current cross-section result is also in agreement with data from the Gargamelle experiment.

Status of the NPDGamma experiment

NASA Astrophysics Data System (ADS)

Fry, J.; Alarcon, R.; Allen, R.; Askanazi, E.; Balascuta, S.; Barron-Palos, L.; Baeßler, S.; Barzilov, A.; Blessinger, C.; Blyth, D.; Bowman, J. D.; Calarco, J. R.; Chupp, T. E.; Coppola, C. E.; Crawford, C.; Craycraft, K.; Dabaghyan, M.; Evans, D.; Favela, J.; Fieseler, C.; Fomin, N.; Fox, W.; Freedman, S.; Frlež, E.; Fu, C.; Garcia, C.; Garishvili, I.; Gericke, M. T.; Gillis, R. C.; Grammer, K.; Greene, G. L.; Hamblen, J.; Hayes, C.; Hersman, F. W.; Ino, T.; Iverson, E. B.; Jones, G. L.; Kabir, L.; Kucucker, S.; Lauss, B.; Li, Y.; Mahurin, R.; Maldonado-Velazquez, M.; McCrea, M.; Masuda, Y.; Mei, J.; Milburn, R.; Mitchell, G. S.; Mueller, P.; Muto, S.; Musgrave, M.; Nann, H.; Novikov, I.; Page, S.; Parsons, D.; Počanić, D.; Penttilä, S. I.; Ramsay, W. D.; Salas-Bacci, A.; Santra, S.; Seo, P.-N.; Sharapov, E.; Sharma, M.; Simmons, F.; Smith, T.; Snow, W. M.; Stuart, J.; Tang, E.; Tang, Z.; Thomison, J.; Tong, T.; Vanderwerp, J.; Waldecker, S.; Wilburn, W. S.; Xu, W.; Yuan, V.; Zhang, Y.

2017-11-01

The NPDGamma experiment measures the parity-violating (PV) gamma asymmetry from polarized cold neutrons captured on protons at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). The (PV) neutron spin asymmetry A γ of photons from polarized cold neutron capture on protons is proportional to the Δ I=1 long range weak meson coupling h_{π }1 between nucleons in the hadronic weak interaction (HWI). Liquid para-hydrogen production data taking concluded in April 2014 and once the background aluminum asymmetry measurements are complete, the PV asymmetry A γ can be extracted. Preliminary results of the analysis of A γ are presented.

Standard model anatomy of WIMP dark matter direct detection. I. Weak-scale matching

NASA Astrophysics Data System (ADS)

Hill, Richard J.; Solon, Mikhail P.

2015-02-01

We present formalism necessary to determine weak-scale matching coefficients in the computation of scattering cross sections for putative dark matter candidates interacting with the Standard Model. We pay particular attention to the heavy-particle limit. A consistent renormalization scheme in the presence of nontrivial residual masses is implemented. Two-loop diagrams appearing in the matching to gluon operators are evaluated. Details are given for the computation of matching coefficients in the universal limit of WIMP-nucleon scattering for pure states of arbitrary quantum numbers, and for singlet-doublet and doublet-triplet mixed states.

Detection of back-to-back proton pairs in charged-current neutrino interactions with the ArgoNeuT detector in the NuMI low energy beam line

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

Acciarri, R.; Adams, C.; Asaadi, J.

2014-07-01

Short range nucleon-nucleon correlations in nuclei (NN SRC) carry important information on nuclear structure and dynamics. NN SRC have been extensively probed through two-nucleon knock- out reactions in both pion and electron scattering experiments. We report here on the detection of two-nucleon knock-out events from neutrino interactions and discuss their topological features as possibly involving NN SRC content in the target argon nuclei. The ArgoNeuT detector in the Main Injector neutrino beam at Fermilab has recorded a sample of 30 fully reconstructed charged current events where the leading muon is accompanied by a pair of protons at the interaction vertex,more » 19 of which have both protons above the Fermi momentum of the Ar nucleus. Out of these 19 events, four are found with the two protons in a strictly back-to-back high momenta configuration directly observed in the final state and can be associated to nucleon Resonance pionless mechanisms involving a pre-existing short range correlated np pair in the nucleus. Another fraction (four events) of the remaining 15 events have a reconstructed back-to-back configuration of a np pair in the initial state, a signature compatible with one-body Quasi Elastic interaction on a neutron in a SRC pair. The detection of these two subsamples of the collected (mu- + 2p) events suggests that mechanisms directly involving nucleon-nucleon SRC pairs in the nucleus are active and can be efficiently explored in neutrino-argon interactions with the LAr TPC technology.« less

Challenges in the global QCD analysis of parton structure of nucleons

NASA Astrophysics Data System (ADS)

Tung, Wu-Ki

2000-12-01

We briefly summarize the current status of global QCD analysis of the parton structure of the nucleon and then highlight the open questions and challenges which confront this endeavor on which much of the phenomenology of the Standard Model and the search of New Physics depend.

Laboratory search for a long-range T-odd, P-odd interaction from axionlike particles using dual-species nuclear magnetic resonance with polarized 129Xe and 131Xe gas.

PubMed

Bulatowicz, M; Griffith, R; Larsen, M; Mirijanian, J; Fu, C B; Smith, E; Snow, W M; Yan, H; Walker, T G

2013-09-06

Various theories beyond the standard model predict new particles with masses in the sub-eV range with very weak couplings to ordinary matter. A new P-odd and T-odd interaction between polarized and unpolarized nucleons proportional to K·r is one such possibility, where r is the distance between the nucleons and K is the spin of the polarized nucleon. Such an interaction involving a scalar coupling gs at one vertex and a pseudoscalar coupling gp at the polarized nucleon vertex can be induced by the exchange of spin-0 bosons. We used the NMR cell test station at Northrop Grumman Corporation to search for NMR frequency shifts in polarized 129Xe and 131Xe when a nonmagnetic zirconia rod is moved near the NMR cell. Long (T2∼20  s) spin-relaxation times allow precision measurements of the NMR frequency ratios, which are insensitive to magnetic field fluctuations. Combined with existing theoretical calculations of the neutron spin contribution to the nuclear angular momentum in xenon nuclei, the measurements improve the laboratory upper bound on the product gsgp(n) by 2 orders of magnitude for distances near 1 mm. The sensitivity of this technique can be increased by at least two more orders of magnitude.

Electromagnetic and neutral-weak response functions of light nuclei

NASA Astrophysics Data System (ADS)

Lovato, Alessandro

2015-10-01

A major goal of nuclear theory is to understand the strong interaction in nuclei as it manifests itself in terms of two- and many-body forces among the nuclear constituents, the protons and neutrons, and the interactions of these constituents with external electroweak probes via one- and many-body currents. Using imaginary-time projection technique, quantum Monte Carlo allows for solving the time-independent Schrödinger equation even for Hamiltonians including highly spin-isospin dependent two- and three- body forces. I will present a recent Green's function Monte Carlo calculation of the quasi-elastic electroweak response functions in light nuclei, needed to describe electron and neutrino scattering. We found that meson-exchange two-body currents generate excess transverse strength from threshold to the quasielastic to the dip region and beyond. These results challenge the conventional picture of quasi elastic inclusive scattering as being largely dominated by single-nucleon knockout processes. These findings are of particular interest for the interpretation of neutrino oscillation signals.

The MOLLER Experiment: ``An Ultra-precise Measurement of the Weak Charge of the Electron using moller Scattering''

NASA Astrophysics Data System (ADS)

Beminiwattha, Rakitha; Moller Collaboration

2017-09-01

Parity Violating Electron Scattering (PVES) is an extremely successful precision frontier tool that has been used for testing the Standard Model (SM) and understanding nucleon structure. Several generations of highly successful PVES programs at SLAC, MIT-Bates, MAMI-Mainz, and Jefferson Lab have contributed to the understanding of nucleon structure and testing the SM. But missing phenomena like matter-antimatter asymmetry, neutrino flavor oscillations, and dark matter and energy suggest that the SM is only a `low energy' effective theory. The MOLLER experiment at Jefferson Lab will measure the weak charge of the electron, QWe = 1 - 4sin2θW , with a precision of 2.4 % by measuring the parity violating asymmetry in electron-electron () scattering and will be sensitive to subtle but measurable deviations from precisely calculable predictions from the SM. The MOLLER experiment will provide the best contact interaction search for leptons at low OR high energy makes it a probe of physics beyond the Standard Model with sensitivities to mass-scales of new PV physics up to 7.5 TeV. Overview of the experiment and recent pre-R&D progress will be reported.

Thermal states of neutron stars with a consistent model of interior

NASA Astrophysics Data System (ADS)

Fortin, M.; Taranto, G.; Burgio, G. F.; Haensel, P.; Schulze, H.-J.; Zdunik, J. L.

2018-04-01

We model the thermal states of both isolated neutron stars and accreting neutron stars in X-ray transients in quiescence and confront them with observations. We use an equation of state calculated using realistic two-body and three-body nucleon interactions, and superfluid nucleon gaps obtained using the same microscopic approach in the BCS approximation. Consistency with low-luminosity accreting neutron stars is obtained, as the direct Urca process is operating in neutron stars with mass larger than 1.1 M⊙ for the employed equation of state. In addition, proton superfluidity and sufficiently weak neutron superfluidity, obtained using a scaling factor for the gaps, are necessary to explain the cooling of middle-aged neutron stars and to obtain a realistic distribution of neutron star masses.

Nuclear Physics Around the Unitarity Limit.

PubMed

König, Sebastian; Grießhammer, Harald W; Hammer, H-W; van Kolck, U

2017-05-19

We argue that many features of the structure of nuclei emerge from a strictly perturbative expansion around the unitarity limit, where the two-nucleon S waves have bound states at zero energy. In this limit, the gross features of states in the nuclear chart are correlated to only one dimensionful parameter, which is related to the breaking of scale invariance to a discrete scaling symmetry and set by the triton binding energy. Observables are moved to their physical values by small perturbative corrections, much like in descriptions of the fine structure of atomic spectra. We provide evidence in favor of the conjecture that light, and possibly heavier, nuclei are bound weakly enough to be insensitive to the details of the interactions but strongly enough to be insensitive to the exact size of the two-nucleon system.

Limits on spin-dependent WIMP-nucleon cross sections from the XENON10 experiment.

PubMed

Angle, J; Aprile, E; Arneodo, F; Baudis, L; Bernstein, A; Bolozdynya, A; Coelho, L C C; Dahl, C E; DeViveiros, L; Ferella, A D; Fernandes, L M P; Fiorucci, S; Gaitskell, R J; Giboni, K L; Gomez, R; Hasty, R; Kastens, L; Kwong, J; Lopes, J A M; Madden, N; Manalaysay, A; Manzur, A; McKinsey, D N; Monzani, M E; Ni, K; Oberlack, U; Orboeck, J; Plante, G; Santorelli, R; dos Santos, J M F; Shagin, P; Shutt, T; Sorensen, P; Schulte, S; Winant, C; Yamashita, M

2008-08-29

XENON10 is an experiment to directly detect weakly interacting massive particles (WIMPs), which may comprise the bulk of the nonbaryonic dark matter in our Universe. We report new results for spin-dependent WIMP-nucleon interactions with 129Xe and 131Xe from 58.6 live days of operation at the Laboratori Nazionali del Gran Sasso. Based on the nonobservation of a WIMP signal in 5.4 kg of fiducial liquid xenon mass, we exclude previously unexplored regions in the theoretically allowed parameter space for neutralinos. We also exclude a heavy Majorana neutrino with a mass in the range of approximately 10 GeV/c2-2 TeV/c2 as a dark matter candidate under standard assumptions for its density and distribution in the galactic halo.

Measurement of the Parity-Violating directional Gamma-ray Asymmetry in Polarized Neutron Capture on ^35Cl

NASA Astrophysics Data System (ADS)

Fomin, Nadia

2012-03-01

The NPDGamma experiment aims to measure the parity-odd correlation between the neutron spin and the direction of the emitted photon in neutron-proton capture. A parity violating asymmetry (to be measured to 10-8) from this process can be directly related to the strength of the hadronic weak interaction between nucleons. As part of the commissioning runs on the Fundamental Neutron Physics beamline at the Spallation Neutron Source at ORNL, the gamma-ray asymmetry from the parity-violating capture of cold neutrons on ^35Cl was measured, primarily to check for systematic effects and false asymmtries. The current precision from existing world measurements on this asymmetry is at the level of 10-6 and we believe we can improve it. The analysis methodology as well as preliminary results will be presented.

Electromagnetic structure of light nuclei

DOE PAGES

Pastore, Saori

2016-03-25

Here, the present understanding of nuclear electromagnetic properties including electromagnetic moments, form factors and transitions in nuclei with A ≤ 10 is reviewed. Emphasis is on calculations based on nuclear Hamiltonians that include two- and three-nucleon realistic potentials, along with one- and two-body electromagnetic currents derived from a chiral effective field theory with pions and nucleons.

Electromagnetic structure of light nuclei

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

Pastore, Saori

Here, the present understanding of nuclear electromagnetic properties including electromagnetic moments, form factors and transitions in nuclei with A ≤ 10 is reviewed. Emphasis is on calculations based on nuclear Hamiltonians that include two- and three-nucleon realistic potentials, along with one- and two-body electromagnetic currents derived from a chiral effective field theory with pions and nucleons.

Incomplete fusion analysis of the 7Li-induced reaction on 93Nb within 3-6.5 MeV/nucleon

NASA Astrophysics Data System (ADS)

Kumar, Deepak; Maiti, Moumita

2017-10-01

Background: It is understood from the recent experimental studies that prompt/resonant breakup, and transfer followed by breakup in the weakly bound Li,76-induced reactions play a significant role in the complete-incomplete fusion (CF-ICF), suppression/enhancement in the fusion cross section around the Coulomb barrier. Purpose: Investigation of ICF over CF by measuring cross sections of the populated residues, produced via different channels in the 7Li-induced reaction on a natNb target within the 3-6.5 MeV/nucleon energy region. Method: The 7Li beam was allowed to hit the self-supporting 93Nb targets, backed by the aluminium (Al) foil alternately, within 3-6.5 MeV/nucleon energy. Populated residues were identified by offline γ -ray spectrometry. Measured excitation functions of different channels were compared with different equilibrium and pre-equilibrium models. Result: The enhancement in cross sections in the proton (˜20 -30 MeV) and α -emitting channels, which may be ascribed to ICF, was observed in the measured energy range when compared to the Hauser-Feshbach and exciton model calculations using empire, which satisfactorily reproduces the neutron channels, compared to the Weisskopf-Ewing model and hybrid Monte Carlo calculations. The increment of the incomplete fusion fraction was observed with rising projectile energy. Conclusion: Contrary to the alice14, experimental results are well reproduced by the empire throughout the measured energy range. The signature of ICF over CF indicates that the breakup/transfer processes are involved in the weakly bound 7Li-induced reaction on 93Nb slightly above the Coulomb barrier.

New Results from the Search for Low-Mass Weakly Interacting Massive Particles with the CDMS Low Ionization Threshold Experiment

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

Agnese, R.; Anderson, A. J.; Aramaki, T.

2016-02-01

The CDMS low ionization threshold experiment (CDMSlite) uses cryogenic germanium detectors operated at a relatively high bias voltage to amplify the phonon signal in the search for weakly interacting massive particles (WIMPs). Results are presented from the second CDMSlite run with an exposure of 70 kg day, which reached an energy threshold for electron recoils as low as 56 eV. A fiducialization cut reduces backgrounds below those previously reported by CDMSlite. New parameter space for the WIMP-nucleon spin-independent cross section is excluded for WIMP masses between 1.6 and 5.5 GeV/c^2.

Experimental constraint on quark electric dipole moments

NASA Astrophysics Data System (ADS)

Liu, Tianbo; Zhao, Zhiwen; Gao, Haiyan

2018-04-01

The electric dipole moments (EDMs) of nucleons are sensitive probes of additional C P violation sources beyond the standard model to account for the baryon number asymmetry of the universe. As a fundamental quantity of the nucleon structure, tensor charge is also a bridge that relates nucleon EDMs to quark EDMs. With a combination of nucleon EDM measurements and tensor charge extractions, we investigate the experimental constraint on quark EDMs, and its sensitivity to C P violation sources from new physics beyond the electroweak scale. We obtain the current limits on quark EDMs as 1.27 ×10-24 e .cm for the up quark and 1.17 ×10-24 e .cm for the down quark at the scale of 4 GeV2 . We also study the impact of future nucleon EDM and tensor charge measurements, and show that upcoming new experiments will improve the constraint on quark EDMs by about 3 orders of magnitude leading to a much more sensitive probe of new physics models.

Probing Novel Properties of Nucleons and Nuclei via Parity Violating Electron Scattering

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

Mercado, Luis

2012-05-01

This thesis reports on two experiments conducted by the HAPPEx (Hall A Proton Parity Experiment) collaboration at the Thomas Jefferson National Accelerator Facility. For both, the weak neutral current interaction (WNC, mediated by the Z 0 boson) is used to probe novel properties of hadronic targets. The WNC interaction amplitude is extracted by measuring the parity-violating asymmetry in the elastic scattering of longitudinally polarized electrons o unpolarized target hadrons. HAPPEx-III, conducted in the Fall of 2009, used a liquid hydrogen target at a momentum transfer of Q 2 = 0.62 GeV 2. The measured asymmetry was used to set newmore » constraints on the contribution of strange quark form factors (G s E,M ) to the nucleon electromagnetic form factors. A value of A PV = -23.803±} 0.778 (stat)± 0.359 (syst) ppm resulted in G s E + 0.517G s M = 0.003± 0.010 (stat)± 0.004 (syst)± 0.009 (FF). PREx, conducted in the Spring of 2010, used a polarized electron beam on a 208Pb target at a momentum transfer of Q 2 = 0.009 GeV 2. This parity-violating asymmetry can be used to obtain a clean measurement of the root-mean-square radius of the neutrons in the 208Pb nucleus. The Z 0 boson couples mainly to neutrons; the neutron weak charge is much larger than that of the proton. The value of this asymmetry is at the sub-ppm level and has a projected experimental fractional precision of 3%. We will describe the accelerator setup used to set controls on helicity-correlated beam asymmetries and the analysis methods for finding the raw asymmetry for HAPPEx-III. We will also discuss in some detail the preparations to meet the experimental challenges associated with measuring such a small asymmetry with the degree of precision required for PREx.« less

Results from a Search for Dark Matter in the Complete LUX Exposure

NASA Astrophysics Data System (ADS)

Akerib, D. S.; Alsum, S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Bramante, R.; Brás, P.; Byram, D.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Chiller, A. A.; Chiller, C.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; Dobi, A.; Dobson, J. E. Y.; Druszkiewicz, E.; Edwards, B. N.; Faham, C. H.; Fiorucci, S.; Gaitskell, R. J.; Gehman, V. M.; Ghag, C.; Gibson, K. R.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Ihm, M.; Jacobsen, R. G.; Ji, W.; Kamdin, K.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lee, C.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Palladino, K. J.; Pease, E. K.; Phelps, P.; Reichhart, L.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solmaz, M.; Solovov, V. N.; Sorensen, P.; Stephenson, S.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W. C.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Xu, J.; Yazdani, K.; Young, S. K.; Zhang, C.; LUX Collaboration

2017-01-01

We report constraints on spin-independent weakly interacting massive particle (WIMP)-nucleon scattering using a 3.35 ×1 04 kg day exposure of the Large Underground Xenon (LUX) experiment. A dual-phase xenon time projection chamber with 250 kg of active mass is operated at the Sanford Underground Research Facility under Lead, South Dakota (USA). With roughly fourfold improvement in sensitivity for high WIMP masses relative to our previous results, this search yields no evidence of WIMP nuclear recoils. At a WIMP mass of 50 GeV c-2 , WIMP-nucleon spin-independent cross sections above 2.2 ×10-46 cm2 are excluded at the 90% confidence level. When combined with the previously reported LUX exposure, this exclusion strengthens to 1.1 ×10-46 cm2 at 50 GeV c-2 .

Can Ab Initio Theory Explain the Phenomenon of Parity Inversion in Be 11 ?

DOE PAGES

Calci, Angelo; Navratil, Petr; Roth, Robert; ...

2016-12-09

The weakly bound exotic 11Be nucleus, famous for its ground-state parity inversion and distinct n + 10Be halo structure, is investigated from first principles using chiral two- and three-nucleon forces. An explicit treatment of continuum effects is found to be indispensable. We study the sensitivity of the 11Be spectrum to the details of the three-nucleon force and demonstrate that only certain chiral interactions are capable of reproducing the parity inversion. With such interactions, the extremely large E1 transition between the bound states is reproduced. We compare our photodisintegration calculations to conflicting experimental data and predict a distinct dip around themore » 3/2 – 1 resonance energy. Finally, we predict low-lying 3/2 + and 9/2 + resonances that are not or not sufficiently measured in experiments.« less

Mesonic Decay of Charm Hypernuclei Λc+

NASA Astrophysics Data System (ADS)

Ghosh, Sabyasachi; Fontoura, Carlos E.; Krein, Gastão

2016-03-01

Λc+ hypernuclei are expected to have binding energies and other properties similar to those of strange hypernuclei in view of the similarity between the quark structures of the strange and charmed hyperons, namely Λ(uds) and Λc+(udc). One striking difference however occurs in their mesonic decays, as there is almost no Pauli blocking in the nucleonic decay of a charm hypernucleus because the final-state nucleons leave the nucleus at high energies. The nuclear medium nevertheless affects the mesonic decays of charm hypernucleus because the nuclear mean fields modify the masses of the charm hyperon. In the present communication we present results of a first investigation of the effects of finite baryon density on different weak mesonic decay channels of the Λc+ baryon. We found a non-negligible reduction of the decay widths as compared to their vacuum values.

Nuclear Physics Around the Unitarity Limit

DOE PAGES

König, Sebastian; Grießhammer, Harald W.; Hammer, H. -W.; ...

2017-05-15

We argue that many features of the structure of nuclei emerge from a strictly perturbative expansion around the unitarity limit, where the two-nucleon S waves have bound states at zero energy. In this limit, the gross features of states in the nuclear chart are correlated to only one dimensionful parameter, which is related to the breaking of scale invariance to a discrete scaling symmetry and set by the triton binding energy. Observables are moved to their physical values by small perturbative corrections, much like in descriptions of the fine structure of atomic spectra. We provide evidence in favor of themore » conjecture that light, and possibly heavier, nuclei are bound weakly enough to be insensitive to the details of the interactions but strongly enough to be insensitive to the exact size of the two-nucleon system.« less

Consequences of high-x proton size fluctuations in small collision systems at √{sNN}=200 GeV

NASA Astrophysics Data System (ADS)

McGlinchey, D.; Nagle, J. L.; Perepelitsa, D. V.

2016-08-01

Recent measurements of jet production rates at large transverse momentum (pT) in the collisions of small projectiles with large nuclei at the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider indicate that they have an unexpected relationship with estimates of the collision centrality. One compelling interpretation of the data is that they capture an xp-dependent decrease in the average interaction strength of the nucleon in the projectile undergoing a hard scattering. A weakly interacting or "shrinking" nucleon in the projectile strikes fewer nucleons in the nucleus, resulting in a particular pattern of centrality-dependent modifications to high-pT processes. We describe a simple one-parameter geometric implementation of this picture within a modified Monte Carlo Glauber model tuned to d +Au jet data, and explore two of its major consequences. First, the model predicts a particular projectile-species effect on the centrality dependence at high xp, opposite to that expected from a final state energy loss effect. Second, we find that some of the large centrality dependence observed for forward dihadron production in d +Au collisions at RHIC may arise from the physics of the "shrinking" projectile nucleon, in addition to impact parameter dependent shadowing or saturation effects at low nuclear x . We conclude that analogous measurements in recently collected p +Au and 3He+Au collision data at RHIC can provide a unique test of these predictions.

Nucleon Structure from 2+1 Flavor Domain Wall QCD at Nearly Physical Pion Mass

NASA Astrophysics Data System (ADS)

Ohta, Shigemi

2011-05-01

The RBC and UKQCD collaborations have been investigating hadron physics in numerical lattice quantum chromodynamics (QCD) with (2+1) flavors of dynamical domain wall fermions (DWF) quarks that preserves continuum-like chiral and flavor symmetries. The strange quark mass is adjusted to physical value via reweighting and degenerate up and down quark masses are set as light as possible. In a recent study of nucleon structure we found a strong dependence on pion mass and lattice spatial extent in isovector axialvector-current form factors. This is likely the first credible evidence for the pion cloud surrounding nucleon. Here we report the status of nucleon structure calculations with a new (2+1)-flavor dynamical DWF ensembles with much lighter pion mass of 180 and 250 MeV and a much larger lattice spatial exent of 4.6 fm. A combination of the Iwasaki and dislocation-suppressing-determinant-ratio (I+DSDR) gauge action and DWF fermion action allows us to generate these ensembles at cutoff of about 1.4 GeV while keeping the residual breaking of chiral symmetry sufficiently small. Nucleon source Gaussian smearing has been optimized. Preliminary nucleon mass estimates are 0.98 and 1.05 GeV.

New limits on interactions between weakly interacting massive particles and nucleons obtained with CsI(Tl) crystal detectors.

PubMed

Kim, S C; Bhang, H; Choi, J H; Kang, W G; Kim, B H; Kim, H J; Kim, K W; Kim, S K; Kim, Y D; Lee, J; Lee, J H; Lee, J K; Lee, M J; Lee, S J; Li, J; Li, J; Li, X R; Li, Y J; Myung, S S; Olsen, S L; Ryu, S; Seong, I S; So, J H; Yue, Q

2012-05-04

New limits are presented on the cross section for weakly interacting massive particle (WIMP) nucleon scattering in the KIMS CsI(Tℓ) detector array at the Yangyang Underground Laboratory. The exposure used for these results is 24 524.3  kg·days. Nuclei recoiling from WIMP interactions are identified by a pulse shape discrimination method. A low energy background due to alpha emitters on the crystal surfaces is identified and taken into account in the analysis. The detected numbers of nuclear recoils are consistent with zero and 90% confidence level upper limits on the WIMP interaction rates are set for electron equivalent energies from 3 to 11 keV. The 90% upper limit of the nuclear recoil event rate for 3.6-5.8 keV corresponding to 2-4 keV in NaI(Tℓ) is 0.0098 counts/kg/keV/day, which is below the annual modulation amplitude reported by DAMA. This is incompatible with interpretations that enhance the modulation amplitude such as inelastic dark matter models. We establish the most stringent cross section limits on spin-dependent WIMP-proton elastic scattering for the WIMP masses greater than 20  GeV/c2.

Deformed shell model study of event rates for WIMP-73Ge scattering

NASA Astrophysics Data System (ADS)

Sahu, R.; Kota, V. K. B.

2017-12-01

The event detection rates for the Weakly Interacting Massive Particles (WIMP) (a dark matter candidate) are calculated with 73Ge as the detector. The calculations are performed within the deformed shell model (DSM) based on Hartree-Fock states. First, the energy levels and magnetic moment for the ground state and two low-lying positive parity states for this nucleus are calculated and compared with experiment. The agreement is quite satisfactory. Then the nuclear wave functions are used to investigate the elastic and inelastic scattering of WIMP from 73Ge; inelastic scattering, especially for the 9/2+ → 5/2+ transition, is studied for the first time. The nuclear structure factors which are independent of supersymmetric model are also calculated as a function of WIMP mass. The event rates are calculated for a given set of nucleonic current parameters. The calculation shows that 73Ge is a good detector for detecting dark matter.

DEAP-3600 Dark Matter Search

NASA Astrophysics Data System (ADS)

Kuźniak, M.; Amaudruz, P.-A.; Batygov, M.; Beltran, B.; Bonatt, J.; Boulay, M. G.; Broerman, B.; Bueno, J. F.; Butcher, A.; Cai, B.; Chen, M.; Chouinard, R.; Cleveland, B. T.; Dering, K.; DiGioseffo, J.; Duncan, F.; Flower, T.; Ford, R.; Giampa, P.; Gorel, P.; Graham, K.; Grant, D. R.; Guliyev, E.; Hallin, A. L.; Hamstra, M.; Harvey, P.; Jillings, C. J.; Lawson, I.; Li, O.; Liimatainen, P.; Majewski, P.; McDonald, A. B.; McElroy, T.; McFarlane, K.; Monroe, J.; Muir, A.; Nantais, C.; Ng, C.; Noble, A. J.; Ouellet, C.; Palladino, K.; Pasuthip, P.; Peeters, S. J. M.; Pollmann, T.; Rau, W.; Retière, F.; Seeburn, N.; Singhrao, K.; Skensved, P.; Smith, B.; Sonley, T.; Tang, J.; Vázquez-Jáuregui, E.; Veloce, L.; Walding, J.; Ward, M.; DEAP Collaboration

2016-04-01

The DEAP-3600 experiment is located 2 km underground at SNOLAB, in Sudbury, Ontario. It is a single-phase detector that searches for dark matter particle interactions within a 1000-kg fiducial mass target of liquid argon. A first generation prototype detector (DEAP-1) with a 7-kg liquid argon target mass demonstrated a high level of pulse-shape discrimination (PSD) for reducing β / γ backgrounds and helped to develop low radioactivity techniques to mitigate surface-related α backgrounds. Construction of the DEAP-3600 detector is nearly complete and commissioning is starting in 2014. The target sensitivity to spin-independent scattering of Weakly Interacting Massive Particles (WIMPs) on nucleons of 10-46cm2 will allow one order of magnitude improvement in sensitivity over current searches at 100 GeV WIMP mass. This paper presents an overview and status of the DEAP-3600 project and discusses plans for a future multi-tonne experiment, DEAP-50T.

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

Avakian, Harut; Pisano, Silvia

The Deep Inelastic Scattering (DIS) proved to be a great tool in testing of the theory of strong in- teractions. Semi-Inclusive DIS (SIDIS), with detection of an additional hadron allowed first stud- ies of 3D structure of the nucleon, moving the main focus from testing the QCD to understanding of strong interactions and quark gluon dynamics to address a number of puzzles accumulated in recent years. Detection of two hadrons in SIDIS, which is even more complicated, provides ac- cess to details of quark gluon interactions inaccessible in single-hadron SIDIS, providing a new avenue to study the complex nucleon structure.more » Large acceptance of the CLAS detector at Jef- ferson Lab, allowing detection of two hadrons, produced back-to-back (b2b) in the current and target fragmentation regions, provides a unique possibility to study the nucleon structure in target fragmentation region, and correlations of target and current fragmentation regions« less

The direct detection of boosted dark matter at high energies and PeV events at IceCube

DOE PAGES

Bhattacharya, A.; Gandhi, R.; Gupta, A.

2015-03-13

We study the possibility of detecting dark matter directly via a small but energetic component that is allowed within present-day constraints. Drawing closely upon the fact that neutral current neutrino nucleon interactions are indistinguishable from DM-nucleon interactions at low energies, we extend this feature to high energies for a small, non-thermal but highly energetic population of DM particle χ, created via the decay of a significantly more massive and long-lived non-thermal relic Φ, which forms the bulk of DM. If χ interacts with nucleons, its cross-section, like the neutrino-nucleus coherent cross-section, can rise sharply with energy leading to deep inelasticmore » scattering, similar to neutral current neutrino-nucleon interactions at high energies. Thus, its direct detection may be possible via cascades in very large neutrino detectors. As a specific example, we apply this notion to the recently reported three ultra-high energy PeV cascade events clustered around 1 – 2 PeV at IceCube (IC). We discuss the features which may help discriminate this scenario from one in which only astrophysical neutrinos constitute the event sample in detectors like IC.« less

Up, down, and strange nucleon axial form factors from lattice QCD

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

Green, Jeremy; Hasan, Nesreen; Meinel, Stefan

Here, we report a calculation of the nucleon axial form factorsmore » $$G_A^q(Q^2)$$ and $$G_P^q(Q^2)$$ for all three light quark flavors $$q\\in\\{u,d,s\\}$$ in the range $$0\\leq Q^2\\lesssim 1.2\\text{ GeV}^2$$ using lattice QCD. Our work was done using a single ensemble with pion mass 317 MeV and made use of the hierarchical probing technique to efficiently evaluate the required disconnected loops. We perform nonperturbative renormalization of the axial current, including a nonperturbative treatment of the mixing between light and strange currents due to the singlet-nonsinglet difference caused by the axial anomaly. The form factor shapes are fit using the model-independent $z$ expansion. From $$G_A^q(Q^2)$$, we determine the quark contributions to the nucleon spin and axial radii. By extrapolating the isovector $$G_P^{u-d}(Q^2)$$, we obtain the induced pseudoscalar coupling relevant for ordinary muon capture and the pion-nucleon coupling constant. We also found that the disconnected contributions to $$G_P$$ form factors are large, and give an interpretation based on the dominant influence of the pseudoscalar poles in these form factors.« less

Up, down, and strange nucleon axial form factors from lattice QCD

DOE PAGES

Green, Jeremy; Hasan, Nesreen; Meinel, Stefan; ...

2017-06-14

Here, we report a calculation of the nucleon axial form factorsmore » $$G_A^q(Q^2)$$ and $$G_P^q(Q^2)$$ for all three light quark flavors $$q\\in\\{u,d,s\\}$$ in the range $$0\\leq Q^2\\lesssim 1.2\\text{ GeV}^2$$ using lattice QCD. Our work was done using a single ensemble with pion mass 317 MeV and made use of the hierarchical probing technique to efficiently evaluate the required disconnected loops. We perform nonperturbative renormalization of the axial current, including a nonperturbative treatment of the mixing between light and strange currents due to the singlet-nonsinglet difference caused by the axial anomaly. The form factor shapes are fit using the model-independent $z$ expansion. From $$G_A^q(Q^2)$$, we determine the quark contributions to the nucleon spin and axial radii. By extrapolating the isovector $$G_P^{u-d}(Q^2)$$, we obtain the induced pseudoscalar coupling relevant for ordinary muon capture and the pion-nucleon coupling constant. We also found that the disconnected contributions to $$G_P$$ form factors are large, and give an interpretation based on the dominant influence of the pseudoscalar poles in these form factors.« less

Results from a search for dark matter in the complete LUX exposure

DOE PAGES

Akerib, D. S.; Alsum, S.; Araújo, H. M.; ...

2017-01-11

Here, we report constraints on spin-independent weakly interacting massive particle (WIMP)-nucleon scattering using a 3.35 ×10 4 kg day exposure of the Large Underground Xenon (LUX) experiment. A dual-phase xenon time projection chamber with 250 kg of active mass is operated at the Sanford Underground Research Facility under Lead, South Dakota (USA). With roughly fourfold improvement in sensitivity for high WIMP masses relative to our previous results, this search yields no evidence of WIMP nuclear recoils. At a WIMP mass of 50 GeV c –2, WIMP-nucleon spin-independent cross sections above 2.2 ×10 –46 cm 2 are excluded at the 90%more » confidence level. When combined with the previously reported LUX exposure, this exclusion strengthens to 1.1 × 10 –46 cm 2 at 50 GeV c –2.« less

The Use of a Gain Monitoring System in the G0 Experiment

NASA Astrophysics Data System (ADS)

Nakos, Melissa T.

2001-11-01

The main goal of the G0 experiment is to find the contributions of the three light quark flavors to the electromagnetic properties of the nucleon by comparing the electromagnetic and neutral weak form factors, measured through the observation of parity-violating asymmetries in elastic electron-nucleon scattering. The experiment will measure the time of flight and the momentum transfer of protons (at forward scattering angles) and electrons (at backward scattering angles). The detectors used in this experiment are plastic scintillators placed in the focal plane of a magnetic spectrometer such that the momentum transfer is directly measured. A gain monitoring system has been designed to track the timing and gain of the photomultiplier tubes at the end of each scintillator. The system is made of a pulsed ultraviolet laser, pure silica fiber optic cables, and a masking system to mimic a real event.

Results from a Search for Dark Matter in the Complete LUX Exposure.

PubMed

Akerib, D S; Alsum, S; Araújo, H M; Bai, X; Bailey, A J; Balajthy, J; Beltrame, P; Bernard, E P; Bernstein, A; Biesiadzinski, T P; Boulton, E M; Bramante, R; Brás, P; Byram, D; Cahn, S B; Carmona-Benitez, M C; Chan, C; Chiller, A A; Chiller, C; Currie, A; Cutter, J E; Davison, T J R; Dobi, A; Dobson, J E Y; Druszkiewicz, E; Edwards, B N; Faham, C H; Fiorucci, S; Gaitskell, R J; Gehman, V M; Ghag, C; Gibson, K R; Gilchriese, M G D; Hall, C R; Hanhardt, M; Haselschwardt, S J; Hertel, S A; Hogan, D P; Horn, M; Huang, D Q; Ignarra, C M; Ihm, M; Jacobsen, R G; Ji, W; Kamdin, K; Kazkaz, K; Khaitan, D; Knoche, R; Larsen, N A; Lee, C; Lenardo, B G; Lesko, K T; Lindote, A; Lopes, M I; Manalaysay, A; Mannino, R L; Marzioni, M F; McKinsey, D N; Mei, D-M; Mock, J; Moongweluwan, M; Morad, J A; Murphy, A St J; Nehrkorn, C; Nelson, H N; Neves, F; O'Sullivan, K; Oliver-Mallory, K C; Palladino, K J; Pease, E K; Phelps, P; Reichhart, L; Rhyne, C; Shaw, S; Shutt, T A; Silva, C; Solmaz, M; Solovov, V N; Sorensen, P; Stephenson, S; Sumner, T J; Szydagis, M; Taylor, D J; Taylor, W C; Tennyson, B P; Terman, P A; Tiedt, D R; To, W H; Tripathi, M; Tvrznikova, L; Uvarov, S; Verbus, J R; Webb, R C; White, J T; Whitis, T J; Witherell, M S; Wolfs, F L H; Xu, J; Yazdani, K; Young, S K; Zhang, C

2017-01-13

We report constraints on spin-independent weakly interacting massive particle (WIMP)-nucleon scattering using a 3.35×10^{4}  kg day exposure of the Large Underground Xenon (LUX) experiment. A dual-phase xenon time projection chamber with 250 kg of active mass is operated at the Sanford Underground Research Facility under Lead, South Dakota (USA). With roughly fourfold improvement in sensitivity for high WIMP masses relative to our previous results, this search yields no evidence of WIMP nuclear recoils. At a WIMP mass of 50  GeV c^{-2}, WIMP-nucleon spin-independent cross sections above 2.2×10^{-46}  cm^{2} are excluded at the 90% confidence level. When combined with the previously reported LUX exposure, this exclusion strengthens to 1.1×10^{-46}  cm^{2} at 50  GeV c^{-2}.

Pulse-shape discrimination between electron and nuclear recoils in a NaI(Tl) crystal

NASA Astrophysics Data System (ADS)

Lee, H. S.; Adhikari, G.; Adhikari, P.; Choi, S.; Hahn, I. S.; Jeon, E. J.; Joo, H. W.; Kang, W. G.; Kim, G. B.; Kim, H. J.; Kim, H. O.; Kim, K. W.; Kim, N. Y.; Kim, S. K.; Kim, Y. D.; Kim, Y. H.; Lee, J. H.; Lee, M. H.; Leonard, D. S.; Li, J.; Oh, S. Y.; Olsen, S. L.; Park, H. K.; Park, H. S.; Park, K. S.; Shim, J. H.; So, J. H.

2015-08-01

We report on the response of a high light-output NaI(Tl) crystal to nuclear recoils induced by neutrons from an Am-Be source and compare the results with the response to electron recoils produced by Compton-scattered 662 keV γ-rays from a 137Cs source. The measured pulse-shape discrimination (PSD) power of the NaI(Tl) crystal is found to be significantly improved because of the high light output of the NaI(Tl) detector. We quantify the PSD power with a quality factor and estimate the sensitivity to the interaction rate for weakly interacting massive particles (WIMPs) with nucleons, and the result is compared with the annual modulation amplitude observed by the DAMA/LIBRA experiment. The sensitivity to spin-independent WIMP-nucleon interactions based on 100 kg·year of data from NaI detectors is estimated with simulated experiments, using the standard halo model.

Studies of the Three-Nucleon System Dynamics in the Deuteron-Proton Breakup Reaction

NASA Astrophysics Data System (ADS)

Ciepał, I.; Kłos, B.; Stephan, E.; Kistryn, St.; Biegun, A.; Bodek, K.; Deltuva, A.; Epelbaum, E.; Eslami-Kalantari, M.; Fonseca, A. C.; Golak, J.; Jha, V.; Kalantar-Nayestanaki, N.; Kamada, H.; Khatri, G.; Kirillov, Da.; Kirillov, Di.; Kliczewski, St.; Kozela, A.; Kravcikova, M.; Machner, H.; Magiera, A.; Martinska, G.; Messchendorp, J.; Nogga, A.; Parol, W.; Ramazani-Moghaddam-Arani, A.; Roy, B. J.; Sakai, H.; Sekiguchi, K.; Sitnik, I.; Siudak, R.; Skibiński, R.; Sworst, R.; Urban, J.; Witała, H.; Zejma, J.

2014-03-01

One of the most important goals of modern nuclear physics is to contruct nuclear force model which properly describes the experimental data. To develop and test predictions of current models the breakup 1H(overrightarrow d, pp)n reaction was investigated experimentally at 100 and 130 MeV deuteron beam energies. Rich set of data for cross section, vector and tensor analyzing powers was obtained with the use of the SALAD and BINA detectors at KVI and Germanium Wall setup at FZ-Jülich. Results are compared with various theoretical approaches which describe the three-nucleon (3N) system dynamics. For correct description of the cross section data both, three-nucleon force (3NF) and Coulomb force, have to be included into calculations and influence of those ingredients is seizable at specific parts of the phase space. In case of the vector analyzing powers very low sensitivity to any effects beyond nucleon-nucleon interaction was found. At 130 MeV, the Axy data are not correctly described when 3NF models are included into calculations.

Neutral-current x-distributions

DOE R&D Accomplishments Database

Friedman, J. I.; Kendall, H. W.; Bogert, D.; Burnstein, R.; Fisk, R.; Fuess, S.; Bofill, J.; Busza, W.; Eldridge, T.; Abolins, M.; Brock, R.; et al.

1984-06-01

The role of the semi leptonic neutral current interaction as a probe of nucleon structure is examined. Previous measurements of neutral current x-distributions are reviewed, and new results from the Fermilab - MIT - MSU collaboration are presented.

Search of low-mass WIMPs with a p -type point contact germanium detector in the CDEX-1 experiment

NASA Astrophysics Data System (ADS)

Zhao, W.; Yue, Q.; Kang, K. J.; Cheng, J. P.; Li, Y. J.; Wong, H. T.; Lin, S. T.; Chang, J. P.; Chen, J. H.; Chen, Q. H.; Chen, Y. H.; Deng, Z.; Du, Q.; Gong, H.; Hao, X. Q.; He, H. J.; He, Q. J.; Huang, H. X.; Huang, T. R.; Jiang, H.; Li, H. B.; Li, J.; Li, J.; Li, J. M.; Li, X.; Li, X. Y.; Li, Y. L.; Lin, F. K.; Liu, S. K.; Lü, L. C.; Ma, H.; Ma, J. L.; Mao, S. J.; Qin, J. Q.; Ren, J.; Ren, J.; Ruan, X. C.; Sharma, V.; Shen, M. B.; Singh, L.; Singh, M. K.; Soma, A. K.; Su, J.; Tang, C. J.; Wang, J. M.; Wang, L.; Wang, Q.; Wu, S. Y.; Wu, Y. C.; Xianyu, Z. Z.; Xiao, R. Q.; Xing, H. Y.; Xu, F. Z.; Xu, Y.; Xu, X. J.; Xue, T.; Yang, L. T.; Yang, S. W.; Yi, N.; Yu, C. X.; Yu, H.; Yu, X. Z.; Zeng, M.; Zeng, X. H.; Zeng, Z.; Zhang, L.; Zhang, Y. H.; Zhao, M. G.; Zhou, Z. Y.; Zhu, J. J.; Zhu, W. B.; Zhu, X. Z.; Zhu, Z. H.; CDEX Collaboration

2016-05-01

The CDEX-1 experiment conducted a search of low-mass (<10 GeV /c2 ) weakly interacting massive particles dark matter at the China Jinping Underground Laboratory using a p-type point-contact germanium detector with a fiducial mass of 915 g at a physics analysis threshold of 475 eVee. We report the hardware setup, detector characterization, data acquisition, and analysis procedures of this experiment. No excess of unidentified events is observed after the subtraction of the known background. Using 335.6 kg-days of data, exclusion constraints on the weakly interacting massive particle-nucleon spin-independent and spin-dependent couplings are derived.

New results from the search for low-mass weakly interacting massive particles with the CDMS low ionization threshold experiment

DOE PAGES

Agnese, R.

2016-02-17

The CDMS low ionization threshold experiment (CDMSlite) uses cryogenic germanium detectors operated at a relatively high bias voltage to amplify the phonon signal in the search for weakly interacting massive particles (WIMPs). Our results are presented from the second CDMSlite run with an exposure of 70 kg days, which reached an energy threshold for electron recoils as low as 56 eV. Furthermore, a fiducialization cut reduces backgrounds below those previously reported by CDMSlite. Lastly, new parameter space for the WIMP-nucleon spin-independent cross section is excluded forWIMP masses between 1.6 and 5.5 GeV/c 2.

Measurement of the multi-TeV neutrino interaction cross-section with IceCube using Earth absorption

NASA Astrophysics Data System (ADS)

Aartsen, M. G.; Hill, G. C.; Kyriacou, A.; Robertson, S.; Wallace, A.; Whelan, B. J.; Ackermann, M.; Bernardini, E.; Blot, S.; Bradascio, F.; Bretz, H.-P.; Brostean-Kaiser, J.; Franckowiak, A.; Jacobi, E.; Karg, T.; Kintscher, T.; Kunwar, S.; Nahnhauer, R.; Satalecka, K.; Spiering, C.; Stachurska, J.; Stasik, A.; Strotjohann, N. L.; Terliuk, A.; Usner, M.; van Santen, J.; Adams, J.; Bagherpour, H.; Aguilar, J. A.; Ansseau, I.; Heereman, D.; Meagher, K.; Meures, T.; O'Murchadha, A.; Pinat, E.; Raab, C.; Ahlers, M.; Koskinen, D. J.; Larson, M. J.; Medici, M.; Rameez, M.; Ahrens, M.; Bohm, C.; Dumm, J. P.; Finley, C.; Flis, S.; Hultqvist, K.; Walck, C.; Zoll, M.; Al Samarai, I.; Bron, S.; Carver, T.; Christov, A.; Montaruli, T.; Altmann, D.; Anton, G.; Glüsenkamp, T.; Katz, U.; Kittler, T.; Tselengidou, M.; Andeen, K.; Plum, M.; Anderson, T.; Delaunay, J. J.; Dunkman, M.; Eller, P.; Huang, F.; Keivani, A.; Lanfranchi, J. L.; Pankova, D. V.; Teši´, G.; Turley, C. F.; Weiss, M. J.; Argüelles, C.; Axani, S.; Collin, G. H.; Conrad, J. M.; Moulai, M.; Auffenberg, J.; Brenzke, M.; Glauch, T.; Haack, C.; Kalaczynski, P.; Koschinsky, J. P.; Leuermann, M.; Rädel, L.; Reimann, R.; Rongen, M.; Sälzer, T.; Schoenen, S.; Schumacher, L.; Stettner, J.; Vehring, M.; Vogel, E.; Wallraff, M.; Waza, A.; Wiebusch, C. H.; Bai, X.; Barron, J. P.; Giang, W.; Grant, D.; Kopper, C.; Moore, R. W.; Nowicki, S. C.; Herrera, S. E. Sanchez; Sarkar, S.; Wandler, F. D.; Weaver, C.; Wood, T. R.; Woolsey, E.; Yanez, J. P.; Barwick, S. W.; Yodh, G.; Baum, V.; Böser, S.; di Lorenzo, V.; Eberhardt, B.; Ehrhardt, T.; Köpke, L.; Krückl, G.; Momenté, G.; Peiffer, P.; Sandroos, J.; Steuer, A.; Wiebe, K.; Bay, R.; Filimonov, K.; Price, P. B.; Woschnagg, K.; Beatty, J. J.; Tjus, J. Becker; Bos, F.; Eichmann, B.; Kroll, M.; Schöneberg, S.; Tenholt, F.; Becker, K.-H.; Bindig, D.; Helbing, K.; Hickford, S.; Hoffmann, R.; Lauber, F.; Naumann, U.; Pollmann, A. Obertacke; Soldin, D.; Benzvi, S.; Cross, R.; Berley, D.; Blaufuss, E.; Cheung, E.; Felde, J.; Friedman, E.; Hellauer, R.; Hoffman, K. D.; Maunu, R.; Olivas, A.; Schmidt, T.; Song, M.; Sullivan, G. W.; Besson, D. Z.; Binder, G.; Klein, S. R.; Miarecki, S.; Palczewski, T.; Tatar, J.; Börner, M.; Fuchs, T.; Hünnefeld, M.; Meier, M.; Menne, T.; Pieloth, D.; Rhode, W.; Ruhe, T.; Sandrock, A.; Schlunder, P.; Soedingrekso, J.; Werthebach, J.; Bose, D.; Dujmovic, H.; in, S.; Jeong, M.; Kang, W.; Kim, J.; Rott, C.; Botner, O.; Burgman, A.; Hallgren, A.; Pérez de Los Heros, C.; Unger, E.; Bourbeau, J.; Braun, J.; Casey, J.; Chirkin, D.; Day, M.; Desiati, P.; Díaz-Vélez, J. C.; Fahey, S.; Ghorbani, K.; Griffith, Z.; Halzen, F.; Hanson, K.; Hokanson-Fasig, B.; Hoshina, K.; Jero, K.; Karle, A.; Kauer, M.; Kelley, J. L.; Kheirandish, A.; Liu, Q. R.; Luszczak, W.; Mancina, S.; McNally, F.; Merino, G.; Schneider, A.; Tobin, M. N.; Tosi, D.; Ty, B.; Vandenbroucke, J.; Wandkowsky, N.; Wendt, C.; Westerhoff, S.; Wille, L.; Wolf, M.; Wood, J.; Xu, D. L.; Yuan, T.; Brayeur, L.; Casier, M.; de Clercq, C.; de Vries, K. D.; de Wasseige, G.; Kunnen, J.; Lünemann, J.; Maggi, G.; Toscano, S.; van Eijndhoven, N.; Clark, K.; Classen, L.; Kappes, A.; Coenders, S.; Huber, M.; Krings, K.; Rea, I. C.; Resconi, E.; Turcati, A.; Cowen, D. F.; de André, J. P. A. M.; Deyoung, T.; Hignight, J.; Lennarz, D.; Mahn, K. B. M.; Micallef, J.; Neer, G.; Rysewyk, D.; Dembinski, H.; Evenson, P. A.; Gaisser, T. K.; Gonzalez, J. G.; Koirala, R.; Pandya, H.; Seckel, D.; Stanev, T.; Tilav, S.; De Ridder, S.; Labare, M.; Ryckbosch, D.; van Driessche, W.; Vanheule, S.; Vraeghe, M.; de With, M.; Hebecker, D.; Kolanoski, H.; Fazely, A. R.; Ter-Antonyan, S.; Xu, X. W.; Gallagher, J.; Gerhardt, L.; Goldschmidt, A.; Nygren, D. R.; Przybylski, G. T.; Stezelberger, T.; Stokstad, R. G.; Ishihara, A.; Kim, M.; Kuwabara, T.; Lu, L.; Mase, K.; Relich, M.; Stößl, A.; Yoshida, S.; Japaridze, G. S.; Jones, B. J. P.; Kiryluk, J.; Lesiak-Bzdak, M.; Niederhausen, H.; Xu, Y.; Kohnen, G.; Kopper, S.; Nakarmi, P.; Pepper, J. A.; Toale, P. A.; Williams, D. R.; Kowalski, M.; Kurahashi, N.; Relethford, B.; Richman, M.; Wills, L.; Madsen, J.; Seunarine, S.; Spiczak, G. M.; Maruyama, R.; Rawlins, K.; Sarkar, S.; Sutherland, M.; Taboada, I.; Tung, C. F.; IceCube Collaboration

2017-11-01

Neutrinos interact only very weakly, so they are extremely penetrating. The theoretical neutrino-nucleon interaction cross-section, however, increases with increasing neutrino energy, and neutrinos with energies above 40 teraelectronvolts (TeV) are expected to be absorbed as they pass through the Earth. Experimentally, the cross-section has been determined only at the relatively low energies (below 0.4 TeV) that are available at neutrino beams from accelerators. Here we report a measurement of neutrino absorption by the Earth using a sample of 10,784 energetic upward-going neutrino-induced muons. The flux of high-energy neutrinos transiting long paths through the Earth is attenuated compared to a reference sample that follows shorter trajectories. Using a fit to the two-dimensional distribution of muon energy and zenith angle, we determine the neutrino-nucleon interaction cross-section for neutrino energies 6.3-980 TeV, more than an order of magnitude higher than previous measurements. The measured cross-section is about 1.3 times the prediction of the standard model, consistent with the expectations for charged- and neutral-current interactions. We do not observe a large increase in the cross-section with neutrino energy, in contrast with the predictions of some theoretical models, including those invoking more compact spatial dimensions or the production of leptoquarks. This cross-section measurement can be used to set limits on the existence of some hypothesized beyond-standard-model particles, including leptoquarks.

Measurement of the multi-TeV neutrino interaction cross-section with IceCube using Earth absorption.

PubMed

2017-11-30

Neutrinos interact only very weakly, so they are extremely penetrating. The theoretical neutrino-nucleon interaction cross-section, however, increases with increasing neutrino energy, and neutrinos with energies above 40 teraelectronvolts (TeV) are expected to be absorbed as they pass through the Earth. Experimentally, the cross-section has been determined only at the relatively low energies (below 0.4 TeV) that are available at neutrino beams from accelerators. Here we report a measurement of neutrino absorption by the Earth using a sample of 10,784 energetic upward-going neutrino-induced muons. The flux of high-energy neutrinos transiting long paths through the Earth is attenuated compared to a reference sample that follows shorter trajectories. Using a fit to the two-dimensional distribution of muon energy and zenith angle, we determine the neutrino-nucleon interaction cross-section for neutrino energies 6.3-980 TeV, more than an order of magnitude higher than previous measurements. The measured cross-section is about 1.3 times the prediction of the standard model, consistent with the expectations for charged- and neutral-current interactions. We do not observe a large increase in the cross-section with neutrino energy, in contrast with the predictions of some theoretical models, including those invoking more compact spatial dimensions or the production of leptoquarks. This cross-section measurement can be used to set limits on the existence of some hypothesized beyond-standard-model particles, including leptoquarks.

Phenomenology of ultrahigh energy neutrino interactions and fluxes

NASA Astrophysics Data System (ADS)

Hussain, Shahid

There are several models that predict the existence of high and ultrahigh energy (UHE) neutrinos; neutrinos that have amazingly high energies---energies above 10 15 eV. No man-made machines, existing or planned, can produce any particles of this high energies. It is the energies of these neutrinos that make them very interesting for the particle physics and astrophysics community; these neutrinos can be a unique tool to study the unknown regimes of energy, space, and time. Consequently, there is intense experimental activity focused on the detection of these neutrinos; no UHE neutrinos have been detected by these experiments so far. However, most of the UHE neutrino flux models predict that the fluxes of these neutrinos might be too small to be detected by the current detectors. Therefore, more powerful detectors are being built and we are at the beginning of a new and exciting era in neutrino astronomy. The interactions and fluxes of UHE neutrinos both are unknown experimentally. Our focus here is to explore, by numerically calculating observable signals from these neutrinos, different scenarios that can arise by the inter play of UHE neutrino interaction and flux models. Given several AGN and cosmogenic neutrino flux models, we look at two possibilities for neutrino interactions: (i) Neutrinos have standard model weak interactions at ultrahigh energies. (ii) neutrino interactions are enhanced around a TeV mass-scale, as implied by low scale gravity models with extra dimensions. The standard model weak and low scale gravity enhanced neutrino-nucleon interactions of UHE neutrinos both produce observable signals. In standard model, the charged current neutrino-nucleon interactions give muons, taus, and particle showers, and the neutral current interactions give particle showers. In low scale gravity, the micro black hole formation (and its subsequent decay) and the graviton exchange both give particle showers. Muons, taus, and the showers can be detected by the optical Cherenkov radiation they produce; showers can also be detected by the coherent radio Cherenkov signal they produce which is much powerful than their optical Cherenkov signal. We give the formalism for calculating muon, tau, and shower rates for the optical (ICECUBE- like) and the shower rates for the radio (RICE-like) Cherenkov detectors. Our focus is on simulation of the radio signal from neutrino-initiated showers and calculation of the expected neutrino-initiated shower rates for RICE. Finally, given the calculated rates for muons, taus, and showers, we discuss what we can say about the models for UHE neutrino fluxes and interactions.

Dark energy and equivalence principle constraints from astrophysical tests of the stability of the fine-structure constant

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

Martins, C.J.A.P.; Pinho, A.M.M.; Alves, R.F.C.

2015-08-01

Astrophysical tests of the stability of fundamental couplings, such as the fine-structure constant α, are becoming an increasingly powerful probe of new physics. Here we discuss how these measurements, combined with local atomic clock tests and Type Ia supernova and Hubble parameter data, constrain the simplest class of dynamical dark energy models where the same degree of freedom is assumed to provide both the dark energy and (through a dimensionless coupling, ζ, to the electromagnetic sector) the α variation. Specifically, current data tightly constrains a combination of ζ and the present dark energy equation of state w{sub 0}. Moreover, inmore » these models the new degree of freedom inevitably couples to nucleons (through the α dependence of their masses) and leads to violations of the Weak Equivalence Principle. We obtain indirect bounds on the Eötvös parameter η that are typically stronger than the current direct ones. We discuss the model-dependence of our results and briefly comment on how the forthcoming generation of high-resolution ultra-stable spectrographs will enable significantly tighter constraints.« less

Nucleon Spin Structure and Constituent Quark Model

NASA Astrophysics Data System (ADS)

Wang, Fan; Qing, Di; Chen, Xiang-Song; Goldman, T.

1998-10-01

The success of the constituent quark model has been challenged by the nucleon spin structure discovered in polarized deep inelastic scattering (DIS). We find that this puzzle is due to misidentifying the axial charge Δ q and the nonrelativistic quark spin. The space component of the quark axial vector current operator, int d^3x\\overlineψ γγ_5ψ =2s_q, defines the quark spin operator s_q, including not only the Pauli spin operator, which corresponds to the nonrelativistic quark spin s_q^NR, but also relativistic and quark-antiquark pair creation (annihilation) correction terms. Both of these suppress the quark spin contribution for a nucleon at rest due to transverse motion of the quark. The relativistic quark orbital angular momentum operator L_q=int d^3x\\overlineψ x× fracpartial iψ includes L^NRq and two correction terms which are exactly the same as those of sq but of opposite sign. They provide compensation which keeps the total nucleon spin frac 12 untouched no matter what kind of quark model is used. Nucleon spin can be decomposed either as s_q+Lq or as s_q^NR+L_q^NR. (The gluon degree of freedom is assumed to be frozen in the nucleon ground state at low energy scales.) The tensor charge δ q=int d^3x\\overlineψ Σ ψ of the nucleon is predicted to have similar but smaller corrections.

Recent progress in ab-initio studies of nuclear reactions of astrophysical interest with A ≤ 3

NASA Astrophysics Data System (ADS)

Marcucci, Laura E.

2018-03-01

We review the most recent theoretical studies of nuclear reactions of astrophysical interest involving few-nucleon systems. In particular, we focus on the consequences for the solar neutrino fluxes of the recent determination for the astrophysical S-factor of the proton weak capture by proton, and on the radiative capture of protons by deuterons in the energy range of interest for Big Bang Nucleosynthesis.

Structure and decays of nuclear three-body systems: The Gamow coupled-channel method in Jacobi coordinates

NASA Astrophysics Data System (ADS)

Wang, S. M.; Michel, N.; Nazarewicz, W.; Xu, F. R.

2017-10-01

Background: Weakly bound and unbound nuclear states appearing around particle thresholds are prototypical open quantum systems. Theories of such states must take into account configuration mixing effects in the presence of strong coupling to the particle continuum space. Purpose: To describe structure and decays of three-body systems, we developed a Gamow coupled-channel (GCC) approach in Jacobi coordinates by employing the complex-momentum formalism. We benchmarked the complex-energy Gamow shell model (GSM) against the new framework. Methods: The GCC formalism is expressed in Jacobi coordinates, so that the center-of-mass motion is automatically eliminated. To solve the coupled-channel equations, we use hyperspherical harmonics to describe the angular wave functions while the radial wave functions are expanded in the Berggren ensemble, which includes bound, scattering, and Gamow states. Results: We show that the GCC method is both accurate and robust. Its results for energies, decay widths, and nucleon-nucleon angular correlations are in good agreement with the GSM results. Conclusions: We have demonstrated that a three-body GSM formalism explicitly constructed in the cluster-orbital shell model coordinates provides results similar to those with a GCC framework expressed in Jacobi coordinates, provided that a large configuration space is employed. Our calculations for A =6 systems and 26O show that nucleon-nucleon angular correlations are sensitive to the valence-neutron interaction. The new GCC technique has many attractive features when applied to bound and unbound states of three-body systems: it is precise, is efficient, and can be extended by introducing a microscopic model of the core.

Semilocal momentum-space regularized chiral two-nucleon potentials up to fifth order

NASA Astrophysics Data System (ADS)

Reinert, P.; Krebs, H.; Epelbaum, E.

2018-05-01

We introduce new semilocal two-nucleon potentials up to fifth order in the chiral expansion. We employ a simple regularization approach for the pion exchange contributions which i) maintains the long-range part of the interaction, ii) is implemented in momentum space and iii) can be straightforwardly applied to regularize many-body forces and current operators. We discuss in detail the two-nucleon contact interactions at fourth order and demonstrate that three terms out of fifteen used in previous calculations can be eliminated via suitably chosen unitary transformations. The removal of the redundant contact terms results in a drastic simplification of the fits to scattering data and leads to interactions which are much softer ( i.e., more perturbative) than our recent semilocal coordinate-space regularized potentials. Using the pion-nucleon low-energy constants from matching pion-nucleon Roy-Steiner equations to chiral perturbation theory, we perform a comprehensive analysis of nucleon-nucleon scattering and the deuteron properties up to fifth chiral order and study the impact of the leading F-wave two-nucleon contact interactions which appear at sixth order. The resulting chiral potentials at fifth order lead to an outstanding description of the proton-proton and neutron-proton scattering data from the self-consistent Granada-2013 database below the pion production threshold, which is significantly better than for any other chiral potential. For the first time, the chiral potentials match in precision and even outperform the available high-precision phenomenological potentials, while the number of adjustable parameters is, at the same time, reduced by about ˜ 40%. Last but not least, we perform a detailed error analysis and, in particular, quantify for the first time the statistical uncertainties of the fourth- and the considered sixth-order contact interactions.

Meson exchange current (MEC) models in neutrino interaction generators

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

Katori, Teppei

2015-05-15

Understanding of the so-called 2 particle-2 hole (2p-2h) effect is an urgent program in neutrino interaction physics for current and future oscillation experiments. Such processes are believed to be responsible for the event excesses observed by recent neutrino experiments. The 2p-2h effect is dominated by the meson exchange current (MEC), and is accompanied by a 2-nucleon emission from the primary vertex, instead of a single nucleon emission from the charged-current quasi-elastic (CCQE) interaction. Current and future high resolution experiments can potentially nail down this effect. For this reason, there are world wide efforts to model and implement this process inmore » neutrino interaction simulations. In these proceedings, I would like to describe how this channel is modeled in neutrino interaction generators.« less

Nuclear effects in (anti)neutrino charge-current quasielastic scattering at MINER νA kinematics

NASA Astrophysics Data System (ADS)

Ivanov, M. V.; Antonov, A. N.; Megias, G. D.; González-Jiménez, R.; Barbaro, M. B.; Caballero, J. A.; Donnelly, T. W.; Udías, J. M.

2018-05-01

We compare the characteristics of the charged-current quasielastic (anti)neutrino scattering obtained in two different nuclear models, the phenomenological SuperScaling Approximation and the model using a realistic spectral function S(p, ɛ) that gives a scaling function in accordance with the (e, e‧ ) scattering data, with the recent data published by the MiniBooNE, MINER νA, and NOMAD collaborations. The spectral function accounts for the nucleon-nucleon (NN) correlations by using natural orbitals from the Jastrow correlation method and has a realistic energy dependence. Both models provide a good description of the MINER νA and NOMAD data without the need of an ad hoc increase of the value of the mass parameter in the axial-vector dipole form factor. The models considered in this work, based on the the impulse approximation (IA), underpredict the MiniBooNE data for the flux-averaged charged-current quasielastic {ν }μ ({\\bar{ν }}μ ){+}12\\text{C} differential cross section per nucleon and the total cross sections, although the shape of the cross sections is represented by the approaches. The discrepancy is most likely due to missing of the effects beyond the IA, e.g., those of the 2p–2h meson exchange currents that have contribution in the transverse responses.

Coupled-cluster computations of atomic nuclei

NASA Astrophysics Data System (ADS)

Hagen, G.; Papenbrock, T.; Hjorth-Jensen, M.; Dean, D. J.

2014-09-01

In the past decade, coupled-cluster theory has seen a renaissance in nuclear physics, with computations of neutron-rich and medium-mass nuclei. The method is efficient for nuclei with product-state references, and it describes many aspects of weakly bound and unbound nuclei. This report reviews the technical and conceptual developments of this method in nuclear physics, and the results of coupled-cluster calculations for nucleonic matter, and for exotic isotopes of helium, oxygen, calcium, and some of their neighbors.

Quasielastic neutrino charged-current scattering off 12C: Effects of the meson exchange currents and large nucleon axial mass

NASA Astrophysics Data System (ADS)

Butkevich, A. V.; Luchuk, S. V.

2018-04-01

The quasielastic scattering of muon neutrino and electrons on a carbon target are analyzed using the relativistic distorted-wave impulse approximation (RDWIA). We also evaluate the contribution of the two-particle and two-hole meson exchange current (2 p -2 h MEC) to electroweak response functions. The nuclear model dependence of the (anti)neutrino cross sections is studied within the RDWIA+MEC approach and RDWIA model with the large nucleon axial mass. It is shown that the results for the squared momentum transfer distribution d σ /d Q2 and for invariant mass of the final hadronic system distribution d σ /d W obtained within these models are substantially different.

A Study of Multi-Λ Hypernuclei Within Spherical Relativistic Mean-Field Approach

NASA Astrophysics Data System (ADS)

Rather, Asloob A.; Ikram, M.; Usmani, A. A.; Kumar, B.; Patra, S. K.

2017-12-01

This research article is a follow up of an earlier work by M. Ikram et al., reported in Int. J. Mod. Phys. E 25, 1650103 (2016) where we searched for Λ magic numbers in experimentally confirmed doubly magic nucleonic cores in light to heavy mass region (i.e., 16 O-208 P b) by injecting Λ's into them. In the present manuscript, working within the state of the art relativistic mean field theory with the inclusion of Λ N and ΛΛ interaction in addition to nucleon-meson NL 3∗ effective force, we extend the search of lambda magic numbers in multi- Λ hypernuclei using the predicted doubly magic nucleonic cores 292120, 304120, 360132, 370132, 336138, 396138 of the elusive superheavy mass regime. In analogy to well established signatures of magicity in conventional nuclear theory, the prediction of hypernuclear magicities is made on the basis of one-, two- Λ separation energy ( S Λ, S 2Λ) and two lambda shell gaps ( δ 2Λ) in multi- Λ hypernuclei. The calculations suggest that the Λ numbers 92, 106, 126, 138, 184, 198, 240, and 258 might be the Λ shell closures after introducing the Λ's in the elusive superheavy nucleonic cores. The appearance of new lambda shell closures apart from the nucleonic ones predicted by various relativistic and non-relativistic theoretical investigations can be attributed to the relatively weak strength of the spin-orbit coupling in hypernuclei compared to normal nuclei. Further, the predictions made in multi- Λ hypernuclei under study resembles closely the magic numbers in conventional nuclear theory suggested by various relativistic and non-relativistic theoretical models. Moreover, in support of the Λ shell closure, the investigation of Λ pairing energy and effective Λ pairing gap has been made. We noticed a very close agreement of the predicted Λ shell closures with the survey made on the pretext of S Λ, S 2Λ, and δ 2Λ except for the appearance of magic numbers corresponding to Λ = 156 which manifest in Λ effective pairing gap and pairing energy. Also, the lambda single-particle spectrum is analyzed to mark the energy shell gap for further strengthening the predictions made on the basis of separation energies and shell gaps. Lambda and nucleon spin-orbit interactions are analyzed to confirm the reduction in magnitude of Λ spin-orbit interaction compared to the nucleonic case, however the interaction profile is similar in both the cases. Lambda and nucleon density distributions have been investigated to reveal the impurity effect of Λ hyperons which make the depression of central density of the core of superheavy doubly magic nuclei. Lambda skin structure is also seen.

Limits on Light Weakly Interacting Massive Particles from the First 102.8 kg×day Data of the CDEX-10 Experiment

NASA Astrophysics Data System (ADS)

Jiang, H.; Jia, L. P.; Yue, Q.; Kang, K. J.; Cheng, J. P.; Li, Y. J.; Wong, H. T.; Agartioglu, M.; An, H. P.; Chang, J. P.; Chen, J. H.; Chen, Y. H.; Deng, Z.; Du, Q.; Gong, H.; He, L.; Hu, J. W.; Hu, Q. D.; Huang, H. X.; Li, H. B.; Li, H.; Li, J. M.; Li, J.; Li, X.; Li, X. Q.; Li, Y. L.; Liao, B.; Lin, F. K.; Lin, S. T.; Liu, S. K.; Liu, Y. D.; Liu, Y. Y.; Liu, Z. Z.; Ma, H.; Ma, J. L.; Pan, H.; Ren, J.; Ruan, X. C.; Sevda, B.; Sharma, V.; Shen, M. B.; Singh, L.; Singh, M. K.; Sun, T. X.; Tang, C. J.; Tang, W. Y.; Tian, Y.; Wang, G. F.; Wang, J. M.; Wang, L.; Wang, Q.; Wang, Y.; Wu, S. Y.; Wu, Y. C.; Xing, H. Y.; Xu, Y.; Xue, T.; Yang, L. T.; Yang, S. W.; Yi, N.; Yu, C. X.; Yu, H. J.; Yue, J. F.; Zeng, X. H.; Zeng, M.; Zeng, Z.; Zhang, F. S.; Zhang, Y. H.; Zhao, M. G.; Zhou, J. F.; Zhou, Z. Y.; Zhu, J. J.; Zhu, Z. H.; CDEX Collaboration

2018-06-01

We report the first results of a light weakly interacting massive particles (WIMPs) search from the CDEX-10 experiment with a 10 kg germanium detector array immersed in liquid nitrogen at the China Jinping Underground Laboratory with a physics data size of 102.8 kg day. At an analysis threshold of 160 eVee, improved limits of 8 ×10-42 and 3 ×10-36 cm2 at a 90% confidence level on spin-independent and spin-dependent WIMP-nucleon cross sections, respectively, at a WIMP mass (mχ ) of 5 GeV /c2 are achieved. The lower reach of mχ is extended to 2 GeV /c2 .

First measurement of the muon neutrino charged current single pion production cross section on water with the T2K near detector

NASA Astrophysics Data System (ADS)

Abe, K.; Andreopoulos, C.; Antonova, M.; Aoki, S.; Ariga, A.; Assylbekov, S.; Autiero, D.; Ban, S.; Barbi, M.; Barker, G. J.; Barr, G.; Bartet-Friburg, P.; Batkiewicz, M.; Bay, F.; Berardi, V.; Berkman, S.; Bhadra, S.; Bienstock, S.; Blondel, A.; Bolognesi, S.; Bordoni, S.; Boyd, S. B.; Brailsford, D.; Bravar, A.; Bronner, C.; Buizza Avanzini, M.; Calland, R. G.; Campbell, T.; Cao, S.; Caravaca Rodríguez, J.; Cartwright, S. L.; Castillo, R.; Catanesi, M. G.; Cervera, A.; Cherdack, D.; Chikuma, N.; Christodoulou, G.; Clifton, A.; Coleman, J.; Collazuol, G.; Coplowe, D.; Cremonesi, L.; Dabrowska, A.; De Rosa, G.; Dealtry, T.; Denner, P. F.; Dennis, S. R.; Densham, C.; Dewhurst, D.; Di Lodovico, F.; Di Luise, S.; Dolan, S.; Drapier, O.; Duffy, K. E.; Dumarchez, J.; Dytman, S.; Dziewiecki, M.; Emery-Schrenk, S.; Ereditato, A.; Feusels, T.; Finch, A. J.; Fiorentini, G. A.; Friend, M.; Fujii, Y.; Fukuda, D.; Fukuda, Y.; Furmanski, A. P.; Galymov, V.; Garcia, A.; Giffin, S. G.; Giganti, C.; Gilje, K.; Gizzarelli, F.; Gonin, M.; Grant, N.; Hadley, D. R.; Haegel, L.; Haigh, M. D.; Hamilton, P.; Hansen, D.; Harada, J.; Hara, T.; Hartz, M.; Hasegawa, T.; Hastings, N. C.; Hayashino, T.; Hayato, Y.; Helmer, R. L.; Hierholzer, M.; Hillairet, A.; Himmel, A.; Hiraki, T.; Hirota, S.; Hogan, M.; Holeczek, J.; Horikawa, S.; Hosomi, F.; Huang, K.; Ichikawa, A. K.; Ieki, K.; Ikeda, M.; Imber, J.; Insler, J.; Intonti, R. A.; Irvine, T. J.; Ishida, T.; Ishii, T.; Iwai, E.; Iwamoto, K.; Izmaylov, A.; Jacob, A.; Jamieson, B.; Jiang, M.; Johnson, S.; Jo, J. H.; Jonsson, P.; Jung, C. K.; Kabirnezhad, M.; Kaboth, A. C.; Kajita, T.; Kakuno, H.; Kameda, J.; Karlen, D.; Karpikov, I.; Katori, T.; Kearns, E.; Khabibullin, M.; Khotjantsev, A.; Kielczewska, D.; Kikawa, T.; Kim, H.; Kim, J.; King, S.; Kisiel, J.; Knight, A.; Knox, A.; Kobayashi, T.; Koch, L.; Koga, T.; Konaka, A.; Kondo, K.; Kopylov, A.; Kormos, L. L.; Korzenev, A.; Koshio, Y.; Kropp, W.; Kudenko, Y.; Kurjata, R.; Kutter, T.; Lagoda, J.; Lamont, I.; Larkin, E.; Lasorak, P.; Laveder, M.; Lawe, M.; Lazos, M.; Lindner, T.; Liptak, Z. J.; Litchfield, R. P.; Li, X.; Longhin, A.; Lopez, J. P.; Lou, T.; Ludovici, L.; Lu, X.; Magaletti, L.; Mahn, K.; Malek, M.; Manly, S.; Marino, A. D.; Marteau, J.; Martin, J. F.; Martins, P.; Martynenko, S.; Maruyama, T.; Matveev, V.; Mavrokoridis, K.; Ma, W. Y.; Mazzucato, E.; McCarthy, M.; McCauley, N.; McFarland, K. S.; McGrew, C.; Mefodiev, A.; Metelko, C.; Mezzetto, M.; Mijakowski, P.; Miller, C. A.; Minamino, A.; Mineev, O.; Mine, S.; Missert, A.; Miura, M.; Moriyama, S.; Mueller, Th. A.; Murphy, S.; Myslik, J.; Nakadaira, T.; Nakahata, M.; Nakamura, K. G.; Nakamura, K.; Nakamura, K. D.; Nakayama, S.; Nakaya, T.; Nakayoshi, K.; Nantais, C.; Nielsen, C.; Nirkko, M.; Nishikawa, K.; Nishimura, Y.; Novella, P.; Nowak, J.; O'Keeffe, H. M.; Ohta, R.; Okumura, K.; Okusawa, T.; Oryszczak, W.; Oser, S. M.; Ovsyannikova, T.; Owen, R. A.; Oyama, Y.; Palladino, V.; Palomino, J. L.; Paolone, V.; Patel, N. D.; Pavin, M.; Payne, D.; Perkin, J. D.; Petrov, Y.; Pickard, L.; Pickering, L.; Pinzon Guerra, E. S.; Pistillo, C.; Popov, B.; Posiadala-Zezula, M.; Poutissou, J.-M.; Poutissou, R.; Przewlocki, P.; Quilain, B.; Radermacher, T.; Radicioni, E.; Ratoff, P. N.; Ravonel, M.; Rayner, M. A. M.; Redij, A.; Reinherz-Aronis, E.; Riccio, C.; Rojas, P.; Rondio, E.; Roth, S.; Rubbia, A.; Rychter, A.; Sacco, R.; Sakashita, K.; Sánchez, F.; Sato, F.; Scantamburlo, E.; Scholberg, K.; Schoppmann, S.; Schwehr, J.; Scott, M.; Seiya, Y.; Sekiguchi, T.; Sekiya, H.; Sgalaberna, D.; Shah, R.; Shaikhiev, A.; Shaker, F.; Shaw, D.; Shiozawa, M.; Shirahige, T.; Short, S.; Smy, M.; Sobczyk, J. T.; Sobel, H.; Sorel, M.; Southwell, L.; Stamoulis, P.; Steinmann, J.; Stewart, T.; Stowell, P.; Suda, Y.; Suvorov, S.; Suzuki, A.; Suzuki, K.; Suzuki, S. Y.; Suzuki, Y.; Tacik, R.; Tada, M.; Takahashi, S.; Takeda, A.; Takeuchi, Y.; Tanaka, H. K.; Tanaka, H. A.; Terhorst, D.; Terri, R.; Thakore, T.; Thompson, L. F.; Tobayama, S.; Toki, W.; Tomura, T.; Touramanis, C.; Tsukamoto, T.; Tzanov, M.; Uchida, Y.; Vacheret, A.; Vagins, M.; Vallari, Z.; Vasseur, G.; Wachala, T.; Wakamatsu, K.; Walter, C. W.; Wark, D.; Warzycha, W.; Wascko, M. O.; Weber, A.; Wendell, R.; Wilkes, R. J.; Wilking, M. J.; Wilkinson, C.; Wilson, J. R.; Wilson, R. J.; Yamada, Y.; Yamamoto, K.; Yamamoto, M.; Yanagisawa, C.; Yano, T.; Yen, S.; Yershov, N.; Yokoyama, M.; Yoo, J.; Yoshida, K.; Yuan, T.; Yu, M.; Zalewska, A.; Zalipska, J.; Zambelli, L.; Zaremba, K.; Ziembicki, M.; Zimmerman, E. D.; Zito, M.; Żmuda, J.; T2K Collaboration

2017-01-01

The T2K off-axis near detector, ND280, is used to make the first differential cross section measurements of muon neutrino charged current single positive pion production on a water target at energies ˜0.8 GeV . The differential measurements are presented as a function of the muon and pion kinematics, in the restricted phase space defined by pπ+>200 MeV /c , pμ>200 MeV /c , cos (θπ+) >0.3 and cos (θμ) >0.3 . The total flux integrated νμ charged current single positive pion production cross section on water in the restricted phase space is measured to be ⟨σ ⟩ϕ =4.25 ±0.48 (stat )±1.56 (syst )×10-40 cm2/nucleon . The total cross section is consistent with the NEUT prediction (5.03 ×10-40 cm2/nucleon ) and 2 σ lower than the GENIE prediction (7.68 ×10-40 cm2/nucleon ). The differential cross sections are in good agreement with the NEUT generator. The GENIE simulation reproduces well the shapes of the distributions, but overestimates the overall cross section normalization.

Improved Limits for Higgs-Portal Dark Matter from LHC Searches.

PubMed

Hoferichter, Martin; Klos, Philipp; Menéndez, Javier; Schwenk, Achim

2017-11-03

Searches for invisible Higgs decays at the Large Hadron Collider constrain dark matter Higgs-portal models, where dark matter interacts with the standard model fields via the Higgs boson. While these searches complement dark matter direct-detection experiments, a comparison of the two limits depends on the coupling of the Higgs boson to the nucleons forming the direct-detection nuclear target, typically parametrized in a single quantity f_{N}. We evaluate f_{N} using recent phenomenological and lattice-QCD calculations, and include for the first time the coupling of the Higgs boson to two nucleons via pion-exchange currents. We observe a partial cancellation for Higgs-portal models that makes the two-nucleon contribution anomalously small. Our results, summarized as f_{N}=0.308(18), show that the uncertainty of the Higgs-nucleon coupling has been vastly overestimated in the past. The improved limits highlight that state-of-the-art nuclear physics input is key to fully exploiting experimental searches.

Contribution to the G 0 violation of parity experience: calculation and simulation of radiative corrections and the background noise study; Contribution a l'experience G0 de violation de la parite : calcul et simulation des corrections radiatives et etude du bruit de fond (in French)

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

Guler, Hayg

2003-12-17

In the framework of quantum chromodynamics, the nucleon is made of three valence quarks surrpounded by a sea of gluons and quark-antiquark pairs. Only the only lightest quarks (u, d and s) contribute significantly to the nucleon properties. In Go we using the property of weak interaction to violate parity symmetry, in order to determine separately the contributions of the three types of quarks to nucleon form factors. The experiment, which takes place at Thomas Jefferson laboratory (USA), aims at measuring parity violation asymmetry in electron-proton scattering. By doing several measurements at different momentum squared of the exchanged photons andmore » for different kinematics (forward angle when the proton is detected and backward angle it will be the electron) will permit to determine separately strange quarks electric and magnetic contributions to nucleon form factors. To extract an asymmetry with small errors, it is necessary to correct all the beam parameters, and to have high enough counting rates in detectors. A special electronics was developed to treat information coming from 16 scintillator pairs for each of the 8 sectors of the Go spectrometer. A complete calculation of radiative corrections has been clone and Monte Carlo simulations with the GEANT program has permitted to determine the shape of the experimental spectra including inelastic background. This work will allow to do a comparison between experimental data and theoretical calculations based on the Standard Model.« less

Light-front representation of chiral dynamics with Δ isobar and large-N c relations

DOE PAGES

Granados, C.; Weiss, C.

2016-06-13

Transverse densities describe the spatial distribution of electromagnetic current in the nucleon at fixed light-front time. At peripheral distances b = O(M π –1) the densities are governed by chiral dynamics and can be calculated model-independently using chiral effective field theory (EFT). Recent work has shown that the EFT results can be represented in first-quantized form, as overlap integrals of chiral light-front wave functions describing the transition of the nucleon to soft-pion-nucleon intermediate states, resulting in a quantum-mechanical picture of the peripheral transverse densities. We now extend this representation to include intermediate states with Δ isobars and implement relations basedmore » on the large-N c limit of QCD. We derive the wave function overlap formulas for the Δ contributions to the peripheral transverse densities by way of a three-dimensional reduction of relativistic chiral EFT expressions. Our procedure effectively maintains rotational invariance and avoids the ambiguities with higher-spin particles in the light-front time-ordered approach. We study the interplay of πN and πΔ intermediate states in the quantum-mechanical picture of the densities in a transversely polarized nucleon. We show that the correct N c-scaling of the charge and magnetization densities emerges as the result of the particular combination of currents generated by intermediate states with degenerate N and Δ. The off-shell behavior of the chiral EFT is summarized in contact terms and can be studied easily. As a result, the methods developed here can be applied to other peripheral densities and to moments of the nucleon's generalized parton distributions.« less

Proton and antiproton production in deep inelastic muon-nucleon scattering at 280 GeV

NASA Astrophysics Data System (ADS)

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

1987-12-01

New results on proton and antiproton production in the target and current fragmentation regions of high energy muon-nucleon scattering are presented. Proton and antiproton production is investigated as a function of Feynman x and rapidity. No significant difference is observed between production on hydrogen and deuterium targets. Correlations between pp,pbar p andbar pbar p pairs are analysed and the results are compared with the predictions of the Lund fragmentation model.

Neutron-neutron quasifree scattering in nd breakup at 10 MeV

NASA Astrophysics Data System (ADS)

Malone, R. C.; Crowe, B.; Crowell, A. S.; Cumberbatch, L. C.; Esterline, J. H.; Fallin, B. A.; Friesen, F. Q. L.; Han, Z.; Howell, C. R.; Markoff, D.; Ticehurst, D.; Tornow, W.; Witała, H.

2016-03-01

The neutron-deuteron (nd) breakup reaction provides a rich environment for testing theoretical models of the neutron-neutron (nn) interaction. Current theoretical predictions based on rigorous ab-initio calculations agree well with most experimental data for this system, but there remain a few notable discrepancies. The cross section for nn quasifree (QFS) scattering is one such anomaly. Two recent experiments reported cross sections for this particular nd breakup configuration that exceed theoretical calculations by almost 20% at incident neutron energies of 26 and 25 MeV [1, 2]. The theoretical values can be brought into agreement with these results by increasing the strength of the 1S0 nn potential matrix element by roughly 10%. However, this modification of the nn effective range parameter and/or the 1S0 scattering length causes substantial charge-symmetry breaking in the nucleon-nucleon force and suggests the possibility of a weakly bound di-neutron state [3]. We are conducting new measurements of the cross section for nn QFS in nd breakup. The measurements are performed at incident neutron beam energies below 20 MeV. The neutron beam is produced via the 2H(d, n)3He reaction. The target is a deuterated plastic cylinder. Our measurements utilize time-of-flight techniques with a pulsed neutron beam and detection of the two emitted neutrons in coincidence. A description of our initial measurements at 10 MeV for a single scattering angle will be presented along with preliminary results. Also, plans for measurements at other energies with broad angular coverage will be discussed.

Cancellation Mechanism for Dark-Matter-Nucleon Interaction.

PubMed

Gross, Christian; Lebedev, Oleg; Toma, Takashi

2017-11-10

We consider a simple Higgs portal dark-matter model, where the standard model is supplemented with a complex scalar whose imaginary part plays the role of weakly interacting massive particle dark matter (DM). We show that the direct DM detection cross section vanishes at the tree level and zero momentum transfer due to a cancellation by virtue of a softly broken symmetry. This cancellation is operative for any mediator masses. As a result, our electroweak-scale dark matter satisfies all of the phenomenological constraints quite naturally.

Isoscalar giant monopole resonance in Sn isotopes using a quantum molecular dynamics model

NASA Astrophysics Data System (ADS)

Tao, C.; Ma, Y. G.; Zhang, G. Q.; Cao, X. G.; Fang, D. Q.; Wang, H. W.; Xu, J.

2013-12-01

The isoscalar giant monopole resonance (GMR) in Sn isotopes and other nuclei is investigated in the framework of the isospin-dependent quantum molecular dynamics (IQMD) model. The spectrum of GMR is calculated by taking the rms radius of a nucleus as its monopole moment. The peak energy, the FWHM, and the strength of the GMR extracted by a Gaussian fit to the spectrum have been studied. The GMR peak energies for Sn isotopes from the calculations using a mass-number-dependent Gaussian wave-packet width σr for nucleons are found to be overestimated and show a weak dependence on the mass number compared with the experimental data. However, it is found that experimental data of the GMR peak energies for 56Ni, 90Zr, and 208Pb as well as Sn isotopes can be nicely reproduced after taking into account the isospin dependence in isotope chains in addition to the mass-number dependence of σr for nucleons in the IQMD model calculation.

Effects of the U boson on the inner edge of neutron star crusts

NASA Astrophysics Data System (ADS)

Zheng, Hao; Chen, Lie-Wen

2012-02-01

We explore effects of the light vector U boson, which is weakly coupled to nucleons, on the transition density ρt and pressure Pt at the inner edge separating the liquid core from the solid crust of neutron stars. Three methods, i.e., the thermodynamical approach, the curvature matrix approach, and the Vlasov equation approach, are used to determine the transition density ρt with the Skyrme effective nucleon-nucleon interactions. We find that the ρt and Pt depend on not only the ratio of coupling strength to mass squared of the U boson g2/μ2 but also its mass μ due to the finite-range interaction from the U-boson exchange. In particular, our results indicate that the ρt and Pt are sensitive to both g2/μ2 and μ if the U-boson mass μ is larger than about 2 MeV. Furthermore, we show that both g2/μ2 and μ can have significant influence on the mass-radius relation and the crustal fraction of total moment of inertia of neutron stars. In addition, we study the exchange term contribution of the U boson based on the density matrix expansion method, and demonstrate that the exchange term effects on the nuclear matter equation of state as well as the ρt and Pt are generally negligible.

The LZ Dark Matter Experiment

NASA Astrophysics Data System (ADS)

Bernard, Ethan; LZ Collaboration

2013-10-01

Astrophysical and cosmological observations show that dark matter is concentrated in halos around galaxies and is approximately five times more abundant than baryonic matter. Dark matter has evaded direct detection despite a series of increasingly sensitive experiments. The LZ (LUX-ZEPLIN) experiment will use a two-phase liquid-xenon time projection chamber to search for elastic scattering of xenon nuclei by WIMP (weakly interactive massive particle) dark matter. The detector will contain seven tons of liquid xenon shielded by an active organic scintillator veto and a water tank within the Sanford Underground Research Facility (SURF) in Lead, South Dakota. The LZ detector scales up the demonstrated light-sensing, cryogenic, radiopurity and shielding technologies of the LUX experiment. Active shielding, position fiducialization, radiopurity control and signal discrimination will reduce backgrounds to levels subdominant to solar neutrino scattering. This experiment will reach a sensitivity to the WIMP-nucleon spin-independent cross section approaching ~ 2 .10-48 cm2 for a 50 GeV WIMP mass, which is about three orders of magnitude smaller than current limits.

Light-front representation of chiral dynamics in peripheral transverse densities

DOE PAGES

Granados, Carlos G.; Weiss, Christian

2015-07-31

The nucleon's electromagnetic form factors are expressed in terms of the transverse densities of charge and magnetization at fixed light-front time. At peripheral transverse distances b = O(M_pi^{-1}) the densities are governed by chiral dynamics and can be calculated model-independently using chiral effective field theory (EFT). We represent the leading-order chiral EFT results for the peripheral transverse densities as overlap integrals of chiral light-front wave functions, describing the transition of the initial nucleon to soft pion-nucleon intermediate states and back. The new representation (a) explains the parametric order of the peripheral transverse densities; (b) establishes an inequality between the spin-independentmore » and -dependent densities; (c) exposes the role of pion orbital angular momentum in chiral dynamics; (d) reveals a large left-right asymmetry of the current in a transversely polarized nucleon and suggests a simple interpretation. The light-front representation enables a first-quantized, quantum-mechanical view of chiral dynamics that is fully relativistic and exactly equivalent to the second-quantized, field-theoretical formulation. It relates the charge and magnetization densities measured in low-energy elastic scattering to the generalized parton distributions probed in peripheral high-energy scattering processes. The method can be applied to nucleon form factors of other operators, e.g. the energy-momentum tensor.« less

Modeling multi-nucleon transfer in symmetric collisions of massive nuclei

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

Welsh, T.; Loveland, W.; Yanez, R.

We propose symmetric collisions of massive nuclei, such as 238U + 248Cm, as ways to make new n-rich heavy nuclei via multi-nucleon transfer (MNT) reactions. We have measured the yields of several projectile-like and target-like fragments from the reaction of 1360 MeV 204Hg + 198Pt. We also find that current models for this symmetric collision (GRAZING, DNS, ImQMD) significantly underestimate the yields of these transfer products, even for small transfers.

Nucleon structure from 2+1-flavor domain-wall QCD

NASA Astrophysics Data System (ADS)

Ohta, Shigemi

2018-03-01

Nucleon-structure calculations of isovector vector-and axialvector-current form factors, transversity and scalar charge, and quark momentum and helicity fractions are reported from two recent 2+1-flavor dynamical domain-wall fermions lattice-QCD ensembles generated jointly by the RIKEN-BNL-Columbia and UKQCD Collaborations with Iwasaki × dislocation-suppressing-determinatn-ratio gauge action at inverse lattice spacing of 1.378(7) GeV and pion mass values of 249.4(3) and 172.3(3) MeV.

Modeling multi-nucleon transfer in symmetric collisions of massive nuclei

DOE PAGES

Welsh, T.; Loveland, W.; Yanez, R.; ...

2017-05-18

We propose symmetric collisions of massive nuclei, such as 238U + 248Cm, as ways to make new n-rich heavy nuclei via multi-nucleon transfer (MNT) reactions. We have measured the yields of several projectile-like and target-like fragments from the reaction of 1360 MeV 204Hg + 198Pt. We also find that current models for this symmetric collision (GRAZING, DNS, ImQMD) significantly underestimate the yields of these transfer products, even for small transfers.

Tau lepton polarization in quasielastic neutrino-nucleon scattering

NASA Astrophysics Data System (ADS)

Kuzmin, Konstantin S.; Lyubushkin, Vladimir V.; Naumov, Vadim A.

2005-02-01

We derive structure functions for the quasielastic production of octet baryons in νn and νp interactions and study the polarization of τ leptons produced in the ΔY=0 reactions. Possible impact of the charged second-class currents is investigated by adopting a simple phenomenological parametrization for the nonstandard scalar and tensor nucleon form factors. Our choice of the unknown parameters is made to satisfy the limits obtained in the (anti)neutrino scattering experiments and rigid restrictions derived from the nuclear structure studies.

Neutrino-nucleus neutral current elastic interactions measurement in MiniBooNE

NASA Astrophysics Data System (ADS)

Perevalov, Denis

The MiniBooNE experiment at the Fermi National Accelerator Laboratory (Fermilab) was designed to search for numu → nu e neutrino oscillations at Deltam 2 ˜ 1 eV2 using an intense neutrino flux with an average energy Enu ˜ 700 MeV. From 2002 to 2009 MiniBooNE has accumulated more than 1.0x1021 protons on target (POT) in both neutrino and antineutrino modes. MiniBooNE provides a perfect platform for detailed measurements of exclusive and semi-inclusive neutrino cross-sections, for which MiniBooNE has the largest samples of events up to date, such as neutral current elastic (NCE), neutral current pi 0, charged current quasi-elastic (CCQE), charged current pi +, and other channels. These measured cross-sections, in turn, allow to improve the knowledge of nucleon structure. This thesis is devoted to the study of NCE interactions. Neutrino-nucleus neutral current elastic scattering (nuN → nu N) accounts for about 18% of all neutrino interactions in MiniBooNE. Using a high-statistics, high purity sample of NCE interactions in MiniBooNE, the flux-averaged NCE differential cross-section has been measured and is being reported here. Further study of the NCE cross-section allowed for probing the structure of nuclei. The main interest in the NCE cross-section is that it may be sensitive to the strange quark contribution to the nucleon spin, Deltas, this however requires a separation of NCE proton (nup → nu p) from NCE neutron (nun → nun ) events, which in general is a challenging task. MiniBooNE uses a Cherenkov detector, which imposes restrictions on the measured nucleon kinematic variables, mainly due to the impossibility to reconstruct the nucleon direction below the Cherenkov threshold. However, at kinetic energies above this threshold MiniBooNE is able to identify NCE proton events that do not experience final state interactions (FSI). These events were used for the Deltas measurement. In this thesis MiniBooNE reports the NCE (n+p) cross-section, the measurement of the axial mass, MA, and the Delta s parameter from the NCE data.

Measurement of Neutrino and Antineutrino Charged-Current Inclusive Cross Sections with the MINERvA Detector

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

Devan, Joshua D.

2015-01-01

Neutrinos are a nearly massless, neutral particle in the Standard Model that only interact via the weak interaction. Experimental confirmation of neutrino oscillations, in which a neutrino created as a particular type (electron, muon or tau) can be observed as a different type after propagating some distance, earned the 2015 Nobel Prize in Physics. Neutrino oscillation experiments rely on accurate measurements of neutrino interactions with matter, such as that presented here. Neutrinos also provide a unique probe of the nucleus, complementary to electron scattering experiments. This thesis presents a measurement of the charged-current inclusive cross section for muon neutrinos and antineutrinos in the energy range 2 to 50 GeV with the MINERvA detector. MINERvA is a neutrino scattering experiment in the NuMI neutrino beam at Fermilab, near Chicago. A cross section measures the probability of an interaction occurring, measured here as a function of neutrino energy. To extract a cross section from data, the observed rate of interactions is corrected for detector efficiency and divided by the number of scattering nucleons in the target and the flux of neutrinos in the beam. The neutrino flux is determined with the low-more » $$\

Measurement of total cross sections for neutrino and antineutrino charged-current interactions in hydrogen and neon

NASA Astrophysics Data System (ADS)

Aderholz, M.; Corrigan, G.; Hoffmann, E.; Jones, G. T.; Jones, R. W. L.; Kennedy, B. W.; Miller, D. B.; Mobayyen, M. M.; Morrison, D. R. O.; Myatt, G.; Radojicic, D.; Schmid, P.; Schmitz, N.; Shotton, P. N.; Towers, S. J.; Wittek, W.; Barnham, K. W. J.; Baton, J. P.; Berggren, M.; Bertrand, D.; Bullock, F. W.; Calicchio, M.; Clayton, E. F.; Coghen, T.; Cooper-Sarkar, A. M.; Erriquez, O.; Fitch, P. J.; Fogli-Muciaccia, M. T.; Guy, J. G.; Hamisi, F.; Hulth, P. O.; Kasper, P.; Klein, H.; Lagraa, M.; Marage, P.; Middleton, R. P.; O'Neale, S. W.; Parker, M. A.; Sacton, J.; Sansum, R. A.; Simopoulou, E.; Vallée, C.; Varvell, K.; Vayaki, A.; Venus, W.; Wachmuth, H.; Wells, J.

1986-06-01

BEBC filled in turn with hydrogen, and with a neon-hydrogen mixture, was exposed to the CERN SPS wide band neutrino and antineutrino beams. The ratios of the charged-current cross sections per nucleon, σ(νH2)/σ(νNe) and σ(νH2)/σ(νNe), between 20 and 300 GeV were found to be 0.656 +/- 0.020 and 1.425 +/- 0.052, respectively. Multiplying these ratios by the revised cross sections in neon, σ(νNe)/E = (0.723 +/- 0.038) × 10-38 cm2/GeV per nucleon and σ(νNe)/E = (0.351 +/- 0.019) × 10-38 cm2/GeV per nucleon, and their ratio, σ(νNe)/σ(νNe) = 0.485 +/- 0.020,, yields values for the total charged-current cross sections on protons, σ(νp)/E and σ(νp)/E, of (0.474 +/- 0.029) × 10-38 cm2/GeV and (0.500 +/- 0.032) × 10-38 cm2/GeV. respectively, and a value for the ratio σ(νp)/σ(νp) of 1.053 +/- 0.066. Present address: University of Glasgow, Glasgow G12 8QQ, UK.

Measurement of the Parity-Violating Asymmetry in Deep Inelastic Scattering at JLab 6 GeV

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

Wang, Diancheng

2013-12-01

The parity-violating asymmetry in deep inelastic scattering (PVDIS) offers us a useful tool to study the weak neutral couplings and the hadronic structure of the nucleon, and provides high precision tests on the Standard Model. During the 6 GeV PVDIS experiment at the Thomas Jefferson National Accelerator Facility, the parity-violating asymmetries A{sub PV} of a polarized electron beam scattering off an unpolarized deuteron target in the deep inelastic scattering region were precisely measured at two Q 2 values of 1.1 and 1.9 (GeV/c) 2. The asymmetry at Q 2=1.9 (GeV/c) 2 can be used to extract the weak coupling combinationmore » 2C 2u - C 2d, assuming the higher twist effect is small. The extracted result from this measurement is in good agreement with the Standard Model prediction, and improves the precision by a factor of five over previous data. In addition, combining the asymmetries at both Q 2 values provides us extra knowledge on the higher twist effects. The parity violation asymmetries in the resonance region were also measured during this experiment. These results are the first A PV data in the resonance region beyond the Δ (1232). They provide evidence that the quark hadron duality works for A PV at the (10-15)% level, and set constraints on nucleon resonance models that are commonly used for background calculations to other parity-violating electron scattering measurements.« less

Quantified Gamow shell model interaction for p s d -shell nuclei

NASA Astrophysics Data System (ADS)

Jaganathen, Y.; Betan, R. M. Id; Michel, N.; Nazarewicz, W.; Płoszajczak, M.

2017-11-01

Background: The structure of weakly bound and unbound nuclei close to particle drip lines is one of the major science drivers of nuclear physics. A comprehensive understanding of these systems goes beyond the traditional configuration interaction approach formulated in the Hilbert space of localized states (nuclear shell model) and requires an open quantum system description. The complex-energy Gamow shell model (GSM) provides such a framework as it is capable of describing resonant and nonresonant many-body states on equal footing. Purpose: To make reliable predictions, quality input is needed that allows for the full uncertainty quantification of theoretical results. In this study, we carry out the optimization of an effective GSM (one-body and two-body) interaction in the p s d f -shell-model space. The resulting interaction is expected to describe nuclei with 5 ≤A ≲12 at the p -s d -shell interface. Method: The one-body potential of the 4He core is modeled by a Woods-Saxon + spin-orbit + Coulomb potential, and the finite-range nucleon-nucleon interaction between the valence nucleons consists of central, spin-orbit, tensor, and Coulomb terms. The GSM is used to compute key fit observables. The χ2 optimization is performed using the Gauss-Newton algorithm augmented by the singular value decomposition technique. The resulting covariance matrix enables quantification of statistical errors within the linear regression approach. Results: The optimized one-body potential reproduces nucleon-4He scattering phase shifts up to an excitation energy of 20 MeV. The two-body interaction built on top of the optimized one-body field is adjusted to the bound and unbound ground-state binding energies and selected excited states of the helium, lithium, and beryllium isotopes up to A =9 . A very good agreement with experimental results was obtained for binding energies. First applications of the optimized interaction include predictions for two-nucleon correlation densities and excitation spectra of light nuclei with quantified uncertainties. Conclusion: The new interaction will enable comprehensive and fully quantified studies of structure and reactions aspects of nuclei from the p s d region of the nuclear chart.

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

Jaganathen, Y.; Betan, R. M. Id; Michel, N.

Background: The structure of weakly bound and unbound nuclei close to particle drip lines is one of the major science drivers of nuclear physics. A comprehensive understanding of these systems goes beyond the traditional configuration interaction approach formulated in the Hilbert space of localized states (nuclear shell model) and requires an open quantum system description. The complex-energy Gamow shell model (GSM) provides such a framework as it is capable of describing resonant and nonresonant many-body states on equal footing. Purpose: To make reliable predictions, quality input is needed that allows for the full uncertainty quantification of theoretical results. In thismore » study, we carry out the optimization of an effective GSM (one-body and two-body) interaction in the psdf-shell-model space. The resulting interaction is expected to describe nuclei with 5 ≤ A ≲ 12 at the p-sd-shell interface. Method: The one-body potential of the 4He core is modeled by a Woods-Saxon + spin-orbit + Coulomb potential, and the finite-range nucleon-nucleon interaction between the valence nucleons consists of central, spin-orbit, tensor, and Coulomb terms. The GSM is used to compute key fit observables. The χ 2 optimization is performed using the Gauss-Newton algorithm augmented by the singular value decomposition technique. The resulting covariance matrix enables quantification of statistical errors within the linear regression approach. Results: The optimized one-body potential reproduces nucleon- 4He scattering phase shifts up to an excitation energy of 20 MeV. The two-body interaction built on top of the optimized one-body field is adjusted to the bound and unbound ground-state binding energies and selected excited states of the helium, lithium, and beryllium isotopes up to A = 9 . A very good agreement with experimental results was obtained for binding energies. First applications of the optimized interaction include predictions for two-nucleon correlation densities and excitation spectra of light nuclei with quantified uncertainties. In conclusion: The new interaction will enable comprehensive and fully quantified studies of structure and reactions aspects of nuclei from the psd region of the nuclear chart.« less

Quantified Gamow shell model interaction for p s d -shell nuclei

DOE PAGES

Jaganathen, Y.; Betan, R. M. Id; Michel, N.; ...

2017-11-20

Background: The structure of weakly bound and unbound nuclei close to particle drip lines is one of the major science drivers of nuclear physics. A comprehensive understanding of these systems goes beyond the traditional configuration interaction approach formulated in the Hilbert space of localized states (nuclear shell model) and requires an open quantum system description. The complex-energy Gamow shell model (GSM) provides such a framework as it is capable of describing resonant and nonresonant many-body states on equal footing. Purpose: To make reliable predictions, quality input is needed that allows for the full uncertainty quantification of theoretical results. In thismore » study, we carry out the optimization of an effective GSM (one-body and two-body) interaction in the psdf-shell-model space. The resulting interaction is expected to describe nuclei with 5 ≤ A ≲ 12 at the p-sd-shell interface. Method: The one-body potential of the 4He core is modeled by a Woods-Saxon + spin-orbit + Coulomb potential, and the finite-range nucleon-nucleon interaction between the valence nucleons consists of central, spin-orbit, tensor, and Coulomb terms. The GSM is used to compute key fit observables. The χ 2 optimization is performed using the Gauss-Newton algorithm augmented by the singular value decomposition technique. The resulting covariance matrix enables quantification of statistical errors within the linear regression approach. Results: The optimized one-body potential reproduces nucleon- 4He scattering phase shifts up to an excitation energy of 20 MeV. The two-body interaction built on top of the optimized one-body field is adjusted to the bound and unbound ground-state binding energies and selected excited states of the helium, lithium, and beryllium isotopes up to A = 9 . A very good agreement with experimental results was obtained for binding energies. First applications of the optimized interaction include predictions for two-nucleon correlation densities and excitation spectra of light nuclei with quantified uncertainties. In conclusion: The new interaction will enable comprehensive and fully quantified studies of structure and reactions aspects of nuclei from the psd region of the nuclear chart.« less

Neutron-deuteron analyzing power data at En=22.5 MeV

NASA Astrophysics Data System (ADS)

Weisel, G. J.; Tornow, W.; Crowell, A. S.; Esterline, J. H.; Hale, G. M.; Howell, C. R.; O'Malley, P. D.; Tompkins, J. R.; Witała, H.

2014-05-01

We present measurements of n-d analyzing power, Ay(θ), at En=22.5 MeV. The experiment uses a shielded neutron source which produced polarized neutrons via the 2H(d⃗,n⃗)3He reaction. It also uses a deuterated liquid-scintillator center detector and six pairs of liquid-scintillator neutron side detectors. Elastic neutron scattering events are identified by using time-of-flight techniques and by setting a window in the center detector pulse-height spectrum. The beam polarization is monitored by using a high-pressure helium gas cell and an additional pair of liquid-scintillator side detectors. The n-d Ay(θ) data were corrected for finite-geometry and multiple-scattering effects using a Monte Carlo simulation of the experiment. The 22.5-MeV data demonstrate that the three-nucleon analyzing power puzzle also exists at this energy. They show a significant discrepancy with predictions of high-precision nucleon-nucleon potentials alone or combined with Tucscon-Melbourne or Urbana IX three-nucleon forces, as well as currently available effective-field theory based potentials of next-to-next-to-next-to-leading order.

The frozen nucleon approximation in two-particle two-hole response functions

DOE PAGES

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

2017-07-10

Here, we present a fast and efficient method to compute the inclusive two-particle two-hole (2p–2h) electroweak responses in the neutrino and electron quasielastic inclusive cross sections. The method is based on two approximations. The first neglects the motion of the two initial nucleons below the Fermi momentum, which are considered to be at rest. This approximation, which is reasonable for high values of the momentum transfer, turns out also to be quite good for moderate values of the momentum transfer q ≳kF. The second approximation involves using in the “frozen” meson-exchange currents (MEC) an effective Δ-propagator averaged over the Fermimore » sea. Within the resulting “frozen nucleon approximation”, the inclusive 2p–2h responses are accurately calculated with only a one-dimensional integral over the emission angle of one of the final nucleons, thus drastically simplifying the calculation and reducing the computational time. The latter makes this method especially well-suited for implementation in Monte Carlo neutrino event generators.« less

The frozen nucleon approximation in two-particle two-hole response functions

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

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

Here, we present a fast and efficient method to compute the inclusive two-particle two-hole (2p–2h) electroweak responses in the neutrino and electron quasielastic inclusive cross sections. The method is based on two approximations. The first neglects the motion of the two initial nucleons below the Fermi momentum, which are considered to be at rest. This approximation, which is reasonable for high values of the momentum transfer, turns out also to be quite good for moderate values of the momentum transfer q ≳kF. The second approximation involves using in the “frozen” meson-exchange currents (MEC) an effective Δ-propagator averaged over the Fermimore » sea. Within the resulting “frozen nucleon approximation”, the inclusive 2p–2h responses are accurately calculated with only a one-dimensional integral over the emission angle of one of the final nucleons, thus drastically simplifying the calculation and reducing the computational time. The latter makes this method especially well-suited for implementation in Monte Carlo neutrino event generators.« less

Measurement of double-differential muon neutrino charged-current interactions on C8 H8 without pions in the final state using the T2K off-axis beam

NASA Astrophysics Data System (ADS)

Abe, K.; Andreopoulos, C.; Antonova, M.; Aoki, S.; Ariga, A.; Assylbekov, S.; Autiero, D.; Barbi, M.; Barker, G. J.; Barr, G.; Bartet-Friburg, P.; Batkiewicz, M.; Berardi, V.; Berkman, S.; Bhadra, S.; Blondel, A.; Bolognesi, S.; Bordoni, S.; Boyd, S. B.; Brailsford, D.; Bravar, A.; Bronner, C.; Buizza Avanzini, M.; Calland, R. G.; Cao, S.; Caravaca Rodríguez, J.; Cartwright, S. L.; Castillo, R.; Catanesi, M. G.; Cervera, A.; Cherdack, D.; Chikuma, N.; Christodoulou, G.; Clifton, A.; Coleman, J.; Collazuol, G.; Cremonesi, L.; Dabrowska, A.; De Rosa, G.; Dealtry, T.; Denner, P. F.; Dennis, S. R.; Densham, C.; Dewhurst, D.; Di Lodovico, F.; Di Luise, S.; Dolan, S.; Drapier, O.; Duffy, K. E.; Dumarchez, J.; Dytman, S.; Dziewiecki, M.; Emery-Schrenk, S.; Ereditato, A.; Feusels, T.; Finch, A. J.; Fiorentini, G. A.; Friend, M.; Fujii, Y.; Fukuda, D.; Fukuda, Y.; Furmanski, A. P.; Galymov, V.; Garcia, A.; Giffin, S. G.; Giganti, C.; Gizzarelli, F.; Gonin, M.; Grant, N.; Hadley, D. R.; Haegel, L.; Haigh, M. D.; Hamilton, P.; Hansen, D.; Hara, T.; Hartz, M.; Hasegawa, T.; Hastings, N. C.; Hayashino, T.; Hayato, Y.; Helmer, R. L.; Hierholzer, M.; Hillairet, A.; Himmel, A.; Hiraki, T.; Hirota, S.; Hogan, M.; Holeczek, J.; Horikawa, S.; Hosomi, F.; Huang, K.; Ichikawa, A. K.; Ieki, K.; Ikeda, M.; Imber, J.; Insler, J.; Intonti, R. A.; Irvine, T. J.; Ishida, T.; Ishii, T.; Iwai, E.; Iwamoto, K.; Izmaylov, A.; Jacob, A.; Jamieson, B.; Jiang, M.; Johnson, S.; Jo, J. H.; Jonsson, P.; Jung, C. K.; Kabirnezhad, M.; Kaboth, A. C.; Kajita, T.; Kakuno, H.; Kameda, J.; Karlen, D.; Karpikov, I.; Katori, T.; Kearns, E.; Khabibullin, M.; Khotjantsev, A.; Kielczewska, D.; Kikawa, T.; Kim, H.; Kim, J.; King, S.; Kisiel, J.; Knight, A.; Knox, A.; Kobayashi, T.; Koch, L.; Koga, T.; Konaka, A.; Kondo, K.; Kopylov, A.; Kormos, L. L.; Korzenev, A.; Koshio, Y.; Kropp, W.; Kudenko, Y.; Kurjata, R.; Kutter, T.; Lagoda, J.; Lamont, I.; Larkin, E.; Lasorak, P.; Laveder, M.; Lawe, M.; Lazos, M.; Lindner, T.; Liptak, Z. J.; Litchfield, R. P.; Li, X.; Longhin, A.; Lopez, J. P.; Ludovici, L.; Lu, X.; Magaletti, L.; Mahn, K.; Malek, M.; Manly, S.; Marino, A. D.; Marteau, J.; Martin, J. F.; Martins, P.; Martynenko, S.; Maruyama, T.; Matveev, V.; Mavrokoridis, K.; Ma, W. Y.; Mazzucato, E.; McCarthy, M.; McCauley, N.; McFarland, K. S.; McGrew, C.; Mefodiev, A.; Mezzetto, M.; Mijakowski, P.; Minamino, A.; Mineev, O.; Mine, S.; Missert, A.; Miura, M.; Moriyama, S.; Mueller, Th. A.; Murphy, S.; Myslik, J.; Nakadaira, T.; Nakahata, M.; Nakamura, K. G.; Nakamura, K.; Nakamura, K. D.; Nakayama, S.; Nakaya, T.; Nakayoshi, K.; Nantais, C.; Nielsen, C.; Nirkko, M.; Nishikawa, K.; Nishimura, Y.; Nowak, J.; O'Keeffe, H. M.; Ohta, R.; Okumura, K.; Okusawa, T.; Oryszczak, W.; Oser, S. M.; Ovsyannikova, T.; Owen, R. A.; Oyama, Y.; Palladino, V.; Palomino, J. L.; Paolone, V.; Patel, N. D.; Pavin, M.; Payne, D.; Perkin, J. D.; Petrov, Y.; Pickard, L.; Pickering, L.; Pinzon Guerra, E. S.; Pistillo, C.; Popov, B.; Posiadala-Zezula, M.; Poutissou, J.-M.; Poutissou, R.; Przewlocki, P.; Quilain, B.; Radicioni, E.; Ratoff, P. N.; Ravonel, M.; Rayner, M. A. M.; Redij, A.; Reinherz-Aronis, E.; Riccio, C.; Rojas, P.; Rondio, E.; Roth, S.; Rubbia, A.; Rychter, A.; Sacco, R.; Sakashita, K.; Sánchez, F.; Sato, F.; Scantamburlo, E.; Scholberg, K.; Schoppmann, S.; Schwehr, J.; Scott, M.; Seiya, Y.; Sekiguchi, T.; Sekiya, H.; Sgalaberna, D.; Shah, R.; Shaikhiev, A.; Shaker, F.; Shaw, D.; Shiozawa, M.; Shirahige, T.; Short, S.; Smy, M.; Sobczyk, J. T.; Sorel, M.; Southwell, L.; Stamoulis, P.; Steinmann, J.; Stewart, T.; Suda, Y.; Suvorov, S.; Suzuki, A.; Suzuki, K.; Suzuki, S. Y.; Suzuki, Y.; Tacik, R.; Tada, M.; Takahashi, S.; Takeda, A.; Takeuchi, Y.; Tanaka, H. K.; Tanaka, H. A.; Terhorst, D.; Terri, R.; Thakore, T.; Thompson, L. F.; Tobayama, S.; Toki, W.; Tomura, T.; Touramanis, C.; Tsukamoto, T.; Tzanov, M.; Uchida, Y.; Vacheret, A.; Vagins, M.; Vallari, Z.; Vasseur, G.; Wachala, T.; Wakamatsu, K.; Walter, C. W.; Wark, D.; Warzycha, W.; Wascko, M. O.; Weber, A.; Wendell, R.; Wilkes, R. J.; Wilking, M. J.; Wilkinson, C.; Wilson, J. R.; Wilson, R. J.; Yamada, Y.; Yamamoto, K.; Yamamoto, M.; Yanagisawa, C.; Yano, T.; Yen, S.; Yershov, N.; Yokoyama, M.; Yoshida, K.; Yuan, T.; Yu, M.; Zalewska, A.; Zalipska, J.; Zambelli, L.; Zaremba, K.; Ziembicki, M.; Zimmerman, E. D.; Zito, M.; Żmuda, J.; T2K Collaboration

2016-06-01

We report the measurement of muon neutrino charged-current interactions on carbon without pions in the final state at the T2K beam energy using 5.734 ×1020 protons on target. For the first time the measurement is reported as a flux-integrated, double-differential cross section in muon kinematic variables (cos θμ, pμ), without correcting for events where a pion is produced and then absorbed by final state interactions. Two analyses are performed with different selections, background evaluations and cross-section extraction methods to demonstrate the robustness of the results against biases due to model-dependent assumptions. The measurements compare favorably with recent models which include nucleon-nucleon correlations but, given the present precision, the measurement does not distinguish among the available models. The data also agree with Monte Carlo simulations which use effective parameters that are tuned to external data to describe the nuclear effects. The total cross section in the full phase space is σ =(0.417 ±0.047 (syst ) ±0.005 (stat ) )×10-38 cm2 nucleon-1 and the cross section integrated in the region of phase space with largest efficiency and best signal-over-background ratio (cos θμ>0.6 and pμ>200 MeV ) is σ =(0.202 ±0.036 (syst ) ±0.003 (stat ) )×10-38 cm2 nucleon-1 .

HZETRN: A heavy ion/nucleon transport code for space radiations

NASA Technical Reports Server (NTRS)

Wilson, John W.; Chun, Sang Y.; Badavi, Forooz F.; Townsend, Lawrence W.; Lamkin, Stanley L.

1991-01-01

The galactic heavy ion transport code (GCRTRN) and the nucleon transport code (BRYNTRN) are integrated into a code package (HZETRN). The code package is computer efficient and capable of operating in an engineering design environment for manned deep space mission studies. The nuclear data set used by the code is discussed including current limitations. Although the heavy ion nuclear cross sections are assumed constant, the nucleon-nuclear cross sections of BRYNTRN with full energy dependence are used. The relation of the final code to the Boltzmann equation is discussed in the context of simplifying assumptions. Error generation and propagation is discussed, and comparison is made with simplified analytic solutions to test numerical accuracy of the final results. A brief discussion of biological issues and their impact on fundamental developments in shielding technology is given.

Neutrino-nucleon cross sections at energies of Megaton-scale detectors

NASA Astrophysics Data System (ADS)

Gazizov, A.; Kowalski, M.; Kuzmin, K. S.; Naumov, V. A.; Spiering, Ch.

2016-04-01

An updated set of (anti)neutrino-nucleon charged and neutral current cross sections at 3 GeV ≲ Eν ≲100 GeV is presented. These cross sections are of particular interest for the detector optimization and data processing and interpretation in the future Megaton-scale experiments like PINGU, ORCA, and Hyper-Kamiokande. Finite masses of charged leptons and target mass corrections in exclusive and deep inelastic (ν̅)νN interactions are taken into account. A new set of QCD NNLO parton density functions, ABMP15, is used for calculation of the DIS cross sections. The sensitivity of the cross sections to phenomenological parameters and to extrapolations of the nucleon structure functions to small x and Q2 is studied. An agreement within the uncertainties of our calculations with experimental data is demonstrated.

Measurement of Muon Antineutrino Quasielastic Scattering on a Hydrocarbon Target at E ν~3.5 GeV

DOE PAGES

Fields, L.; Chvojka, J.; Aliaga, L.; ...

2013-07-11

We have isolated ν¯ μ charged-current quasielastic (QE) interactions occurring in the segmented scintillator tracking region of the MINERvA detector running in the NuMI neutrino beam at Fermilab. We measure the flux-averaged differential cross section, dσ/dQ², and compare to several theoretical models of QE scattering. Good agreement is obtained with a model where the nucleon axial mass, M A, is set to 0.99 GeV/c² but the nucleon vector form factors are modified to account for the observed enhancement, relative to the free nucleon case, of the cross section for the exchange of transversely polarized photons in electron-nucleus scattering. Our datamore » at higher Q² favor this interpretation over an alternative in which the axial mass is increased.« less

Neutrino-nucleus neutral current elastic interactions measurement in MiniBooNE

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

Perevalov, Denis

2009-12-01

The MiniBooNE experiment at the Fermi National Accelerator Laboratory (Fermilab) was designed to search for v μ → v e neutrino oscillations at Δm 2 ~ 1 eV 2 using an intense neutrino flux with an average energy E v ~ 700 MeV. From 2002 to 2009 MiniBooNE has accumulated more than 1.0 x 10 21 protons on target (POT) in both neutrino and antineutrino modes. MiniBooNE provides a perfect platform for detailed measurements of exclusive and semiinclusive neutrino cross-sections, for which MiniBooNE has the largest samples of events up to date, such as neutral current elastic (NCE), neutral currentmore » π 0, charged current quasi-elastic (CCQE), charged current π +, and other channels. These measured cross-sections, in turn, allow to improve the knowledge of nucleon structure. This thesis is devoted to the study of NCE interactions. Neutrino-nucleus neutral current elastic scattering (vN → vN) accounts for about 18% of all neutrino interactions in MiniBooNE. Using a high-statistics, high purity sample of NCE interactions in MiniBooNE, the flux-averaged NCE differential cross-section has been measured and is being reported here. Further study of the NCE cross-section allowed for probing the structure of nuclei. The main interest in the NCE cross-section is that it may be sensitive to the strange quark contribution to the nucleon spin, Δs, this however requires a separation of NCE proton (vp → vp) from NCE neutron (vn → vn) events, which in general is a challenging task. MiniBooNE uses a Cherenkov detector, which imposes restrictions on the measured nucleon kinematic variables, mainly due to the impossibility to reconstruct the nucleon direction below the Cherenkov threshold. However, at kinetic energies above this threshold MiniBooNE is able to identify NCE proton events that do not experience final state interactions (FSI). These events were used for the Δs measurement. In this thesis MiniBooNE reports the NCE (n+p) cross-section, the measurement of the axial mass, M A, and the Δs parameter from the NCE data.« less

New physics with ultra-high-energy neutrinos

DOE PAGES

Marfatia, D.; McKay, D. W.; Weiler, T. J.

2015-07-03

Now that PeV neutrinos have been discovered by IceCube, we optimistically entertain the possibility that neutrinos with energy above 100PeV exist. Here, we evaluate the dependence of event rates of such neutrinos on the neutrino-nucleon cross section at observatories that detect particles, atmospheric fluorescence, or Cherenkov radiation, initiated by neutrino interactions. We consider how (i)a simple scaling of the total standard model neutrino-nucleon cross section, (ii) a new elastic neutral current interaction, and (iii) anew completely inelastic interaction, individually impact event rates.

Modeling multi-nucleon transfer in symmetric collisions of massive nuclei

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

Welsh, T.; Loveland, W.; Yanez, R.

Symmetric collisions of massive nuclei, such as U-238 + Cm-248, have been proposed as ways to make new n-rich heavy nuclei via multi-nucleon transfer (MNT) reactions. We have measured the yields of several projectile-like and target-like fragments from the reaction of 1360 MeV Hg-204 + Pt-198. We find that current models for this symmetric collision (GRAZING, DNS, ImQMD) significantly underestimate the yields of these transfer products, even for small transfers. (C) 2017 The Author(s). Published by Elsevier B.V.

Research program in nuclear and solid state physics. [including pion absorption spectra and muon spin precession

NASA Technical Reports Server (NTRS)

1974-01-01

The survey of negative pion absorption reactions on light and medium nuclei was continued. Muon spin precession was studied using an iron target. An impulse approximation model of the pion absorption process implied that the ion will absorb almost exclusively on nucleon pairs, single nucleon absorption being suppressed by energy and momentum conservation requirements. For measurements on both paramagnetic and ferromagnetic iron, the external magnetic field was supplied by a large C-type electromagnet carrying a current of about 100 amperes.

Three-Body Nature of N* and Δ* Resonances from Sequential Decay Chains

NASA Astrophysics Data System (ADS)

Thiel, A.; Sokhoyan, V.; Gutz, E.; van Pee, H.; Anisovich, A. V.; Bacelar, J. C. S.; Bantes, B.; Bartholomy, O.; Bayadilov, D.; Beck, R.; Beloglazov, Yu.; Castelijns, R.; Crede, V.; Dutz, H.; Elsner, D.; Ewald, R.; Frommberger, F.; Fuchs, M.; Funke, Ch.; Gregor, R.; Gridnev, A.; Hillert, W.; Hoffmeister, Ph.; Horn, I.; Jaegle, I.; Junkersfeld, J.; Kalinowsky, H.; Kammer, S.; Kleber, V.; Klein, Frank; Klein, Friedrich; Klempt, E.; Kotulla, M.; Krusche, B.; Lang, M.; Löhner, H.; Lopatin, I.; Lugert, S.; Mertens, T.; Messchendorp, J. G.; Metag, V.; Metsch, B.; Nanova, M.; Nikonov, V.; Novinski, D.; Novotny, R.; Ostrick, M.; Pant, L.; Pfeiffer, M.; Piontek, D.; Roy, A.; Sarantsev, A. V.; Schmidt, Ch.; Schmieden, H.; Shende, S.; Süle, A.; Sumachev, V. V.; Szczepanek, T.; Thoma, U.; Trnka, D.; Varma, R.; Walther, D.; Wendel, Ch.; Wilson, A.; Cbelsa/Taps Collaboration

2015-03-01

The N π0π0 decays of positive-parity N* and Δ* resonances at about 2 GeV are studied at ELSA by photoproduction of two neutral pions off protons. The data reveal clear evidence for several intermediate resonances: Δ (1232 ) , N (1520 )3 /2- , and N (1680 )5 /2+ , with spin parities JP=3 /2+ , 3 /2- , and 5 /2+. The partial wave analysis (within the Bonn-Gatchina approach) identifies N (1440 )1 /2+ and the N (π π )S wave (abbreviated as N σ here) as further isobars and assigns the final states to the formation of nucleon and Δ resonances and to nonresonant contributions. We observe the known Δ (1232 )π decays of Δ (1910 )1 /2+ , Δ (1920 )3 /2+, Δ (1905 )5 /2+, Δ (1950 )7 /2+, and of the corresponding spin-parity series in the nucleon sector, N (1880 )1 /2+, N (1900 )3 /2+, N (2000 )5 /2+, and N (1990 )7 /2+ . For the nucleon resonances, these decay modes are reported here for the first time. Further new decay modes proceed via N (1440 )1 /2+π , N (1520 )3 /2-π , N (1680 )5 /2+π , and N σ . The latter decay modes are observed in the decay of N* resonances and at most weakly in Δ* decays. It is argued that these decay modes provide evidence for a 3-quark nature of N* resonances rather than a quark-diquark structure.

Computing the nucleon charge and axial radii directly at Q2=0 in lattice QCD

NASA Astrophysics Data System (ADS)

Hasan, Nesreen; Green, Jeremy; Meinel, Stefan; Engelhardt, Michael; Krieg, Stefan; Negele, John; Pochinsky, Andrew; Syritsyn, Sergey

2018-02-01

We describe a procedure for extracting momentum derivatives of nucleon matrix elements on the lattice directly at Q2=0 . This is based on the Rome method for computing momentum derivatives of quark propagators. We apply this procedure to extract the nucleon isovector magnetic moment and charge radius as well as the isovector induced pseudoscalar form factor at Q2=0 and the axial radius. For comparison, we also determine these quantities with the traditional approach of computing the corresponding form factors, i.e. GEv(Q2) and GMv(Q2) for the case of the vector current and GPv(Q2) and GAv(Q2) for the axial current, at multiple Q2 values followed by z -expansion fits. We perform our calculations at the physical pion mass using a 2HEX-smeared Wilson-clover action. To control the effects of excited-state contamination, the calculations were done at three source-sink separations and the summation method was used. The derivative method produces results consistent with those from the traditional approach but with larger statistical uncertainties especially for the isovector charge and axial radii.

Universes without the weak force: Astrophysical processes with stable neutrons

NASA Astrophysics Data System (ADS)

Grohs, E.; Howe, Alex R.; Adams, Fred C.

2018-02-01

We investigate a class of universes in which the weak interaction is not in operation. We consider how astrophysical processes are altered in the absence of weak forces, including big bang nucleosynthesis (BBN), galaxy formation, molecular cloud assembly, star formation, and stellar evolution. Without weak interactions, neutrons no longer decay, and the universe emerges from its early epochs with a mixture of protons, neutrons, deuterium, and helium. The baryon-to-photon ratio must be smaller than the canonical value in our Universe to allow free nucleons to survive the BBN epoch without being incorporated into heavier nuclei. At later times, the free neutrons readily combine with protons to make deuterium in sufficiently dense parts of the interstellar medium, and provide a power source before they are incorporated into stars. Almost all of the neutrons are incorporated into deuterium nuclei before stars are formed. As a result, stellar evolution proceeds primarily through strong interactions, with deuterium first burning into helium, and then helium fusing into carbon. Low-mass deuterium-burning stars can be long-lived, and higher-mass stars can synthesize the heavier elements necessary for life. Although somewhat different from our own, such universes remain potentially habitable.

Measurement of the muon neutrino inclusive charged-current cross section in the energy range of 1-3 GeV with the T2K INGRID detector

NASA Astrophysics Data System (ADS)

Abe, K.; Andreopoulos, C.; Antonova, M.; Aoki, S.; Ariga, A.; Assylbekov, S.; Autiero, D.; Barbi, M.; Barker, G. J.; Barr, G.; Bartet-Friburg, P.; Batkiewicz, M.; Bay, F.; Berardi, V.; Berkman, S.; Bhadra, S.; Blondel, A.; Bolognesi, S.; Bordoni, S.; Boyd, S. B.; Brailsford, D.; Bravar, A.; Bronner, C.; Calland, R. G.; Cao, S.; Caravaca Rodríguez, J.; Cartwright, S. L.; Castillo, R.; Catanesi, M. G.; Cervera, A.; Cherdack, D.; Chikuma, N.; Christodoulou, G.; Clifton, A.; Coleman, J.; Collazuol, G.; Cremonesi, L.; Dabrowska, A.; De Rosa, G.; Dealtry, T.; Dennis, S. R.; Densham, C.; Dewhurst, D.; Di Lodovico, F.; Di Luise, S.; Dolan, S.; Drapier, O.; Duffy, K.; Dumarchez, J.; Dytman, S.; Dziewiecki, M.; Emery-Schrenk, S.; Ereditato, A.; Feusels, T.; Finch, A. J.; Fiorentini, G. A.; Friend, M.; Fujii, Y.; Fukuda, D.; Fukuda, Y.; Furmanski, A. P.; Galymov, V.; Garcia, A.; Giffin, S.; Giganti, C.; Gilje, K.; Gonin, M.; Grant, N.; Hadley, D. R.; Haegel, L.; Haigh, M. D.; Hamilton, P.; Hansen, D.; Hara, T.; Hartz, M.; Hasegawa, T.; Hastings, N. C.; Hayashino, T.; Hayato, Y.; Helmer, R. L.; Hierholzer, M.; Hillairet, A.; Himmel, A.; Hiraki, T.; Hirota, S.; Holeczek, J.; Horikawa, S.; Hosomi, F.; Huang, K.; Ichikawa, A. K.; Ieki, K.; Ikeda, M.; Imber, J.; Insler, J.; Intonti, R. A.; Irvine, T. J.; Ishida, T.; Ishii, T.; Iwai, E.; Iwamoto, K.; Izmaylov, A.; Jacob, A.; Jamieson, B.; Jiang, M.; Johnson, S.; Jo, J. H.; Jonsson, P.; Jung, C. K.; Kabirnezhad, M.; Kaboth, A. C.; Kajita, T.; Kakuno, H.; Kameda, J.; Karlen, D.; Karpikov, I.; Katori, T.; Kearns, E.; Khabibullin, M.; Khotjantsev, A.; Kielczewska, D.; Kikawa, T.; Kim, H.; Kim, J.; King, S.; Kisiel, J.; Kobayashi, T.; Koch, L.; Koga, T.; Konaka, A.; Kondo, K.; Kopylov, A.; Kormos, L. L.; Korzenev, A.; Koshio, Y.; Kropp, W.; Kudenko, Y.; Kurjata, R.; Kutter, T.; Lagoda, J.; Lamont, I.; Larkin, E.; Laveder, M.; Lawe, M.; Lazos, M.; Lindner, T.; Liptak, Z. J.; Litchfield, R. P.; Longhin, A.; Lopez, J. P.; Ludovici, L.; Lu, X.; Magaletti, L.; Mahn, K.; Malek, M.; Manly, S.; Marino, A. D.; Marteau, J.; Martin, J. F.; Martins, P.; Martynenko, S.; Maruyama, T.; Matveev, V.; Mavrokoridis, K.; Ma, W. Y.; Mazzucato, E.; McCarthy, M.; McCauley, N.; McFarland, K. S.; McGrew, C.; Mefodiev, A.; Mezzetto, M.; Mijakowski, P.; Miller, C. A.; Minamino, A.; Mineev, O.; Mine, S.; Missert, A.; Miura, M.; Moriyama, S.; Mueller, Th. A.; Murphy, S.; Myslik, J.; Nakadaira, T.; Nakahata, M.; Nakamura, K. G.; Nakamura, K.; Nakamura, K. D.; Nakayama, S.; Nakaya, T.; Nakayoshi, K.; Nantais, C.; Nielsen, C.; Nirkko, M.; Nishikawa, K.; Nishimura, Y.; Nowak, J.; O'Keeffe, H. M.; Ohta, R.; Okumura, K.; Okusawa, T.; Oryszczak, W.; Oser, S. M.; Ovsyannikova, T.; Owen, R. A.; Oyama, Y.; Palladino, V.; Palomino, J. L.; Paolone, V.; Payne, D.; Perkin, J. D.; Petrov, Y.; Pickard, L.; Pickering, L.; Pinzon Guerra, E. S.; Pistillo, C.; Popov, B.; Posiadala-Zezula, M.; Poutissou, J.-M.; Poutissou, R.; Przewlocki, P.; Quilain, B.; Radicioni, E.; Ratoff, P. N.; Ravonel, M.; Rayner, M. A. M.; Redij, A.; Reinherz-Aronis, E.; Riccio, C.; Rojas, P.; Rondio, E.; Roth, S.; Rubbia, A.; Rychter, A.; Sacco, R.; Sakashita, K.; Sánchez, F.; Sato, F.; Scantamburlo, E.; Scholberg, K.; Schoppmann, S.; Schwehr, J. D.; Scott, M.; Seiya, Y.; Sekiguchi, T.; Sekiya, H.; Sgalaberna, D.; Shah, R.; Shaikhiev, A.; Shaker, F.; Shaw, D.; Shiozawa, M.; Shirahige, T.; Short, S.; Smy, M.; Sobczyk, J. T.; Sorel, M.; Southwell, L.; Stamoulis, P.; Steinmann, J.; Stewart, T.; Suda, Y.; Suvorov, S.; Suzuki, A.; Suzuki, K.; Suzuki, S. Y.; Suzuki, Y.; Tacik, R.; Tada, M.; Takahashi, S.; Takeda, A.; Takeuchi, Y.; Tanaka, H. K.; Tanaka, H. A.; Terhorst, D.; Terri, R.; Thompson, L. F.; Tobayama, S.; Toki, W.; Tomura, T.; Touramanis, C.; Tsukamoto, T.; Tzanov, M.; Uchida, Y.; Vacheret, A.; Vagins, M.; Vallari, Z.; Vasseur, G.; Wachala, T.; Wakamatsu, K.; Walter, C. W.; Wark, D.; Warzycha, W.; Wascko, M. O.; Weber, A.; Wendell, R.; Wilkes, R. J.; Wilking, M. J.; Wilkinson, C.; Wilson, J. R.; Wilson, R. J.; Yamada, Y.; Yamamoto, K.; Yamamoto, M.; Yanagisawa, C.; Yano, T.; Yen, S.; Yershov, N.; Yokoyama, M.; Yoo, J.; Yoshida, K.; Yuan, T.; Yu, M.; Zalewska, A.; Zalipska, J.; Zambelli, L.; Zaremba, K.; Ziembicki, M.; Zimmerman, E. D.; Zito, M.; Żmuda, J.; T2K Collaboration

2016-04-01

We report a measurement of the νμ-nucleus inclusive charged-current cross section (=σc c ) on iron using data from the INGRID detector exposed to the J-PARC neutrino beam. The detector consists of 14 modules in total, which are spread over a range of off-axis angles from 0° to 1.1°. The variation in the neutrino energy spectrum as a function of the off-axis angle, combined with event topology information, is used to calculate this cross section as a function of neutrino energy. The cross section is measured to be σc c(1.1 GeV )=1.10 ±0.15 (1 0-38 cm2/nucleon) , σc c(2.0 GeV )=2.07 ±0.27 (1 0-38 cm2/nucleon) , and σc c(3.3 GeV )=2.29 ±0.45 (1 0-38 cm2/nucleon), at energies of 1.1, 2.0, and 3.3 GeV, respectively. These results are consistent with the cross section calculated by the neutrino interaction generators currently used by T2K. More importantly, the method described here opens up a new way to determine the energy dependence of neutrino-nucleus cross sections.

EMC effect for light nuclei: New results from Jefferson Lab

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

Aji Daniel

High energy lepton scattering has been the primary tool for mapping out the quark distributions of nucleons and nuclei. Measurements of deep inelastic scattering in nuclei show that the quark distributions in heavy nuclei are not simply the sum of the quark distributions of the constituent proton and neutron, as one might expect for a weakly bound system. This modification of the quark distributions in nuclei is known as the EMC effect. I will discuss the results from Jefferson Lab (JLab) experiment E03-103, a precise measurement of the EMC effect in few-body nuclei with emphasis on the large x region.more » Data from the light nuclei suggests that the nuclear dependence of the high x quark distribution may depend on the nucleon's local environment, rather than being a purely bulk effect. In addition, I will also discuss about a future experiment at the upgraded 12 GeV Jefferson Lab facility which will further investigate the role of the local nuclear environment and the influence of detailed nuclear structure to the modification of quark distributions.« less

Search for Large Extra Dimensions Based on Observations of Neutron Stars with the Fermi-LAT

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

Berenji, Bijan

Large extra dimensions (LED) have been proposed to account for the apparent weakness of gravitation. These theories also indicate that the postulated massive Kaluza-Klein (KK) gravitons may be produced by nucleon-nucleon bremsstrahlung in the course of core collapse of supernovae. Hannestad and Raffelt have predicted energy spectra of gamma ray emission from the decay of KK gravitons trapped by the gravity of the remnant neutron stars (NS). These and other authors have used EGRET data on NS to obtain stringent limits on LED. Fermi-LAT is observing radio pulsar positions obtained from radio and x-ray catalogs. NS with certain characteristics aremore » unlikely emitter of gamma rays, and emit in radio and perhaps x-rays. This talk will focus on the blind analysis we plan to perform, which has been developed using the 1st 2 months of all sky data and Monte Carlo simulations, to obtain limits on LED based on about 1 year of Fermi-LAT data. Preliminary limits from this analysis using these first 2 months of data will be also be discussed.« less

Prospects for future experiments to search for nucleon decay

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

Ayres, D.S.; Heller, K.; LoSecco, J.

1982-01-01

We review the status of theoretical expectations and experimental searches for nucleon decay, and predict the sensitivities which could be reached by future experiments. For the immediate future, we concur with the conclusions of the 1982 Summer Workshop on Proton Decay Experiments: all detectors now in operation or construction will be relatively insensitive to some potentially important decay modes. Next-generation experiments must therefore be designed to search for these modes, and should be undertaken whether or not present experiments detect nucleon decay in other modes. These future experiments should be designed to push the lifetime limits on all decay modesmore » to the levels at which irreducible cosmic-ray neutrino-induced backgrounds become important. Since the technology for these next-generation experiments is available now, the timetable for starting work on them will be determined by funding constraints and not by the need for extensive development of detectors. Efforts to develop advanced detector techniques should also be pursued, in order to mount more sensitive searches than can be envisioned using current technology, or to provide the most precise measurements possible of the properties of the nucleon decay interaction if it should occur at a detectable rate.« less

Nucleon form factors from quenched lattice QCD with domain wall fermions

NASA Astrophysics Data System (ADS)

Sasaki, Shoichi; Yamazaki, Takeshi

2008-07-01

We present a quenched lattice calculation of the weak nucleon form factors: vector [FV(q2)], induced tensor [FT(q2)], axial vector [FA(q2)] and induced pseudoscalar [FP(q2)] form factors. Our simulations are performed on three different lattice sizes L3×T=243×32, 163×32, and 123×32 with a lattice cutoff of a-1≈1.3GeV and light quark masses down to about 1/4 the strange quark mass (mπ≈390MeV) using a combination of the DBW2 gauge action and domain wall fermions. The physical volume of our largest lattice is about (3.6fm)3, where the finite volume effects on form factors become negligible and the lower momentum transfers (q2≈0.1GeV2) are accessible. The q2 dependences of form factors in the low q2 region are examined. It is found that the vector, induced tensor, and axial-vector form factors are well described by the dipole form, while the induced pseudoscalar form factor is consistent with pion-pole dominance. We obtain the ratio of axial to vector coupling gA/gV=FA(0)/FV(0)=1.219(38) and the pseudoscalar coupling gP=mμFP(0.88mμ2)=8.15(54), where the errors are statistical errors only. These values agree with experimental values from neutron β decay and muon capture on the proton. However, the root mean-squared radii of the vector, induced tensor, and axial vector underestimate the known experimental values by about 20%. We also calculate the pseudoscalar nucleon matrix element in order to verify the axial Ward-Takahashi identity in terms of the nucleon matrix elements, which may be called as the generalized Goldberger-Treiman relation.

Multinucleon pion absorption on {sup 4}He into the pppn final state

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

Lehmann, A.; Backenstoss, G.; Koehler, J.

1997-10-01

Results from a 4{pi} solid angle measurement of the reaction {pi}{sup +4}He{r_arrow}pppn at incident pion energies of T{sub {pi}{sup +}}= 70, 118, 162, 239, and 330 MeV are presented. Integrated cross sections are given for the reactions where three nucleons participate, leading to energetic (ppp) or (ppn) final states, and for states where four nucleons are involved (pppn). The two three-nucleon absorption modes were investigated in particular, and an energy dependent isospin ratio of the cross sections of {sigma}{sub ppn}/ {sigma}{sub ppp}=3.6{plus_minus}1.3, 2.6 {plus_minus}0.5, 1.8{plus_minus}0.3, 1.4{plus_minus} 0.2, and 1.8{plus_minus}0.6 was determined from 70 to 330 MeV. The differential cross sectionsmore » were described by a complete set of eight independent variables and compared to simple cascade and phase space models. From this analysis the contributions from initial state interactions to the multinucleon absorption cross sections were found to be more important at higher pion energies, while those from final state interactions are stronger at lower energies. However, both mechanisms combined were found to account for not more than one-third of the total pppn multinucleon yield. The remaining strength is reasonably well reproduced by phase space models, but shows a dependence on the incident pion{close_quote}s orbital angular momentum. The isospin structure of the (ppp) and (ppn) final states is not understood, nor are some structures in their distributions. The four-nucleon yield (pppn) was found to be weak (1{endash}8{percent} of the total absorption cross section) and shows no evidence for a {open_quotes}double- {Delta}{close_quotes} excitation. {copyright} {ital 1997} {ital The American Physical Society}« less

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

Yokosawa, A.

Structures appearing in various experimental data (particularly those with polarized beams) in nucleon-nucleon systems are reviewed. A number of candidates are presented for dibaryon resonances which can couple to nucleon-nucleon systems. The present status of experimental data in the nucleon-nucleon system is discussed. Details of N-N scattering are written elsewhere, and here relatively new aspects are presented.

Weak charge form factor and radius of 208Pb through parity violation in electron scattering

DOE PAGES

Horowitz, C. J.; Ahmed, Z.; Jen, C. -M.; ...

2012-03-26

We use distorted wave electron scattering calculations to extract the weak charge form factor F W(more » $$\\bar{q}$$), the weak charge radius R W, and the point neutron radius R n, of 208Pb from the PREX parity violating asymmetry measurement. The form factor is the Fourier transform of the weak charge density at the average momentum transfer $$\\bar{q}$$ = 0.475 fm -1. We find F W($$\\bar{q}$$) = 0.204 ± 0.028(exp) ± 0.001(model). We use the Helm model to infer the weak radius from F W($$\\bar{q}$$). We find RW = 5.826 ± 0.181(exp) ± 0.027(model) fm. Here the exp error includes PREX statistical and systematic errors, while the model error describes the uncertainty in R W from uncertainties in the surface thickness σ of the weak charge density. The weak radius is larger than the charge radius, implying a 'weak charge skin' where the surface region is relatively enriched in weak charges compared to (electromagnetic) charges. We extract the point neutron radius R n = 5.751 ± 0.175 (exp) ± 0.026(model) ± 0.005(strange) fm, from R W. Here there is only a very small error (strange) from possible strange quark contributions. We find R n to be slightly smaller than R W because of the nucleon's size. As a result, we find a neutron skin thickness of R n-R p = 0.302 ± 0.175 (exp) ± 0.026 (model) ± 0.005 (strange) fm, where R p is the point proton radius.« less

Quark-hadron duality constraints on $$\\gamma Z$$ box corrections to parity-violating elastic scattering

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

Hall, Nathan L.; Blunden, Peter G.; Melnitchouk, Wally

2015-12-08

We examine the interference \\gamma Z box corrections to parity-violating elastic electron--proton scattering in the light of the recent observation of quark-hadron duality in parity-violating deep-inelastic scattering from the deuteron, and the approximate isospin independence of duality in the electromagnetic nucleon structure functions down to Q 2 \\approx 1 GeV 2. Assuming that a similar behavior also holds for the \\gamma Z proton structure functions, we find that duality constrains the γ Z box correction to the proton's weak charge to be Re V γ Z V = (5.4 \\pm 0.4) \\times 10 -3 at the kinematics of the Qmore » weak experiment. Within the same model we also provide estimates of the γ Z corrections for future parity-violating experiments, such as MOLLER at Jefferson Lab and MESA at Mainz.« less

Nucleon and deuteron scattering cross sections from 25 MV/Nucleon to 22.5 GeV/Nucleon

NASA Technical Reports Server (NTRS)

Townsend, L. W.; Wilson, J. W.; Bidasaria, H. B.

1983-01-01

Within the context of a double-folding optical potential approximation to the exact nucleus-nucleus multiple-scattering series, eikonal scattering theory is used to generate tables of nucleon and deuteron total and absorption cross sections at kinetic energies between 25 MeV/nucleon and 22.5 GeV/nucleon for use in cosmic-ray transport and shielding studies. Comparisons of predictions for nucleon-nucleus and deuteron-nucleus absorption and total cross sections with experimental data are also made.

Results from the Super Cryogenic Dark Matter Search Experiment at Soudan

DOE PAGES

Agnese, R.; Aramaki, T.; Arnquist, I. J.; ...

2018-02-09

Here, we report the result of a blinded search for weakly interacting massive particles (WIMPs) using the majority of the SuperCDMS Soudan data set. With an exposure of 1690 kg d, a single candidate event is observed, consistent with expected backgrounds. This analysis (combined with previous Ge results) sets an upper limit on the spin-independent WIMP–nucleon cross section of 1.4×10 -44 (1.0×10 -44) cm 2 at 46 GeV/c 2. These results set the strongest limits for WIMP–germanium-nucleus interactions for masses >12 GeV/c 2.

Results from the Super Cryogenic Dark Matter Search Experiment at Soudan

NASA Astrophysics Data System (ADS)

Agnese, R.; Aramaki, T.; Arnquist, I. J.; Baker, W.; Balakishiyeva, D.; Banik, S.; Barker, D.; Basu Thakur, R.; Bauer, D. A.; Binder, T.; Bowles, M. A.; Brink, P. L.; Bunker, R.; Cabrera, B.; Caldwell, D. O.; Calkins, R.; Cartaro, C.; Cerdeño, D. G.; Chang, Y.; Chen, Y.; Cooley, J.; Cornell, B.; Cushman, P.; Daal, M.; Di Stefano, P. C. F.; Doughty, T.; Fascione, E.; Figueroa-Feliciano, E.; Fritts, M.; Gerbier, G.; Germond, R.; Ghaith, M.; Godfrey, G. L.; Golwala, S. R.; Hall, J.; Harris, H. R.; Hong, Z.; Hoppe, E. W.; Hsu, L.; Huber, M. E.; Iyer, V.; Jardin, D.; Jastram, A.; Jena, C.; Kelsey, M. H.; Kennedy, A.; Kubik, A.; Kurinsky, N. A.; Loer, B.; Lopez Asamar, E.; Lukens, P.; MacDonell, D.; Mahapatra, R.; Mandic, V.; Mast, N.; Miller, E. H.; Mirabolfathi, N.; Mohanty, B.; Morales Mendoza, J. D.; Nelson, J.; Orrell, J. L.; Oser, S. M.; Page, K.; Page, W. A.; Partridge, R.; Penalver Martinez, M.; Pepin, M.; Phipps, A.; Poudel, S.; Pyle, M.; Qiu, H.; Rau, W.; Redl, P.; Reisetter, A.; Reynolds, T.; Roberts, A.; Robinson, A. E.; Rogers, H. E.; Saab, T.; Sadoulet, B.; Sander, J.; Schneck, K.; Schnee, R. W.; Scorza, S.; Senapati, K.; Serfass, B.; Speller, D.; Stein, M.; Street, J.; Tanaka, H. A.; Toback, D.; Underwood, R.; Villano, A. N.; von Krosigk, B.; Welliver, B.; Wilson, J. S.; Wilson, M. J.; Wright, D. H.; Yellin, S.; Yen, J. J.; Young, B. A.; Zhang, X.; Zhao, X.; SuperCDMS Collaboration

2018-02-01

We report the result of a blinded search for weakly interacting massive particles (WIMPs) using the majority of the SuperCDMS Soudan data set. With an exposure of 1690 kg d, a single candidate event is observed, consistent with expected backgrounds. This analysis (combined with previous Ge results) sets an upper limit on the spin-independent WIMP-nucleon cross section of 1.4 ×10-44 (1.0 ×10-44) cm2 at 46 GeV /c2 . These results set the strongest limits for WIMP-germanium-nucleus interactions for masses >12 GeV /c2.

Results from the Super Cryogenic Dark Matter Search Experiment at Soudan

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

Agnese, R.; Aramaki, T.; Arnquist, I. J.

Here, we report the result of a blinded search for weakly interacting massive particles (WIMPs) using the majority of the SuperCDMS Soudan data set. With an exposure of 1690 kg d, a single candidate event is observed, consistent with expected backgrounds. This analysis (combined with previous Ge results) sets an upper limit on the spin-independent WIMP–nucleon cross section of 1.4×10 -44 (1.0×10 -44) cm 2 at 46 GeV/c 2. These results set the strongest limits for WIMP–germanium-nucleus interactions for masses >12 GeV/c 2.

Results from the Super Cryogenic Dark Matter Search Experiment at Soudan

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

Agnese, R.; Aramaki, T.; Arnquist, I. J.

We report the result of a blinded search for Weakly Interacting Massive Particles (WIMPs) using the full SuperCDMS Soudan dataset. With an exposure of 1690 kg days, a single event was observed after unblinding, consistent with expected backgrounds. This analysis (combined with previous Ge results) sets an upper limit on the spin-independent WIMP-nucleon cross section of 1.4x10^-44 (1.0x10^-44) cm^2 at 46 GeV/c^2 . These results set the strongest limits for WIMP-germanium-nucleus interactions for masses >12 GeV/c^2.

Semi-inclusive charged-current neutrino-nucleus reactions

DOE PAGES

Moreno, O.; Donnelly, T. W.; Van Orden, J. W.; ...

2014-07-17

The general, universal formalism for semi-inclusive charged-current (anti)neutrino-nucleus reactions is given for studies of any hadronic system, namely, either nuclei or the nucleon itself. The detailed developments are presented with the former in mind and are further specialized to cases where the final-state charged lepton and an ejected nucleon are presumed to be detected. General kinematics for such processes are summarized and then explicit expressions are developed for the leptonic and hadronic tensors involved and for the corresponding responses according to the usual charge, longitudinal and transverse projections, keeping finite the masses of all particles involved. In the case ofmore » the hadronic responses, general symmetry principles are invoked to determine which contributions can occur. As a result, the general leptonic-hadronic tensor contraction is given as well as the cross section for the process.« less

Comparative study of the neutrino-nucleon cross section at ultrahigh energies

NASA Astrophysics Data System (ADS)

Gonçalves, V. P.; Hepp, P.

2011-01-01

The high-energy neutrino cross section is a crucial ingredient in the calculation of the event rate in high-energy neutrino telescopes. Currently, there are several approaches that predict different behaviors for its magnitude for ultrahigh energies. In this paper, we present a comparison between the predictions based on linear Dokshitzer-Gribov-Lipatov-Altarelli-Parisi dynamics, nonlinear QCD, and the imposition of a Froissart-like behavior at high energies. In particular, we update the predictions based on the color glass condensate, presenting for the first time the results for σνN using the solution of the running coupling Balitsky-Kovchegov equation. Our results demonstrate that the current theoretical uncertainty for the neutrino-nucleon cross section reaches a factor of three for neutrino energies around 1011GeV and increases to a factor of five for 1013GeV.

Effective field theory description of halo nuclei

NASA Astrophysics Data System (ADS)

Hammer, H.-W.; Ji, C.; Phillips, D. R.

2017-10-01

Nuclear halos emerge as new degrees of freedom near the neutron and proton driplines. They consist of a core and one or a few nucleons which spend most of their time in the classically-forbidden region outside the range of the interaction. Individual nucleons inside the core are thus unresolved in the halo configuration, and the low-energy effective interactions are short-range forces between the core and the valence nucleons. Similar phenomena occur in clusters of 4He atoms, cold atomic gases near a Feshbach resonance, and some exotic hadrons. In these weakly-bound quantum systems universal scaling laws for s-wave binding emerge that are independent of the details of the interaction. Effective field theory (EFT) exposes these correlations and permits the calculation of non-universal corrections to them due to short-distance effects, as well as the extension of these ideas to systems involving the Coulomb interaction and/or binding in higher angular-momentum channels. Halo nuclei exhibit all these features. Halo EFT, the EFT for halo nuclei, has been used to compute the properties of single-neutron, two-neutron, and single-proton halos of s-wave and p-wave type. This review summarizes these results for halo binding energies, radii, Coulomb dissociation, and radiative capture, as well as the connection of these properties to scattering parameters, thereby elucidating the universal correlations between all these observables. We also discuss how Halo EFT's encoding of the long-distance physics of halo nuclei can be used to check and extend ab initio calculations that include detailed modeling of their short-distance dynamics.

Laser acceleration of quasi-monoenergetic MeV ion beams.

PubMed

Hegelich, B M; Albright, B J; Cobble, J; Flippo, K; Letzring, S; Paffett, M; Ruhl, H; Schreiber, J; Schulze, R K; Fernández, J C

2006-01-26

Acceleration of particles by intense laser-plasma interactions represents a rapidly evolving field of interest, as highlighted by the recent demonstration of laser-driven relativistic beams of monoenergetic electrons. Ultrahigh-intensity lasers can produce accelerating fields of 10 TV m(-1) (1 TV = 10(12) V), surpassing those in conventional accelerators by six orders of magnitude. Laser-driven ions with energies of several MeV per nucleon have also been produced. Such ion beams exhibit unprecedented characteristics--short pulse lengths, high currents and low transverse emittance--but their exponential energy spectra have almost 100% energy spread. This large energy spread, which is a consequence of the experimental conditions used to date, remains the biggest impediment to the wider use of this technology. Here we report the production of quasi-monoenergetic laser-driven C5+ ions with a vastly reduced energy spread of 17%. The ions have a mean energy of 3 MeV per nucleon (full-width at half-maximum approximately 0.5 MeV per nucleon) and a longitudinal emittance of less than 2 x 10(-6) eV s for pulse durations shorter than 1 ps. Such laser-driven, high-current, quasi-monoenergetic ion sources may enable significant advances in the development of compact MeV ion accelerators, new diagnostics, medical physics, inertial confinement fusion and fast ignition.

Three-Nucleon Forces and Triplet Pairing in Neutron Matter

NASA Astrophysics Data System (ADS)

Papakonstantinou, P.; Clark, J. W.

2017-12-01

The existence of superfluidity of the neutron component in the core of a neutron star, associated specifically with triplet P-wave pairing, is currently an open question that is central to interpretation of the observed cooling curves and other neutron-star observables. Ab initio theoretical calculations aimed at resolving this issue face unique challenges in the relevant high-density domain, which reaches beyond the saturation density of symmetrical nuclear matter. These issues include uncertainties in the three-nucleon (3N) interaction and in the effects of strong short-range correlations—and more generally of in-medium modification of nucleonic self-energies and interactions. A survey of existing solutions of the gap equations in the triplet channel demonstrates that the net impact on the gap magnitude of 3N forces, coupled channels, and mass renormalization shows extreme variation dependent on specific theoretical inputs, in some cases even pointing to the absence of a triplet gap, thus motivating a detailed analysis of competing effects within a well-controlled model. In the present study, we track the effects of the 3N force and in-medium modifications in the representative case of the ^3P_2 channel, based on the Argonne v_{18} two-nucleon (2N) interaction supplemented by 3N interactions of the Urbana IX family. Sensitivity of the results to the input interaction is clearly demonstrated. We point out consistency issues with respect to the simultaneous treatment of 3N forces and in-medium effects, which warrant further investigation. We consider this pilot study as the first step toward a systematic and comprehensive exploration of coupled-channel ^3P F_2 pairing using a broad range of 2N and 3N interactions from the current generation of refined semi-phenomenological models and models derived from chiral effective field theory.

Correlations and currents in 3He studied with the (e, e'pp) reaction

NASA Astrophysics Data System (ADS)

Groep, David Leo

2000-01-01

Nucleon-nucleon correlations, especially those of short-range character, can be well studied with electron-induced two-nucleon knockout reactions at intermediate electron energies. However, these reactions are not only driven by one-body currents, i.e., coupling of the virtual photon to one of the nucleons of a correlated pair, a process that directly probes NN-correlations. Also two-body currents, resulting from intermediate Delta-excitation and coupling to exchanged mesons, as well as final state interactions, influence the experimental cross section. Exclusive measurements of the three-body breakup of 3He offer the opportunity to compare data to microscopic calculations. The relative importance of competing two-proton knockout mechanisms can be investigated by varying the energy and momentum of the virtual photon. The experiment was performed with the electron beam extracted from the Amsterdam Pulse Stretcher (AmPS) at NIKHEF; the incident electron energy was 564 MeV. A cryogenic, high-pressure 3He gas target was used with a thickness of 270 mg/cm^2. Scattered electrons were detected in the QDQ magnetic spectrometer and both emitted protons in the HADRON plastic scintillator arrays. Cross sections were determined for three values of the three-momentum transfer of the virtual photon (q=305, 375, and 445 MeV/c) at an energy transfer value omega of 220 MeV. At q=375 MeV/c, measurements were performed over a continuous range in energy transfer from 170 to 290 MeV. The data are compared to results of continuum-Faddeev calculations performed by Golak et al., that account for rescattering among the emitted nucleons. Various potential models were used in the calculations: Bonn-B, CD-Bonn, Nijmegen-93 and Argonne v18 . Presentation of the data as a function of the missing or neutron momentum, pm, shows that the cross section decreases exponentially as a function of pm. Calculations performed with only a one-body hadronic current operator show fair agreement with data obtained at pm < 100 MeV/c at omega = 220 MeV for all q-values. It can therefore be concluded that at omega = 220 MeV and pm < 100 MeV/c the cross section is dominated by direct knockout of two protons via a one-body hadronic current. At higher neutron momentum values, data and theoretical predictions differ up to a fac tor of five for all values of omega. Within the range of energy transfer values probed in this experiment, the high pm domain is expected to be strongly influenced by intermediate excitation in the proton-neutron pair. Within specific regions of phase space, where two nucleons are emitted with comparable momentum vectors, rescattering processes strongly influence the cross section. For a such a region, measured at q=445 MeV/c, good agreement was found between data and the continuum- Faddeev calculations as a function of the pn momentum difference in the final state. Information on the wave function of 3He may be obtained in the domain omega = 220 MeV and pm < 100 MeV/c by representing the cross section as a function of pdiff1, which can be related to the relative momentum of the constituents of the two-proton pair in the initial state. The observed decrease of the cross section reflects the behaviour of the wave function and is well reproduced by calculations. At present, the data do not permit to express preference for any one of the potential models considered.

Exploring Nucleon Spin Structure Through Neutrino Neutral-Current Interactions in MicroBooNE

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

Woodruff, Katherine

2017-02-02

The net contribution of the strange quark spins to the proton spin,more » $$\\Delta s$$, can be determined from neutral current elastic neutrino-proton interactions at low momentum transfer combined with data from electron-proton scattering. The probability of neutrino-proton interactions depends in part on the axial form factor, which represents the spin structure of the proton and can be separated into its quark flavor contributions. Low momentum transfer neutrino neutral current interactions can be measured in MicroBooNE, a high-resolution liquid argon time projection chamber (LArTPC) in its first year of running in the Booster Neutrino Beamline at Fermilab. The signal for these interactions in MicroBooNE is a single short proton track. We present our work on the automated reconstruction and classification of proton tracks in LArTPCs, an important step in the determination of neutrino- nucleon cross sections and the measurement of $$\\Delta s$$.« less

Measurement of the inclusive νμ charged current cross section on iron and hydrocarbon in the T2K on-axis neutrino beam

NASA Astrophysics Data System (ADS)

Abe, K.; Adam, J.; Aihara, H.; Akiri, T.; Andreopoulos, C.; Aoki, S.; Ariga, A.; Assylbekov, S.; Autiero, D.; Barbi, M.; Barker, G. J.; Barr, G.; Bass, M.; Batkiewicz, M.; Bay, F.; Berardi, V.; Berger, B. E.; Berkman, S.; Bhadra, S.; Blaszczyk, F. d. M.; Blondel, A.; Bojechko, C.; Bordoni, S.; Boyd, S. B.; Brailsford, D.; Bravar, A.; Bronner, C.; Buchanan, N.; Calland, R. G.; Caravaca Rodríguez, J.; Cartwright, S. L.; Castillo, R.; Catanesi, M. G.; Cervera, A.; Cherdack, D.; Christodoulou, G.; Clifton, A.; Coleman, J.; Coleman, S. J.; Collazuol, G.; Connolly, K.; Cremonesi, L.; Dabrowska, A.; Danko, I.; Das, R.; Davis, S.; de Perio, P.; De Rosa, G.; Dealtry, T.; Dennis, S. R.; Densham, C.; Dewhurst, D.; Di Lodovico, F.; Di Luise, S.; Drapier, O.; Duboyski, T.; Duffy, K.; Dumarchez, J.; Dytman, S.; Dziewiecki, M.; Emery-Schrenk, S.; Ereditato, A.; Escudero, L.; Finch, A. J.; Friend, M.; Fujii, Y.; Fukuda, Y.; Furmanski, A. P.; Galymov, V.; Giffin, S.; Giganti, C.; Gilje, K.; Goeldi, D.; Golan, T.; Gonin, M.; Grant, N.; Gudin, D.; Hadley, D. R.; Haesler, A.; Haigh, M. D.; Hamilton, P.; Hansen, D.; Hara, T.; Hartz, M.; Hasegawa, T.; Hastings, N. C.; Hayato, Y.; Hearty, C.; Helmer, R. L.; Hierholzer, M.; Hignight, J.; Hillairet, A.; Himmel, A.; Hiraki, T.; Hirota, S.; Holeczek, J.; Horikawa, S.; Huang, K.; Ichikawa, A. K.; Ieki, K.; Ieva, M.; Ikeda, M.; Imber, J.; Insler, J.; Irvine, T. J.; Ishida, T.; Ishii, T.; Iwai, E.; Iwamoto, K.; Iyogi, K.; Izmaylov, A.; Jacob, A.; Jamieson, B.; Johnson, R. A.; Jo, J. H.; Jonsson, P.; Jung, C. K.; Kabirnezhad, M.; Kaboth, A. C.; Kajita, T.; Kakuno, H.; Kameda, J.; Kanazawa, Y.; Karlen, D.; Karpikov, I.; Katori, T.; Kearns, E.; Khabibullin, M.; Khotjantsev, A.; Kielczewska, D.; Kikawa, T.; Kilinski, A.; Kim, J.; Kisiel, J.; Kitching, P.; Kobayashi, T.; Koch, L.; Kolaceke, A.; Konaka, A.; Kormos, L. L.; Korzenev, A.; Koseki, K.; Koshio, Y.; Kreslo, I.; Kropp, W.; Kubo, H.; Kudenko, Y.; Kurjata, R.; Kutter, T.; Lagoda, J.; Laihem, K.; Lamont, I.; Larkin, E.; Laveder, M.; Lawe, M.; Lazos, M.; Lindner, T.; Lister, C.; Litchfield, R. P.; Longhin, A.; Ludovici, L.; Magaletti, L.; Mahn, K.; Malek, M.; Manly, S.; Marino, A. D.; Marteau, J.; Martin, J. F.; Martynenko, S.; Maruyama, T.; Matveev, V.; Mavrokoridis, K.; Mazzucato, E.; McCarthy, M.; McCauley, N.; McFarland, K. S.; McGrew, C.; Metelko, C.; Mijakowski, P.; Miller, C. A.; Minamino, A.; Mineev, O.; Missert, A.; Miura, M.; Moriyama, S.; Mueller, Th. A.; Murakami, A.; Murdoch, M.; Murphy, S.; Myslik, J.; Nakadaira, T.; Nakahata, M.; Nakamura, K.; Nakayama, S.; Nakaya, T.; Nakayoshi, K.; Nielsen, C.; Nirkko, M.; Nishikawa, K.; Nishimura, Y.; O'Keeffe, H. M.; Ohta, R.; Okumura, K.; Okusawa, T.; Oryszczak, W.; Oser, S. M.; Otani, M.; Owen, R. A.; Oyama, Y.; Palladino, V.; Palomino, J. L.; Paolone, V.; Payne, D.; Perevozchikov, O.; Perkin, J. D.; Petrov, Y.; Pickard, L.; Pinzon Guerra, E. S.; Pistillo, C.; Plonski, P.; Poplawska, E.; Popov, B.; Posiadala, M.; Poutissou, J.-M.; Poutissou, R.; Przewlocki, P.; Quilain, B.; Radicioni, E.; Ratoff, P. N.; Ravonel, M.; Rayner, M. A. M.; Redij, A.; Reeves, M.; Reinherz-Aronis, E.; Retiere, F.; Rodrigues, P. A.; Rojas, P.; Rondio, E.; Roth, S.; Rubbia, A.; Ruterbories, D.; Sacco, R.; Sakashita, K.; Sánchez, F.; Sato, F.; Scantamburlo, E.; Scholberg, K.; Schoppmann, S.; Schwehr, J.; Scott, M.; Seiya, Y.; Sekiguchi, T.; Sekiya, H.; Sgalaberna, D.; Shiozawa, M.; Short, S.; Shustrov, Y.; Sinclair, P.; Smith, B.; Smy, M.; Sobczyk, J. T.; Sobel, H.; Sorel, M.; Southwell, L.; Stamoulis, P.; Steinmann, J.; Still, B.; Suda, Y.; Suzuki, A.; Suzuki, K.; Suzuki, S. Y.; Suzuki, Y.; Szeglowski, T.; Tacik, R.; Tada, M.; Takahashi, S.; Takeda, A.; Takeuchi, Y.; Tanaka, H. K.; Tanaka, H. A.; Tanaka, M. M.; Terhorst, D.; Terri, R.; Thompson, L. F.; Thorley, A.; Tobayama, S.; Toki, W.; Tomura, T.; Totsuka, Y.; Touramanis, C.; Tsukamoto, T.; Tzanov, M.; Uchida, Y.; Vacheret, A.; Vagins, M.; Vasseur, G.; Wachala, T.; Waldron, A. V.; Walter, C. W.; Wark, D.; Wascko, M. O.; Weber, A.; Wendell, R.; Wilkes, R. J.; Wilking, M. J.; Wilkinson, C.; Williamson, Z.; Wilson, J. R.; Wilson, R. J.; Wongjirad, T.; Yamada, Y.; Yamamoto, K.; Yanagisawa, C.; Yano, T.; Yen, S.; Yershov, N.; Yokoyama, M.; Yuan, T.; Yu, M.; Zalewska, A.; Zalipska, J.; Zambelli, L.; Zaremba, K.; Ziembicki, M.; Zimmerman, E. D.; Zito, M.; Żmuda, J.; T2K Collaboration

2014-09-01

We report a measurement of the νμ inclusive charged current cross sections on iron and hydrocarbon in the Tokai-to-Kamioka (T2K) on-axis neutrino beam. The measured inclusive charged current cross sections on iron and hydrocarbon averaged over the T2K on-axis flux with a mean neutrino energy of 1.51 GeV are (1.444±0.002(stat)-0.157+0.189(syst))×10-38 cm2/nucleon and (1.379±0.009(stat)-0.147+0.178(syst))×10-38 cm2/nucleon, respectively, and their cross-section ratio is 1.047±0.007(stat)±0.035(syst). These results agree well with the predictions of the neutrino interaction model, and thus we checked the correct treatment of the nuclear effect for iron and hydrocarbon targets in the model within the measurement precisions.

Extraction of In-Medium Nucleon-Nucleon Amplitude From Experiment

NASA Technical Reports Server (NTRS)

Tripathi, R. K.; Cucinotta, Francis A.; Wilson, John W.

1998-01-01

The in-medium nucleon-nucleon amplitudes are extracted from the available proton-nucleus total reaction cross sections data. The retrieval of the information from the experiment makes the estimate of reaction cross sections very reliable. Simple expressions are given for the in-medium nucleon-nucleon amplitudes for any system of colliding nuclei as a function of energy. Excellent agreement with experimental observations is demonstrated in the ion-nucleus interactions.

Production cross sections for Lee-Wick massive electromagnetic bosons and for spin-zero and spin-one W bosons at high energies.

NASA Technical Reports Server (NTRS)

Linsker, R.

1972-01-01

Production cross sections for three types of hypothetical particles are calculated in the presented paper. Several (Z, Z') cases were studied corresponding to elastic scattering off protons and neutrons (either free or embedded within a Fermi sea), coherent scattering off a nucleus, and inelastic scattering off a proton (in which case Z' denotes a nucleon resonance or hadronic system in the continuum). Detailed structure-function data are used to improve the accuracy of the inelastic scattering calculation. Results of calculations are given for beam energies between 50 and 10,000 GeV, and masses between 5 and 40 GeV for the massive Lee-Wick spin-1 boson. Cross sections were computed for resonant and semiweak processes. The production cross section of spin-zero weak intermediate bosons was found to be at least one order of magnitude smaller than for spin-1 weak bosons in nearly all regions of interest. The production cross section of spin-zero weak intermediate bosons for inelastic scattering off protons compares with that for elastic scattering in the regions of interest. In the case of massive spin-1 bosons and spin-1 weak intermediates, the main contribution to total production cross section off protons is elastic.

ω and η (η') Mesons from NN and nd Collisions at Intermediate Energies

NASA Astrophysics Data System (ADS)

Kaptari, L. P.; Kämpfer, B.

The production of pseudo scalar, η, η‧, and vector, ω, ρ, ϕ, mesons in NN collisions at threshold-near energies is analyzed within a covariant effective meson-nucleon theory. It is shown that a good description of cross sections and angular distributions, for vector meson production, can be accomplished by considering meson and nucleon currents only, while for pseudo scalar production an inclusion of nucleon resonances is needed. The di-electron production from subsequent Dalitz decay of the produced mesons, η‧ → γγ* → γe+e- and ω → πγ* → πe+e- is also considered and numerical results are presented for intermediate energies and kinematics of possible experiments with HADES, CLAS and KEK-PS. We argue that the transition form factor ω → γ*π as well as η‧ → γ*γ can be defined in a fairly model independent way and the feasibility of an experimental access to transition form factors is discussed.

Pion-nucleon scattering: from chiral perturbation theory to Roy-Steiner equations

NASA Astrophysics Data System (ADS)

Kubis, Bastian; Hoferichter, Martin; de Elvira, Jacobo Ruiz; Meißner, Ulf-G.

2016-11-01

Ever since Weinberg's seminal predictions of the pion-nucleon scattering amplitudes at threshold, this process has been of central interest for the study of chiral dynamics involving nucleons. The scattering lengths or the pion-nucleon σ-term are fundamental quantities characterizing the explicit breaking of chiral symmetry by means of the light quark masses. On the other hand, pion-nucleon dynamics also strongly affects the long-range part of nucleon-nucleon potentials, and hence has a far-reaching impact on nuclear physics. We discuss the fruitful combination of dispersion-theoretical methods, in the form of Roy-Steiner equations, with chiral dynamics to determine pion-nucleon scattering amplitudes at low energies with high precision.*

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

Yokosawa, A.

We review structures appearing in various experimental data (particularly those with polarized beams) in nucleon-nucleon systems. We present a number of candidates for dibaryon resonances which can couple to nucleon-nucleon systems.

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

Yokosawa, A.

Structures appearing in various experimental data (particularly those with polarized beams) in nucleon-nucleon systems are reviewed. A number of candidates are presented for dibaryon resonances which can couple to nucleon-nucleon systems.

Nuclear spin-isospin excitations from covariant quasiparticle-vibration coupling

NASA Astrophysics Data System (ADS)

Robin, Caroline; Litvinova, Elena

2016-09-01

Methods based on the relativistic Lagrangian of quantum hadrodynamics and nuclear field theory provide a consistent framework for the description of nuclear excitations, naturally connecting the high- and medium-energy scales of mesons to the low-energy domain of nucleonic collective motion. Applied in the neutral channel, this approach has been quite successful in describing the overall transition strength up to high excitation energies, as well as fine details of the low-lying distribution. Recently, this method has been extended to the description of spin-isospin excitations in open-shell nuclei. In the charge-exchange channel, the coupling between nucleons and collective vibrations generates a time-dependent proton-neutron effective interaction, in addition to the static pion and rho-meson exchange, and introduces complex configurations that induce fragmentation and spreading of the resonances. Such effects have a great impact on the quenching of the strength and on the computing of weak reaction rates that are needed for astrophysics modeling. Gamow-Teller transitions in medium-mass nuclei and associated beta-decay half-lives will be presented. Further developments aiming to include additional ground-state correlations will also be discussed. This work is supported by US-NSF Grants PHY-1404343 and PHY-1204486.

Search for WIMP inelastic scattering off xenon nuclei with XENON100

NASA Astrophysics Data System (ADS)

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; di Gangi, P.; di Giovanni, A.; Diglio, S.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Itay, R.; Kaminsky, B.; Kazama, S.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Lopes, J. A. M.; Manfredini, A.; Maris, I.; Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.; Mora, K.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Pizzella, V.; Piro, M.-C.; Plante, G.; Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Rupp, N.; Dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Silva, M.; Simgen, H.; Sivers, M. V.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Vargas, M.; Wang, H.; Wang, Z.; Wei, Y.; Weinheimer, C.; Wulf, J.; Ye, J.; Zhang, Y.; Xenon Collaboration

2017-07-01

We present the first constraints on the spin-dependent, inelastic scattering cross section of weakly interacting massive particles (WIMPs) on nucleons from XENON100 data with an exposure of 7.64 ×103 kg .days . XENON100 is a dual-phase xenon time projection chamber with 62 kg of active mass, operated at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy and designed to search for nuclear recoils from WIMP-nucleus interactions. Here we explore inelastic scattering, where a transition to a low-lying excited nuclear state of Xe 129 is induced. The experimental signature is a nuclear recoil observed together with the prompt deexcitation photon. We see no evidence for such inelastic WIMP-Xe 129 interactions. A profile likelihood analysis allows us to set a 90% C.L. upper limit on the inelastic, spin-dependent WIMP-nucleon cross section of 3.3 ×10-38 cm2 at 100 GeV /c2 . This is the most constraining result to date, and sets the pathway for an analysis of this interaction channel in upcoming, larger dual-phase xenon detectors.

Cosmic-ray isotopic composition of C, N, O, Ne, Mg, Si nuclei in the energy range 50-200 MeV per nucleon measured by the Voyager spacecraft during the solar minimum period

NASA Technical Reports Server (NTRS)

Lukasiak, A.; Ferrando, P.; Mcdonald, F. B.; Webber, W. R.

1994-01-01

The isotopic composition of C, N, O, Ne, Mg, Si cosmic ray nuclei has been measured in the energy range 50-200 MeV per nucleon using data collected by the High-Energy Telescope of the cosmic-ray subsystem experiment on the Voyager 1 and 2 spacecraft. These data were collected during the period of minimum solar activity in 1986-1988 at an average distance of 27 AU with an effective solar modulation that was much less than at the Earth. The isotope analysis, based on the energy loss - total energy method, has a mass resolution of 0.2 amu for carbon and 0.4 amu at silicon. We find a (C-13)/(C-12) ratio slightly lower and a (O-18)/(O-16) ratio slightly enhanced over their solar system value. We also observe the previously reported enhancement of the (Ne-22)/(Ne-20) ratio relative to solar at the cosmic-ray source but only a weak, if any, enhancement of the (Mg-25)/(Mg-24), (Mg-26)/(Mg 24), and (Si-30)/(Si-28) ratios.

Current status of GALS setup in JINR

NASA Astrophysics Data System (ADS)

Zemlyanoy, S.; Avvakumov, K.; Fedosseev, V.; Bark, R.; Blazczak, Z.; Janas, Z.

2017-11-01

This is a brief report on the current status of the new GAs cell based Laser ionization Setup (GALS) at the Flerov Laboratory for Nuclear Reactions (FLNR) of the Joint Institute for Nuclear Research (JINR) in Dubna. GALS will exploit available beams from the U-400M cyclotron in low energy multi-nucleon transfer reactions to study exotic neutron-rich nuclei located in the "north-east" region of nuclear map. Products from 4.5 to 9 MeV/nucleon heavy-ion collisions, such as 136Xe on 208Pb, are thermalized and neutralized in a high pressure gas cell and subsequently selectively laser re-ionized. In order to choose the best scheme of ion extraction the results of computer simulations of two different systems are presented. The first off- and online experiment will be performed on osmium atoms that is regarded as a most convenient element for producing isotopes with neutron number in the vicinity of the magic N = 126.

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

Golak, J.; Skibinski, R.; Topolnicki, K.

Here, we solve three-nucleon Faddeev equations with nucleon-nucleon and three-nucleon forces derived consistently in the framework of chiral perturbation theory at next-to-next-to-next-to-leading order in the chiral expansion. In this first investigation we include only matrix elements of the three-nucleon force for partial waves with the total two-nucleon (three-nucleon) angular momenta up to 3 (5/2). Low-energy neutron-deuteron elastic scattering and deuteron breakup reaction are studied. Emphasis is put on A y puzzle in elastic scattering and cross sections in symmetric-space-star and neutron-neutron quasi-free-scattering breakup configurations, for which large discrepancies between data and theory have been reported.

Electromagnetic and neutral-weak response functions of 4He and 12C

NASA Astrophysics Data System (ADS)

Lovato, A.; Gandolfi, S.; Carlson, J.; Pieper, Steven C.; Schiavilla, R.

2015-06-01

Background: A major goal of nuclear theory is to understand the strong interaction in nuclei as it manifests itself in terms of two- and many-body forces among the nuclear constituents, the protons and neutrons, and the interactions of these constituents with external electroweak probes via one- and many-body currents. Purpose: The objective of the present work is to calculate the quasielastic electroweak response functions in light nuclei within the realistic dynamical framework outlined above. These response functions determine the inclusive cross section as function of the lepton momentum and energy transfers. Methods: Their ab initio calculation is a very challenging quantum many-body problem, since it requires summation over the entire excitation spectrum of the nucleus and inclusion in the electroweak currents of one- and many-body terms. Green's functions Monte Carlo methods allow one to circumvent both difficulties by computing the response in imaginary time (the so-called Euclidean response) and hence summing implicitly over the bound and continuum states of the nucleus, and by implementing specific algorithms designed to deal with the complicated spin-isospin structure of nuclear many-body operators. Results: Theoretical predictions for 4He and 12C, confirmed by experiment in the electromagnetic case, show that two-body currents generate excess transverse strength from threshold to the quasielastic to the dip region and beyond. Conclusions: These results challenge the conventional picture of quasielastic inclusive scattering as being largely dominated by single-nucleon knockout processes.

Electromagnetic and neutral-weak response functions of 4He and 12C

DOE PAGES

Lovato, A.; Gandolfi, Stefano; Carlson, Joseph Allen; ...

2015-06-04

A major goal of nuclear theory is to understand the strong interaction in nuclei as it manifests itself in terms of two- and many-body forces among the nuclear constituents, the protons and neutrons, and the interactions of these constituents with external electroweak probes via one- and many-body currents. The objective of the present work is to calculate the quasielastic electroweak response functions in light nuclei within the realistic dynamical framework outlined above. These response functions determine the inclusive cross section as function of the lepton momentum and energy transfers. Their ab initio calculation is a very challenging quantum many-body problem,more » since it requires summation over the entire excitation spectrum of the nucleus and inclusion in the electroweak currents of one- and many-body terms. Green's functions Monte Carlo methods allow one to circumvent both difficulties by computing the response in imaginary time (the so-called Euclidean response) and hence summing implicitly over the bound and continuum states of the nucleus, and by implementing specific algorithms designed to deal with the complicated spin-isospin structure of nuclear many-body operators. Theoretical predictions for 4He and 12C, confirmed by experiment in the electromagnetic case, show that two-body currents generate excess transverse strength from threshold to the quasielastic to the dip region and beyond. In conclusion, these results challenge the conventional picture of quasielastic inclusive scattering as being largely dominated by single-nucleon knockout processes.« less

Nucleon properties in the Polyakov quark-meson model

NASA Astrophysics Data System (ADS)

Li, Yingying; Hu, Jinniu; Mao, Hong

2018-05-01

We study the nucleon as a nontopological soliton in a quark medium as well as in a nucleon medium in terms of the Polyakov quark-meson (PQM) model with two flavors at finite temperature and density. The constituent quark masses evolving with the temperature at various baryon chemical potentials are calculated and the equations of motion are solved according to the proper boundary conditions. The PQM model predicts an increasing size of the nucleon and a reduction of the nucleon mass in both hot environment. However, the phase structure is different from each other in quark and nucleon mediums. There is a crossover in the low-density region and a first-order phase transition in the high-density region in quark medium, whereas there exists a crossover characterized by the overlap of the nucleons in nucleon medium.

Low-energy neutron-deuteron reactions with N 3LO chiral forces

DOE PAGES

Golak, J.; Skibinski, R.; Topolnicki, K.; ...

2014-11-27

Here, we solve three-nucleon Faddeev equations with nucleon-nucleon and three-nucleon forces derived consistently in the framework of chiral perturbation theory at next-to-next-to-next-to-leading order in the chiral expansion. In this first investigation we include only matrix elements of the three-nucleon force for partial waves with the total two-nucleon (three-nucleon) angular momenta up to 3 (5/2). Low-energy neutron-deuteron elastic scattering and deuteron breakup reaction are studied. Emphasis is put on A y puzzle in elastic scattering and cross sections in symmetric-space-star and neutron-neutron quasi-free-scattering breakup configurations, for which large discrepancies between data and theory have been reported.

Nucleon-nucleon interactions via Lattice QCD: Methodology. HAL QCD approach to extract hadronic interactions in lattice QCD

NASA Astrophysics Data System (ADS)

Aoki, Sinya

2013-07-01

We review the potential method in lattice QCD, which has recently been proposed to extract nucleon-nucleon interactions via numerical simulations. We focus on the methodology of this approach by emphasizing the strategy of the potential method, the theoretical foundation behind it, and special numerical techniques. We compare the potential method with the standard finite volume method in lattice QCD, in order to make pros and cons of the approach clear. We also present several numerical results for nucleon-nucleon potentials.

Baryon spectroscopy with polarization observables from CLAS

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

Strauch, Steffen

The spectrum of nucleon excitations is dominated by broad and overlapping resonances. Polarization observables in photoproduction reactions are key in the study of these excitations. They give indispensable constraints to partial-wave analyses and help clarify the spectrum. A series of polarized photoproduction experiments have been performed at the Thomas Jefferson National Accelerator Facility with the CEBAF Large Acceptance Spectrometer (CLAS). These measurements include data with linearly and circularly polarized tagged-photon beams, longitudinally and transversely polarized proton and deuterium targets, and recoil polarizations through the observation of the weak decay of hyperons. An overview of these studies and recent results willmore » be given.« less

Measurements of dielectron production in Au + Au collisions at s N N = 200 GeV from the STAR experiment

DOE PAGES

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

2015-08-24

We report on measurements of dielectron (e⁺e⁻) production in Au+Au collisions at a center-of-mass energy of 200 GeV per nucleon-nucleon pair using the STAR detector at RHIC. Systematic measurements of the dielectron yield as a function of transverse momentum (p T) and collision centrality show an enhancement compared to a cocktail simulation of hadronic sources in the low invariant-mass region (M ee < 1GeV/c 2). This enhancement cannot be reproduced by the ρ-meson vacuum spectral function. In minimum-bias collisions, in the invariant-mass range of 0.30 – 0.76GeV/c², integrated over the full p T acceptance, the enhancement factor is 1.76±0.06(stat.)±0.26(sys.)±0.29(cocktail). Themore » enhancement factor exhibits weak centrality and p T dependence in STAR's accessible kinematic regions, while the excess yield in this invariant-mass region as a function of the number of participating nucleons follows a power-law shape with a power of 1.44±0.10. Models that assume an in-medium broadening of the ρ-meson spectral function consistently describe the observed excess in these measurements. In addition, we report on measurements of ω- and Φ-meson production through their e⁺e⁻ decay channel. These measurements show good agreement with Tsallis blast-wave model predictions, as well as, in the case of the Φ meson, results through its K⁺K⁻ decay channel. In the intermediate invariant-mass region (1.1 < M ee < 3GeV/c²), we investigate the spectral shapes from different collision centralities. Physics implications for possible in-medium modification of charmed hadron production and other physics sources are discussed.« less

Relativistic optical model on the basis of the Moscow potential and lower phase shifts for nucleon-nucleon scattering at laboratory energies of up to 3 GeV

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

Knyr, V. A.; Neudatchin, V. G.; Khokhlov, N. A.

Data of a partial-wave analysis of nucleon-nucleon scattering at energies of up to E{sub lab} = 3 GeV (lower partial waves) and the properties of the deuteron are described within the relativistic optical model based on deep attractive quasipotentials involving forbidden states (as exemplified by the Moscow potential). Partial-wave potentials are derived by the inverse-scattering-problem method based on the Marchenko equation by using present-day data from the partial-wave analysis of nucleon-nucleon scattering at energies of up to 3 GeV. Channel coupling is taken into account. The imaginary parts of the potentials are deduced from the phase equation of the variable-phasemore » approach. The general situation around the manifestation of quark effects in nucleon-nucleon interaction is discussed.« less

A 3% Measurement of the Beam Normal Single Spin Asymmetry in Forward Angle Elastic Electron-Proton Scattering using the Qweak Setup

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

Waidyawansa, Dinayadura Buddhini

2013-08-01

The beam normal single spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable of the imaginary part of the two-photon exchange process. Moreover, it is a potential source of false asymmetry in parity violating electron scattering experiments. The Q{sub weak} experiment uses parity violating electron scattering to make a direct measurement of the weak charge of the proton. The targeted 4% measurement of the weak charge of the proton probes for parity violating new physics beyond the Standard Model. The beam normal single spin asymmetry at Q{sub weak} kinematics is at least threemore » orders of magnitude larger than 5 ppb precision of the parity violating asymmetry. To better understand this parity conserving background, the Q{sub weak} Collaboration has performed elastic scattering measurements with fully transversely polarized electron beam on the proton and aluminum. This dissertation presents the analysis of the 3% measurement (1.3% statistical and 2.6% systematic) of beam normal single spin asymmetry in electronproton scattering at a Q2 of 0.025 (GeV/c)2. It is the most precise existing measurement of beam normal single spin asymmetry available at the time. A measurement of this precision helps to improve the theoretical models on beam normal single spin asymmetry and thereby our understanding of the doubly virtual Compton scattering process.« less

The current matrix elements from HAL QCD method

NASA Astrophysics Data System (ADS)

Watanabe, Kai; Ishii, Noriyoshi

2018-03-01

HAL QCD method is a method to construct a potential (HAL QCD potential) that reproduces the NN scattering phase shift faithful to the QCD. The HAL QCD potential is obtained from QCD by eliminating the degrees of freedom of quarks and gluons and leaving only two particular hadrons. Therefor, in the effective quantum mechanics of two nucleons defined by HAL QCD potential, the conserved current consists not only of the nucleon current but also an extra current originating from the potential (two-body current). Though the form of the two-body current is closely related to the potential, it is not straight forward to extract the former from the latter. In this work, we derive the the current matrix element formula in the quantum mechanics defined by the HAL QCD potential. As a first step, we focus on the non-relativistic case. To give an explicit example, we consider a second quantized non-relativistic two-channel coupling model which we refer to as the original model. From the original model, the HAL QCD potential for the open channel is constructed by eliminating the closed channel in the elastic two-particle scattering region. The current matrix element formula is derived by demanding the effective quantum mechanics defined by the HAL QCD potential to respond to the external field in the same way as the original two-channel coupling model.

Renormalization of the Brazilian chiral nucleon-nucleon potential

NASA Astrophysics Data System (ADS)

Da Rocha, Carlos A.; Timóteo, Varese S.

2013-03-01

In this work we present a renormalization of the Brazilian nucleon-nucleon (NN) potential using a subtractive method. We show that the exchange of correlated two pion is important for isovector channels, mainly in tensor and central potentials.

The Role of the Isospin 3/2 Component in Elastic Neutron-Deuteron Scattering and in the Deuteron Breakup Reaction

NASA Astrophysics Data System (ADS)

Witała, H.; Golak, J.; Skibiński, R.; Topolnicki, K.; Kamada, H.

We discuss the importance of the three-nucleon isospin T = 3/2 component in elastic neutron-deuteron scattering and in the deuteron breakup reaction. The contribution of this amplitude originates from charge-independence breaking of the nucleon-nucleon potential. We study the magnitude of that contribution to the elastic scattering and breakup observables, taking the Av18 nucleon-nucleon potential alone or combined with the Urbana IX three-nucleon force as well as the locally regularized chiral N4LO nucleon-nucleon potential alone or supplemented by the chiral N2LO three-nucleon force. We find that the isospin T = 3/2 component is important for the breakup reaction and the proper treatment of charge-independence breaking in this case requires the inclusion of the 1S 0 state with isospin T = 3/2. For neutron-deuteron elastic scattering the T = 3/2 contributions are insignificant and charge-independence breaking can be accounted for by neglecting T = 3/2 component and using the effective t-matrix generated with the so-called “2/3 ‑ 1/3″ rule.

Many body effects in nuclear matter QCD sum rules

NASA Astrophysics Data System (ADS)

Drukarev, E. G.; Ryskin, M. G.; Sadovnikova, V. A.

2017-12-01

We calculate the single-particle nucleon characteristics in symmetric nuclear matter with inclusion of the 3N and 4N interactions. We calculated the contribution of the 3N interactions earlier, now we add that of the 4N ones. The contribution of the 4N forces to nucleon self energies is expressed in terms of the nonlocal scalar condensate (d = 3) and of the configurations of the vector-scalar and the scalar-scalar quark condensates (d = 6) in which two diquark operators act on two different nucleons of the matter.These four-quark condensates are obtained in the model-independent way. The density dependence of the nucleon effective mass, of the vector self energy and of the single-particle potential energy are obtained. We traced the dependence of the nucleon characteristics on the actual value of the pion-nucleon sigma term. We obtained also the nucleon characteristics in terms of the quasifree nucleons, with the noninteracting nucleons surrounded by their pion clouds as the starting point. This approach leads to strict hierarchy of the many body forces.

Nucleon matter equation of state, particle number fluctuations, and shear viscosity within UrQMD box calculations

NASA Astrophysics Data System (ADS)

Motornenko, A.; Bravina, L.; Gorenstein, M. I.; Magner, A. G.; Zabrodin, E.

2018-03-01

Properties of equilibrated nucleon system are studied within the ultra-relativistic quantum molecular dynamics (UrQMD) transport model. The UrQMD calculations are done within a finite box with periodic boundary conditions. The system achieves thermal equilibrium due to nucleon-nucleon elastic scattering. For the UrQMD-equilibrium state, nucleon energy spectra, equation of state, particle number fluctuations, and shear viscosity η are calculated. The UrQMD results are compared with both, statistical mechanics and Chapman-Enskog kinetic theory, for a classical system of nucleons with hard-core repulsion.

Quantum Monte Carlo methods for nuclear physics

DOE PAGES

Carlson, J.; Gandolfi, S.; Pederiva, F.; ...

2015-09-09

Quantum Monte Carlo methods have proved valuable to study the structure and reactions of light nuclei and nucleonic matter starting from realistic nuclear interactions and currents. These ab-initio calculations reproduce many low-lying states, moments, and transitions in light nuclei, and simultaneously predict many properties of light nuclei and neutron matter over a rather wide range of energy and momenta. The nuclear interactions and currents are reviewed along with a description of the continuum quantum Monte Carlo methods used in nuclear physics. These methods are similar to those used in condensed matter and electronic structure but naturally include spin-isospin, tensor, spin-orbit,more » and three-body interactions. A variety of results are presented, including the low-lying spectra of light nuclei, nuclear form factors, and transition matrix elements. Low-energy scattering techniques, studies of the electroweak response of nuclei relevant in electron and neutrino scattering, and the properties of dense nucleonic matter as found in neutron stars are also described. Furthermore, a coherent picture of nuclear structure and dynamics emerges based upon rather simple but realistic interactions and currents.« less

Quantum Monte Carlo methods for nuclear physics

DOE PAGES

Carlson, Joseph A.; Gandolfi, Stefano; Pederiva, Francesco; ...

2014-10-19

Quantum Monte Carlo methods have proved very valuable to study the structure and reactions of light nuclei and nucleonic matter starting from realistic nuclear interactions and currents. These ab-initio calculations reproduce many low-lying states, moments and transitions in light nuclei, and simultaneously predict many properties of light nuclei and neutron matter over a rather wide range of energy and momenta. We review the nuclear interactions and currents, and describe the continuum Quantum Monte Carlo methods used in nuclear physics. These methods are similar to those used in condensed matter and electronic structure but naturally include spin-isospin, tensor, spin-orbit, and three-bodymore » interactions. We present a variety of results including the low-lying spectra of light nuclei, nuclear form factors, and transition matrix elements. We also describe low-energy scattering techniques, studies of the electroweak response of nuclei relevant in electron and neutrino scattering, and the properties of dense nucleonic matter as found in neutron stars. A coherent picture of nuclear structure and dynamics emerges based upon rather simple but realistic interactions and currents.« less

Precision muon physics

NASA Astrophysics Data System (ADS)

Gorringe, T. P.; Hertzog, D. W.

2015-09-01

The muon is playing a unique role in sub-atomic physics. Studies of muon decay both determine the overall strength and establish the chiral structure of weak interactions, as well as setting extraordinary limits on charged-lepton-flavor-violating processes. Measurements of the muon's anomalous magnetic moment offer singular sensitivity to the completeness of the standard model and the predictions of many speculative theories. Spectroscopy of muonium and muonic atoms gives unmatched determinations of fundamental quantities including the magnetic moment ratio μμ /μp, lepton mass ratio mμ /me, and proton charge radius rp. Also, muon capture experiments are exploring elusive features of weak interactions involving nucleons and nuclei. We will review the experimental landscape of contemporary high-precision and high-sensitivity experiments with muons. One focus is the novel methods and ingenious techniques that achieve such precision and sensitivity in recent, present, and planned experiments. Another focus is the uncommonly broad and topical range of questions in atomic, nuclear and particle physics that such experiments explore.

A global fit of the MSSM with GAMBIT

NASA Astrophysics Data System (ADS)

Athron, Peter; Balázs, Csaba; Bringmann, Torsten; Buckley, Andy; Chrząszcz, Marcin; Conrad, Jan; Cornell, Jonathan M.; Dal, Lars A.; Edsjö, Joakim; Farmer, Ben; Jackson, Paul; Krislock, Abram; Kvellestad, Anders; Mahmoudi, Farvah; Martinez, Gregory D.; Putze, Antje; Raklev, Are; Rogan, Christopher; Saavedra, Aldo; Savage, Christopher; Scott, Pat; Serra, Nicola; Weniger, Christoph; White, Martin

2017-12-01

We study the seven-dimensional Minimal Supersymmetric Standard Model (MSSM7) with the new GAMBIT software framework, with all parameters defined at the weak scale. Our analysis significantly extends previous weak-scale, phenomenological MSSM fits, by adding more and newer experimental analyses, improving the accuracy and detail of theoretical predictions, including dominant uncertainties from the Standard Model, the Galactic dark matter halo and the quark content of the nucleon, and employing novel and highly-efficient statistical sampling methods to scan the parameter space. We find regions of the MSSM7 that exhibit co-annihilation of neutralinos with charginos, stops and sbottoms, as well as models that undergo resonant annihilation via both light and heavy Higgs funnels. We find high-likelihood models with light charginos, stops and sbottoms that have the potential to be within the future reach of the LHC. Large parts of our preferred parameter regions will also be accessible to the next generation of direct and indirect dark matter searches, making prospects for discovery in the near future rather good.

Deuterium target data for precision neutrino-nucleus cross sections

DOE PAGES

Meyer, Aaron S.; Betancourt, Minerba; Gran, Richard; ...

2016-06-23

Amplitudes derived from scattering data on elementary targets are basic inputs to neutrino-nucleus cross section predictions. A prominent example is the isovector axial nucleon form factor, F A(q 2), which controls charged current signal processes at accelerator-based neutrino oscillation experiments. Previous extractions of F A from neutrino-deuteron scattering data rely on a dipole shape assumption that introduces an unquantified error. A new analysis of world data for neutrino-deuteron scattering is performed using a model-independent, and systematically improvable, representation of F A. A complete error budget for the nucleon isovector axial radius leads to r A 2 = 0.46(22)fm 2, withmore » a much larger uncertainty than determined in the original analyses. The quasielastic neutrino-neutron cross section is determined as σ(ν μn → μ -p)| Ev=1 GeV = 10.1(0.9)×10 -39cm 2. The propagation of nucleon-level constraints and uncertainties to nuclear cross sections is illustrated using MINERvA data and the GENIE event generator. Furthermore, these techniques can be readily extended to other amplitudes and processes.« less

On Complex Nuclei Energetics in LENR

NASA Astrophysics Data System (ADS)

Miley, George H.; Hora, Heinz

2005-03-01

Swimming Electron Layer (SEL) theory plus fission of ``complex nuclei'' were proposed earlier to explain reaction products observed in electrolysis with multi-layer thin-film metallic electrodesootnotetext1.G.H. Miley, and J.A. Patterson, J. New Energy, Vol. 1, pp.11-15, (1996).. SEL was then extended to treat gas-diffusion driven transmutation experimentsootnotetextG. H. Miley and H. Hora, ``Nuclear Reactions in Solids,'' APS DNP Mtg., East Lansing, MI, Oct (2002).. It is also consistent with measured charged-particle emission during thin-film electrolysis and x-ray emission during plasma bombardment experimentsootnotetextA. Karabut, ``X-ray emission in high-current glow discharge,'' Proc., ICCF-9, Beijing China, May (2002).. The binding energy per complex nucleon can be estimated by an energy balance combined with identification of products for each complex e.g. complexes of A 39 have ˜ 0.05 MeV/Nucleon, etc, in thin film electrolysis. Energies in gas diffusion experiments are lower due to the reduced trap site potential at the multi-atom surface. In the case of x-ray emission, complexes involve subsurface defect center traps, giving only a few keV/Nucleon, consistent with experiments^3.

PREFACE: Focus section on Hadronic Physics

NASA Astrophysics Data System (ADS)

Roberts, Craig; Swanson, Eric

2007-07-01

Hadronic physics is the study of strongly interacting matter and its underlying theory, Quantum Chromodynamics (QCD). The field had its beginnings after World War Two, when hadrons were discovered in ever increasing numbers. Today, it encompasses topics like the quark-gluon structure of hadrons at varying scales, the quark-gluon plasma and hadronic matter at extreme temperature and density; it also underpins nuclear physics and has significant impact on particle physics, astrophysics, and cosmology. Among the goals of hadronic physics are to determine the parameters of QCD, understand the origin and characteristics of confinement, understand the dynamics and consequences of dynamical chiral symmetry breaking, explore the role of quarks and gluons in nuclei and in matter under extreme conditions and understand the quark and gluon structure of hadrons. In general, the process is one of discerning the relevant degrees of freedom and relating these to the fundamental fields of QCD. The emphasis is on understanding QCD, rather than testing it. The papers gathered in this special focus section of Journal of Physics G: Nuclear and Particle Physics attempt to cover this broad range of subjects. Alkofer and Greensite examine the issue of quark and gluon confinement with the focus on models of the QCD vacuum, lattice gauge theory investigations, and the relationship to the AdS/CFT correspondence postulate. Arrington et al. review nucleon form factors and their role in determining quark orbital momentum, the strangeness content of the nucleon, meson cloud effects, and the transition from nonperturbative to perturbative QCD dynamics. The physics associated with hadronic matter at high temperature and density and at low Bjorken-x at the Relativistic Heavy Ion Collider (RHIC), the SPS at CERN, and at the future LHC is summarized by d'Enterria. The article of Lee and Smith examines experiment and theory associated with electromagnetic meson production from nucleons and illustrates how the structure of the nucleon is revealed. Reimer reviews how the Drell--Yan process can be used to explore the sea quark structure of nucleons, thereby probing such phenomena as flavour asymmetry in the nucleon and nuclear medium modification of nucleon properties. The exploitation of the B factories has led to a resurgence of interest in heavy quark spectroscopy. Concurrently, interest in light quark spectroscopy and gluonic excitations remains high, with several new experimental efforts in the planning or building stages. The current status of all of this is reviewed by Rosner. Finally, Vogelsang summarizes the status of polarized deep inelastic lepton-nucleon scattering experiments at RHIC and their impact on the theoretical understanding of nucleon helicity structure, gluon polarization in the nucleus, and transverse spin asymmetries. Of course, hadronic physics is a much broader subject than can be conveyed in this special focus section; advances in effective field theory, lattice gauge theory, generalised parton distributions and many other subfields are not covered here. Nevertheless, we hope that this focus section will help the reader appreciate the vitality, breadth of endeavour, and the phenomenological richness of hadronic physics.

Nucleonic coal detector with independent, hydropneumatic suspension

NASA Technical Reports Server (NTRS)

Jones, E. W.; Handy, K.

1977-01-01

The design of a nucleonic, coal interface detector which measures the depth of coal on the roof and floor of a coal mine is presented. The nucleonic source and the nucleonic detector are on independent hydropneumatic suspensions to reduce the measurement errors due to air gap.

Structure of the Nucleon and its Excitations

NASA Astrophysics Data System (ADS)

Kamleh, Waseem; Leinweber, Derek; Liu, Zhan-wei; Stokes, Finn; Thomas, Anthony; Thomas, Samuel; Wu, Jia-jun

2018-03-01

The structure of the ground state nucleon and its finite-volume excitations are examined from three different perspectives. Using new techniques to extract the relativistic components of the nucleon wave function, the node structure of both the upper and lower components of the nucleon wave function are illustrated. A non-trivial role for gluonic components is manifest. In the second approach, the parity-expanded variational analysis (PEVA) technique is utilised to isolate states at finite momenta, enabling a novel examination of the electric and magnetic form factors of nucleon excitations. Here the magnetic form factors of low-lying odd-parity nucleons are particularly interesting. Finally, the structure of the nucleon spectrum is examined in a Hamiltonian effective field theory analysis incorporating recent lattice-QCD determinations of low-lying two-particle scattering-state energies in the finite volume. The Roper resonance of Nature is observed to originate from multi-particle coupled-channel interactions while the first radial excitation of the nucleon sits much higher at approximately 1.9 GeV.

Effects of the nucleon radius on neutron stars in a quark mean field model

NASA Astrophysics Data System (ADS)

Zhu, Zhen-Yu; Li, Ang

2018-03-01

We study the effects of free space nucleon radius on nuclear matter and neutron stars within the framework of the quark mean field model. The nucleon radius is treated self-consistently with this model, where quark confinement is adjusted to fit different values of nucleon radius. Corrections due to center-of-mass motion, quark-pion coupling, and one gluon exchange are included to obtain the nucleon mass in vacuum. The meson coupling constants that describe the behavior of the many-body nucleonic system are constructed by reproducing the empirical saturation properties of nuclear matter, including the recent determinations of symmetry energy parameters. Our results show that the nucleon radius in free space has negligible effects on the nuclear matter equation of state and neutron star mass-radius relations, which is different from the conclusion drawn in previous studies. We further explore that the sensitivity of star radius on the nucleon radius found in earlier publications is actually from the symmetry energy and its slope.

Leading order relativistic hyperon-nucleon interactions in chiral effective field theory

NASA Astrophysics Data System (ADS)

Li, Kai-Wen; Ren, Xiu-Lei; Geng, Li-Sheng; Long, Bing-Wei

2018-01-01

We apply a recently proposed covariant power counting in nucleon-nucleon interactions to study strangeness S=-1 {{\\varLambda }}N-{{\\varSigma }}N interactions in chiral effective field theory. At leading order, Lorentz invariance introduces 12 low energy constants, in contrast to the heavy baryon approach, where only five appear. The Kadyshevsky equation is adopted to resum the potential in order to account for the non-perturbative nature of hyperon-nucleon interactions. A fit to the 36 hyperon-nucleon scattering data points yields {χ }2≃ 16, which is comparable with the sophisticated phenomenological models and the next-to-leading order heavy baryon approach. However, one cannot achieve a simultaneous description of the nucleon-nucleon phase shifts and strangeness S=-1 hyperon-nucleon scattering data at leading order. Supported by the National Natural Science Foundation of China (11375024, 11522539, 11375120), the China Postdoctoral Science Foundation (2016M600845, 2017T100008) and the Fundamental Research Funds for the Central Universities

Two-Nucleon Momentum Distributions Measured in 3He(e,e'pp)n

NASA Astrophysics Data System (ADS)

Niyazov, R. A.; Weinstein, L. B.; Adams, G.; Ambrozewicz, P.; Anciant, E.; Anghinolfi, M.; Asavapibhop, B.; Asryan, G.; Audit, G.; Auger, T.; Avakian, H.; Bagdasaryan, H.; Ball, J. P.; Barrow, S.; Battaglieri, M.; Beard, K.; Bektasoglu, M.; Bellis, M.; Benmouna, N.; Berman, B. L.; Bertozzi, W.; Bianchi, N.; Biselli, A. S.; Boiarinov, S.; Bonner, B. E.; Bouchigny, S.; Bradford, R.; Branford, D.; Brooks, W. K.; Burkert, V. D.; Butuceanu, C.; Calarco, J. R.; Carman, D. S.; Carnahan, B.; Cetina, C.; Chen, S.; Ciciani, L.; Cole, P. L.; Coleman, A.; Cords, D.; Corvisiero, P.; Crabb, D.; Crannell, H.; Cummings, J. P.; de Sanctis, E.; Dashyan, N.; Devita, R.; Degtyarenko, P. V.; Denizli, H.; Dennis, L.; Dharmawardane, K. V.; Dhuga, K. S.; Djalali, C.; Dodge, G. E.; Doughty, D.; Dragovitsch, P.; Dugger, M.; Dytman, S.; Dzyubak, O. P.; Eckhause, M.; Egiyan, H.; Egiyan, K. S.; Elouadrhiri, L.; Empl, A.; Eugenio, P.; Fatemi, R.; Feuerbach, R. J.; Ficenec, J.; Forest, T. A.; Funsten, H.; Gavalian, G.; Gilad, S.; Gilfoyle, G. P.; Giovanetti, K. L.; Girard, P.; Gordon, C. I.; Gothe, R. W.; Griffioen, K.; Guidal, M.; Guillo, M.; Guo, L.; Gyurjyan, V.; Hadjidakis, C.; Hakobyan, R. S.; Hardie, J.; Heddle, D.; Hersman, F. W.; Hicks, K.; Holtrop, M.; Hu, J.; Hyde-Wright, C. E.; Ilieva, Y.; Ingram, W.; Ito, M. M.; Jenkins, D.; Joo, K.; Juengst, H. G.; Kelley, J. H.; Kellie, J.; Khandaker, M.; Kim, D. H.; Kim, K. Y.; Kim, K.; Kim, M. S.; Kim, W.; Klein, A.; Klein, F. J.; Klimenko, A. V.; Klusman, M.; Kossov, M.; Kramer, L. H.; Kuang, Y.; Kuhn, S. E.; Kuhn, J.; Lachniet, J.; Laget, J. M.; Langheinrich, J.; Lawrence, D.; Li, Ji; Livingston, K.; Lukashin, K.; Manak, J. J.; Marchand, C.; McAleer, S.; McLauchlan, S.; McNabb, J. W.; Mecking, B. A.; Mehrabyan, S.; Melone, J. J.; Mestayer, M. D.; Meyer, C. A.; Mikhailov, K.; Mirazita, M.; Miskimen, R.; Morand, L.; Morrow, S. A.; Muccifora, V.; Mueller, J.; Mutchler, G. S.; Napolitano, J.; Nasseripour, R.; Nelson, S. O.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Niczyporuk, B. B.; Nozar, M.; O'Rielly, G. V.; Osipenko, M.; Park, K.; Pasyuk, E.; Peterson, G.; Philips, S. A.; Pivnyuk, N.; Pocanic, D.; Pogorelko, O.; Polli, E.; Pozdniakov, S.; Preedom, B. M.; Price, J. W.; Prok, Y.; Protopopescu, D.; Qin, L. M.; Raue, B. A.; Riccardi, G.; Ricco, G.; Ripani, M.; Ritchie, B. G.; Ronchetti, F.; Rossi, P.; Rowntree, D.; Rubin, P. D.; Sabatié, F.; Sabourov, K.; Salgado, C.; Santoro, J. P.; Sapunenko, V.; Schumacher, R. A.; Serov, V. S.; Shafi, A.; Sharabian, Y. G.; Shaw, J.; Simionatto, S.; Skabelin, A. V.; Smith, E. S.; Smith, L. C.; Sober, D. I.; Spraker, M.; Stavinsky, A.; Stepanyan, S.; Stoler, P.; Strakovsky, I. I.; Strauch, S.; Taiuti, M.; Taylor, S.; Tedeschi, D. J.; Thoma, U.; Thompson, R.; Todor, L.; Tur, C.; Ungaro, M.; Vineyard, M. F.; Vlassov, A. V.; Wang, K.; Weller, H.; Weygand, D. P.; Whisnant, C. S.; Wolin, E.; Wood, M. H.; Yegneswaran, A.; Yun, J.; Zhang, B.

2004-02-01

We have measured the 3He(e,e'pp)n reaction at 2.2GeV over a wide kinematic range. The kinetic energy distribution for “fast” nucleons (p>250 MeV/c) peaks where two nucleons each have 20% or less, and the third nucleon has most of the transferred energy. These fast pp and pn pairs are back to back with little momentum along the three-momentum transfer, indicating that they are spectators. Calculations by Sargsian and by Laget also indicate that we have measured distorted two-nucleon momentum distributions by striking one nucleon and detecting the spectator correlated pair.

Calculation of the nucleon structure function from the nucleon wave function

NASA Technical Reports Server (NTRS)

Hussar, Paul E.

1993-01-01

Harmonic oscillator wave functions have played an historically important role in our understanding of the structure of the nucleon, most notably by providing insight into the mass spectra of the low-lying states. High energy scattering experiments are known to give us a picture of the nucleon wave function at high-momentum transfer and in a frame in which the nucleon is traveling fast. A simple model that crosses the twin bridges of momentum scale and Lorentz frame that separate the pictures of the nucleon wave function provided by the deep inelastic scattering data and by the oscillator model is presented.

The chiral quark condensate and pion decay constant in nuclear matter at next-to-leading order

NASA Astrophysics Data System (ADS)

Lacour, A.; Oller, J. A.; Meißner, U.-G.

2010-12-01

Making use of the recently developed chiral power counting for the physics of nuclear matter (Oller et al 2010 J. Phys. G: Nucl. Part. Phys. 37 015106, Lacour et al Ann. Phys. at press), we evaluate the in-medium chiral quark condensate up to next-to-leading order for both symmetric nuclear matter and neutron matter. Our calculation includes the full in-medium iteration of the leading order local and one-pion exchange nucleon-nucleon interactions. Interestingly, we find a cancellation between the contributions stemming from the quark mass dependence of the nucleon mass appearing in the in-medium nucleon-nucleon interactions. Only the contributions originating from the explicit quark mass dependence of the pion mass survive. This cancellation is the reason of previous observations concerning the dominant role of the long-range pion contributions and the suppression of short-range nucleon-nucleon interactions. We find that the linear density contribution to the in-medium chiral quark condensate is only slightly modified for pure neutron matter by the nucleon-nucleon interactions. For symmetric nuclear matter, the in-medium corrections are larger, although smaller compared to other approaches due to the full iteration of the lowest order nucleon-nucleon tree-level amplitudes. Our calculation satisfies the Hellmann-Feynman theorem to the order worked out. Also we address the problem of calculating the leading in-medium corrections to the pion decay constant. We find that there are no extra in-medium corrections that violate the Gell-Mann-Oakes-Renner relation up to next-to-leading order.

Proceedings of RIKEN BNL Research Center Workshop: Brookhaven Summer Program on Nucleon Spin Physics

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

Aschenauer, A.; Qiu, Jianwei; Vogelsang, W.

Understanding the structure of the nucleon is of fundamental importance in sub-atomic physics. Already the experimental studies on the electro-magnetic form factors in the 1950s showed that the nucleon has a nontrivial internal structure, and the deep inelastic scattering experiments in the 1970s revealed the partonic substructure of the nucleon. Modern research focuses in particular on the spin and the gluonic structure of the nucleon. Experiments using deep inelastic scattering or polarized p-p collisions are carried out in the US at the CEBAF and RHIC facilities, respectively, and there are other experimental facilities around the world. More than twenty yearsmore » ago, the European Muon Collaboration published their first experimental results on the proton spin structure as revealed in polarized deep inelastic lepton-nucleon scattering, and concluded that quarks contribute very little to the proton's spin. With additional experimental and theoretical investigations and progress in the following years, it is now established that, contrary to naive quark model expectations, quarks and anti-quarks carry only about 30% of the total spin of the proton. Twenty years later, the discovery from the polarized hadron collider at RHIC was equally surprising. For the phase space probed by existing RHIC experiments, gluons do not seem to contribute any to the proton's spin. To find out what carries the remaining part of proton's spin is a key focus in current hadronic physics and also a major driving force for the new generation of spin experiments at RHIC and Jefferson Lab and at a future Electron Ion Collider. It is therefore very important and timely to organize a series of annual spin physics meetings to summarize the status of proton spin physics, to focus the effort, and to layout the future perspectives. This summer program on 'Nucleon Spin Physics' held at Brookhaven National Laboratory (BNL) on July 14-27, 2010 [http://www.bnl.gov/spnsp/] is the second one following the Berkeley Summer Program taken place in June of 2009. This program at BNL focused on theory and had many presentations on a wide range of theoretical aspects on nucleon spin, from perturbative-QCD calculations to models, and to the first principle lattice calculation. It also had a good number of summary talks from all major experimental collaborations on spin physics. The program facilitated many discussions between theorists as well as experimentalists. With five transparencies from each presentation at the Summer Program, this proceedings provides a valuable summary on the status and progress, as well as the future prospects of spin physics.« less

Binding energies and modelling of nuclei in semiclassical simulations

NASA Astrophysics Data System (ADS)

Pérez-García, M. Ángeles; Tsushima, K.; Valcarce, A.

2008-03-01

We study the binding energies of spin isospin saturated nuclei with nucleon number 8⩽A⩽100 in semiclassical Monte Carlo many-body simulations. The model Hamiltonian consists of (i) nucleon kinetic energy, (ii) a nucleon nucleon interaction potential, and (iii) an effective Pauli potential which depends on density. The basic ingredients of the nucleon nucleon potential are a short-range repulsion, and a medium-range attraction. Our results demonstrate that one can always expect to obtain the empirical binding energies for a set of nuclei by introducing a proper density dependent Pauli potential in terms of a single variable, the nucleon number, A. The present work shows that in the suggested procedure there is a delicate counterbalance of kinetic and potential energetic contributions allowing a good reproduction of the experimental nuclear binding energies. This type of calculations may be of interest in further reproduction of other properties of nuclei such as radii and also exotic nuclei.

Requirements for Simulating Space Radiation With Particle Accelerators

NASA Technical Reports Server (NTRS)

Schimmerling, W.; Wilson, J. W.; Cucinotta, F.; Kim, M-H Y.

2004-01-01

Interplanetary space radiation consists of fully ionized nuclei of atomic elements with high energy for which only the few lowest energy ions can be stopped in shielding materials. The health risk from exposure to these ions and their secondary radiations generated in the materials of spacecraft and planetary surface enclosures is a major limiting factor in the management of space radiation risk. Accurate risk prediction depends on a knowledge of basic radiobiological mechanisms and how they are modified in the living tissues of a whole organism. To a large extent, this knowledge is not currently available. It is best developed at ground-based laboratories, using particle accelerator beams to simulate the components of space radiation. Different particles, in different energy regions, are required to study different biological effects, including beams of argon and iron nuclei in the energy range 600 to several thousand MeV/nucleon and carbon beams in the energy range of approximately 100 MeV/nucleon to approximately 1000 MeV/nucleon. Three facilities, one each in the United States, in Germany and in Japan, currently have the partial capability to satisfy these constraints. A facility has been proposed using the Brookhaven National Laboratory Booster Synchrotron in the United States; in conjunction with other on-site accelerators, it will be able to provide the full range of heavy ion beams and energies required. International cooperation in the use of these facilities is essential to the development of a safe international space program.

Study of p-4He total reaction cross-section using Glauber and Coulomb-modified Glauber models

NASA Astrophysics Data System (ADS)

Tag El-Din, Ibrahim M. A.; Taha, M. M.; Hassan, Samia S. A.

2014-02-01

The total nuclear reaction cross-section σR for p-4He in the energy range from 25 MeV to 1000 MeV is calculated within Glauber and Coulomb-modified Glauber models. The Coulomb-modified Glauber model (CMGM) is introduced via modification of the Coulomb trajectory of the projectile from a straight line, and calculation of the effective radius of interaction. The effects of in-medium nucleon-nucleon (NN) total cross-section, phase variation, high order momentum transfer component of nucleon-nucleon elastic scattering amplitude and Pauli blocking are studied. It is pointed out that the phase variation of the nucleon-nucleon amplitude plays a significant role in describing σR with γ = -1.6 fm2 at in-medium nuclear density ϱ = 0 and γ = -2 fm2 at ϱ = 0.17 fm-3 in the whole energy range. A remarkable fit to the available experimental data is obtained by invoking Pauli blocking and high order momentum transfer of nucleon-nucleon (NN) elastic scattering amplitude for Ep < 100 MeV.

Tracking rare-isotope beams with microchannel plates

DOE PAGES

Rogers, A. M.; Sanetullaev, A.; Lynch, W. G.; ...

2015-06-06

A system of two microchannel-plate detectors has been successfully implemented for tracking projectile-fragmentation beams. The detectors provide interaction positions, angles, and arrival Limes of ions at the reaction target. Furthermore, the current design is an adaptation of an assembly used for low-energy beams (~1.4 MeV/nucleon). In order to improve resolution in tracking high-energy heavy-ion beams, the magnetic field strength between the secondary-electron accelerating foil and the microchannel plate had to be increased substantially. Results from an experiment using a 37-MeV/nucleon 56Ni beam show that the tracking system can achieve sub-nanosecond timing resolution and a position resolution of ~1 mm formore » beam intensities up to 5 x 10 5 pps.« less

Electromagnetic Meson Production in the Nucleon Resonance Region

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

Volker Burkert; T.-S. H. Lee

Recent experimental and theoretical advances in investigating electromagnetic meson production reactions in the nucleon resonance region are reviewed. The article gives a description of current experimental facilities with electron and photon beams and presents a unified derivation of most of the phenomenological approaches being used to extract the resonance parameters from the data. The analyses of {pi} and {eta} production data and the resulting transition form factors for the {Delta}(1232)P{sub 33}, N(1535)S{sub 11}, N(1440)P{sub 11}, and N(1520)D{sub 13} resonances are discussed in detail. The status of our understanding of the reactions with production of two pions, kaons, and vector mesonsmore » is also reviewed.« less

Tracking rare-isotope beams with microchannel plates

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

Rogers, A. M.; Sanetullaev, A.; Lynch, W. G.

A system of two microchannel-plate detectors has been successfully implemented for tracking projectile-fragmentation beams. The detectors provide interaction positions, angles, and arrival Limes of ions at the reaction target. Furthermore, the current design is an adaptation of an assembly used for low-energy beams (~1.4 MeV/nucleon). In order to improve resolution in tracking high-energy heavy-ion beams, the magnetic field strength between the secondary-electron accelerating foil and the microchannel plate had to be increased substantially. Results from an experiment using a 37-MeV/nucleon 56Ni beam show that the tracking system can achieve sub-nanosecond timing resolution and a position resolution of ~1 mm formore » beam intensities up to 5 x 10 5 pps.« less

Directed flow of charged particles at midrapidity relative to the spectator plane in Pb-Pb collisions at √(s(NN))=2.76 TeV.

PubMed

Abelev, B; Adam, J; Adamová, D; Adare, A M; Aggarwal, M M; Aglieri Rinella, G; Agnello, M; Agocs, A G; Agostinelli, A; Ahammed, Z; Ahmad, N; Ahmad Masoodi, A; Ahmed, I; Ahn, S A; Ahn, S U; Aimo, I; Ajaz, M; Akindinov, A; Aleksandrov, D; Alessandro, B; Alexandre, D; Alici, A; Alkin, A; Alme, J; Alt, T; Altini, V; Altinpinar, S; Altsybeev, I; Andrei, C; Andronic, A; Anguelov, V; Anielski, J; Anson, C; Antičić, T; Antinori, F; Antonioli, P; Aphecetche, L; Appelshäuser, H; Arbor, N; Arcelli, S; Arend, A; Armesto, N; Arnaldi, R; Aronsson, T; Arsene, I C; Arslandok, M; Asryan, A; Augustinus, A; Averbeck, R; Awes, T C; Äystö, J; Azmi, M D; Bach, M; Badalà, A; Baek, Y W; Bailhache, R; Bala, R; Baldisseri, A; Baltasar Dos Santos Pedrosa, F; Bán, J; Baral, R C; Barbera, R; Barile, F; Barnaföldi, G G; Barnby, L S; Barret, V; Bartke, J; Basile, M; Bastid, N; Basu, S; Bathen, B; Batigne, G; Batyunya, B; Batzing, P C; Baumann, C; Bearden, I G; Beck, H; Behera, N K; Belikov, I; Bellini, F; Bellwied, R; 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Djuvsland, Ø; Dobrin, A; Dobrowolski, T; Dönigus, B; Dordic, O; Dubey, A K; Dubla, A; Ducroux, L; Dupieux, P; Dutta Majumdar, A K; Elia, D; Elwood, B G; Emschermann, D; Engel, H; Erazmus, B; Erdal, H A; Eschweiler, D; Espagnon, B; Estienne, M; Esumi, S; Evans, D; Evdokimov, S; Eyyubova, G; Fabris, D; Faivre, J; Falchieri, D; Fantoni, A; Fasel, M; Fehlker, D; Feldkamp, L; Felea, D; Feliciello, A; Fenton-Olsen, B; Feofilov, G; Fernández Téllez, A; Ferretti, A; Festanti, A; Figiel, J; Figueredo, M A S; Filchagin, S; Finogeev, D; Fionda, F M; Fiore, E M; Floratos, E; Floris, M; Foertsch, S; Foka, P; Fokin, S; Fragiacomo, E; Francescon, A; Frankenfeld, U; Fuchs, U; Furget, C; Fusco Girard, M; Gaardhøje, J J; Gagliardi, M; Gago, A; Gallio, M; Gangadharan, D R; Ganoti, P; Garabatos, C; Garcia-Solis, E; Gargiulo, C; Garishvili, I; Gerhard, J; Germain, M; Gheata, A; Gheata, M; Ghidini, B; Ghosh, P; Gianotti, P; Giubellino, P; Gladysz-Dziadus, E; Glässel, P; Goerlich, L; Gomez, R; Ferreiro, E G; González-Zamora, P; Gorbunov, S; Goswami, A; Gotovac, S; Graczykowski, L K; Grajcarek, R; Grelli, A; Grigoras, A; Grigoras, C; Grigoriev, V; Grigoryan, A; Grigoryan, S; Grinyov, B; Grion, N; Gros, P; Grosse-Oetringhaus, J F; Grossiord, J-Y; Grosso, R; Guber, F; Guernane, R; Guerzoni, B; Guilbaud, M; Gulbrandsen, K; Gulkanyan, H; Gunji, T; Gupta, A; Gupta, R; Haake, R; Haaland, Ø; Hadjidakis, C; Haiduc, M; Hamagaki, H; Hamar, G; Han, B H; Hanratty, L D; Hansen, A; Harris, J W; Harton, A; Hatzifotiadou, D; Hayashi, S; Hayrapetyan, A; Heckel, S T; Heide, M; Helstrup, H; Herghelegiu, A; Herrera Corral, G; Herrmann, N; Hess, B A; Hetland, K F; Hicks, B; Hippolyte, B; Hori, Y; Hristov, P; Hřivnáčová, I; Huang, M; Humanic, T J; Hwang, D S; Ichou, R; Ilkaev, R; Ilkiv, I; Inaba, M; Incani, E; Innocenti, P G; Innocenti, G M; Ionita, C; Ippolitov, M; Irfan, M; Ivanov, V; Ivanov, M; Ivanov, A; Ivanytskyi, O; Jachołkowski, A; Jacobs, P M; Jahnke, C; Jang, H J; Janik, M A; Jayarathna, P H S Y; Jena, S; Jha, D M; Jimenez Bustamante, R T; Jones, P G; Jung, H; Jusko, A; Kaidalov, A B; Kalcher, S; Kaliňák, P; Kalliokoski, T; Kalweit, A; Kang, J H; Kaplin, V; Kar, S; Karasu Uysal, A; Karavichev, O; Karavicheva, T; Karpechev, E; Kazantsev, A; Kebschull, U; Keidel, R; Ketzer, B; Khan, M M; Khan, P; Khan, K H; Khan, S A; Khanzadeev, A; Kharlov, Y; Kileng, B; Kim, J S; Kim, B; Kim, T; Kim, D J; Kim, S; Kim, M; Kim, D W; Kim, J H; Kim, M; Kirsch, S; Kisel, I; Kiselev, S; Kisiel, A; Kiss, G; Klay, J L; Klein, J; Klein-Bösing, C; Kliemant, M; Kluge, A; Knichel, M L; Knospe, A G; Köhler, M K; Kollegger, T; Kolojvari, A; Kompaniets, M; Kondratiev, V; Kondratyeva, N; Konevskikh, A; Kovalenko, V; Kowalski, M; Kox, S; Koyithatta Meethaleveedu, G; Kral, J; Králik, I; Kramer, F; Kravčáková, A; Krelina, M; Kretz, M; Krivda, M; Krizek, F; Krus, M; Kryshen, E; Krzewicki, M; Kucera, V; Kucheriaev, Y; Kugathasan, T; Kuhn, C; Kuijer, P G; Kulakov, I; Kumar, J; Kurashvili, P; Kurepin, A; Kurepin, A B; Kuryakin, A; Kushpil, S; Kushpil, V; Kvaerno, H; Kweon, M J; Kwon, Y; Ladrón de Guevara, P; Lagana Fernandes, C; Lakomov, I; Langoy, R; La Pointe, S L; Lara, C; Lardeux, A; La Rocca, P; Lea, R; Lechman, M; Lee, G R; Lee, S C; Legrand, I; Lehnert, J; Lemmon, R C; Lenhardt, M; Lenti, V; León, H; Leoncino, M; León Monzón, I; Lévai, P; Li, S; Lien, J; Lietava, R; Lindal, S; Lindenstruth, V; Lippmann, C; Lisa, M A; Ljunggren, H M; Lodato, D F; Loenne, P I; Loggins, V R; Loginov, V; Lohner, D; Loizides, C; Loo, K K; Lopez, X; López Torres, E; Løvhøiden, G; Lu, X-G; Luettig, P; Lunardon, M; Luo, J; Luparello, G; Luzzi, C; Ma, R; Ma, K; Madagodahettige-Don, D M; Maevskaya, A; Mager, M; Mahapatra, D P; Maire, A; Malaev, M; Maldonado Cervantes, I; Malinina, L; Mal'kevich, D; Malzacher, P; Mamonov, A; Manceau, L; Mangotra, L; Manko, V; Manso, F; Manzari, V; Marchisone, M; Mareš, J; Margagliotti, G V; Margotti, A; Marín, A; Markert, C; Marquard, M; Martashvili, I; Martin, N A; Martin Blanco, J; Martinengo, P; 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Oppedisano, C; Ortiz Velasquez, A; Oskarsson, A; Ostrowski, P; Otwinowski, J; Oyama, K; Ozawa, K; Pachmayer, Y; Pachr, M; Padilla, F; Pagano, P; Paić, G; Painke, F; Pajares, C; Pal, S K; Palaha, A; Palmeri, A; Papikyan, V; Pappalardo, G S; Park, W J; Passfeld, A; Patalakha, D I; Paticchio, V; Paul, B; Pavlinov, A; Pawlak, T; Peitzmann, T; Pereira Da Costa, H; Pereira De Oliveira Filho, E; Peresunko, D; Pérez Lara, C E; Perrino, D; Peryt, W; Pesci, A; Pestov, Y; Petráček, V; Petran, M; Petris, M; Petrov, P; Petrovici, M; Petta, C; Piano, S; Pikna, M; Pillot, P; Pinazza, O; Pinsky, L; Pitz, N; Piyarathna, D B; Planinic, M; Płoskoń, M; Pluta, J; Pocheptsov, T; Pochybova, S; Podesta-Lerma, P L M; Poghosyan, M G; Polák, K; Polichtchouk, B; Poljak, N; Pop, A; Porteboeuf-Houssais, S; Pospíšil, V; Potukuchi, B; Prasad, S K; Preghenella, R; Prino, F; Pruneau, C A; Pshenichnov, I; Puddu, G; Punin, V; Putschke, J; Qvigstad, H; Rachevski, A; Rademakers, A; Rak, J; Rakotozafindrabe, A; Ramello, L; Raniwala, S; Raniwala, R; Räsänen, S S; Rascanu, B T; Rathee, D; Rauch, W; Rauf, A W; Razazi, V; Read, K F; Real, J S; Redlich, K; Reed, R J; Rehman, A; Reichelt, P; Reicher, M; Reidt, F; Renfordt, R; Reolon, A R; Reshetin, A; Rettig, F; Revol, J-P; Reygers, K; Riccati, L; Ricci, R A; Richert, T; Richter, M; Riedler, P; Riegler, W; Riggi, F; Rivetti, A; Rodríguez Cahuantzi, M; Rodriguez Manso, A; Røed, K; Rogochaya, E; Rohr, D; Röhrich, D; Romita, R; Ronchetti, F; Rosnet, P; Rossegger, S; Rossi, A; Roy, P; Roy, C; Rubio Montero, A J; Rui, R; Russo, R; Ryabinkin, E; Rybicki, A; Sadovsky, S; Safařík, K; Sahoo, R; Sahu, P K; Saini, J; Sakaguchi, H; Sakai, S; Sakata, D; Salgado, C A; Salzwedel, J; Sambyal, S; Samsonov, V; Sanchez Castro, X; Sándor, L; Sandoval, A; Sano, M; Santagati, G; Santoro, R; Sarkar, D; Scapparone, E; Scarlassara, F; Scharenberg, R P; Schiaua, C; Schicker, R; Schmidt, C; Schmidt, H R; Schuchmann, S; Schukraft, J; Schulc, M; Schuster, T; Schutz, Y; Schwarz, K; Schweda, K; Scioli, G; Scomparin, E; Scott, P A; Scott, R; Segato, G; Selyuzhenkov, I; Senyukov, S; Seo, J; Serci, S; Serradilla, E; Sevcenco, A; Shabetai, A; Shabratova, G; Shahoyan, R; Sharma, N; Sharma, S; Rohni, S; Shigaki, K; Shtejer, K; Sibiriak, Y; Siddhanta, S; Siemiarczuk, T; Silvermyr, D; Silvestre, C; Simatovic, G; Simonetti, G; Singaraju, R; Singh, R; Singha, S; Singhal, V; Sinha, T; Sinha, B C; Sitar, B; Sitta, M; Skaali, T B; Skjerdal, K; Smakal, R; Smirnov, N; Snellings, R J M; Søgaard, C; Soltz, R; Song, J; Song, M; Soos, C; Soramel, F; Spacek, M; Sputowska, I; Spyropoulou-Stassinaki, M; Srivastava, B K; Stachel, J; Stan, I; Stefanek, G; Steinpreis, M; Stenlund, E; Steyn, G; Stiller, J H; Stocco, D; Stolpovskiy, M; Strmen, P; Suaide, A A P; Subieta Vásquez, M A; Sugitate, T; Suire, C; Suleymanov, M; Sultanov, R; Sumbera, M; Susa, T; Symons, T J M; Szanto de Toledo, A; Szarka, I; Szczepankiewicz, A; Szymański, M; Takahashi, J; Tangaro, M A; Tapia Takaki, J D; Tarantola Peloni, A; Tarazona Martinez, A; Tauro, A; Tejeda Muñoz, G; Telesca, A; Ter Minasyan, A; Terrevoli, C; Thäder, J; Thomas, D; Tieulent, R; Timmins, A R; Tlusty, D; Toia, A; Torii, H; Toscano, L; Trubnikov, V; Truesdale, D; Trzaska, W H; Tsuji, T; Tumkin, A; Turrisi, R; Tveter, T S; Ulery, J; Ullaland, K; Ulrich, J; Uras, A; Urciuoli, G M; Usai, G L; Vajzer, M; Vala, M; Valencia Palomo, L; Vallero, S; Vande Vyvre, P; Van Hoorne, J W; van Leeuwen, M; Vannucci, L; Vargas, A; Varma, R; Vasileiou, M; Vasiliev, A; Vechernin, V; Veldhoen, M; Venaruzzo, M; Vercellin, E; Vergara, S; Vernet, R; Verweij, M; Vickovic, L; Viesti, G; Viinikainen, J; Vilakazi, Z; Villalobos Baillie, O; Vinogradov, Y; Vinogradov, A; Vinogradov, L; Virgili, T; Viyogi, Y P; Vodopyanov, A; Völkl, M A; Voloshin, K; Voloshin, S; Volpe, G; von Haller, B; Vorobyev, I; Vranic, D; Vrláková, J; Vulpescu, B; Vyushin, A; Wagner, B; Wagner, V; Wagner, J; Wang, Y; Wang, M; Wang, Y; Watanabe, D; Watanabe, K; Weber, M; Wessels, J P; Westerhoff, U; Wiechula, J; Wielanek, D; Wikne, J; Wilde, M; Wilk, G; Wilkinson, J; Williams, M C S; Winn, M; Windelband, B; Xiang, C; Yaldo, C G; Yamaguchi, Y; Yang, H; Yang, S; Yang, P; Yano, S; Yasnopolskiy, S; Yi, J; Yin, Z; Yoo, I-K; Yoon, J; Yushmanov, I; Zaccolo, V; Zach, C; Zampolli, C; Zaporozhets, S; Zarochentsev, A; Závada, P; Zaviyalov, N; Zbroszczyk, H; Zelnicek, P; Zgura, I S; Zhalov, M; Zhang, Y; Zhang, X; Zhang, F; Zhang, H; Zhou, Y; Zhou, F; Zhou, D; Zhu, H; Zhu, X; Zhu, J; Zhu, J; Zichichi, A; Zimmermann, A; Zinovjev, G; Zoccarato, Y; Zynovyev, M; Zyzak, M

2013-12-06

The directed flow of charged particles at midrapidity is measured in Pb-Pb collisions at √(s(NN))=2.76 TeV relative to the collision symmetry plane defined by the spectator nucleons. A negative slope of the rapidity-odd directed flow component with approximately 3 times smaller magnitude than found at the highest RHIC energy is observed. This suggests a smaller longitudinal tilt of the initial system and disfavors the strong fireball rotation predicted for the LHC energies. The rapidity-even directed flow component is measured for the first time with spectators and found to be independent of pseudorapidity with a sign change at transverse momenta p(T) between 1.2 and 1.7  GeV/c. Combined with the observation of a vanishing rapidity-even p(T) shift along the spectator deflection this is strong evidence for dipolelike initial density fluctuations in the overlap zone of the nuclei. Similar trends in the rapidity-even directed flow and the estimate from two-particle correlations at midrapidity, which is larger by about a factor of 40, indicate a weak correlation between fluctuating participant and spectator symmetry planes. These observations open new possibilities for investigation of the initial conditions in heavy-ion collisions with spectator nucleons.

Numerical Exact Ab Initio Four-Nucleon Scattering Calculations: from Dream to Reality

NASA Astrophysics Data System (ADS)

Fonseca, A. C.; Deltuva, A.

2017-03-01

In the present manuscript we review the work of the last ten years on the pursuit to obtain numerical exact solutions of the four-nucleon scattering problem using the most advanced force models that fit two nucleon data up to pion production threshold with a χ ^2 per data point approximately one, together with the Coulomb interaction between protons; three- and four-nucleon forces are also included in the framework of a meson exchange potential model where NN couples to NΔ. Failure to describe the world data on four-nucleon scattering observables in the framework of a non relativistic scattering approach falls necessarily on the force models one uses. Four-nucleon observables pose very clear challenges, particular in the low energy region where there are a number of resonances whose position and width needs to be dynamically generated by the nucleon-nucleon (NN) interactions one uses. In addition, our calculations constitute the most advance piece of work where observables for all four-nucleon reactions involving isospin I=0, I=0 coupled to I=1 and isospin I=1 initial states are calculated at energies both below and above breakup threshold. We also present a very extensive comparison between calculated results and data for cross sections and spin observables. Therefore the present work reveals both the shortcomings and successes of some of the present NN force models in describing four-nucleon data and serve as a benchmark for future developments.

Nucleon effective masses in neutron-rich matter

NASA Astrophysics Data System (ADS)

Li, Bao-An; Cai, Bao-Jun; Chen, Lie-Wen; Xu, Jun

2018-03-01

Various kinds of isovector nucleon effective masses are used in the literature to characterize the momentum/energy dependence of the nucleon symmetry potential or self-energy due to the space/time non-locality of the underlying isovector strong interaction in neutron-rich nucleonic matter. The multifaceted studies on nucleon isovector effective masses are multi-disciplinary in nature. Besides structures, masses and low-lying excited states of nuclei as well as nuclear reactions, studies of the isospin dependence of short-range correlations in nuclei from scatterings of high-energy electrons and protons on heavy nuclei also help understand nucleon effective masses especially the so-called E-mass in neutron-rich matter. A thorough understanding of all kinds of nucleon effective masses has multiple impacts on many interesting issues in both nuclear physics and astrophysics. Indeed, essentially all microscopic many-body theories and phenomenological models with various nuclear forces available in the literature have been used to calculate single-nucleon potentials and the associated nucleon effective masses in neutron-rich matter. There are also fundamental principles connecting different aspects and impacts of isovector strong interactions. In particular, the Hugenholtz-Van Hove theorem connects analytically nuclear symmetry energy with both isoscalar and isovector nucleon effective masses as well as their own momentum dependences. It also reveals how the isospin-quartic term in the equation of state of neutron-rich matter depends on the high-order momentum-derivatives of both isoscalar and isovector nucleon potentials. The Migdal-Luttinger theorem facilitates the extraction of nucleon E-mass and its isospin dependence from experimentally constrained single-nucleon momentum distributions. The momentum/energy dependence of the symmetry potential and the corresponding neutron-proton effective mass splitting also affect transport properties and the liquid-gas phase transition in neutron-rich matter. Moreover, they influence the dynamics and isospin-sensitive observables of heavy-ion collisions through both the Vlasov term and the collision integrals of the Boltzmann-Uehling-Uhlenbeck transport equation. We review here some of the significant progresses made in recent years by the nuclear physics community in resolving some of the hotly debated and longstanding issues regarding nucleon effective masses especially in dense neutron-rich matter. We also point out some of the remaining key issues requiring further investigations in the era of high precision experiments using advanced rare isotope beams.

The Large Underground Xenon (LUX) experiment

DOE PAGES

Akerib, D. S.; Bai, X.; Bedikian, S.; ...

2012-11-29

The Large Underground Xenon (LUX) collaboration has designed and constructed a dual-phase xenon detector, in order to conduct a search for Weakly Interacting Massive Particles (WIMPs), a leading dark matter candidate. The goal of the LUX detector is to clearly detect (or exclude) WIMPS with a spin independent cross section per nucleon of 2×10 -46 cm 2, equivalent to ~1 event/100 kg/month in the inner 100-kg fiducial volume (FV) of the 370-kg detector. The overall background goals are set to have <1 background events characterized as possible WIMPs in the FV in 300 days of running. This work describes themore » design and construction of the LUX detector.« less

Constructing Nucleon Operators on a Lattice for Form Factors with High Momentum Transfer

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

Syritsyn, Sergey; Gambhir, Arjun S.; Musch, Bernhard U.

We present preliminary results of computing nucleon form factor at high momentum transfer using the 'boosted' or 'momentum' smearing. We use gauge configurations generated with N f = 2 + 1dynamical Wilson-clover fermions and study the connected as well as disconnected contributions to the nucleon form factors. Our initial results indicate that boosted smearing helps to improve the signal for nucleon correlators at high momentum. However, we also find evidence for large excited state contributions, which will likely require variational analysis to isolate the boosted nucleon ground state.

Pionic retardation effects in two-pion-exchange three-nucleon forces

NASA Astrophysics Data System (ADS)

Coon, S. A.; Friar, J. L.

1986-09-01

Those two-pion-exchange three-nucleon forces which arise from nuclear processes that involve only pions and nucleons are calculated. Among the processes which contribute are pion seagulls (e.g., nucleon-antinucleon pair terms) and overlapping, retarded pion exchanges. The resulting potential is shown to be a (v/c)2 relativistic correction, and satisfies nontrivial constraints from special relativity. The relativistic ambiguities found before in treatments of relativistic corrections to the one-pion-exchange nuclear charge operator and two-body potential are also present in the three-nucleon potential. The resulting three-nucleon force differs from the original Tucson-Melbourne potential only in the presence of several new nonlocal terms, and in the specification of the choice of ambiguity parameters in the latter potential.

4He binding energy calculation including full tensor-force effects

NASA Astrophysics Data System (ADS)

Fonseca, A. C.

1989-09-01

The four-body equations of Alt, Grassberger, and Sandhas are solved in the version where the (2)+(2) subamplitudes are treated exactly by convolution, using one-term separable Yamaguchy nucleon-nucleon potentials in the 1S0 and 3S1-3D1 channels. The resulting jp=1/2+ and (3/2+ three-body subamplitudes are represented in a separable form using the energy-dependent pole expansion. Converged bound-state results are calculated for the first time using the full interaction, and are compared with those obtained from a simplified treatment of the tensor force. The Tjon line that correlates three-nucleon and four-nucleon binding energies is shown using different nucleon-nucleon potentials. In all calculations the Coulomb force has been neglected.

Improved Simulation of the Pre-equilibrium Triton Emission in Nuclear Reactions Induced by Nucleons

NASA Astrophysics Data System (ADS)

Konobeyev, A. Yu.; Fischer, U.; Pereslavtsev, P. E.; Blann, M.

2014-04-01

A new approach is proposed for the calculation of non-equilibrium triton energy distributions in nuclear reactions induced by nucleons of intermediate energies. It combines models describing the nucleon pick-up, the coalescence and the triton knock-out processes. Emission and absorption rates for excited particles are represented by the pre-equilibrium hybrid model. The model of Sato, Iwamoto, Harada is used to describe the nucleon pick-up and the coalescence of nucleons from exciton configurations starting from (2p,1h) states. The contribution of the direct nucleon pick-up is described phenomenologically. Multiple pre-equilibrium emission of tritons is accounted for. The calculated triton energy distributions are compared with available experimental data.

PREFACE: Focus section on Hadronic Physics Focus section on Hadronic Physics

NASA Astrophysics Data System (ADS)

Roberts, Craig; Swanson, Eric

2007-07-01

Hadronic physics is the study of strongly interacting matter and its underlying theory, Quantum Chromodynamics (QCD). The field had its beginnings after World War Two, when hadrons were discovered in ever increasing numbers. Today, it encompasses topics like the quark-gluon structure of hadrons at varying scales, the quark-gluon plasma and hadronic matter at extreme temperature and density; it also underpins nuclear physics and has significant impact on particle physics, astrophysics, and cosmology. Among the goals of hadronic physics are to determine the parameters of QCD, understand the origin and characteristics of confinement, understand the dynamics and consequences of dynamical chiral symmetry breaking, explore the role of quarks and gluons in nuclei and in matter under extreme conditions and understand the quark and gluon structure of hadrons. In general, the process is one of discerning the relevant degrees of freedom and relating these to the fundamental fields of QCD. The emphasis is on understanding QCD, rather than testing it. The papers gathered in this special focus section of Journal of Physics G: Nuclear and Particle Physics attempt to cover this broad range of subjects. Alkofer and Greensite examine the issue of quark and gluon confinement with the focus on models of the QCD vacuum, lattice gauge theory investigations, and the relationship to the AdS/CFT correspondence postulate. Arrington et al. review nucleon form factors and their role in determining quark orbital momentum, the strangeness content of the nucleon, meson cloud effects, and the transition from nonperturbative to perturbative QCD dynamics. The physics associated with hadronic matter at high temperature and density and at low Bjorken-x at the Relativistic Heavy Ion Collider (RHIC), the SPS at CERN, and at the future LHC is summarized by d'Enterria. The article of Lee and Smith examines experiment and theory associated with electromagnetic meson production from nucleons and illustrates how the structure of the nucleon is revealed. Reimer reviews how the Drell--Yan process can be used to explore the sea quark structure of nucleons, thereby probing such phenomena as flavour asymmetry in the nucleon and nuclear medium modification of nucleon properties. The exploitation of the B factories has led to a resurgence of interest in heavy quark spectroscopy. Concurrently, interest in light quark spectroscopy and gluonic excitations remains high, with several new experimental efforts in the planning or building stages. The current status of all of this is reviewed by Rosner. Finally, Vogelsang summarizes the status of polarized deep inelastic lepton-nucleon scattering experiments at RHIC and their impact on the theoretical understanding of nucleon helicity structure, gluon polarization in the nucleus, and transverse spin asymmetries. Of course, hadronic physics is a much broader subject than can be conveyed in this special focus section; advances in effective field theory, lattice gauge theory, generalised parton distributions and many other subfields are not covered here. Nevertheless, we hope that this focus section will help the reader appreciate the vitality, breadth of endeavour, and the phenomenological richness of hadronic physics.

Leading chiral logarithms for the nucleon mass

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

Vladimirov, Alexey A.; Bijnens, Johan

2016-01-22

We give a short introduction to the calculation of the leading chiral logarithms, and present the results of the recent evaluation of the LLog series for the nucleon mass within the heavy baryon theory. The presented results are the first example of LLog calculation in the nucleon ChPT. We also discuss some regularities observed in the leading logarithmical series for nucleon mass.

Momentum distribution of nucleons in the deuteron on the basis of the Moscow potential

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

Neudatchin, V. G.; Khokhlov, N. A.

Themomentum distribution of nucleons in the deuteron is calculated for the Moscow and Paris nucleon-nucleon potentials. It is shown that the Moscow potential provides a better description of the distribution deduced from data on the reaction d(e, e Prime p)n in the region close to the kinematical region of quasielastic proton knockout.

A Simple Method for Nucleon-Nucleon Cross Sections in a Nucleus

NASA Technical Reports Server (NTRS)

Tripathi, R. K.; Cucinotta, Francis A.; Wilson, John W.

1999-01-01

A simple reliable formalism is presented for obtaining nucleon-nucleon cross sections within a nucleus in nuclear collisions for a given projectile and target nucleus combination at a given energy for use in transport, Monte Carlo, and other calculations. The method relies on extraction of these values from experiments and has been tested and found to give excellent results.

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

Yokosawa, A.

We review experimental results concerning polarization phenomena in nucleon-nucleon scattering in which both the elastic scattering and hadron-production reaction are included. We also present summary of S = 0 dibaryon resonances and candidates by reviewing experimental data in the nucleon-nucleon system, ..gamma..d channel, ..pi..d elastic scattering, pp ..-->.. ..pi..d channel, deuteron break-up reactions, and narrow structures in missing-mass spectra. 93 refs., 26 figs.

Complete set of deuteron analyzing powers from d ⃗p elastic scattering at 190 MeV/nucleon

NASA Astrophysics Data System (ADS)

Sekiguchi, K.; Witała, H.; Akieda, T.; Eto, D.; Kon, H.; Wada, Y.; Watanabe, A.; Chebotaryov, S.; Dozono, M.; Golak, J.; Kamada, H.; Kawakami, S.; Kubota, Y.; Maeda, Y.; Miki, K.; Milman, E.; Ohkura, A.; Sakai, H.; Sakaguchi, S.; Sakamoto, N.; Sasano, M.; Shindo, Y.; Skibiński, R.; Suzuki, H.; Tabata, M.; Uesaka, T.; Wakasa, T.; Yako, K.; Yamamoto, T.; Yanagisawa, Y.; Yasuda, J.

2017-12-01

All deuteron analyzing powers for elastic deuteron-proton (d p ) scattering have been measured with a polarized deuteron beam at 186.6 MeV/nucleon. They are compared with results of three-nucleon Faddeev calculations based on the standard, high-precision nucleon-nucleon (N N ) potentials alone or combined with commonly used three-nucleon force (3 N F ) models such as the Tucson-Melbourne '99 or the Urbana IX. Predicted 3 N F effects localized at backward angles are supported only partially by the data. The data are also compared to predictions based on locally regularized chiral N N potentials. An estimation of theoretical truncation uncertainties in the consecutive orders of chiral expansion suggests that the observed discrepancies between this modern theory and the data could probably be explained by including chiral 3 N F 's in future calculations. A systematic comparison to the deuteron analyzing power data previously taken at incident energies from 70 to 294 MeV/nucleon clearly shows that not only the cross section but also the analyzing powers reveal growing 3 N F effects when the three-nucleon system energy is increased.

Probing the Repulsive Core of the Nucleon-Nucleon Interaction via the 4He(e,e`pN) Triple-Coincidence Reaction

DOE PAGES

Korover, Igor; Muangma, Navaphon; Hen, Or; ...

2014-07-01

We studied simultaneously the 4He(e,e'p), 4He(e,e'pp), and 4He(e,e'pn) reactions at Q 2=2 [GeV/c] 2 and x B >1, for a (e,e'p) missing-momentum range of 400 to 830 MeV/c. The knocked-out proton was detected in coincidence with a proton or neutron recoiling almost back to back to the missing momentum, leaving the residual A=2 system at low excitation energy. These data were used to identify two-nucleon short-range correlated pairs and to deduce their isospin structure as a function of missing momentum in a region where the nucleon-nucleon force is expected to change from predominantly tensor to repulsive. Neutron-proton pairs dominate themore » high-momentum tail of the nucleon momentum distributions, but their abundance is reduced as the nucleon momentum increases beyond ~500 MeV/c. The extracted fraction of proton-proton pairs is small and almost independent of the missing momentum in the range we studied. Our data are compared with ab-initio calculations of two-nucleon momentum distributions in 4He.« less

Axial-Current Matrix Elements in Light Nuclei from Lattice QCD

NASA Astrophysics Data System (ADS)

Savage, M.; Beane, S.; Chang, E.; Davoudi, Z.; Detmold, W.; Orginos, K.; Shanahan, P.; Tiburzi, B.; Wagman, M.; Winter, F.; Nplqcd Collaboration

I present results from the first lattice QCD calculations of axial-current matrix elements in light nuclei, performed by the NPLQCD collaboration. Precision calculations of these matrix elements, and the subsequent extraction of multi-nucleon axial-current operators, are essential in refining theoretical predictions of the proton-proton fusion cross section, neutrino-nucleus cross sections and $\\beta\\beta$-decay rates of nuclei. In addition, they are expected to shed light on the phenomenological quenching of $g_A$ that is required in nuclear many-body calculations.

Origin and Properties of Quiet-time 0.11–1.28 MeV Nucleon{sup −1} Heavy-ion Population Near 1 au

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

Dayeh, M. A.; Desai, M. I.; Ebert, R. W.

Using measurements from the Advanced Composition Explorer /Ultra-Low Energy Isotope Spectrometer near 1 au, we surveyed the composition and spectra of heavy ions (He-through-Fe) during quiet times from 1998 January 1 to 2015 December 31 at suprathermal energies between ∼0.11 and ∼1.28 MeV nucleon{sup −1}. The selected time period covers the maxima of solar cycles 23 and 24 and the extended solar minimum in between. We find the following. (1) The number of quiet hours in each year correlates well with the sunspot number, year 2009 was the quietest for about 82% of the time. (2) The composition of themore » quiet-time suprathermal heavy-ion population ({sup 3}He, C-through-Fe) correlates well with the level of solar activity, exhibiting SEP-like composition signatures during solar maximum, and CIR- or solar wind-like composition during solar minimum. (3) The heavy-ion (C–Fe) spectra exhibit suprathermal tails at energies of 0.11–0.32 MeV nucleon{sup −1} with power-law spectral indices ranging from 1.40 to 2.97. Fe spectra soften (steepen, i.e., spectral index increases) smoothly with increasing energies compared with Fe, indicating a rollover behavior of Fe at higher energies (0.45–1.28 MeV nucleon{sup −1}). (4) Spectral indices of Fe and O do not appear to exhibit clear solar cycle dependence. (2) and (3) imply that during IP quiet times and at energies above ∼0.1 MeV nucleon{sup −1}, the IP medium is dominated by material from prior solar and interplanetary events. We discuss the implications of these extended observations in the context of the current understanding of the suprathermal ion population near 1 au.« less

Central depression in nucleonic densities: Trend analysis in the nuclear density functional theory approach

NASA Astrophysics Data System (ADS)

Schuetrumpf, B.; Nazarewicz, W.; Reinhard, P.-G.

2017-08-01

Background: The central depression of nucleonic density, i.e., a reduction of density in the nuclear interior, has been attributed to many factors. For instance, bubble structures in superheavy nuclei are believed to be due to the electrostatic repulsion. In light nuclei, the mechanism behind the density reduction in the interior has been discussed in terms of shell effects associated with occupations of s orbits. Purpose: The main objective of this work is to reveal mechanisms behind the formation of central depression in nucleonic densities in light and heavy nuclei. To this end, we introduce several measures of the internal nucleonic density. Through the statistical analysis, we study the information content of these measures with respect to nuclear matter properties. Method: We apply nuclear density functional theory with Skyrme functionals. Using the statistical tools of linear least square regression, we inspect correlations between various measures of central depression and model parameters, including nuclear matter properties. We study bivariate correlations with selected quantities as well as multiple correlations with groups of parameters. Detailed correlation analysis is carried out for 34Si for which a bubble structure has been reported recently, 48Ca, and N =82 , 126, and 184 isotonic chains. Results: We show that the central depression in medium-mass nuclei is very sensitive to shell effects, whereas for superheavy systems it is firmly driven by the electrostatic repulsion. An appreciable semibubble structure in proton density is predicted for 294Og, which is currently the heaviest nucleus known experimentally. Conclusion: Our correlation analysis reveals that the central density indicators in nuclei below 208Pb carry little information on parameters of nuclear matter; they are predominantly driven by shell structure. On the other hand, in the superheavy nuclei there exists a clear relationship between the central nucleonic density and symmetry energy.

An astrophysical engine that stores gravitational work as nuclear Coulomb energy

NASA Astrophysics Data System (ADS)

Clayton, Donald

2014-03-01

I describe supernovae gravity machines that store large internal nuclear Coulomb energy, 0.80Z2A- 1 / 3MeV per nucleus. Excess of it is returned later by electron capture and positron emission. Decay energy manifests as (1) observable gamma-ray lines (2) light curves of supernovae (3) chemical energy of free carbon dissociated from CO molecules (4) huge abundances of radiogenic daughters. I illustrate by rapid silicon burning, a natural epoch in SN II. Gravitational work produces the high temperatures that photoeject nucleons and alpha particles from heavy nuclei. These are retained by other nuclei to balance photoejection rates (quasiequilibrium). The abundance distribution adjusts slowly as remaining abundance of Z = N 28Si decomposes, so p, n, α recaptures hug the Z = N line. This occurs in milliseconds, too rapidly for weak decay to alter bulk Z/N ratio. The figure displays those quasiequilibrium abundances color-coded to their decays. Z = N = 2k nuclei having k < 11 are stable, whereas k > 10 are radioactive owing to excess Coulomb energy. Weak decays radiate that excess energy weeks later to fuel the four macroscopic energetic phenomena cited. How startling to think of the Coulomb nuclear force as storing cosmic energy and its weak decay releasing macroscopic activation to SNII.

Pionic retardation effects in two-pion-exchange three-nucleon forces

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

Coon, S.A.; Friar, J.L.

1986-09-01

Those two-pion-exchange three-nucleon forces which arise from nuclear processes that involve only pions and nucleons are calculated. Among the processes which contribute are pion seagulls (e.g., nucleon-antinucleon pair terms) and overlapping, retarded pion exchanges. The resulting potential is shown to be a (v-italic/c-italic)/sup 2/ relativistic correction, and satisfies nontrivial constraints from special relativity. The relativistic ambiguities found before in treatments of relativistic corrections to the one-pion-exchange nuclear charge operator and two-body potential are also present in the three-nucleon potential. The resulting three-nucleon force differs from the original Tucson-Melbourne potential only in the presence of several new nonlocal terms, and inmore » the specification of the choice of ambiguity parameters in the latter potential.« less

A survey of the alpha-nucleon interaction

NASA Astrophysics Data System (ADS)

Ali, S.; Ahmad, A. A. Z.; Ferdous, N.

1985-10-01

This paper gives a survey of the alpha-nucleon interaction and then describes experimental work on angular distributions of differential scattering cross sections and polarizations in proton-alpha and neutron-alpha scattering. The phenomenological approach, which includes the study of both local and nonlocal potentials reproducing the experimental alpha-nucleon scattering data, is discussed. Basic studies of the alpha-nucleon interaction attempting to build an interaction between an alpha particle and a nucleon from first principles are then described. The authors then present a critical discussion of the results with some concluding remarks suggesting the direction for further investigation.

Roles of antinucleon degrees of freedom in the relativistic random phase approximation

NASA Astrophysics Data System (ADS)

Kurasawa, Haruki; Suzuki, Toshio

2015-11-01

The roles of antinucleon degrees of freedom in the relativistic random phase approximation (RPA) are investigated. The energy-weighted sum of the RPA transition strengths is expressed in terms of the double commutator between the excitation operator and the Hamiltonian, as in nonrelativistic models. The commutator, however, should not be calculated in the usual way in the local field theory, because, otherwise, the sum vanishes. The sum value obtained correctly from the commutator is infinite, owing to the Dirac sea. Most of the previous calculations take into account only some of the nucleon-antinucleon states, in order to avoid divergence problems. As a result, RPA states with negative excitation energy appear, which make the sum value vanish. Moreover, disregarding the divergence changes the sign of nuclear interactions in the RPA equation that describes the coupling of the nucleon particle-hole states with the nucleon-antinucleon states. Indeed, the excitation energies of the spurious state and giant monopole states in the no-sea approximation are dominated by these unphysical changes. The baryon current conservation can be described without touching the divergence problems. A schematic model with separable interactions is presented, which makes the structure of the relativistic RPA transparent.

Probing the strange nature of the nucleon with phi photoproduction

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

Lowry, M.M.

1997-03-06

The presence inside the nucleon of a significant component of strange-antistrange quark pairs has been invoked to explain a number of current puzzles in the low energy realm of QCD. The {sigma} term in {pi}N scattering is a venerable conundrum which can be explained with a 10%--20% admixture. The spin crisis brought on by the EMC result and follow on experiments was first interpreted as requiring a large strange content of s quarks whose spin helped cancel the contribution of the u and d quarks to the nucleon spin, again of order 10%. Excess phi meson production in p{anti p}more » annihilation at LEAR has also been explained in terms of up to a 19% admixture of s{anti s} pairs. Charm production in deep-inelastic neutrino scattering would appear to provide evidence for a 3% strange sea. It is clear that a definite probe of the strange quark content would be an invaluable tool in unraveling a number of mysteries. The longitudinal beam target asymmetry in {psi} photoproduction is a particularly sensitive probe of that content. It is explored here.« less

Global QCD Analysis of the Nucleon Tensor Charge with Lattice QCD Constraints

NASA Astrophysics Data System (ADS)

Shows, Harvey, III; Melnitchouk, Wally; Sato, Nobuo

2017-09-01

By studying the parton distribution functions (PDFs) of a nucleon, we probe the partonic scale of nature, exploring what it means to be a nucleon. In this study, we are interested in the transversity PDF-the least studied of the three collinear PDFs. By conducting a global analysis on experimental data from semi-inclusive deep inelastic scattering (SIDIS), as well as single-inclusive e+e- annihilation (SIA), we extract the fit parameters needed to describe the transverse moment dependent (TMD) transversity PDF, as well as the Collins fragmentation function. Once the collinear transversity PDF is obtained by integrating the extracted TMD PDF, we wish to resolve discrepancies between lattice QCD calculations and phenomenological extractions of the tensor charge from data. Here we show our results for the transversity distribution and tensor charge. Using our method of iterative Monte Carlo, we now have a more robust understanding of the transversity PDF. With these results we are able to progress in our understanding of TMD PDFs, as well as testify to the efficacy of current lattice QCD calculations. This work is made possible through support from NSF award 1659177 to Old Dominion University.

Wounded nucleons, wounded quarks: an update

NASA Astrophysics Data System (ADS)

Bialas, A.

2008-04-01

History and recent developments of the concept of wounded hadronic constituents are summarized, with the special attention to the quark-diquark model of particle production in nucleon-nucleon and nucleus-nucleus collisions.

Nucleon-nucleon scattering from fully dynamical lattice QCD.

PubMed

Beane, S R; Bedaque, P F; Orginos, K; Savage, M J

2006-07-07

We present results of the first fully dynamical lattice QCD determination of nucleon-nucleon scattering lengths in the 1S0 channel and 3S1 - 3D1 coupled channels. The calculations are performed with domain-wall valence quarks on the MILC staggered configurations with a lattice spacing of b = 0.125 fm in the isospin-symmetric limit, and in the absence of electromagnetic interactions.

Antineutrino Charged-Current Reactions on Hydrocarbon with Low Momentum Transfer

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

Gran, R.; Betancourt, M.; Elkins, M.

We report on multi-nucleon effects in low momentum transfer (more » $< 0.8$ GeV/c) anti-neutrino interactions on scintillator. These data are from the 2010-11 anti-neutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well-described when a screening effect at low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasi-elastic, $$\\Delta$$ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this anti-neutrino sample. We present the results as a double-differential cross section to accelerate investigation of alternate models for anti-neutrino scattering off nuclei.« less

Anti-Neutrino Charged-Current Reactions on Scintillator with Low Momentum Transfer

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

Gran, R.; et al.

2018-03-25

We report on multi-nucleon effects in low momentum transfer (more » $< 0.8$ GeV/c) anti-neutrino interactions on scintillator. These data are from the 2010-11 anti-neutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well-described when a screening effect at low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasi-elastic, $$\\Delta$$ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this anti-neutrino sample. We present the results as a double-differential cross section to accelerate investigation of alternate models for anti-neutrino scattering off nuclei.« less

Anti-Neutrino Charged-Current Reactions on Scintillator with Low Momentum Transfer

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

Gran, R.; et al.

2018-06-01

We report on multi-nucleon effects in low momentum transfer (more » $< 0.8$ GeV/c) anti-neutrino interactions on scintillator. These data are from the 2010-11 anti-neutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well-described when a screening effect at low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasi-elastic, $$\\Delta$$ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this anti-neutrino sample. We present the results as a double-differential cross section to accelerate investigation of alternate models for anti-neutrino scattering off nuclei.« less

Neutrino nuclear responses for double beta decays and astro neutrinos by charge exchange reactions

NASA Astrophysics Data System (ADS)

Ejiri, Hiroyasu

2014-09-01

Neutrino nuclear responses are crucial for neutrino studies in nuclei. Charge exchange reactions (CER) are shown to be used to study charged current neutrino nuclear responses associated with double beta decays(DBD)and astro neutrino interactions. CERs to be used are high energy-resolution (He3 ,t) reactions at RCNP, photonuclear reactions via IAR at NewSUBARU and muon capture reactions at MUSIC RCNP and MLF J-PARC. The Gamow Teller (GT) strengths studied by CERs reproduce the observed 2 neutrino DBD matrix elements. The GT and spin dipole (SD) matrix elements are found to be reduced much due to the nucleon spin isospin correlations and the non-nucleonic (delta isobar) nuclear medium effects. Impacts of the reductions on the DBD matrix elements and astro neutrino interactions are discussed.

Antineutrino Charged-Current Reactions on Hydrocarbon with Low Momentum Transfer

DOE PAGES

Gran, R.; Betancourt, M.; Elkins, M.; ...

2018-06-01

We report on multi-nucleon effects in low momentum transfer (more » $< 0.8$ GeV/c) anti-neutrino interactions on scintillator. These data are from the 2010-11 anti-neutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well-described when a screening effect at low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasi-elastic, $$\\Delta$$ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this anti-neutrino sample. We present the results as a double-differential cross section to accelerate investigation of alternate models for anti-neutrino scattering off nuclei.« less

Short-Range Nucleon-Nucleon Correlations

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

Douglas Higinbotham

2011-10-01

Valence-shell nucleon knock-out experiments, such as 12C(e,e'p)11B, measure less strength then is predicted by independent particle shell model calculations. The theoretical solution to this problem is to include the correlations between the nucleons in the nucleus in the calculations. Motivated by these results, many electron scattering experiments have tried to directly observe these correlations in order to gain new insight into the short-range part of the nucleon-nucleon potential. Unfortunately, many competing mechanisms can cause the same observable final-state as an initial-state correlation, making truly isolating the signal extremely challenging. This paper reviews the recent experimental evidence for short-range correlations, asmore » well as explores the possibility that such correlations are responsible for the EMC effect in the 0.3 < xB < 0.7 deep inelastic scattering ratios.« less

Ab initio many-body calculations of nucleon- 4He scattering with three-nucleon forces

DOE PAGES

Hupin, Guillaume; Langhammer, Joachim; Navratil, Petr; ...

2013-11-27

We extend the ab initio no-core shell model/resonating-group method to include three-nucleon (3N) interactions for the description of nucleon-nucleus collisions. We outline the formalism, give algebraic expressions for the 3N-force integration kernels, and discuss computational aspects of two alternative implementations. The extended theoretical framework is then applied to nucleon- 4He elastic scattering using similarity-renormalization-group (SRG)-evolved nucleon-nucleon plus 3N potentials derived from chiral effective field theory. We analyze the convergence properties of the calculated phase shifts and explore their dependence upon the SRG evolution parameter. We include up to six excited states of the 4He target and find significant effects frommore » the inclusion of the chiral 3N force, e.g., it enhances the spin-orbit splitting between the 3/2 – and 1/2 – resonances and leads to an improved agreement with the phase shifts obtained from an accurate R-matrix analysis of the five-nucleon experimental data. As a result, we find remarkably good agreement with measured differential cross sections at various energies below the d+ 3H threshold, while analyzing powers manifest larger deviations from experiment for certain energies and angles.« less

Nucleon localization and fragment formation in nuclear fission

DOE PAGES

Zhang, C. L.; Schuetrumpf, B.; Nazarewicz, W.

2016-12-27

An electron localization measure was originally introduced to characterize chemical bond structures in molecules. Recently, a nucleon localization based on Hartree-Fock densities has been introduced to investigate α-cluster structures in light nuclei. Compared to the local nucleonic densities, the nucleon localization function has been shown to be an excellent indicator of shell effects and cluster correlations. In this work, using the spatial nucleon localization measure, we investigated the emergence of fragments in fissioning heavy nuclei using the self-consistent energy density functional method with a quantified energy density functional optimized for fission studies. We studied the particle densities and spatial nucleonmore » localization distributions along the fission pathways of 264Fm, 232Th, and 240Pu. We demonstrated that the fission fragments were formed fairly early in the evolution, well before scission. To illustrate the usefulness of the localization measure, we showed how the hyperdeformed state of 232Th could be understood in terms of a quasimolecular state made of 132Sn and 100Zr fragments. Compared to nucleonic distributions, the nucleon localization function more effectively quantifies nucleonic clustering: its characteristic oscillating pattern, traced back to shell effects, is a clear fingerprint of cluster/fragment configurations. This is of particular interest for studies of fragment formation and fragment identification in fissioning nuclei.« less

Strangeness S =-1 hyperon-nucleon interactions: Chiral effective field theory versus lattice QCD

NASA Astrophysics Data System (ADS)

Song, Jing; Li, Kai-Wen; Geng, Li-Sheng

2018-06-01

Hyperon-nucleon interactions serve as basic inputs to studies of hypernuclear physics and dense (neutron) stars. Unfortunately, a precise understanding of these important quantities has lagged far behind that of the nucleon-nucleon interaction due to lack of high-precision experimental data. Historically, hyperon-nucleon interactions are either formulated in quark models or meson exchange models. In recent years, lattice QCD simulations and chiral effective field theory approaches start to offer new insights from first principles. In the present work, we contrast the state-of-the-art lattice QCD simulations with the latest chiral hyperon-nucleon forces and show that the leading order relativistic chiral results can already describe the lattice QCD data reasonably well. Given the fact that the lattice QCD simulations are performed with pion masses ranging from the (almost) physical point to 700 MeV, such studies provide a useful check on both the chiral effective field theory approaches as well as lattice QCD simulations. Nevertheless more precise lattice QCD simulations are eagerly needed to refine our understanding of hyperon-nucleon interactions.

Effects of the pion-nucleon potential in 197Au+197Au collisions at 1.5 GeV/nucleon

NASA Astrophysics Data System (ADS)

Xie, Wen-Jie; Su, Jun; Zhu, Long; Zhang, Feng-Shou

2018-06-01

The influence of the pion-nucleon potential on the pion dynamics in 197Au+197Au collisions at 1.5 GeV/nucleon for different centrality intervals is investigated in the framework of the isospin-dependent quantum molecular dynamics model. It is found that the observables related to pions, such as the rapidity distributions, the rapidity dependencies of the directed flow and the elliptic flow, the centrality dependencies of the directed flow and the elliptic flow, and the transverse momentum distribution of the strength function of the azimuthal anisotropy are sensitive to the pion-nucleon potential. The pion multiplicity and the polar-angle distributions of pions are less affected by the pion-nucleon potential. The comparisons to the experimental data, in particular to the rapidity distributions of the directed flow and the elliptic flow, favor the stronger pion-nucleon potential derived from the phenomenological ansatz proposed by Gale and Kapusta [C. Gale and J. Kapusta, Phys. Rev. C 35, 2107 (1987), 10.1103/PhysRevC.35.2107].

Improved Limits on Scattering of Weakly Interacting Massive Particles from Reanalysis of 2013 LUX Data.

PubMed

Akerib, D S; Araújo, H M; Bai, X; Bailey, A J; Balajthy, J; Beltrame, P; Bernard, E P; Bernstein, A; Biesiadzinski, T P; Boulton, E M; Bradley, A; Bramante, R; Cahn, S B; Carmona-Benitez, M C; Chan, C; Chapman, J J; Chiller, A A; Chiller, C; Currie, A; Cutter, J E; Davison, T J R; de Viveiros, L; Dobi, A; Dobson, J E Y; Druszkiewicz, E; Edwards, B N; Faham, C H; Fiorucci, S; Gaitskell, R J; Gehman, V M; Ghag, C; Gibson, K R; Gilchriese, M G D; Hall, C R; Hanhardt, M; Haselschwardt, S J; Hertel, S A; Hogan, D P; Horn, M; Huang, D Q; Ignarra, C M; Ihm, M; Jacobsen, R G; Ji, W; Kazkaz, K; Khaitan, D; Knoche, R; Larsen, N A; Lee, C; Lenardo, B G; Lesko, K T; Lindote, A; Lopes, M I; Malling, D C; Manalaysay, A; Mannino, R L; Marzioni, M F; McKinsey, D N; Mei, D-M; Mock, J; Moongweluwan, M; Morad, J A; Murphy, A St J; Nehrkorn, C; Nelson, H N; Neves, F; O'Sullivan, K; Oliver-Mallory, K C; Ott, R A; Palladino, K J; Pangilinan, M; Pease, E K; Phelps, P; Reichhart, L; Rhyne, C; Shaw, S; Shutt, T A; Silva, C; Solovov, V N; Sorensen, P; Stephenson, S; Sumner, T J; Szydagis, M; Taylor, D J; Taylor, W; Tennyson, B P; Terman, P A; Tiedt, D R; To, W H; Tripathi, M; Tvrznikova, L; Uvarov, S; Verbus, J R; Webb, R C; White, J T; Whitis, T J; Witherell, M S; Wolfs, F L H; Yazdani, K; Young, S K; Zhang, C

2016-04-22

We present constraints on weakly interacting massive particles (WIMP)-nucleus scattering from the 2013 data of the Large Underground Xenon dark matter experiment, including 1.4×10^{4}  kg day of search exposure. This new analysis incorporates several advances: single-photon calibration at the scintillation wavelength, improved event-reconstruction algorithms, a revised background model including events originating on the detector walls in an enlarged fiducial volume, and new calibrations from decays of an injected tritium β source and from kinematically constrained nuclear recoils down to 1.1 keV. Sensitivity, especially to low-mass WIMPs, is enhanced compared to our previous results which modeled the signal only above a 3 keV minimum energy. Under standard dark matter halo assumptions and in the mass range above 4  GeV c^{-2}, these new results give the most stringent direct limits on the spin-independent WIMP-nucleon cross section. The 90% C.L. upper limit has a minimum of 0.6 zb at 33  GeV c^{-2} WIMP mass.

Improved limits on scattering of weakly interacting massive particles from reanalysis of 2013 LUX data

DOE PAGES

Akerib, D. S.

2016-04-20

Here, we present constraints on weakly interacting massive particles (WIMP)-nucleus scattering from the 2013 data of the Large Underground Xenon dark matter experiment, including 1.4 × 10 4 kg day of search exposure. This new analysis incorporates several advances: single-photon calibration at the scintillation wavelength, improved event-reconstruction algorithms, a revised background model including events originating on the detector walls in an enlarged fiducial volume, and new calibrations from decays of an injected tritium β source and from kinematically constrained nuclear recoils down to 1.1 keV. Sensitivity, especially to low-mass WIMPs, is enhanced compared to our previous results which modeled themore » signal only above a 3 keV minimum energy. Under standard dark matter halo assumptions and in the mass range above 4 GeV c –2, these new results give the most stringent direct limits on the spin-independent WIMP-nucleon cross section. The 90% C.L. upper limit has a minimum of 0.6 zb at 33 GeV c –2 WIMP mass.« less

Improved Limits on Scattering of Weakly Interacting Massive Particles from Reanalysis of 2013 LUX Data

NASA Astrophysics Data System (ADS)

Akerib, D. S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Bradley, A.; Bramante, R.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Chapman, J. J.; Chiller, A. A.; Chiller, C.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; de Viveiros, L.; Dobi, A.; Dobson, J. E. Y.; Druszkiewicz, E.; Edwards, B. N.; Faham, C. H.; Fiorucci, S.; Gaitskell, R. J.; Gehman, V. M.; Ghag, C.; Gibson, K. R.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Ihm, M.; Jacobsen, R. G.; Ji, W.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lee, C.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Malling, D. C.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Ott, R. A.; Palladino, K. J.; Pangilinan, M.; Pease, E. K.; Phelps, P.; Reichhart, L.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solovov, V. N.; Sorensen, P.; Stephenson, S.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Yazdani, K.; Young, S. K.; Zhang, C.; LUX Collaboration

2016-04-01

We present constraints on weakly interacting massive particles (WIMP)-nucleus scattering from the 2013 data of the Large Underground Xenon dark matter experiment, including 1.4 ×104 kg day of search exposure. This new analysis incorporates several advances: single-photon calibration at the scintillation wavelength, improved event-reconstruction algorithms, a revised background model including events originating on the detector walls in an enlarged fiducial volume, and new calibrations from decays of an injected tritium β source and from kinematically constrained nuclear recoils down to 1.1 keV. Sensitivity, especially to low-mass WIMPs, is enhanced compared to our previous results which modeled the signal only above a 3 keV minimum energy. Under standard dark matter halo assumptions and in the mass range above 4 GeV c-2 , these new results give the most stringent direct limits on the spin-independent WIMP-nucleon cross section. The 90% C.L. upper limit has a minimum of 0.6 zb at 33 GeV c-2 WIMP mass.

Measurements of the neutron polarized structure function at SLAC

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

Young, C.C.; E-142 Collaboration

1995-08-01

Detailed measurements of unpolarized or spin-averaged nucleon structure functions over the past two decades have led to detailed knowledge of the nucleon`s internal momentum distribution. Polarized nucleon structure function measurements, which probe the nucleon`s internal spin distribution, started at SLAC in 1976. E-142 has recently measured the neutron polarized structure function g{sub 1}{sup n}(x) over the range 0.03 {le} {times} {le} 0.6 at an average Q{sup 2} of 2 GeV{sup 2} and found the integral I{sup n} = {integral}{sub 0}{sup 1}g{sub 1}{sup n}(x)dx={minus}0.022{plus_minus}0.011. E-143, which took data recently, has measured g{sub 1}{sup p} and g{sub 1}{sup 4}. Two more experimentsmore » (E-154 and E-155) will extend these measurements to lower x and higher Q{sup 2}.« less

Measurements of hadron mean free path for the particle-producing collisions in nuclear matter

NASA Technical Reports Server (NTRS)

Strugalski, Z.

1985-01-01

It is not obvious a priority that the cross-section for a process in hadron collisions with free nucleons is the same as that for the process in hadron collisions with nucleons inside a target nucleus. The question arises: what is the cross-section for a process in a hadron collision with nucleon on inside the atomic nucleus. The answer to it must be found in experiments. The mean free path for particle-producing collisions of pions in nuclear matter is determined experimentally using pion-xenon nucleus collisions at 3.5 GeV/c momentum. Relation between the mean free path in question lambda sub in nucleons fm squared and the cross-section in units of fm squared/nucleon for collisions of the hadron with free nucleon is: lambda sub i = k/cross section sub i, where k = 3.00 plus or minus 0.26.

Nucleon-nucleon scattering in a strong external magnetic field and the neutrino emissivity

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

Bavarsad, E.; Mohammadi, R.; Haghighat, M.

The nucleon-nucleon scattering in a large magnetic background is considered to find its potential to change the neutrino emissivity of the neutron stars. For this purpose, we consider the one-pion-exchange approximation to find the nucleon-nucleon (NN) cross section in a background field as large as 10{sup 15}-10{sup 18} G. We show that the NN cross section in neutron stars with temperatures in the range 0.1-5 MeV can be changed up to the 1 order of magnitude with respect to the one in the absence of the magnetic field. In the limit of the soft neutrino emission, the neutrino emissivity canmore » be written in terms of the NN-scattering amplitude; therefore, the large magnetic fields can dramatically change the neutrino emissivity of the neutron stars as well.« less

Measurement of parity-violating asymmetry in electron-deuteron inelastic scattering

DOE PAGES

Wang, D.; Pan, K.; Subedi, R.; ...

2015-04-01

The parity-violating asymmetries between a longitudinally-polarized electron beam and an unpolarized deuterium target have been measured recently. The measurement covered two kinematic points in the deep inelastic scattering region and five in the nucleon resonance region. We provide here details of the experimental setup, data analysis, and results on all asymmetry measurements including parity-violating electron asymmetries and those of inclusive pion production and beam-normal asymmetries. The parity-violating deep-inelastic asymmetries were used to extract the electron-quark weak effective couplings, and the resonance asymmetries provided the first evidence for quark-hadron duality in electroweak observables. These electron asymmetries and their interpretation were publishedmore » earlier, but are presented here in more detail.« less

Study of Omega-proton correlations in heavy-ion collisions

NASA Astrophysics Data System (ADS)

Han, Yifei; STAR Collaboration

2015-10-01

Recently the STAR experiment at RHIC measured Lambda-Lambda correlations from Au+Au collisions at √{sNN} = 200 GeV to search for the H particle (uuddss). The correlation strength indicated that the Lambda-Lambda interaction is weak and is unlikely to be attractive enough to form a bound state. A recent lattice QCD calculation predicted a possible di-baryon bound state with Omega-nucleon. Thus, we will extend the correlation measurements to Omega-proton, which could potentially be a sensitive approach to search for such a state. We will present the Omega-proton correlations based on data collected by STAR in Au+Au collisions at √{sNN} =200 GeV, and discuss the physics implications. for the STAR collaboration.

Effective field theory search for high-energy nuclear recoils using the XENON100 dark matter detector

NASA Astrophysics Data System (ADS)

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; di Gangi, P.; di Giovanni, A.; Diglio, S.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Itay, R.; Kaminsky, B.; Kazama, S.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Lopes, J. A. M.; Manfredini, A.; Maris, I.; Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.; Morâ, K.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Pizzella, V.; Piro, M.-C.; Plante, G.; Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Rupp, N.; Dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Silva, M.; Simgen, H.; Sivers, M. V.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Vargas, M.; Wang, H.; Wang, Z.; Wei, Y.; Weinheimer, C.; Wulf, J.; Ye, J.; Zhang., Y.; Farmer, B.; Xenon Collaboration

2017-08-01

We report on weakly interacting massive particles (WIMPs) search results in the XENON100 detector using a nonrelativistic effective field theory approach. The data from science run II (34 kg ×224.6 live days) were reanalyzed, with an increased recoil energy interval compared to previous analyses, ranging from (6.6 -240 ) keVnr . The data are found to be compatible with the background-only hypothesis. We present 90% confidence level exclusion limits on the coupling constants of WIMP-nucleon effective operators using a binned profile likelihood method. We also consider the case of inelastic WIMP scattering, where incident WIMPs may up-scatter to a higher mass state, and set exclusion limits on this model as well.

Measurement of Two- and Three-Nucleon Short-Range Correlation Probabilities in Nuclei

NASA Astrophysics Data System (ADS)

Egiyan, K. S.; Dashyan, N. B.; Sargsian, M. M.; Strikman, M. I.; Weinstein, L. B.; Adams, G.; Ambrozewicz, P.; Anghinolfi, M.; Asavapibhop, B.; Asryan, G.; Avakian, H.; Baghdasaryan, H.; Baillie, N.; Ball, J. P.; Baltzell, N. A.; Batourine, V.; Battaglieri, M.; Bedlinskiy, I.; Bektasoglu, M.; Bellis, M.; Benmouna, N.; Biselli, A. S.; Bonner, B. E.; Bouchigny, S.; Boiarinov, S.; Bradford, R.; Branford, D.; Brooks, W. K.; Bültmann, S.; Burkert, V. D.; Bultuceanu, C.; Calarco, J. R.; Careccia, S. L.; Carman, D. S.; Carnahan, B.; Chen, S.; Cole, P. L.; Coltharp, P.; Corvisiero, P.; Crabb, D.; Crannell, H.; Cummings, J. P.; Sanctis, E. De; Devita, R.; Degtyarenko, P. V.; Denizli, H.; Dennis, L.; Dharmawardane, K. V.; Djalali, C.; Dodge, G. E.; Donnelly, J.; Doughty, D.; Dragovitsch, P.; Dugger, M.; Dytman, S.; Dzyubak, O. P.; Egiyan, H.; Elouadrhiri, L.; Empl, A.; Eugenio, P.; Fatemi, R.; Fedotov, G.; Feuerbach, R. J.; Forest, T. A.; Funsten, H.; Gavalian, G.; Gevorgyan, N. G.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guillo, M.; Guler, N.; Guo, L.; Gyurjyan, V.; Hadjidakis, C.; Hardie, J.; Hersman, F. W.; Hicks, K.; Hleiqawi, I.; Holtrop, M.; Hu, J.; Huertas, M.; Hyde-Wright, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Ito, M. M.; Jenkins, D.; Jo, H. S.; Joo, K.; Juengst, H. G.; Kellie, J. D.; Khandaker, M.; Kim, K. Y.; Kim, K.; Kim, W.; Klein, A.; Klein, F. J.; Klimenko, A.; Klusman, M.; Kramer, L. H.; Kubarovsky, V.; Kuhn, J.; Kuhn, S. E.; Kuleshov, S.; Lachniet, J.; Laget, J. M.; Langheinrich, J.; Lawrence, D.; Lee, T.; Livingston, K.; Maximon, L. C.; McAleer, S.; McKinnon, B.; McNabb, J. W.; Mecking, B. A.; Mestayer, M. D.; Meyer, C. A.; Mibe, T.; Mikhailov, K.; Minehart, R.; Mirazita, M.; Miskimen, R.; Mokeev, V.; Morrow, S. A.; Mueller, J.; Mutchler, G. S.; Nadel-Turonski, P.; Napolitano, J.; Nasseripour, R.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Niczyporuk, B. B.; Niyazov, R. A.; O'Rielly, G. V.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Pasyuk, E.; Peterson, C.; Pierce, J.; Pivnyuk, N.; Pocanic, D.; Pogorelko, O.; Polli, E.; Pozdniakov, S.; Preedom, B. M.; Price, J. W.; Prok, Y.; Protopopescu, D.; Qin, L. M.; Raue, B. A.; Riccardi, G.; Ricco, G.; Ripani, M.; Ritchie, B. G.; Ronchetti, F.; Rosner, G.; Rossi, P.; Rowntree, D.; Rubin, P. D.; Sabatié, F.; Salgado, C.; Santoro, J. P.; Sapunenko, V.; Schumacher, R. A.; Serov, V. S.; Sharabian, Y. G.; Shaw, J.; Smith, E. S.; Smith, L. C.; Sober, D. I.; Stavinsky, A.; Stepanyan, S.; Stokes, B. E.; Stoler, P.; Strauch, S.; Suleiman, R.; Taiuti, M.; Taylor, S.; Tedeschi, D. J.; Thompson, R.; Tkabladze, A.; Tkachenko, S.; Todor, L.; Tur, C.; Ungaro, M.; Vineyard, M. F.; Vlassov, A. V.; Weygand, D. P.; Williams, M.; Wolin, E.; Wood, M. H.; Yegneswaran, A.; Yun, J.; Zana, L.; Zhang, J.

2006-03-01

The ratios of inclusive electron scattering cross sections of 4He, 12C, and 56Fe to 3He have been measured at 11.4 GeV2, the ratios exhibit two separate plateaus, at 1.52.25. This pattern is predicted by models that include 2- and 3-nucleon short-range correlations (SRC). Relative to A=3, the per-nucleon probabilities of 3-nucleon SRC are 2.3, 3.1, and 4.4 times larger for A=4, 12, and 56. This is the first measurement of 3-nucleon SRC probabilities in nuclei.

The structure of the nucleon: Elastic electromagnetic form factors

DOE PAGES

Punjabi, V.; Perdrisat, C. F.; Jones, M. K.; ...

2015-07-10

Precise proton and neutron form factor measurements at Jefferson Lab, using spin observables, have recently made a significant contribution to the unraveling of the internal structure of the nucleon. Accurate experimental measurements of the nucleon form factors are a test-bed for understanding how the nucleon's static properties and dynamical behavior emerge from QCD, the theory of the strong interactions between quarks. There has been enormous theoretical progress, since the publication of the Jefferson Lab proton form factor ratio data, aiming at reevaluating the picture of the nucleon. We will review the experimental and theoretical developments in this field and discussmore » the outlook for the future.« less

Quantum Monte Carlo calculations of electromagnetic transitions in $^8$Be with meson-exchange currents derived from chiral effective field theory

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

Pastore, S.; Wiringa, Robert B.; Pieper, Steven C.

2014-08-01

We report quantum Monte Carlo calculations of electromagnetic transitions inmore » $^8$Be. The realistic Argonne $$v_{18}$$ two-nucleon and Illinois-7 three-nucleon potentials are used to generate the ground state and nine excited states, with energies that are in excellent agreement with experiment. A dozen $M1$ and eight $E2$ transition matrix elements between these states are then evaluated. The $E2$ matrix elements are computed only in impulse approximation, with those transitions from broad resonant states requiring special treatment. The $M1$ matrix elements include two-body meson-exchange currents derived from chiral effective field theory, which typically contribute 20--30\\% of the total expectation value. Many of the transitions are between isospin-mixed states; the calculations are performed for isospin-pure states and then combined with the empirical mixing coefficients to compare to experiment. In general, we find that transitions between states that have the same dominant spatial symmetry are in decent agreement with experiment, but those transitions between different spatial symmetries are often significantly underpredicted.« less

Identification of nuclear effects in neutrino-carbon interactions at low three-momentum transfer

DOE PAGES

Rodrigues, P. A.

2016-02-17

Two different nuclear-medium effects are isolated using a low three-momentum transfer subsample of neutrino-carbon scattering data from the MINERvA neutrino experiment. The observed hadronic energy in charged-current νμ interactions is combined with muon kinematics to permit separation of the quasielastic and Δ(1232) resonance processes. First, we observe a small cross section at very low energy transfer that matches the expected screening effect of long-range nucleon correlations. Second, additions to the event rate in the kinematic region between the quasielastic and Δ resonance processes are needed to describe the data. The data in this kinematic region also have an enhanced populationmore » of multiproton final states. Contributions predicted for scattering from a nucleon pair have both properties; the model tested in this analysis is a significant improvement but does not fully describe the data. We present the results as a double-differential cross section to enable further investigation of nuclear models. Furthermore, improved description of the effects of the nuclear environment are required by current and future neutrino oscillation experiments.« less

Measurement of νμ and ν¯μ induced neutral current single π0 production cross sections on mineral oil at Eν˜O (1 GeV)

NASA Astrophysics Data System (ADS)

Aguilar-Arevalo, A. A.; Anderson, C. E.; Bazarko, A. O.; Brice, S. J.; Brown, B. C.; Bugel, L.; Cao, J.; Coney, L.; Conrad, J. M.; Cox, D. C.; Curioni, A.; Djurcic, Z.; Finley, D. A.; Fleming, B. T.; Ford, R.; Garcia, F. G.; Garvey, G. T.; Gonzales, J.; Grange, J.; Green, C.; Green, J. A.; Hart, T. L.; Hawker, E.; Imlay, R.; Johnson, R. A.; Karagiorgi, G.; Kasper, P.; Katori, T.; Kobilarcik, T.; Kourbanis, I.; Koutsoliotas, S.; Laird, E. M.; Linden, S. K.; Link, J. M.; Liu, Y.; Liu, Y.; Louis, W. C.; Mahn, K. B. M.; Marsh, W.; Mauger, C.; McGary, V. T.; McGregor, G.; Metcalf, W.; Meyers, P. D.; Mills, F.; Mills, G. B.; Monroe, J.; Moore, C. D.; Mousseau, J.; Nelson, R. H.; Nienaber, P.; Nowak, J. A.; Osmanov, B.; Ouedraogo, S.; Patterson, R. B.; Pavlovic, Z.; Perevalov, D.; Polly, C. C.; Prebys, E.; Raaf, J. L.; Ray, H.; Roe, B. P.; Russell, A. D.; Sandberg, V.; Schirato, R.; Schmitz, D.; Shaevitz, M. H.; Shoemaker, F. C.; Smith, D.; Soderberg, M.; Sorel, M.; Spentzouris, P.; Spitz, J.; Stancu, I.; Stefanski, R. J.; Sung, M.; Tanaka, H. A.; Tayloe, R.; Tzanov, M.; de Water, R. G. Van; Wascko, M. O.; White, D. H.; Wilking, M. J.; Yang, H. J.; Zeller, G. P.; Zimmerman, E. D.; MiniBooNE Collaboration

2010-01-01

MiniBooNE reports the first absolute cross sections for neutral current single π0 production on CH2 induced by neutrino and antineutrino interactions measured from the largest sets of NC π0 events collected to date. The principal result consists of differential cross sections measured as functions of π0 momentum and π0 angle averaged over the neutrino flux at MiniBooNE. We find total cross sections of (4.76±0.05stat±0.76sys)×10-40cm2/nucleon at a mean energy of ⟨Eν⟩=808MeV and (1.48±0.05stat±0.23sys)×10-40cm2/nucleon at a mean energy of ⟨Eν⟩=664MeV for νμ and ν¯μ induced production, respectively. In addition, we have included measurements of the neutrino and antineutrino total cross sections for incoherent exclusive NC 1π0 production corrected for the effects of final state interactions to compare to prior results.

Remarks on the pion-nucleon σ-term

NASA Astrophysics Data System (ADS)

Hoferichter, Martin; Ruiz de Elvira, Jacobo; Kubis, Bastian; Meißner, Ulf-G.

2016-09-01

The pion-nucleon σ-term can be stringently constrained by the combination of analyticity, unitarity, and crossing symmetry with phenomenological information on the pion-nucleon scattering lengths. Recently, lattice calculations at the physical point have been reported that find lower values by about 3σ with respect to the phenomenological determination. We point out that a lattice measurement of the pion-nucleon scattering lengths could help resolve the situation by testing the values extracted from spectroscopy measurements in pionic atoms.

New Measurements of High-Momentum Nucleons and Short-Range Structures in Nuclei

DOE PAGES

Fomin, N.; Arrington, J.; Asaturyan, R.; ...

2012-02-01

We present new, high-Q 2 measurements of inclusive electron scattering from high-momentum nucleons in nuclei. This yields an improved extraction of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data extend to the kinematic regime where three-nucleon correlations are expected to dominate and we observe significantly greater strength in this region than previous measurements.

Realistic calculations for c-coefficients of the isobaric mass multiplet equation in 1 p 0 f shell nuclei

NASA Astrophysics Data System (ADS)

Ormand, Erich; Brown, Alex; Hjorth-Jensen, Morten

2017-09-01

We present calculations for the c-coefficients of the isobaric mass multiplet equation for nuclei from A = 42 to A = 54 based on two-body effective interactions derived from three realistic nucleon-nucleon interactions: CD-Bonn, N3LO, and Argonne V18. The two-body effective interactions were derived using G-matrix or Vlowk augmented by perturbation theory extended to third order. We demonstrate a clear dependence in the c-coefficients on the short-ranged charge-symmetry breaking (CSB) part of the strong interaction, which is required to reproduce their overall behavior as a function of excitation (angular momentum). We find, however, that the CSB component in all three realistic nucleon-nucleon interactions is too large when compared to experiment, and that, furthermore, there is significant disagreement between each of the three interactions. This implies either: 1) a deficiency in our understanding of isospin-symmetry breaking in the nucleon-nucleon interaction, 2) significant isospin-symmetry breaking in the initial three-nucleon interaction, or 3) large contributions to isospin-symmetry breaking in three-nucleon interactions induced by the renormalization procedure. This work performed for the U.S. DOE by LLNL under Contract DE-AC52-07NA27344. WEO: DOE/NP FWP SCW0498. BAB: NSF Grant No. PHY-1404442. MHJ: NSF Grant No. PHY-1404159 and the Research Council of Norway contract ISP-Fysikk/216699.

Optimizing EDELWEISS detectors for low-mass WIMP searches

NASA Astrophysics Data System (ADS)

Arnaud, Q.; Armengaud, E.; Augier, C.; Benoît, A.; Bergé, L.; Billard, J.; Broniatowski, A.; Camus, P.; Cazes, A.; Chapellier, M.; Charlieux, F.; de Jésus, M.; Dumoulin, L.; Eitel, K.; Foerster, N.; Gascon, J.; Giuliani, A.; Gros, M.; Hehn, L.; Jin, Y.; Juillard, A.; Kleifges, M.; Kozlov, V.; Kraus, H.; Kudryavtsev, V. A.; Le-Sueur, H.; Maisonobe, R.; Marnieros, S.; Navick, X.-F.; Nones, C.; Olivieri, E.; Pari, P.; Paul, B.; Poda, D.; Queguiner, E.; Rozov, S.; Sanglard, V.; Scorza, S.; Siebenborn, B.; Vagneron, L.; Weber, M.; Yakushev, E.; EDELWEISS Collaboration

2018-01-01

The physics potential of EDELWEISS detectors for the search of low-mass weakly interacting massive particles (WIMPs) is studied. Using a data-driven background model, projected exclusion limits are computed using frequentist and multivariate analysis approaches, namely, profile likelihood and boosted decision tree. Both current and achievable experimental performances are considered. The optimal strategy for detector optimization depends critically on whether the emphasis is put on WIMP masses below or above ˜5 GeV /c2 . The projected sensitivity for the next phase of the EDELWEISS-III experiment at the Modane Underground Laboratory (LSM) for low-mass WIMP search is presented. By 2018 an upper limit on the spin-independent WIMP-nucleon cross section of σSI=7 ×10-42 cm2 is expected for a WIMP mass in the range 2 - 5 GeV /c2 . The requirements for a future hundred-kilogram-scale experiment designed to reach the bounds imposed by the coherent scattering of solar neutrinos are also described. By improving the ionization resolution down to 50 eVe e , we show that such an experiment installed in an even lower background environment (e.g., at SNOLAB) together with an exposure of 1 000 kg .yr , should allow us to observe about 80 B 8 neutrino events after discrimination.

Search for Neutrinos from Annihilation of Captured Low-Mass Dark Matter Particles in the Sun by Super-Kamiokande

NASA Astrophysics Data System (ADS)

Choi, K.; Abe, K.; Haga, Y.; Hayato, Y.; Iyogi, K.; Kameda, J.; Kishimoto, Y.; Miura, M.; Moriyama, S.; Nakahata, M.; Nakano, Y.; Nakayama, S.; Sekiya, H.; Shiozawa, M.; Suzuki, Y.; Takeda, A.; Tomura, T.; Wendell, R. A.; Irvine, T.; Kajita, T.; Kametani, I.; Kaneyuki, K.; Lee, K. P.; Nishimura, Y.; Okumura, K.; McLachlan, T.; Labarga, L.; Kearns, E.; Raaf, J. L.; Stone, J. L.; Sulak, L. R.; Berkman, S.; Tanaka, H. A.; Tobayama, S.; Goldhaber, M.; Carminati, G.; Kropp, W. R.; Mine, S.; Renshaw, A.; Smy, M. B.; Sobel, H. W.; Ganezer, K. S.; Hill, J.; Hong, N.; Kim, J. Y.; Lim, I. T.; Akiri, T.; Himmel, A.; Scholberg, K.; Walter, C. W.; Wongjirad, T.; Ishizuka, T.; Tasaka, S.; Jang, J. S.; Learned, J. G.; Matsuno, S.; Smith, S. N.; Hasegawa, T.; Ishida, T.; Ishii, T.; Kobayashi, T.; Nakadaira, T.; Nakamura, K.; Oyama, Y.; Sakashita, K.; Sekiguchi, T.; Tsukamoto, T.; Suzuki, A. T.; Takeuchi, Y.; Bronner, C.; Hirota, S.; Huang, K.; Ieki, K.; Ikeda, M.; Kikawa, T.; Minamino, A.; Nakaya, T.; Suzuki, K.; Takahashi, S.; Fukuda, Y.; Itow, Y.; Mitsuka, G.; Mijakowski, P.; Hignight, J.; Imber, J.; Jung, C. K.; Yanagisawa, C.; Ishino, H.; Kibayashi, A.; Koshio, Y.; Mori, T.; Sakuda, M.; Yano, T.; Kuno, Y.; Tacik, R.; Kim, S. B.; Okazawa, H.; Choi, Y.; Nishijima, K.; Koshiba, M.; Totsuka, Y.; Yokoyama, M.; Martens, K.; Marti, Ll.; Vagins, M. R.; Martin, J. F.; de Perio, P.; Konaka, A.; Wilking, M. J.; Chen, S.; Zhang, Y.; Wilkes, R. J.; Super-Kamiokande Collaboration

2015-04-01

Super-Kamiokande (SK) can search for weakly interacting massive particles (WIMPs) by detecting neutrinos produced from WIMP annihilations occurring inside the Sun. In this analysis, we include neutrino events with interaction vertices in the detector in addition to upward-going muons produced in the surrounding rock. Compared to the previous result, which used the upward-going muons only, the signal acceptances for light (few-GeV /c2-200 -GeV /c2 ) WIMPs are significantly increased. We fit 3903 days of SK data to search for the contribution of neutrinos from WIMP annihilation in the Sun. We found no significant excess over expected atmospheric-neutrino background and the result is interpreted in terms of upper limits on WIMP-nucleon elastic scattering cross sections under different assumptions about the annihilation channel. We set the current best limits on the spin-dependent WIMP-proton cross section for WIMP masses below 200 GeV /c2 (at 10 GeV /c2 , 1.49 ×10-39 cm2 for χ χ →b b ¯ and 1.31 ×10-40 cm2 for χ χ →τ+τ- annihilation channels), also ruling out some fraction of WIMP candidates with spin-independent coupling in the few-GeV /c2 mass range.

Neutrinoless double-β decay in effective field theory: The light-Majorana neutrino-exchange mechanism

NASA Astrophysics Data System (ADS)

Cirigliano, Vincenzo; Dekens, Wouter; Mereghetti, Emanuele; Walker-Loud, André

2018-06-01

We present the first chiral effective theory derivation of the neutrinoless double-β decay n n →p p potential induced by light Majorana neutrino exchange. The effective-field-theory framework has allowed us to identify and parametrize short- and long-range contributions previously missed in the literature. These contributions cannot be absorbed into parametrizations of the single-nucleon form factors. Starting from the quark and gluon level, we perform the matching onto chiral effective field theory and subsequently onto the nuclear potential. To derive the nuclear potential mediating neutrinoless double-β decay, the hard, soft, and potential neutrino modes must be integrated out. This is performed through next-to-next-to-leading order in the chiral power counting, in both the Weinberg and pionless schemes. At next-to-next-to-leading order, the amplitude receives additional contributions from the exchange of ultrasoft neutrinos, which can be expressed in terms of nuclear matrix elements of the weak current and excitation energies of the intermediate nucleus. These quantities also control the two-neutrino double-β decay amplitude. Finally, we outline strategies to determine the low-energy constants that appear in the potentials, by relating them to electromagnetic couplings and/or by matching to lattice QCD calculations.

Nucleon spin-averaged forward virtual Compton tensor at large Q 2

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

Hill, Richard J.; Paz, Gil

The nucleon spin-averaged forward virtual Compton tensor determines important physical quantities such as electromagnetically-induced mass differences of nucleons, and two-photon exchange contributions in hydrogen spectroscopy. It depends on two kinematic variables:more » $$\

ΛcN interaction from lattice QCD and its application to Λc hypernuclei

NASA Astrophysics Data System (ADS)

Miyamoto, Takaya; Aoki, Sinya; Doi, Takumi; Gongyo, Shinya; Hatsuda, Tetsuo; Ikeda, Yoichi; Inoue, Takashi; Iritani, Takumi; Ishii, Noriyoshi; Kawai, Daisuke; Murano, Keiko; Nemura, Hidekatsu; Sasaki, Kenji

2018-03-01

The interaction between Λc and a nucleon (N) is investigated by employing the HAL QCD method in the (2 + 1)-flavor lattice QCD on a (2.9fm) 3 volume at mπ ≃ 410 , 570 , 700 MeV. We study the central potential in S10 channel as well as central and tensor potentials in S31-3D1 channel, and find that the tensor potential for Λc N is negligibly weak and central potentials in both S10 and S31-3D1 channels are almost identical with each other except at short distances. Phase shifts and scattering lengths calculated with these potentials show that the interaction of Λc N system is attractive and has a similar strength in S10 and S31 channels at low energies (i.e. the kinetic energy less than about 40 MeV). While the attractions are not strong enough to form two-body bound states, our results lead to a possibility to form Λc hypernuclei for sufficiently large atomic numbers (A). To demonstrate this, we derive a single-folding potential for Λc hypernuclei from the Λc-nucleon potential obtained in lattice QCD, and find that Λc hypernuclei can exist for A ≥ 12 with the binding energies of a few MeV. We also estimate the Coulomb effect for the Λc hypernuclei.

Large-basis ab initio no-core shell model and its application to {sup 12}C

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

Navratil, P.; Vary, J. P.; Barrett, B. R.

2000-11-01

We present the framework for the ab initio no-core nuclear shell model and apply it to obtain properties of {sup 12}C. We derive two-body effective interactions microscopically for specific model spaces from the realistic CD-Bonn and the Argonne V8' nucleon-nucleon (NN) potentials. We then evaluate binding energies, excitation spectra, radii, and electromagnetic transitions in the 0{Dirac_h}{Omega}, 2{Dirac_h}{Omega}, and 4{Dirac_h}{Omega} model spaces for the positive-parity states and the 1{Dirac_h}{Omega}, 3{Dirac_h}{Omega}, and 5{Dirac_h}{Omega} model spaces for the negative-parity states. Dependence on the model-space size, on the harmonic-oscillator frequency, and on the type of the NN potential, used for the effective interaction derivation,more » are studied. In addition, electromagnetic and weak neutral elastic charge form factors are calculated in the impulse approximation. Sensitivity of the form-factor ratios to the strangeness one-body form-factor parameters and to the influence of isospin-symmetry violation is evaluated and discussed. Agreement between theory and experiment is favorable for many observables, while others require yet larger model spaces and/or three-body forces. The limitations of the present results are easily understood by virtue of the trends established and previous phenomenological results.« less

Some highlights in few-body nuclear physics.

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

Holt, R. J.

2000-12-07

During the past five years, there have been tremendous advances in both experiments and theoretical calculations in few-body nuclear systems. Advances in technology have permitted experiments of unprecedented accuracy. Jefferson Laboratory has begun operation and the first round of experimental results have become available. New polarization techniques have been exploited at a number of laboratories, in particular, at Jefferson Lab, IUCF, RIKEN, NIKHEF, Mainz, MIT-Bates and HERMES. Some of these results will be shown here. In addition, there have been tremendous advances in few-body theory. Five modern two-nucleon potentials have which describe the nucleon-nucleon data extremely well have become available.more » A standard model of nuclear physics based on these two nucleon potentials as well as modern three-nucleon forces has emerged. This standard model has enjoyed tremendous success in the few body systems. Exact three-body calculations have been extended into the continuum in order to take full advantage of scattering data in advancing our understanding of the the few-nucleon system. In addition, the application of chiral symmetry has become an important constraint on nucleon-nucleon as well as three-nucleon forces. As a result of all these efforts, we have seen rapid developments in the three-body force. Despite these advances, there remain some extremely important open issues: (1) What is the role of quarks and gluons in nuclear structure; (2) Can we distinguish meson exchange from quark interchange; (3) Is few-body theory sufficient to describe simultaneously the mass 2, 3 and 4 form factors; (4) What is the isospin and spin dependence of the three-body force; (5) Are there medium modifications for nucleons and mesons in nuclei; (6) Is there an enhancement of antiquarks or pions in nuclei related to the binding; and (7) Are short range correlations observable in nuclei? In this paper the author summarizes the status of our understanding of these issues.« less

Axial-Current Matrix Elements in Light Nuclei from Lattice QCD

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

Savage, Martin; Shanahan, Phiala E.; Tiburzi, Brian C.

2016-12-01

I present results from the first lattice QCD calculations of axial-current matrix elements in light nuclei, performed by the NPLQCD collaboration. Precision calculations of these matrix elements, and the subsequent extraction of multi-nucleon axial-current operators, are essential in refining theoretical predictions of the proton-proton fusion cross section, neutrino-nucleus cross sections andmore » $$\\beta\\beta$$-decay rates of nuclei. In addition, they are expected to shed light on the phenomenological quenching of $$g_A$$ that is required in nuclear many-body calculations.« less

Few-Nucleon Research at TUNL: Probing Two- and Three-Nucleon Interactions with Neutrons

NASA Astrophysics Data System (ADS)

Howell, C. R.; Tornow, W.; Witała, H.

2016-03-01

The central goal of few-nucleon research at the Triangle Universities Nuclear Laboratory (TUNL) is to perform measurements that contribute to advancing ab-initio calculations of nuclear structure and reactions. The program aims include evaluating theoretical treatments of few-nucleon reaction dynamics through strategically comparing theory predictions to data, determining properties of the neutron-neutron interaction that are not accessible in two-nucleon reactions, and searching for evidence of longrange features of three-nucleon interactions, e.g., spin and isospin dependence. This paper will review studies of three- and four-nucleon systems at TUNL conducted using unpolarized and polarized neutron beams. Measurements of neutron-induced reactions performed by groups at TUNL over the last six years are described in comparison with theory predictions. The results are discussed in the context of the program goals stated above. Measurements of vector analyzing powers for elastic scattering in A=3 and A=4 systems, differential cross sections for neutron-deuteron elastic scattering and neutrondeuteron breakup in several final-state configurations are described. The findings from these studies and plans for the coming three years are presented in the context of worldwide activities in this front, in particular, research presented in this session.

Electromagnetic and axial-vector form factors of the quarks and nucleon

NASA Astrophysics Data System (ADS)

Dahiya, Harleen; Randhawa, Monika

2017-11-01

In light of the improved precision of the experimental measurements and enormous theoretical progress, the nucleon form factors have been evaluated with an aim to understand how the static properties and dynamical behavior of nucleons emerge from the theory of strong interactions between quarks. We have analyzed the vector and axial-vector nucleon form factors (GE,Mp,n(Q2) and GAp,n(Q2)) using the spin observables in the chiral constituent quark model (χCQM) which has made a significant contribution to the unraveling of the internal structure of the nucleon in the nonperturbative regime. We have also presented a comprehensive analysis of the flavor decomposition of the form factors (GEq(Q2), GMq(Q2) and GAq(Q2) for q = u,d,s) within the framework of χCQM with emphasis on the extraction of the strangeness form factors which are fundamental to determine the spin structure and test the chiral symmetry breaking effects in the nucleon. The Q2 dependence of the vector and axial-vector form factors of the nucleon has been studied using the conventional dipole form of parametrization. The results are in agreement with the available experimental data.

Nucleon interaction data bases for background estimates

NASA Technical Reports Server (NTRS)

Wilson, John W.; Townsend, Lawrence W.

1989-01-01

Nucleon interaction data bases available in the open literature are examined for potential use in a recently developed nucleon transport code. Particular attention is given to secondary particle penetration and the multiple charged ion products. A brief description of the transport algorithm is given.

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

Granados, Carlos; Weiss, Christian

The nucleon's peripheral transverse charge and magnetization densities are computed in chiral effective field theory. The densities are represented in first-quantized form, as overlap integrals of chiral light-front wave functions describing the transition of the nucleon to soft pion-nucleon intermediate states. The orbital motion of the pion causes a large left-right asymmetry in a transversely polarized nucleon. As a result, the effect attests to the relativistic nature of chiral dynamics [pion momenta k = O(M π)] and could be observed in form factor measurements at low momentum transfer.

Origin of the anomalous long lifetime of ¹⁴C.

PubMed

Maris, P; Vary, J P; Navrátil, P; Ormand, W E; Nam, H; Dean, D J

2011-05-20

We report the microscopic origins of the anomalously suppressed beta decay of ¹⁴C to ¹⁴N using the ab initio no-core shell model with the Hamiltonian from the chiral effective field theory including three-nucleon force terms. The three-nucleon force induces unexpectedly large cancellations within the p shell between contributions to beta decay, which reduce the traditionally large contributions from the nucleon-nucleon interactions by an order of magnitude, leading to the long lifetime of ¹⁴C.

Study of W boson production in pPb collisions at √{sNN} = 5.02 TeV

NASA Astrophysics Data System (ADS)

Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Erö, J.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knünz, V.; Krammer, M.; Krätschmer, I.; Liko, D.; Mikulec, I.; Rabady, D.; Rahbaran, B.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Treberer-Treberspurg, W.; Waltenberger, W.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Alderweireldt, S.; Bansal, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Knutsson, A.; Lauwers, J.; Luyckx, S.; Ochesanu, S.; Rougny, R.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D'Hondt, J.; Daci, N.; Heracleous, N.; Keaveney, J.; Lowette, S.; Maes, M.; Olbrechts, A.; Python, Q.; Strom, D.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Caillol, C.; Clerbaux, B.; De Lentdecker, G.; Dobur, D.; Favart, L.; Gay, A. P. R.; Grebenyuk, A.; Léonard, A.; Mohammadi, A.; Perniè, L.; Randleconde, A.; Reis, T.; Seva, T.; Thomas, L.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Zenoni, F.; Adler, V.; Beernaert, K.; Benucci, L.; Cimmino, A.; Costantini, S.; Crucy, S.; Dildick, S.; Fagot, A.; Garcia, G.; Mccartin, J.; Ocampo Rios, A. A.; Poyraz, D.; Ryckbosch, D.; Salva Diblen, S.; Sigamani, M.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Beluffi, C.; Bruno, G.; Castello, R.; Caudron, A.; Ceard, L.; Da Silveira, G. G.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Jafari, A.; Jez, P.; Komm, M.; Lemaitre, V.; Nuttens, C.; Perrini, L.; Pin, A.; Piotrzkowski, K.; Popov, A.; Quertenmont, L.; Selvaggi, M.; Vidal Marono, M.; Vizan Garcia, J. M.; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Aldá Júnior, W. L.; Alves, G. A.; Brito, L.; Correa Martins Junior, M.; Dos Reis Martins, T.; Molina, J.; Mora Herrera, C.; Pol, M. E.; Rebello Teles, P.; Carvalho, W.; Chinellato, J.; Custódio, A.; Da Costa, E. M.; De Jesus Damiao, D.; De Oliveira Martins, C.; Fonseca De Souza, S.; Malbouisson, H.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Prado Da Silva, W. L.; Santaolalla, J.; Santoro, A.; Sznajder, A.; Tonelli Manganote, E. J.; Vilela Pereira, A.; Bernardes, C. A.; Dogra, S.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Aleksandrov, A.; Genchev, V.; Hadjiiska, R.; Iaydjiev, P.; Marinov, A.; Piperov, S.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Glushkov, I.; Litov, L.; Pavlov, B.; Petkov, P.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Cheng, T.; Du, R.; Jiang, C. H.; Plestina, R.; Romeo, F.; Tao, J.; Wang, Z.; Asawatangtrakuldee, C.; Ban, Y.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Xu, Z.; Zhang, L.; Zou, W.; Avila, C.; Cabrera, A.; Chaparro Sierra, L. F.; Florez, C.; Gomez, J. P.; Gomez Moreno, B.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Polic, D.; Puljak, I.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Kadija, K.; Luetic, J.; Mekterovic, D.; Sudic, L.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Bodlak, M.; Finger, M.; Finger, M.; Assran, Y.; Ellithi Kamel, A.; Mahmoud, M. A.; Radi, A.; Kadastik, M.; Murumaa, M.; Raidal, M.; Tiko, A.; Eerola, P.; Voutilainen, M.; Härkönen, J.; Karimäki, V.; Kinnunen, R.; Kortelainen, M. J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Wendland, L.; Talvitie, J.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Favaro, C.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Malcles, J.; Rander, J.; Rosowsky, A.; Titov, M.; Arleo, F.; Baffioni, S.; Beaudette, F.; Busson, P.; Chapon, E.; Charlot, C.; Dahms, T.; Dalchenko, M.; Dobrzynski, L.; Filipovic, N.; Florent, A.; Granier de Cassagnac, R.; Mastrolorenzo, L.; Miné, P.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Ortona, G.; Paganini, P.; Regnard, S.; Salerno, R.; Sauvan, J. B.; Sirois, Y.; Veelken, C.; Yilmaz, Y.; Zabi, A.; Agram, J.-L.; Andrea, J.; Aubin, A.; Bloch, D.; Brom, J.-M.; Chabert, E. C.; Collard, C.; Conte, E.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Goetzmann, C.; Le Bihan, A.-C.; Skovpen, K.; Van Hove, P.; Gadrat, S.; Beauceron, S.; Beaupere, N.; Bernet, C.; Boudoul, G.; Bouvier, E.; Brochet, S.; Carrillo Montoya, C. A.; Chasserat, J.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fan, J.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Kurca, T.; Lethuillier, M.; Mirabito, L.; Perries, S.; Ruiz Alvarez, J. D.; Sabes, D.; Sgandurra, L.; Sordini, V.; Vander Donckt, M.; Verdier, P.; Viret, S.; Xiao, H.; Tsamalaidze, Z.; Autermann, C.; Beranek, S.; Bontenackels, M.; Edelhoff, M.; Feld, L.; Heister, A.; Klein, K.; Lipinski, M.; Ostapchuk, A.; Preuten, M.; Raupach, F.; Sammet, J.; Schael, S.; Schulte, J. F.; Weber, H.; Wittmer, B.; Zhukov, V.; Ata, M.; Brodski, M.; Dietz-Laursonn, E.; Duchardt, D.; Erdmann, M.; Fischer, R.; Güth, A.; Hebbeker, T.; Heidemann, C.; Hoepfner, K.; Klingebiel, D.; Knutzen, S.; Kreuzer, P.; Merschmeyer, M.; Meyer, A.; Millet, P.; Olschewski, M.; Padeken, K.; Papacz, P.; Reithler, H.; Schmitz, S. A.; Sonnenschein, L.; Teyssier, D.; Thüer, S.; Weber, M.; Cherepanov, V.; Erdogan, Y.; Flügge, G.; Geenen, H.; Geisler, M.; Haj Ahmad, W.; Hoehle, F.; Kargoll, B.; Kress, T.; Kuessel, Y.; Künsken, A.; Lingemann, J.; Nowack, A.; Nugent, I. M.; Pooth, O.; Stahl, A.; Aldaya Martin, M.; Asin, I.; Bartosik, N.; Behr, J.; Behrens, U.; Bell, A. J.; Bethani, A.; Borras, K.; Burgmeier, A.; Cakir, A.; Calligaris, L.; Campbell, A.; Choudhury, S.; Costanza, F.; Diez Pardos, C.; Dolinska, G.; Dooling, S.; Dorland, T.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Flucke, G.; Garay Garcia, J.; Geiser, A.; Gizhko, A.; Gunnellini, P.; Hauk, J.; Hempel, M.; Jung, H.; Kalogeropoulos, A.; Kasemann, M.; Katsas, P.; Kieseler, J.; Kleinwort, C.; Korol, I.; Krücker, D.; Lange, W.; Leonard, J.; Lipka, K.; Lobanov, A.; Lohmann, W.; Lutz, B.; Mankel, R.; Marfin, I.; Melzer-Pellmann, I.-A.; Meyer, A. B.; Mittag, G.; Mnich, J.; Mussgiller, A.; Naumann-Emme, S.; Nayak, A.; Ntomari, E.; Perrey, H.; Pitzl, D.; Placakyte, R.; Raspereza, A.; Ribeiro Cipriano, P. M.; Roland, B.; Ron, E.; Sahin, M. Ö.; Salfeld-Nebgen, J.; Saxena, P.; Schoerner-Sadenius, T.; Schröder, M.; Seitz, C.; Spannagel, S.; Vargas Trevino, A. D. R.; Walsh, R.; Wissing, C.; Blobel, V.; Centis Vignali, M.; Draeger, A. R.; Erfle, J.; Garutti, E.; Goebel, K.; Görner, M.; Haller, J.; Hoffmann, M.; Höing, R. 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R.; Alexander, J.; Chatterjee, A.; Chaves, J.; Chu, J.; Dittmer, S.; Eggert, N.; Mirman, N.; Nicolas Kaufman, G.; Patterson, J. R.; Ryd, A.; Salvati, E.; Skinnari, L.; Sun, W.; Teo, W. D.; Thom, J.; Thompson, J.; Tucker, J.; Weng, Y.; Winstrom, L.; Wittich, P.; Winn, D.; Abdullin, S.; Albrow, M.; Anderson, J.; Apollinari, G.; Bauerdick, L. A. T.; Beretvas, A.; Berryhill, J.; Bhat, P. C.; Bolla, G.; Burkett, K.; Butler, J. N.; Cheung, H. W. K.; Chlebana, F.; Cihangir, S.; Elvira, V. D.; Fisk, I.; Freeman, J.; Gottschalk, E.; Gray, L.; Green, D.; Grünendahl, S.; Gutsche, O.; Hanlon, J.; Hare, D.; Harris, R. M.; Hirschauer, J.; Hooberman, B.; Jindariani, S.; Johnson, M.; Joshi, U.; Klima, B.; Kreis, B.; Kwan, S.; Linacre, J.; Lincoln, D.; Lipton, R.; Liu, T.; Lykken, J.; Maeshima, K.; Marraffino, J. M.; Martinez Outschoorn, V. I.; Maruyama, S.; Mason, D.; McBride, P.; Merkel, P.; Mishra, K.; Mrenna, S.; Nahn, S.; Newman-Holmes, C.; O'Dell, V.; Prokofyev, O.; Sexton-Kennedy, E.; Sharma, S.; Soha, A.; Spalding, W. J.; Spiegel, L.; Taylor, L.; Tkaczyk, S.; Tran, N. V.; Uplegger, L.; Vaandering, E. W.; Vidal, R.; Whitbeck, A.; Whitmore, J.; Yang, F.; Acosta, D.; Avery, P.; Bortignon, P.; Bourilkov, D.; Carver, M.; Curry, D.; Das, S.; De Gruttola, M.; Di Giovanni, G. P.; Field, R. D.; Fisher, M.; Furic, I. K.; Hugon, J.; Konigsberg, J.; Korytov, A.; Kypreos, T.; Low, J. F.; Matchev, K.; Mei, H.; Milenovic, P.; Mitselmakher, G.; Muniz, L.; Rinkevicius, A.; Shchutska, L.; Snowball, M.; Sperka, D.; Yelton, J.; Zakaria, M.; Hewamanage, S.; Linn, S.; Markowitz, P.; Martinez, G.; Rodriguez, J. L.; Adams, T.; Askew, A.; Bochenek, J.; Diamond, B.; Haas, J.; Hagopian, S.; Hagopian, V.; Johnson, K. F.; Prosper, H.; Veeraraghavan, V.; Weinberg, M.; Baarmand, M. M.; Hohlmann, M.; Kalakhety, H.; Yumiceva, F.; Adams, M. R.; Apanasevich, L.; Berry, D.; Betts, R. R.; Bucinskaite, I.; Cavanaugh, R.; Evdokimov, O.; Gauthier, L.; Gerber, C. E.; Hofman, D. J.; Kurt, P.; O'Brien, C.; Sandoval Gonzalez, I. D.; Silkworth, C.; Turner, P.; Varelas, N.; Bilki, B.; Clarida, W.; Dilsiz, K.; Haytmyradov, M.; Merlo, J.-P.; Mermerkaya, H.; Mestvirishvili, A.; Moeller, A.; Nachtman, J.; Ogul, H.; Onel, Y.; Ozok, F.; Penzo, A.; Rahmat, R.; Sen, S.; Tan, P.; Tiras, E.; Wetzel, J.; Yi, K.; Anderson, I.; Barnett, B. A.; Blumenfeld, B.; Bolognesi, S.; Fehling, D.; Gritsan, A. V.; Maksimovic, P.; Martin, C.; Swartz, M.; Xiao, M.; Baringer, P.; Bean, A.; Benelli, G.; Bruner, C.; Gray, J.; Kenny, R. P., III; Majumder, D.; Malek, M.; Murray, M.; Noonan, D.; Sanders, S.; Sekaric, J.; Stringer, R.; Wang, Q.; Wood, J. S.; Chakaberia, I.; Ivanov, A.; Kaadze, K.; Khalil, S.; Makouski, M.; Maravin, Y.; Saini, L. K.; Skhirtladze, N.; Svintradze, I.; Gronberg, J.; Lange, D.; Rebassoo, F.; Wright, D.; Baden, A.; Belloni, A.; Calvert, B.; Eno, S. C.; Gomez, J. A.; Hadley, N. J.; Jabeen, S.; Kellogg, R. G.; Kolberg, T.; Lu, Y.; Mignerey, A. C.; Pedro, K.; Skuja, A.; Tonjes, M. B.; Tonwar, S. C.; Apyan, A.; Barbieri, R.; Bierwagen, K.; Busza, W.; Cali, I. A.; Di Matteo, L.; Gomez Ceballos, G.; Goncharov, M.; Gulhan, D.; Klute, M.; Lai, Y. S.; Lee, Y.-J.; Levin, A.; Luckey, P. D.; Paus, C.; Ralph, D.; Roland, C.; Roland, G.; Stephans, G. S. F.; Sumorok, K.; Velicanu, D.; Veverka, J.; Wyslouch, B.; Yang, M.; Zanetti, M.; Zhukova, V.; Dahmes, B.; Gude, A.; Kao, S. C.; Klapoetke, K.; Kubota, Y.; Mans, J.; Nourbakhsh, S.; Pastika, N.; Rusack, R.; Singovsky, A.; Tambe, N.; Turkewitz, J.; Acosta, J. G.; Oliveros, S.; Avdeeva, E.; Bloom, K.; Bose, S.; Claes, D. R.; Dominguez, A.; Gonzalez Suarez, R.; Keller, J.; Knowlton, D.; Kravchenko, I.; Lazo-Flores, J.; Meier, F.; Ratnikov, F.; Snow, G. R.; Zvada, M.; Dolen, J.; Godshalk, A.; Iashvili, I.; Kharchilava, A.; Kumar, A.; Rappoccio, S.; Alverson, G.; Barberis, E.; Baumgartel, D.; Chasco, M.; Massironi, A.; Morse, D. M.; Nash, D.; Orimoto, T.; Trocino, D.; Wang, R.-J.; Wood, D.; Zhang, J.; Hahn, K. A.; Kubik, A.; Mucia, N.; Odell, N.; Pollack, B.; Pozdnyakov, A.; Schmitt, M.; Stoynev, S.; Sung, K.; Velasco, M.; Won, S.; Brinkerhoff, A.; Chan, K. M.; Drozdetskiy, A.; Hildreth, M.; Jessop, C.; Karmgard, D. J.; Kellams, N.; Lannon, K.; Lynch, S.; Marinelli, N.; Musienko, Y.; Pearson, T.; Planer, M.; Ruchti, R.; Smith, G.; Valls, N.; Wayne, M.; Wolf, M.; Woodard, A.; Antonelli, L.; Brinson, J.; Bylsma, B.; Durkin, L. S.; Flowers, S.; Hart, A.; Hill, C.; Hughes, R.; Kotov, K.; Ling, T. Y.; Luo, W.; Puigh, D.; Rodenburg, M.; Winer, B. L.; Wolfe, H.; Wulsin, H. W.; Driga, O.; Elmer, P.; Hardenbrook, J.; Hebda, P.; Koay, S. A.; Lujan, P.; Marlow, D.; Medvedeva, T.; Mooney, M.; Olsen, J.; Piroué, P.; Quan, X.; Saka, H.; Stickland, D.; Tully, C.; Werner, J. S.; Zuranski, A.; Brownson, E.; Malik, S.; Mendez, H.; Ramirez Vargas, J. E.; Barnes, V. E.; Benedetti, D.; Bortoletto, D.; De Mattia, M.; Gutay, L.; Hu, Z.; Jha, M. K.; Jones, M.; Jung, K.; Kress, M.; Leonardo, N.; Miller, D. H.; Neumeister, N.; Primavera, F.; Radburn-Smith, B. C.; Shi, X.; Shipsey, I.; Silvers, D.; Svyatkovskiy, A.; Wang, F.; Xie, W.; Xu, L.; Zablocki, J.; Parashar, N.; Stupak, J.; Adair, A.; Akgun, B.; Ecklund, K. M.; Geurts, F. J. M.; Li, W.; Michlin, B.; Padley, B. P.; Redjimi, R.; Roberts, J.; Zabel, J.; Betchart, B.; Bodek, A.; de Barbaro, P.; Demina, R.; Eshaq, Y.; Ferbel, T.; Galanti, M.; Garcia-Bellido, A.; Goldenzweig, P.; Han, J.; Harel, A.; Hindrichs, O.; Khukhunaishvili, A.; Korjenevski, S.; Petrillo, G.; Vishnevskiy, D.; Ciesielski, R.; Demortier, L.; Goulianos, K.; Mesropian, C.; Arora, S.; Barker, A.; Chou, J. P.; Contreras-Campana, C.; Contreras-Campana, E.; Duggan, D.; Ferencek, D.; Gershtein, Y.; Gray, R.; Halkiadakis, E.; Hidas, D.; Kaplan, S.; Lath, A.; Panwalkar, S.; Park, M.; Patel, R.; Salur, S.; Schnetzer, S.; Sheffield, D.; Somalwar, S.; Stone, R.; Thomas, S.; Thomassen, P.; Walker, M.; Rose, K.; Spanier, S.; York, A.; Bouhali, O.; Castaneda Hernandez, A.; Eusebi, R.; Flanagan, W.; Gilmore, J.; Kamon, T.; Khotilovich, V.; Krutelyov, V.; Montalvo, R.; Osipenkov, I.; Pakhotin, Y.; Perloff, A.; Roe, J.; Rose, A.; Safonov, A.; Suarez, I.; Tatarinov, A.; Ulmer, K. A.; Akchurin, N.; Cowden, C.; Damgov, J.; Dragoiu, C.; Dudero, P. R.; Faulkner, J.; Kovitanggoon, K.; Kunori, S.; Lee, S. W.; Libeiro, T.; Volobouev, I.; Appelt, E.; Delannoy, A. G.; Greene, S.; Gurrola, A.; Johns, W.; Maguire, C.; Mao, Y.; Melo, A.; Sharma, M.; Sheldon, P.; Snook, B.; Tuo, S.; Velkovska, J.; Arenton, M. W.; Boutle, S.; Cox, B.; Francis, B.; Goodell, J.; Hirosky, R.; Ledovskoy, A.; Li, H.; Lin, C.; Neu, C.; Wood, J.; Clarke, C.; Harr, R.; Karchin, P. E.; Kottachchi Kankanamge Don, C.; Lamichhane, P.; Sturdy, J.; Belknap, D. A.; Carlsmith, D.; Cepeda, M.; Dasu, S.; Dodd, L.; Duric, S.; Friis, E.; Hall-Wilton, R.; Herndon, M.; Hervé, A.; Klabbers, P.; Lanaro, A.; Lazaridis, C.; Levine, A.; Loveless, R.; Mohapatra, A.; Ojalvo, I.; Perry, T.; Pierro, G. A.; Polese, G.; Ross, I.; Sarangi, T.; Savin, A.; Smith, W. H.; Taylor, D.; Vuosalo, C.; Woods, N.

2015-11-01

The first study of W boson production in pPb collisions is presented, for bosons decaying to a muon or electron, and a neutrino. The measurements are based on a data sample corresponding to an integrated luminosity of 34.6 nb-1 at a nucleon-nucleon centre-of-mass energy of √{sNN} = 5.02 TeV, collected by the CMS experiment. The W boson differential cross sections, lepton charge asymmetry, and forward-backward asymmetries are measured for leptons of transverse momentum exceeding 25 GeV/c, and as a function of the lepton pseudorapidity in the |ηlab | < 2.4 range. Deviations from the expectations based on currently available parton distribution functions are observed, showing the need for including W boson data in nuclear parton distribution global fits.

The nucleon as a test case to calculate vector-isovector form factors at low energies

NASA Astrophysics Data System (ADS)

Leupold, Stefan

2018-01-01

Extending a recent suggestion for hyperon form factors to the nucleon case, dispersion theory is used to relate the low-energy vector-isovector form factors of the nucleon to the pion vector form factor. The additionally required input, i.e. the pion-nucleon scattering amplitudes are determined from relativistic next-to-leading-order (NLO) baryon chiral perturbation theory including the nucleons and optionally the Delta baryons. Two methods to include pion rescattering are compared: a) solving the Muskhelishvili-Omnès (MO) equation and b) using an N/D approach. It turns out that the results differ strongly from each other. Furthermore the results are compared to a fully dispersive calculation of the (subthreshold) pion-nucleon amplitudes based on Roy-Steiner (RS) equations. In full agreement with the findings from the hyperon sector it turns out that the inclusion of Delta baryons is not an option but a necessity to obtain reasonable results. The magnetic isovector form factor depends strongly on a low-energy constant of the NLO Lagrangian. If it is adjusted such that the corresponding magnetic radius is reproduced, then the results for the corresponding pion-nucleon scattering amplitude (based on the MO equation) agree very well with the RS results. Also in the electric sector the Delta degrees of freedom are needed to obtain the correct order of magnitude for the isovector charge and the corresponding electric radius. Yet quantitative agreement is not achieved. If the subtraction constant that appears in the solution of the MO equation is not taken from nucleon+Delta chiral perturbation theory but adjusted such that the electric radius is reproduced, then one obtains also in this sector a pion-nucleon scattering amplitude that agrees well with the RS results.

Small air showers and collider physics

NASA Technical Reports Server (NTRS)

Capdevielle, J. N.; Gawin, J.; Grochalska, B.

1985-01-01

At energies lower than 2.5 X 10 to the 5 GeV (in Lab. system), more accurate information on nucleon-nucleon collision (p-p collider and on primary composition now exist. The behavior of those both basic elements in cosmic ray phenomenology from ISR energy suggests some tendencies for reasonable extrapolation in the next decade 2.0x10 to the 5 to 2.0x10 to the 6 GeV. Small showers in altitude, recorded in the decade 2 X 10 to the 4 to 2 X 10 to the 5 GeV offers a good tool to testify the validity of all the Monte-Carlo simulation analysis and appreciate how nucleon-air collision are different from nucleon-nucleon collisions.

COSY-11: an Experimental Facility for Studying Meson Production in Free and Quasi-free Nucleon-Nucleon Collisions

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

Klaja, P.; Janusz, M.; Jarczyk, L.

2005-10-26

The COSY-11 experimental setup is an internal facility installed at the COoler SYnchrotron COSY in Juelich. It allows to investigate meson production in free and quasi-free nucleon-nucleon collisions, eg. pp {yields} pp meson and pd {yields} pspnp meson reactions. Drift chambers and scintillators permit to measure outgoing protons, separated in the magnetic field of the COSY-11 dipole. Neutrons are registered in the neutron modular detector installed downstream from the target. Recently, the experimental setup has been extended with spectator detector, deuteron drift chamber and polarization monitoring system, and since then meson production can be investigated also as a function ofmore » spin and isospin of colliding nucleons.« less

Measurements of Correlated Pair Momentum Distributions in 3He(e,e'pp)n with CLAS

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

Niyazov, Rustam

2003-05-01

We have measured the 3He(e,e'pp)n reaction at 2.2 and 4.4 GeV over a wide kinematic range. The kinetic energy distribution for ''fast'' nucleons (p > 250 MeV/c) peaks where two nucleons each have 20% or less and the third or ''leading'' nucleon carries most of the transferred energy. These fast nucleon pairs (both pp and pn) are back-to-back and carry very little momentum alongmore » $$\\vec{q}$$, indicating that they are spectators. Experimental and theoretical evidence indicates that we have measured NN correlations in 3He(e,e'pp)n by striking the third nucleon and detecting the spectator correlated pair.« less

Nuclear stopping in central Xe+Sn collisions: Confrontation with experimental data

NASA Astrophysics Data System (ADS)

Rajni, Vermani, Yogesh K.

2018-05-01

The influence of symmetry energy and cross section on nuclear stopping is studied in central 54129Xe+50 120Sn Sn collisions at Fermi energies (Elab≈ 20-100 MeV/nucleon). The analysis is conducted using isospin dependent quantum molecular dynamics (IQMD) transport model. Model calculations are done using reduced isospin dependent nucleon-nucleon cross section (σiso) and isospin independent cross section (σnoiso). Calculations using the two versions of cross section are analyzed with and without symmetry energy (Esym). The results are then compared with the experimental data taken with 4π multidetector INDRA. From this comparison, we conclude that nuclear stopping and related production of light charged particles (LCPs) are strongly influenced by isospin dependence of nucleon-nucleon cross section.

Solutions of the Schrodinger Equation Using Approximate Nucleon-Nucleon and Lambda-Nucleon Potentials.

ERIC Educational Resources Information Center

Banerjee, S. N.; Chakraborty, S. N.

1980-01-01

Presents the outline of an approach related to the teaching of the chapter on bound and scattering states in a short-range potential, which forms a standard part of an undergraduate quantum mechanics course or nuclear physics course. (HM)

Induced Hyperon-Nucleon-Nucleon Interactions and the Hyperon Puzzle.

PubMed

Wirth, Roland; Roth, Robert

2016-10-28

We present the first ab initio calculations for p-shell hypernuclei including hyperon-nucleon-nucleon (YNN) contributions induced by a similarity renormalization group transformation of the initial hyperon-nucleon interaction. The transformation including the YNN terms conserves the spectrum of the Hamiltonian while drastically improving model-space convergence of the importance-truncated no-core model, allowing a precise extraction of binding and excitation energies. Results using a hyperon-nucleon interaction at leading order in chiral effective field theory for lower- to mid-p-shell hypernuclei show a good reproduction of experimental excitation energies while hyperon separation energies are typically overestimated. The induced YNN contributions are strongly repulsive and we show that they are related to a decoupling of the Σ hyperons from the hypernuclear system, i.e., a suppression of the Λ-Σ conversion terms in the Hamiltonian. This is linked to the so-called hyperon puzzle in neutron-star physics and provides a basic mechanism for the explanation of strong ΛNN three-baryon forces.

Chiral perturbation theory and nucleon-pion-state contaminations in lattice QCD

NASA Astrophysics Data System (ADS)

Bär, Oliver

2017-05-01

Multiparticle states with additional pions are expected to be a non-negligible source of excited-state contamination in lattice simulations at the physical point. It is shown that baryon chiral perturbation theory can be employed to calculate the contamination due to two-particle nucleon-pion-states in various nucleon observables. Leading order results are presented for the nucleon axial, tensor and scalar charge and three Mellin moments of parton distribution functions (quark momentum fraction, helicity and transversity moment). Taking into account phenomenological results for the charges and moments the impact of the nucleon-pion-states on lattice estimates for these observables can be estimated. The nucleon-pion-state contribution results in an overestimation of all charges and moments obtained with the plateau method. The overestimation is at the 5-10% level for source-sink separations of about 2 fm. The source-sink separations accessible in contemporary lattice simulations are found to be too small for chiral perturbation theory to be directly applicable.

Spin asymmetries for vector boson production in polarized p + p collisions

DOE PAGES

Huang, Jin; Kang, Zhong-Bo; Vitev, Ivan; ...

2016-01-28

We study the cross section for vector boson (W ±/Z 0/γ more » $$\\star$$) production in polarized nucleon-nucleon collisions for low transverse momentum of the observed vector boson. For the case where one measures the transverse momentum and azimuthal angle of the vector bosons, we present the cross sections and the associated spin asymmetries in terms of transverse momentum dependent parton distribution functions (TMDs) at tree level within the TMD factorization formalism. To assess the feasibility of experimental measurements, we estimate the spin asymmetries forW ±/Z 0 boson production in polarized proton-proton collisions at the Relativistic Heavy Ion Collider by using current knowledge of the relevant TMDs. Here, we find that some of these asymmetries can be sizable if the suppression effect from TMD evolution is not too strong. The W program at RHIC can, thus, test and constrain spin theory by providing unique information on the universality properties of TMDs, TMD evolution, and the nucleon structure. For example, the single transverse spin asymmetries could be used to probe the well-known Sivers function f$$⊥q\\atop{1T}$$, as well as the transversal helicity distribution g$$q\\atop{1T}$$ via the parity-violating nature of W production.« less

Nucleon form factors in dispersively improved chiral effective field theory: Scalar form factor

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

Alarcon Soriano, Jose Manuel; Weiss, Christian

We propose a method for calculating the nucleon form factors (FFs) ofmore » $G$-parity-even operators by combining Chiral Effective Field Theory ($$\\chi$$EFT) and dispersion analysis. The FFs are expressed as dispersive integrals over the two-pion cut at $$t > 4 M_\\pi^2$$. The spectral functions are obtained from the elastic unitarity condition and expressed as products of the complex $$\\pi\\pi \\rightarrow N\\bar N$$ partial-wave amplitudes and the timelike pion FF. $$\\chi$$EFT is used to calculate the ratio of the partial-wave amplitudes and the pion FF, which is real and free of $$\\pi\\pi$$ rescattering in the $t$-channel ($N/D$ method). The rescattering effects are then incorporated by multiplying with the squared modulus of the empirical pion FF. The procedure results in a marked improvement compared to conventional $$\\chi$$EFT calculations of the spectral functions. We apply the method to the nucleon scalar FF and compute the scalar spectral function, the scalar radius, the $t$-dependent FF, and the Cheng-Dashen discrepancy. Higher-order chiral corrections are estimated through the $$\\pi N$$ low-energy constants. Results are in excellent agreement with dispersion-theoretical calculations. We elaborate several other interesting aspects of our method. The results show proper scaling behavior in the large-$$N_c$$ limit of QCD because the $$\\chi$$EFT includes $N$ and $$\\Delta$$ intermediate states. The squared modulus of the timelike pion FF required by our method can be extracted from Lattice QCD calculations of vacuum correlation functions of the operator at large Euclidean distances. Our method can be applied to the nucleon FFs of other operators of interest, such as the isovector-vector current, the energy-momentum tensor, and twist-2 QCD operators (moments of generalized parton distributions).« less

Nucleon form factors in dispersively improved chiral effective field theory: Scalar form factor

DOE PAGES

Alarcon Soriano, Jose Manuel; Weiss, Christian

2017-11-20

We propose a method for calculating the nucleon form factors (FFs) ofmore » $G$-parity-even operators by combining Chiral Effective Field Theory ($$\\chi$$EFT) and dispersion analysis. The FFs are expressed as dispersive integrals over the two-pion cut at $$t > 4 M_\\pi^2$$. The spectral functions are obtained from the elastic unitarity condition and expressed as products of the complex $$\\pi\\pi \\rightarrow N\\bar N$$ partial-wave amplitudes and the timelike pion FF. $$\\chi$$EFT is used to calculate the ratio of the partial-wave amplitudes and the pion FF, which is real and free of $$\\pi\\pi$$ rescattering in the $t$-channel ($N/D$ method). The rescattering effects are then incorporated by multiplying with the squared modulus of the empirical pion FF. The procedure results in a marked improvement compared to conventional $$\\chi$$EFT calculations of the spectral functions. We apply the method to the nucleon scalar FF and compute the scalar spectral function, the scalar radius, the $t$-dependent FF, and the Cheng-Dashen discrepancy. Higher-order chiral corrections are estimated through the $$\\pi N$$ low-energy constants. Results are in excellent agreement with dispersion-theoretical calculations. We elaborate several other interesting aspects of our method. The results show proper scaling behavior in the large-$$N_c$$ limit of QCD because the $$\\chi$$EFT includes $N$ and $$\\Delta$$ intermediate states. The squared modulus of the timelike pion FF required by our method can be extracted from Lattice QCD calculations of vacuum correlation functions of the operator at large Euclidean distances. Our method can be applied to the nucleon FFs of other operators of interest, such as the isovector-vector current, the energy-momentum tensor, and twist-2 QCD operators (moments of generalized parton distributions).« less

Nucleon decay and atmospheric neutrinos in the Mont Blanc experiment

NASA Technical Reports Server (NTRS)

Battistoni, G.; Bellotti, E.; Bologne, G.; Campana, P.; Castagnoli, C.; Chiarella, V.; Ciocio, A.; Cundy, D. C.; Dettorepiazzoli, B.; Fiorini, E.

1985-01-01

In the NUSEX experiment, during 2.8 years of operation, 31 fully contained events have been collected; 3 among them are nucleon decay candidates, while the others have been attributed to upsilon interactions. Limits on nucleon lifetime and determinations of upsilon interaction rates are presented.

Nucleon resonances in exclusive reactions of photo- and electroproduction of mesons

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

Skorodumina, Iu. A.; Burkert, V. D.; Golovach, E. N.

2015-11-01

Methods for extracting nucleon resonance parameters from experimental data are reviewed. The formalism for the description of exclusive reactions of meson photo- and electroproduction off nucleons is discussed. Recent experimental data on exclusive meson production in the scattering of electrons and photons off protons are analyzed.

Partial-wave analysis of nucleon-nucleon elastic scattering data

DOE PAGES

Workman, Ron L.; Briscoe, William J.; Strakovsky, Igor I.

2016-12-19

Energy-dependent and single-energy fits to the existing nucleon-nucleon database have been updated to incorporate recent measurements. The fits cover a region from threshold to 3 GeV, in the laboratory kinetic energy, for proton-proton scattering, with an upper limit of 1.3 GeV for neutron-proton scattering. Experiments carried out at the COSY-WASA and COSY-ANKE facilities have had a significant impact on the partial-wave solutions. Lastly, results are discussed in terms of both partial-wave and direct reconstruction amplitudes.

Energy spectrum of cosmic-ray iron nucleus observed with emulsion chamber

NASA Technical Reports Server (NTRS)

Sato, Y.; Shimada, E.; Ohta, I.; Tasaka, S.; Tanaka, S.; Sugimoto, H.; Taira, K.; Tateyama, N.

1985-01-01

Energy spectrum of cosmic-ray Fe-nucleus has been measured from 4 GeV per nucleon to beyond 100 GeV per nucleon. The data were obtained using emulsion chambers on a balloon from Sanriku, Japan. The energies were estimated by the opening angle method after calibrated using 1.88 GeV per nucleon Fe collisions. The spectrum of Fe is approximately E-2.5 in the range from 10 to 200 GeV per nucleon. This result is in good agreement with those of other experiments.

High proton momenta and nucleon-nucleon correlations in the reaction /sup 3/He(e,e'p)

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

Marchand, C.; Bernheim, M.; Dunn, P.C.

1988-04-25

Electron-scattering cross sections for the reaction /sup 3/He(e,e'p) have been measured for recoil momenta between 300 and 600 MeV/c and for missing energies up to 90 MeV. Proton momentum distributions in /sup 3/He, corrected for final-state--interaction and meson-exchange effects, have been obtained from 318 to 600 MeV/c for the pd channel and from 290 to 515 MeV/c for the ppn channel. Explicit evidence for nucleon-nucleon correlations is presented.

Structure of the Lightest Tin Isotopes

NASA Astrophysics Data System (ADS)

Morris, T. D.; Simonis, J.; Stroberg, S. R.; Stumpf, C.; Hagen, G.; Holt, J. D.; Jansen, G. R.; Papenbrock, T.; Roth, R.; Schwenk, A.

2018-04-01

We link the structure of nuclei around 100Sn, the heaviest doubly magic nucleus with equal neutron and proton numbers (N =Z =50 ), to nucleon-nucleon (N N ) and three-nucleon (N N N ) forces constrained by data of few-nucleon systems. Our results indicate that 100Sn is doubly magic, and we predict its quadrupole collectivity. We present precise computations of 101Sn based on three-particle-two-hole excitations of 100Sn, and we find that one interaction accurately reproduces the small splitting between the lowest Jπ=7 /2+ and 5 /2+ states.

Matching Pion-Nucleon Roy-Steiner Equations to Chiral Perturbation Theory.

PubMed

Hoferichter, Martin; Ruiz de Elvira, Jacobo; Kubis, Bastian; Meissner, Ulf-G

2015-11-06

We match the results for the subthreshold parameters of pion-nucleon scattering obtained from a solution of Roy-Steiner equations to chiral perturbation theory up to next-to-next-to-next-to-leading order, to extract the pertinent low-energy constants including a comprehensive analysis of systematic uncertainties and correlations. We study the convergence of the chiral series by investigating the chiral expansion of threshold parameters up to the same order and discuss the role of the Δ(1232) resonance in this context. Results for the low-energy constants are also presented in the counting scheme usually applied in chiral nuclear effective field theory, where they serve as crucial input to determine the long-range part of the nucleon-nucleon potential as well as three-nucleon forces.

Matching Pion-Nucleon Roy-Steiner Equations to Chiral Perturbation Theory

NASA Astrophysics Data System (ADS)

Hoferichter, Martin; Ruiz de Elvira, Jacobo; Kubis, Bastian; Meißner, Ulf-G.

2015-11-01

We match the results for the subthreshold parameters of pion-nucleon scattering obtained from a solution of Roy-Steiner equations to chiral perturbation theory up to next-to-next-to-next-to-leading order, to extract the pertinent low-energy constants including a comprehensive analysis of systematic uncertainties and correlations. We study the convergence of the chiral series by investigating the chiral expansion of threshold parameters up to the same order and discuss the role of the Δ (1232 ) resonance in this context. Results for the low-energy constants are also presented in the counting scheme usually applied in chiral nuclear effective field theory, where they serve as crucial input to determine the long-range part of the nucleon-nucleon potential as well as three-nucleon forces.

Holographic estimate of the meson cloud contribution to nucleon axial form factor

NASA Astrophysics Data System (ADS)

Ramalho, G.

2018-04-01

We use light-front holography to estimate the valence quark and the meson cloud contributions to the nucleon axial form factor. The free couplings of the holographic model are determined by the empirical data and by the information extracted from lattice QCD. The holographic model provides a good description of the empirical data when we consider a meson cloud mixture of about 30% in the physical nucleon state. The estimate of the valence quark contribution to the nucleon axial form factor compares well with the lattice QCD data for small pion masses. Our estimate of the meson cloud contribution to the nucleon axial form factor has a slower falloff with the square momentum transfer compared to typical estimates from quark models with meson cloud dressing.

REVIEWS OF TOPICAL PROBLEMS: Cooling of neutron stars and superfluidity in their cores

NASA Astrophysics Data System (ADS)

Yakovlev, Dmitrii G.; Levenfish, Kseniya P.; Shibanov, Yurii A.

1999-08-01

We study the heat capacity and neutrino emission reactions (direct and modified Urca processes, nucleon-nucleon bremsstrahlung, Cooper pairing of nucleons) in the supranuclear density matter of neutron star cores with superfluid neutrons and protons. Various superfluidity types are analysed (singlet-state pairing and two types of triplet-state pairing, without and with gap nodes at the nucleon Fermi surface). The results are used for cooling simulations of isolated neutron stars. Both the standard cooling and the cooling enhanced by the direct Urca process are strongly affected by nucleon superfluidity. Comparison of the cooling theory of isolated neutron stars with observations of their thermal radiation may give stringent constraints on the critical temperatures of the neutron and proton superfluidities in the neutron star cores.

Nucleon effective E-mass in neutron-rich matter from the Migdal–Luttinger jump

DOE PAGES

Cai, Bao-Jun; Li, Bao-An

2016-03-25

The well-known Migdal-Luttinger theorem states that the jump of the single-nucleon momentum distribution at the Fermi surface is equal to the inverse of the nucleon effective E-mass. Recent experiments studying short-range correlations (SRC) in nuclei using electron-nucleus scatterings at the Jefferson National Laboratory (JLAB) together with model calculations constrained significantly the Migdal-Luttinger jump at saturation density of nuclear matter. We show that the corresponding nucleon effective E-mass is consequently constrained to M-0(*,E)/M approximate to 2.22 +/- 0.35 in symmetric nuclear matter (SNM) and the E-mass of neutrons is smaller than that of protons in neutron-rich matter. Moreover, the average depletionmore » of the nucleon Fermi sea increases (decreases) approximately linearly with the isospin asymmetry delta according to kappa(p/n) approximate to 0.21 +/- 0.06 +/- (0.19 +/- 0.08)delta for protons (neutrons). These results will help improve our knowledge about the space-time non-locality of the single-nucleon potential in neutron-rich nucleonic matter Useful in both nuclear physics and astrophysics. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP(3).« less

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

Zhang, C. L.; Schuetrumpf, B.; Nazarewicz, W.

An electron localization measure was originally introduced to characterize chemical bond structures in molecules. Recently, a nucleon localization based on Hartree-Fock densities has been introduced to investigate α-cluster structures in light nuclei. Compared to the local nucleonic densities, the nucleon localization function has been shown to be an excellent indicator of shell effects and cluster correlations. In this work, using the spatial nucleon localization measure, we investigated the emergence of fragments in fissioning heavy nuclei using the self-consistent energy density functional method with a quantified energy density functional optimized for fission studies. We studied the particle densities and spatial nucleonmore » localization distributions along the fission pathways of 264Fm, 232Th, and 240Pu. We demonstrated that the fission fragments were formed fairly early in the evolution, well before scission. To illustrate the usefulness of the localization measure, we showed how the hyperdeformed state of 232Th could be understood in terms of a quasimolecular state made of 132Sn and 100Zr fragments. Compared to nucleonic distributions, the nucleon localization function more effectively quantifies nucleonic clustering: its characteristic oscillating pattern, traced back to shell effects, is a clear fingerprint of cluster/fragment configurations. This is of particular interest for studies of fragment formation and fragment identification in fissioning nuclei.« less

Intrinsic operators for the electromagnetic nuclear current

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

J. Adam, Jr.; H. Arenhovel

1996-09-01

The intrinsic electromagnetic nuclear meson exchange charge and current operators arising from a separation of the center-of-mass motion are derived for a one-boson-exchange model for the nuclear interaction with scalar, pseudoscalar and vector meson exchange including leading order relativistic terms. Explicit expressions for the meson exchange operators corresponding to the different meson types are given in detail for a two-nucleon system. These intrinsic operators are to be evaluated between intrinsic wave functions in their center-of-mass frame.

Charm dimuon production in neutrino-nucleon interactions in the NOMAD experiment

NASA Astrophysics Data System (ADS)

Petti, Roberto; Samoylov, Oleg

2012-09-01

We present our new measurement of charm dimuon production in neutrino-iron interactions based upon the full statistics collected by the NOMAD experiment. After background subtraction we observe 15,340 charm dimuon events, providing the largest sample currently available. The analysis exploits the large inclusive charged current sample (about 9 million events after all analysis cuts) to constrain the total systematic uncertainty to about 2%. The extraction of strange sea and charm production parameters is also discussed.

Charm dimuon production in neutrino-nucleon interactions in the NOMAD experiment

NASA Astrophysics Data System (ADS)

Petti, R.; Samoylov, O. B.

2011-12-01

We present our new measurement of charm dimuon production in neutrino-iron interactions based upon the full statistics collected by the NOMAD experiment. After background subtraction we observe 15,340 charm dimuon events, providing the largest sample currently available. The analysis exploits the large inclusive charged current sample (about 9 million events after all analysis cuts) to constrain the total systematic uncertainty to ˜2%. The extraction of strange sea and charm production parameters is also discussed.

Magnetic structure of light nuclei from lattice QCD

DOE PAGES

Chang, Emmanuel; Detmold, William; Orginos, Kostas; ...

2015-12-09

Lattice QCD with background magnetic fields is used to calculate the magnetic moments and magnetic polarizabilities of the nucleons and of light nuclei withmore » $$A\\le4$$, along with the cross-section for the $M1$ transition $$np\\rightarrow d\\gamma$$, at the flavor SU(3)-symmetric point where the pion mass is $$m_\\pi\\sim 806$$ MeV. These magnetic properties are extracted from nucleon and nuclear energies in six uniform magnetic fields of varying strengths. The magnetic moments are presented in a recent Letter. For the charged states, the extraction of the polarizability requires careful treatment of Landau levels, which enter non-trivially in the method that is employed. The nucleon polarizabilities are found to be of similar magnitude to their physical values, with $$\\beta_p=5.22(+0.66/-0.45)(0.23) \\times 10^{-4}$$ fm$^3$ and $$\\beta_n=1.253(+0.056/-0.067)(0.055) \\times 10^{-4}$$ fm$^3$, exhibiting a significant isovector component. The dineutron is bound at these heavy quark masses and its magnetic polarizability, $$\\beta_{nn}=1.872(+0.121/-0.113)(0.082) \\times 10^{-4}$$ fm$^3$ differs significantly from twice that of the neutron. A linear combination of deuteron scalar and tensor polarizabilities is determined by the energies of the $$j_z=\\pm 1$$ deuteron states, and is found to be $$\\beta_{d,\\pm 1}=4.4(+1.6/-1.5)(0.2) \\times 10^{-4}$$ fm$^3$. The magnetic polarizabilities of the three-nucleon and four-nucleon systems are found to be positive and similar in size to those of the proton, $$\\beta_{^{3}\\rm He}=5.4(+2.2/-2.1)(0.2) \\times 10^{-4}$$ fm$^3$, $$\\beta_{^{3}\\rm H}=2.6(1.7)(0.1) \\times 10^{-4}$$ fm$^3$, $$\\beta_{^{4}\\rm He}=3.4(+2.0/-1.9)(0.2) \\times 10^{-4}$$ fm$^3$. Mixing between the $$j_z=0$$ deuteron state and the spin-singlet $np$ state induced by the background magnetic field is used to extract the short-distance two-nucleon counterterm, $${\\bar L}_1$$, of the pionless effective theory for $NN$ systems (equivalent to the meson-exchange current contribution in nuclear potential models), that dictates the cross-section for the $$np\\to d\\gamma$$ process near threshold. Thus, combined with previous determinations of NN scattering parameters, this enables an ab initio determination of the threshold cross-section at these unphysical masses.« less

Probing short-range nucleon-nucleon interactions with an electron-ion collider

DOE PAGES

Miller, Gerald A.; Sievert, Matthew D.; Venugopalan, Raju

2016-04-07

For this research, we derive the cross section for exclusive vector meson production in high-energy deeply inelastic scattering off a deuteron target that disintegrates into a proton and a neutron carrying large relative momentum in the final state. This cross section can be expressed in terms of a novel gluon transition generalized parton distribution (T-GPD); the hard scale in the final state makes the T-GPD sensitive to the short-distance nucleon-nucleon interaction. We perform a toy model computation of this process in a perturbative framework and discuss the time scales that allow the separation of initial- and final-state dynamics in themore » T-GPD. We outline the more general computation based on the factorization suggested by the toy computation: In particular, we discuss the relative role of “pointlike” and “geometric” Fock configurations that control the parton dynamics of short-range nucleon-nucleon scattering. With the aid of exclusive J/ψ production data at the Hadron-Electron Ring Accelerator at DESY, as well as elastic nucleon-nucleon cross sections, we estimate rates for exclusive deuteron photodisintegration at a future Electron-Ion Collider (EIC). Our results, obtained using conservative estimates of EIC integrated luminosities, suggest that center-of-mass energies sNN ~12GeV 2 of the neutron-proton subsystem can be accessed. We argue that the high energies of the EIC can address outstanding dynamical questions regarding the short-range quark-gluon structure of nuclear forces by providing clean gluon probes of such “knockout” exclusive reactions in light and heavy nuclei.« less

Robert Hofstadter, Electron Scattering, the Structure of the Nucleons, and

Science.gov Websites

, Electron Scattering, the Structure of the Nucleons, and Scintillation Counters Resources with Additional -point particles and therefore possessed structure. For this work Hofstadter was awarded the Nobel Prize structure of the nucleons, and scintillation counters is available in electronic documents and on the Web

Effect of in-medium nucleon-nucleon cross section on proton-proton momentum correlation in intermediate-energy heavy-ion collisions

NASA Astrophysics Data System (ADS)

Wang, Ting-Ting; Ma, Yu-Gang; Zhang, Chun-Jian; Zhang, Zheng-Qiao

2018-03-01

The proton-proton momentum correlation function from different rapidity regions is systematically investigated for the Au + Au collisions at different impact parameters and different energies from 400 A MeV to 1500 A MeV in the framework of the isospin-dependent quantum molecular dynamics model complemented by the Lednický-Lyuboshitz analytical method. In particular, the in-medium nucleon-nucleon cross-section dependence of the correlation function is brought into focus, while the impact parameter and energy dependence of the momentum correlation function are also explored. The sizes of the emission source are extracted by fitting the momentum correlation functions using the Gaussian source method. We find that the in-medium nucleon-nucleon cross section obviously influences the proton-proton momentum correlation function, which is from the whole-rapidity or projectile or target rapidity region at smaller impact parameters, but there is no effect on the mid-rapidity proton-proton momentum correlation function, which indicates that the emission mechanism differs between projectile or target rapidity and mid-rapidity protons.

Detailed characterization of the 1087 MeV/nucleon iron-56 beam used for radiobiology at the alternating gradient synchrotron

NASA Technical Reports Server (NTRS)

Zeitlin, C.; Heilbronn, L.; Miller, J.

1998-01-01

We report beam characterization and dosimetric measurements made using a 56Fe beam extracted from the Brookhaven National Laboratory Alternating Gradient Synchrotron (AGS) with a kinetic energy of 1087 MeV/nucleon. The measurements reveal that the depth-dose distribution of this beam differs significantly from that obtained with a 600 MeV/nucleon iron beam used in several earlier radiobiology experiments at the Lawrence Berkeley National Laboratory's BEVALAC. We present detailed measurements of beam parameters relevant for radiobiology, including track- and dose-averaged linear energy transfer (LET), fragment composition and LET spectra measured behind sample holders used in irradiations of biological samples. We also report measurements of fluence behind three depths (1.94, 4.68 and 9.35 g cm(-2)) of polyethylene targets with the 1087 MeV/nucleon beam, and behind 1.94 g cm(-2) of polyethylene with a 610 MeV/nucleon beam delivered by the AGS. These results are compared to earlier measurements with the 600 MeV/nucleon beam at the BEVALAC.

Search for halo nucleus in Mg isotopes through the measurements of reaction cross sections towards the vicinity of neutron drip line

NASA Astrophysics Data System (ADS)

Takechi, M.; Suzuki, S.; Nishimura, D.; Fukuda, M.; Ohtsubo, T.; Nagashima, M.; Suzuki, T.; Yamaguchi, T.; Ozawa, A.; Moriguchi, T.; Ohishi, H.; Sumikama, T.; Geissel, H.; Ishihara, M.; Aoi, N.; Chen, Rui-Jiu; Fang, De-Qing; Fukuda, N.; Fukuoka, S.; Furuki, H.; Inabe, N.; Ishibashi, Y.; Itoh, T.; Izumikawa, T.; Kameda, D.; Kubo, T.; Lee, C. S.; Lantz, M.; Ma, Yu-Gang; Matsuta, K.; Mihara, M.; Momota, S.; Nagae, D.; Nishikiori, R.; Niwa, T.; Ohnishi, T.; Okumura, K.; Ogura, T.; Sakurai, H.; Sato, K.; Shimbara, Y.; Suzuki, H.; Takeda, H.; Takeuchi, S.; Tanaka, K.; Uenishi, H.; Winkler, M.; Yanagisawa, Y.; Watanabe, S.; Minomo, K.; Tagami, S.; Shimada, M.; Kimura, M.; Matsumoto, T.; Shimizu, Y. R.; Yahiro, M.

2014-03-01

Reaction cross sections (σR) for 24-38Mg on C targets at the energies of around 240 MeV/nucleon have been measured precisely at RIBF, RIKEN for the purpose of obtaining the crucial information on the changes of nuclear structure in unstable nuclei, especially around the so-called "island of inversion" region. In the island of inversion region, which includes neutron-rich Ne, Na, and Mg isotopes, the vanishing of the N = 20 magic number for neutrons have been discussed along with nuclear deformation. The present result suggest deformation features of Mg isotopes and shows a large cross section of weakly-bound nucleus 37Mg, which could be caused by a neutron halo formation.

Hadron-rich cosmic-ray families detected by emulsion chamber.

NASA Astrophysics Data System (ADS)

Navia, C. E.; Augusto, C. R. K.; Pinto, F. A.; Shibuya, H.

1995-11-01

Observed hadrons in excess, larger-than-expected charged mesons (pions) in cosmic-ray families detected in emulsion chamber experiment at mountain altitude and produced in a cosmic-ray hadronic interaction not far from the PeV energy region are studied. The hypothesis that these extra hadrons could be a bundle of surviving nuclear fragments (nucleons) is verified through a simulation method using a hybrid code composed of a superposition model to describe the number of interacting nucleon-nucleon pairs in a nucleus-nucleus collision. Together with the UA5 algorithm to describe a nucleon-nucleon collision, atmospheric propagation structure is also considered. A comparison between simulation output with experimental data shows that the surviving-nuclear-fragments hypothesis is not enough to explain the non-pionic hadron excess, even if a heavy dominance composition in the primary flux is considered.

Dispersive analysis of the scalar form factor of the nucleon

NASA Astrophysics Data System (ADS)

Hoferichter, M.; Ditsche, C.; Kubis, B.; Meißner, U.-G.

2012-06-01

Based on the recently proposed Roy-Steiner equations for pion-nucleon ( πN) scattering [1], we derive a system of coupled integral equations for the π π to overline N N and overline K K to overline N N S-waves. These equations take the form of a two-channel Muskhelishvili-Omnès problem, whose solution in the presence of a finite matching point is discussed. We use these results to update the dispersive analysis of the scalar form factor of the nucleon fully including overline K K intermediate states. In particular, we determine the correction {Δ_{σ }} = σ ( {2M_{π }^2} ) - {σ_{{π N}}} , which is needed for the extraction of the pion-nucleon σ term from πN scattering, as a function of pion-nucleon subthreshold parameters and the πN coupling constant.

Systematic Study of Three-Nucleon Systems Dynamics in the Cross Section of the Deuteron-Proton Breakup Reaction

NASA Astrophysics Data System (ADS)

Kłos, B.; Ciepał, I.; Jamróz, B.; Khatri, G.; Kistryn, S.; Kozela, A.; Magiera, A.; Parol, W.; Skwira-Chalot, I.; Stephan, E.

2014-08-01

An experiment to investigate the 1H( d, pp) n breakup reaction using a deuteron beam of 340, 380 and 400 MeV and the WASA detector has been performed at the Cooler Synchrotron COSY-Jülich. The main goal was the detailed study of various aspects of few-nucleon dynamics in the medium energy region, with particular emphasis on relativistic effects and their interplay with three nucleon forces. These effects become more important with increasing available energy in the three nucleon system. Therefore the investigations at high energies are crucial to understand their nature. The almost 4 π geometry of the WASA detector gives an unique possibility to study various aspects of dynamics of processes in the three-nucleon reaction. Preliminary results obtained using the WASA detector are presented.

Analyzing power Ay(θ) of n-3He elastic scattering between 1.60 and 5.54 MeV.

PubMed

Esterline, J; Tornow, W; Deltuva, A; Fonseca, A C

2013-04-12

Comprehensive and high-accuracy n-3He elastic scattering analyzing power Ay(θ) angular distributions were obtained at five incident neutron energies between 1.60 and 5.54 MeV. The data are compared to rigorous four-nucleon calculations using high-precision nucleon-nucleon potential models; three-nucleon force effects are found to be very small. The agreement between data and calculations is fair at the lower energies and becomes less satisfactory with increasing neutron energy. Comparison to p-3He scattering over the same energy range exhibits unexpectedly large isospin effects.

Medium-heavy nuclei from nucleon-nucleon interactions in lattice QCD

NASA Astrophysics Data System (ADS)

Inoue, Takashi; Aoki, Sinya; Charron, Bruno; Doi, Takumi; Hatsuda, Tetsuo; Ikeda, Yoichi; Ishii, Noriyoshi; Murano, Keiko; Nemura, Hidekatsu; Sasaki, Kenji; HAL QCD Collaboration

2015-01-01

On the basis of the Brueckner-Hartree-Fock method with the nucleon-nucleon forces obtained from lattice QCD simulations, the properties of the medium-heavy doubly magic nuclei such as 16O and 40Ca are investigated. We found that those nuclei are bound for the pseudoscalar meson mass MPS≃470 MeV. The mass number dependence of the binding energies, single-particle spectra, and density distributions are qualitatively consistent with those expected from empirical data at the physical point, although these hypothetical nuclei at heavy quark mass have smaller binding energies than the real nuclei.

The scalar and electromagnetic form factors of the nucleon in dispersively improved Chiral EFT

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

Alarcon, Jose Manuel

We present a method for calculating the nucleon form factors of G-parity-even operators. This method combines chiral effective field theory (χEFT) and dispersion theory. Through unitarity we factorize the imaginary part of the form factors into a perturbative part, calculable with χEFT, and a non-perturbative part, obtained through other methods. We consider the scalar and electromagnetic (EM) form factors of the nucleon. The results show an important improvement compared to standard chiral calculations, and can be used in analysis of the low-energy properties of the nucleon.

Computing nucleon EDM on a lattice

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

Abramczyk, Michael; Izubuchi, Taku

I will discuss briefly recent changes in the methodology of computing the baryon EDM on a lattice. The associated correction substantially reduces presently existing lattice values for the proton and neutron theta-induced EDMs, so that even the most precise previous lattice results become consistent with zero. On one hand, this change removes previous disagreements between these lattice results and the phenomenological estimates of the nucleon EDM. On the other hand, the nucleon EDM becomes much harder to compute on a lattice. In addition, I will review the progress in computing quark chromo-EDM-induced nucleon EDM using chiral quark action.

Isospin splitting of nucleon effective mass and symmetry energy in isotopic nuclear reactions

NASA Astrophysics Data System (ADS)

Guo, Ya-Fei; Chen, Peng-Hui; Niu, Fei; Zhang, Hong-Fei; Jin, Gen-Ming; Feng, Zhao-Qing

2017-10-01

Within an isospin and momentum dependent transport model, the dynamics of isospin particles (nucleons and light clusters) in Fermi-energy heavy-ion collisions are investigated for constraining the isospin splitting of nucleon effective mass and the symmetry energy at subsaturation densities. The impacts of the isoscalar and isovector parts of the momentum dependent interaction on the emissions of isospin particles are explored, i.e., the mass splittings of and (). The single and double neutron to proton ratios of free nucleons and light particles are thoroughly investigated in the isotopic nuclear reactions of 112Sn+112Sn and 124Sn+124Sn at incident energies of 50 and 120 MeV/nucleon, respectively. It is found that both the effective mass splitting and symmetry energy impact the kinetic energy spectra of the single ratios, in particular at the high energy tail (larger than 20 MeV). The isospin splitting of nucleon effective mass slightly impacts the double ratio spectra at the energy of 50 MeV/nucleon. A soft symmetry energy with stiffness coefficient of γ s=0.5 is constrained from the experimental data with the Fermi-energy heavy-ion collisions. Supported by Major State Basic Research Development Program in China (2014CB845405, 2015CB856903), National Natural Science Foundation of China (11722546, 11675226, 11675066, U1332207) and Youth Innovation Promotion Association of Chinese Academy of Sciences

SevenOperators, a Mathematica script for harmonic oscillator nuclear matrix elements arising in semileptonic electroweak interactions

NASA Astrophysics Data System (ADS)

Haxton, Wick; Lunardini, Cecilia

2008-09-01

Semi-leptonic electroweak interactions in nuclei—such as β decay, μ capture, charged- and neutral-current neutrino reactions, and electron scattering—are described by a set of multipole operators carrying definite parity and angular momentum, obtained by projection from the underlying nuclear charge and three-current operators. If these nuclear operators are approximated by their one-body forms and expanded in the nucleon velocity through order |p→|/M, where p→ and M are the nucleon momentum and mass, a set of seven multipole operators is obtained. Nuclear structure calculations are often performed in a basis of Slater determinants formed from harmonic oscillator orbitals, a choice that allows translational invariance to be preserved. Harmonic-oscillator single-particle matrix elements of the multipole operators can be evaluated analytically and expressed in terms of finite polynomials in q, where q is the magnitude of the three-momentum transfer. While results for such matrix elements are available in tabular form, with certain restriction on quantum numbers, the task of determining the analytic form of a response function can still be quite tedious, requiring the folding of the tabulated matrix elements with the nuclear density matrix, and subsequent algebra to evaluate products of operators. Here we provide a Mathematica script for generating these matrix elements, which will allow users to carry out all such calculations by symbolic manipulation. This will eliminate the errors that may accompany hand calculations and speed the calculation of electroweak nuclear cross sections and rates. We illustrate the use of the new script by calculating the cross sections for charged- and neutral-current neutrino scattering in 12C. Program summaryProgram title: SevenOperators Catalogue identifier: AEAY_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEAY_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 2227 No. of bytes in distributed program, including test data, etc.: 19 382 Distribution format: tar.gz Programming language: Mathematica Computer: Any computer running Mathematica; tested on Mac OS X PowerPC (32-bit) running Mathematica 6.0.0 Operating system: Any running Mathematica RAM: Memory requirements determined by Mathematica; 512 MB or greater RAM and hard drive space of at least 3.0 GB recommended Classification: 17.16, 17.19 Nature of problem: Algebraic evaluation of harmonic oscillator nuclear matrix elements for the one-body multipole operators governing semi-leptonic weak interactions, such as charged- or neutral-current neutrino scattering off nuclei. Solution method: Mathematica evaluation of associated angular momentum algebra and spherical Bessel function radial integrals. Running time: Depends on the complexity of the one-body density matrix employed, but times of a few seconds are typical.

Wounded Nucleon Model and Deuteron--Gold Collisions at RHIC

NASA Astrophysics Data System (ADS)

Bialas, A.; Czyz, W.

2005-03-01

It is shown that the wounded nucleon model describes very well the recent PHOBOS data on particle production in D--Au collisions at 200 GeV. Contribution to particle production from a single wounded nucleon is determined. A two-component model is formulated and shown to account for most of the important features of the data.

Polarization Transfer in the Reaction 4He($$\\vec{v}$$,e'$$\\vec{p}$$) 3H in the Quasielastic Scattering Region

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

Dieterich, Sonja

2002-05-01

There has been a longstanding issue concerning possible nucleon modifications in a (dense) nuclear medium. Polarization transfer data for exclusive quasielastic electron scattering are a sensitive to the ratio of the electric and magnetic nucleon form factors in the medium. Although proper interpretation of the results requires accounting for such effects as final state interactions and meson exchange currents, their effect on polarization transfer is predicted to be small. Studies of model dependencies, e.g., the off-shell current operator and spinor distortions, have been done. Final results of a measurement of polarization transfer in the 4He(more » $$\\vec{v}$$,e'$$\\vec{p}$$) 3H reaction will be discussed. The experiments were carried out at MAMI, Mainz at a Q 2 of 0.4 GeV 2 and at the Thomas Jefferson Lab, Newport News, Virginia at the Q 2 values 0.5, 1.0, 1.6 and 2.6 GeV 2. Measured values of the transferred and induced polarization are compared with various theoretical calculations. The experiment showed a difference between the fully relativistic model with may indicate medium modifications of the form factor.« less

Hard breakup of two nucleons from the He3 nucleus

NASA Astrophysics Data System (ADS)

Sargsian, Misak M.; Granados, Carlos

2009-07-01

We investigate a large angle photodisintegration of two nucleons from the He3 nucleus within the framework of the hard rescattering model (HRM). In the HRM a quark of one nucleon knocked out by an incoming photon rescatters with a quark of the other nucleon leading to the production of two nucleons with large relative momentum. Assuming the dominance of the quark-interchange mechanism in a hard nucleon-nucleon scattering, the HRM allows the expression of the amplitude of a two-nucleon breakup reaction through the convolution of photon-quark scattering, NN hard scattering amplitude, and nuclear spectral function, which can be calculated using a nonrelativistic He3 wave function. The photon-quark scattering amplitude can be explicitly calculated in the high energy regime, whereas for NN scattering one uses the fit of the available experimental data. The HRM predicts several specific features for the hard breakup reaction. First, the cross section will approximately scale as s-11. Second, the s11 weighted cross section will have the shape of energy dependence similar to that of s10 weighted NN elastic scattering cross section. Also one predicts an enhancement of the pp breakup relative to the pn breakup cross section as compared to the results from low energy kinematics. Another result is the prediction of different spectator momentum dependencies of pp and pn breakup cross sections. This is due to the fact that the same-helicity pp-component is strongly suppressed in the ground state wave function of He3. Because of this suppression the HRM predicts significantly different asymmetries for the cross section of polarization transfer NN breakup reactions for circularly polarized photons. For the pp breakup this asymmetry is predicted to be zero while for the pn it is close to (2)/(3).

Probing midrapidity source characteristics with charged particles and neutrons in the 35Cl+natTa reaction at 43 MeV/nucleon

NASA Astrophysics Data System (ADS)

Larochelle, Y.; St-Pierre, C.; Beaulieu, L.; Colonna, N.; Gingras, L.; Ball, G. C.; Bowman, D. R.; Colonna, M.; D'erasmo, G.; Fiore, E.; Fox, D.; Galindo-Uribarri, A.; Hagberg, E.; Horn, D.; Laforest, R.; Pantaleo, A.; Roy, R.; Tagliente, G.

1999-02-01

The characteristics of the midrapidity and target sources (apparent temperatures, velocities, and neutron multiplicities) extracted from the neutron energy spectra, have been measured for various quasiprojectile (QP) excitation energies, reconstructed from charged particles of well defined peripheral events in the 35Cl+natTa reaction at 43 MeV/nucleon. The reconstructed excitation energy of the QP is always smaller than the excitation energy calculated from its velocity, assuming pure dissipative binary collision. The latter observation combined with the neutron multiplicity at midrapidity and the apparent temperature suggests important preequilibrium and/or dynamical effects in the entrance channel. The midrapidity source moves at a velocity lower than the nucleon-nucleon center of mass velocity showing the importance of the attractive mean-field potential from the target even at 43 MeV/nucleon. The above picture is confirmed by comparison to Boltzman-Nordheim-Vlasov (BNV) simulations.

Ab initio description of p-shell hypernuclei.

PubMed

Wirth, Roland; Gazda, Daniel; Navrátil, Petr; Calci, Angelo; Langhammer, Joachim; Roth, Robert

2014-11-07

We present the first ab initio calculations for p-shell single-Λ hypernuclei. For the solution of the many-baryon problem, we develop two variants of the no-core shell model with explicit Λ and Σ(+),Σ(0),Σ(-) hyperons including Λ-Σ conversion, optionally supplemented by a similarity renormalization group transformation to accelerate model-space convergence. In addition to state-of-the-art chiral two- and three-nucleon interactions, we use leading-order chiral hyperon-nucleon interactions and a recent meson-exchange hyperon-nucleon interaction. We validate the approach for s-shell hypernuclei and apply it to p-shell hypernuclei, in particular to (Λ)(7)Li, (Λ)(9)Be, and (Λ)(13)C. We show that the chiral hyperon-nucleon interactions provide ground-state and excitation energies that generally agree with experiment within the cutoff dependence. At the same time we demonstrate that hypernuclear spectroscopy provides tight constraints on the hyperon-nucleon interactions.

Pseudoscalar Meson Electroproduction and Transversity

NASA Astrophysics Data System (ADS)

Goldstein, Gary R.; Liuti, Simonetta

2011-02-01

Exclusive meson leptoproduction from nucleons in the deeply virtual exchanged boson limit can be described by generalized parton distributions (GPDs). Including spin dependence in the description requires 8 independent quark-parton and gluon-parton functions. The chiral even subset of 4 quark-nucleon GPDs are related to nucleon form factors and to parton distribution functions. The chiral odd set of 4 quark-nucleon GPDs are related to transversity, the tensor charge, and other quantities related to transversity. Different meson or photon production processes access different combinations of GPDs. This is analyzed in terms of t-channel exchange quantum numbers, JPC and it is shown that pseudoscalar production can isolate chiral odd GPDs. There is a sensitive dependence in various cross sections and asymmetries on the tensor charge of the nucleon and other transversity parameters. In a second section, analyticity and completeness are shown to limit the partonic interpret ation of the GPDs in the ERBL region.

Insights into nucleon structure from parton distributions

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

Melnitchouk, Wally

2017-05-01

We review recent progress in understanding the substructure of the nucleon from global QCD analysis of parton distribution functions (PDFs). New high-precision data onW-boson production in p ¯ p collisions have significantly reduced the uncertainty on the d=u PDF ratio at large values of x, indirectly constraining models of the medium modification of bound nucleons. Drell-Yan data from pp and pd scattering reveal new information on the d¯-u¯ asymmetry, clarifying the role of chiral symmetry breaking in the nucleon. In the strange sector, a new chiral SU(3) analysis finds a valence-like component of the strange-quark PDF, giving rise to amore » nontrivial s- ¯ s asymmetry at moderate x values. We also review recent analyses of charm in the nucleon, which have found conflicting indications of the size of the nonperturbative charm component.« less

Nuclear medium effects in structure functions of nucleon at moderate Q2

NASA Astrophysics Data System (ADS)

Haider, H.; Zaidi, F.; Sajjad Athar, M.; Singh, S. K.; Ruiz Simo, I.

2015-11-01

Recent experiments performed on inclusive electron scattering from nuclear targets have measured the nucleon electromagnetic structure functions F1 (x ,Q2), F2 (x ,Q2) and FL (x ,Q2) in 12C, 27Al, 56Fe and 64Cu nuclei. The measurements have been done in the energy region of 1 GeV2

BEC-BCS crossover and the liquid-gas phase transition in hot and dense nuclear matter

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

Jin Meng; Urban, Michael; Schuck, Peter

2010-08-15

The effect of nucleon-nucleon correlations in symmetric nuclear matter at finite temperature is studied beyond BCS theory. Starting from a Hartree-Fock description of nuclear matter with the Gogny effective interaction, we add correlations corresponding to the formation of preformed pairs and scattering states above the superfluid critical temperature within the in-medium T-matrix approach, which is analogous to the Nozieres-Schmitt-Rink theory. We calculate the critical temperature for a BEC superfluid of deuterons, of a BCS superfluid of nucleons, and in the crossover between these limits. The effect of the correlations on thermodynamic properties (equation of state, energy, entropy) and the liquid-gasmore » phase transition is discussed. Our results show that nucleon-nucleon correlations beyond BCS play an important role for the properties of nuclear matter, especially in the low-density region.« less

Magnetic Polarizability of Virtual (s\\bar{s}) and (c\\bar{c}) Pairs in the Nucleon

NASA Astrophysics Data System (ADS)

Filip, Peter

2017-12-01

We suggest 3 P 0 quantum state of virtual (s\\bar{s}) pairs in the nucleon can be polarised by the internal fields permeating the volume of the nucleon (proton or neutron). Due to the quadratic Zeeman interaction, 3 P 0 wavefunction of virtual (q\\bar{q}) pairs acquires the admixture of 1 P 10 quantum state in the magnetic field, which generates the antiparallel polarization of s and \\bar{s} quarks (in the nucleon). Considering the internal magnetic fields of neutron and proton (originating from their measured magnetic dipole moments), we suggest the induced s-quark polarization in the neutron to be of the oposite direction compared to the proton case. We mention the influence of the internal chromo-magnetic fields on the quantum state of (q\\bar{q}) pairs in the nucleon and we discuss also the expected behaviour of virtual (c\\bar{c}) pairs.

Scaling within the spectral function approach

NASA Astrophysics Data System (ADS)

Sobczyk, J. E.; Rocco, N.; Lovato, A.; Nieves, J.

2018-03-01

Scaling features of the nuclear electromagnetic response functions unveil aspects of nuclear dynamics that are crucial for interpreting neutrino- and electron-scattering data. In the large momentum-transfer regime, the nucleon-density response function defines a universal scaling function, which is independent of the nature of the probe. In this work, we analyze the nucleon-density response function of 12C, neglecting collective excitations. We employ particle and hole spectral functions obtained within two distinct many-body methods, both widely used to describe electroweak reactions in nuclei. We show that the two approaches provide compatible nucleon-density scaling functions that for large momentum transfers satisfy first-kind scaling. Both methods yield scaling functions characterized by an asymmetric shape, although less pronounced than that of experimental scaling functions. This asymmetry, only mildly affected by final state interactions, is mostly due to nucleon-nucleon correlations, encoded in the continuum component of the hole spectral function.

Nonperturbative derivation of the interaction potential of static nucleons

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

Izmailov, A.F.; Kessel', A.R.; Fainberg, V.Y.

1989-05-01

A new approach is used to calculate the interaction potential of nucleons which describes virtual processes of exchange of scalar and pseudoscalar mesons in all orders in the nucleon{endash}meson local coupling constant. The theory contains a natural parameter---a limiting momentum {ital p}{sub {ital m}}. The nucleon{endash}nucleon potential of scalar mesodynamics for various values of {ital p}{sub {ital m}} reproduces accurately the well known phenomenological potentials, such as the Hamada{endash}Johnston potential, the Reid soft-core potential, and the de Toureil{endash}Sprung supersoft-core potential.{sup 15} In pseudoscalar mesodynamics, it has been possible to reproduce completely the behavior of the empirical tensor potential. The shapemore » of the central potential at all distances is reproduced in the states {tau}=0, {sigma}=0 and {tau}=0, {sigma}=1, and at intermediate and large distances in the states {tau}=1, {sigma}=0 and {tau}=1, {sigma}=1.« less

AN INDIRECT SEARCH FOR WEAKLY INTERACTING MASSIVE PARTICLES IN THE SUN USING 3109.6 DAYS OF UPWARD-GOING MUONS IN SUPER-KAMIOKANDE

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

Tanaka, T.; Abe, K.; Hayato, Y.

2011-12-01

We present the result of an indirect search for high energy neutrinos from Weakly Interacting Massive Particle (WIMP) annihilation in the Sun using upward-going muon (upmu) events at Super-Kamiokande. Data sets from SKI-SKIII (3109.6 days) were used for the analysis. We looked for an excess of neutrino signal from the Sun as compared with the expected atmospheric neutrino background in three upmu categories: stopping, non-showering, and showering. No significant excess was observed. The 90% C.L. upper limits of upmu flux induced by WIMPs of 100 GeV c{sup -2} were 6.4 Multiplication-Sign 10{sup -15} cm{sup -2} s{sup -1} and 4.0 Multiplication-Signmore » 10{sup -15} cm{sup -2} s{sup -1} for the soft and hard annihilation channels, respectively. These limits correspond to upper limits of 4.5 Multiplication-Sign 10{sup -39} cm{sup -2} and 2.7 Multiplication-Sign 10{sup -40} cm{sup -2} for spin-dependent WIMP-nucleon scattering cross sections in the soft and hard annihilation channels, respectively.« less

Coherent neutrinoproduction of photons and pions in a chiral effective field theory for nuclei

NASA Astrophysics Data System (ADS)

Zhang, Xilin; Serot, Brian D.

2012-09-01

Background: The neutrinoproduction of photons and pions from nucleons and nuclei is relevant to the background analysis in neutrino-oscillation experiments [for example, the MiniBooNE; MiniBooNE Collaboration, A. A. Aquilar-Arevalo , Phys. Rev. Lett.0031-900710.1103/PhysRevLett.100.032301 100, 032301 (2008)]. The production from nucleons and incoherent production with Eν⩽0.5GeV have been studied in B. D. Serot and X. Zhang, Phys. Rev. CPRVCAN0556-281310.1103/PhysRevC.86.015501 86, 015501 (2012); and X. Zhang and B. D. Serot, Phys. Rev. C1110-865710.1103/PhysRevC.86.035502 86, 035502 (2012).Purpose: Study coherent productions with Eν⩽0.5GeV. Also address the contributions of two contact terms in neutral current (NC) photon production that are partially related to the proposed anomalous ω(ρ), Z boson, and photon interactions.Methods: We work in the framework of a Lorentz-covariant effective field theory (EFT), which contains nucleons, pions, the Δ (1232) (Δs), isoscalar scalar (σ) and vector (ω) fields, and isovector vector (ρ) fields, and incorporates a nonlinear realization of (approximate) SU(2)L⊗SU(2)R chiral symmetry. A revised version of the so-called “optimal approximation” is applied, where one-nucleon interaction amplitude is factorized out and the medium-modifications and pion wave function distortion are included. The calculation is tested against the coherent pion photoproduction data.Results: The computation shows an agreement with the pion photoproduction data, although precisely determining the Δ modification is entangled with one mentioned contact term. The uncertainty in the Δ modification leads to uncertainties in both pion and photon neutrinoproductions. In addition, the contact term plays a significant role in NC photon production.Conclusions: First, the contact term increases NC photon production by ˜10% assuming a reasonable range of the contact coupling, which however seems not significant enough to explain the MiniBooNE excess. A high energy computation is needed to gain a firm conclusion and will be presented elsewhere. Second, the behavior of coherent neutrinoproductions computed here is significantly different from the expectation at high energy by ignoring the vector current contribution.

A proposed U.S./China theoretical/experimental collaborative effort on baryon resonance extraction

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

P.L. Cole

2009-12-01

In this paper we discuss the reasons for our work towards establishing a new collaboration between Jefferson Lab (JLab) and the Institute of High Energy Physics (IHEP) in Beijing. We seek to combine experimentalists and theorists into a dedicated group focused on better understanding the current and future data from JLab and from the Beijing Electron Positron Collider (BEPC). Recent JLab results on the extraction of single- and double-polarization observables in both the 1{pi}- and 2{pi}-channel show their high sensitivity to small production amplitudes and therefore their importance for the extraction of resonance parameters. The Beijing Electron Spectrometer (BES) atmore » the BEPC has collected high statistics data on J/{Psi} production. Its decay into baryon-antibaryon channels offers a unique and complementary way of probing nucleon resonances. The CEBAF Large Acceptance Spectrometer, CLAS, has access to N* form factors at high Q{sup 2}, which is advantageous for the study of dynamical properties of nucleon resonances, while the low-background BES results will be able to provide guidance for the search for less-dominant excited states at JLab. Moreover, with the recently approved experimental proposal Nucleon Resonance Studies with CLAS12 and the high-quality data streaming from BES-III and CLAS, the time has come for forging a new Trans-Pacific collaboration of theorists and experimentalists on NSTAR physics.« less

SYMPLECTIC INVARIANTS AND FLOWERS' CLASSIFICATION OF SHELL MODEL STATES

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

Helmers, K.

1961-01-01

Flowers has given a classification of shell model states in j-j coupling for a fixed number of nucleons in a shell with respect to a symplectic group. The relation between these classifications for the various nucleon numbers is studied and is found to be governed by another symplectic group, the transformations of which in general change the nucleon number. (auth)

Lattice quantum chromodynamical approach to nuclear physics

NASA Astrophysics Data System (ADS)

Aoki, Sinya; Doi, Takumi; Hatsuda, Tetsuo; Ikeda, Yoichi; Inoue, Takashi; Ishii, Noriyoshi; Murano, Keiko; Nemura, Hidekatsu; Sasaki, Kenji; HAL QCD Collaboration

2012-09-01

We review recent progress in the HAL QCD method, which was recently proposed to investigate hadron interactions in lattice quantum chromodynamics (QCD). The strategy to extract the energy-independent non-local potential in lattice QCD is explained in detail. The method is applied to study nucleon-nucleon, nucleon-hyperon, hyperon-hyperon, and meson-baryon interactions. Several extensions of the method are also discussed.

Cross Sections From Scalar Field Theory

NASA Technical Reports Server (NTRS)

Norbury, John W.; Dick, Frank; Norman, Ryan B.; Nasto, Rachel

2008-01-01

A one pion exchange scalar model is used to calculate differential and total cross sections for pion production through nucleon- nucleon collisions. The collisions involve intermediate delta particle production and decay to nucleons and a pion. The model provides the basic theoretical framework for scalar field theory and can be applied to particle production processes where the effects of spin can be neglected.

Experimental study of the space-time development of the particle production process in hadron-nucleon collisions, using massive target nucleus as a detector

NASA Technical Reports Server (NTRS)

Strugalski, Z.

1985-01-01

Experimental study of the space-time development of the particle production process in hadronic collisions at its initial stage was performed. Massive target nuclei have been used as fine detectors of properties of the particle production process development within time intervals smaller than 10 to the 22nd power s and spatial distances smaller than 10 to the 12th power cm. In hadron-nucleon collisions, in particular in nucleon-nucleon collisions, the particle production process goes through intermediate objects in 2 yields 2 type endoergic reactions. The objects decay into commonly observed resonances and paricles.

Unraveling the physical meaning of the Jaffe-Manohar decomposition of the nucleon spin

NASA Astrophysics Data System (ADS)

Wakamatsu, M.

2016-09-01

A general consensus now is that there are two physically inequivalent complete decompositions of the nucleon spin, i.e. the decomposition of the canonical type and that of mechanical type. The well-known Jaffe-Manohar decomposition is of the former type. Unfortunately, there is a wide-spread misbelief that this decomposition matches the partonic picture, which states that motion of quarks in the nucleon is approximately free. In the present monograph, we reveal that this understanding is not necessarily correct and that the Jaffe-Manohar decomposition is not such a decomposition, which natively reflects the intrinsic (or static) orbital angular momentum structure of the nucleon.

Search for three-nucleon short-range correlations in light nuclei

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

Ye, Z.; Solvignon, P.; Nguyen, D.

Here, we present new data probing short-range correlations (SRCs) in nuclei through the measurement of electron scattering off high-momentum nucleons in nuclei. The inclusive 4He/ 3He cross section ratio is observed to be both x and Q 2 independent for 1.5 < x < 2, confirming the dominance of two- nucleon (2N) short-range correlations (SRCs). For x > 2, our data do not support a previous claim of three-nucleon (3N) correlation dominance. While contributions beyond those from stationary 2N- SRCs are observed, our data show that isolating 3N-SRCs is more complicated than for 2N-SRCs.

Search for three-nucleon short-range correlations in light nuclei

DOE PAGES

Ye, Z.; Solvignon, P.; Nguyen, D.; ...

2018-06-18

Here, we present new data probing short-range correlations (SRCs) in nuclei through the measurement of electron scattering off high-momentum nucleons in nuclei. The inclusive 4He/ 3He cross section ratio is observed to be both x and Q 2 independent for 1.5 < x < 2, confirming the dominance of two- nucleon (2N) short-range correlations (SRCs). For x > 2, our data do not support a previous claim of three-nucleon (3N) correlation dominance. While contributions beyond those from stationary 2N- SRCs are observed, our data show that isolating 3N-SRCs is more complicated than for 2N-SRCs.

Multi-hadron-state contamination in nucleon observables from chiral perturbation theory

NASA Astrophysics Data System (ADS)

Bär, Oliver

2018-03-01

Multi-particle states with additional pions are expected to be a non-negligible source of the excited-state contamination in lattice simulations at the physical point. It is shown that baryon chiral perturbation theory (ChPT) can be employed to calculate the contamination due to two-particle nucleon-pion states in various nucleon observables. Results to leading order are presented for the nucleon axial, tensor and scalar charge and three Mellin moments of parton distribution functions: the average quark momentum fraction, the helicity and the transversity moment. Taking into account experimental and phenomenological results for the charges and moments the impact of the nucleon-pionstates on lattice estimates for these observables can be estimated. The nucleon-pion-state contribution leads to an overestimation of all charges and moments obtained with the plateau method. The overestimation is at the 5-10% level for source-sink separations of about 2 fm. Existing lattice data is not in conflict with the ChPT predictions, but the comparison suggests that significantly larger source-sink separations are needed to compute the charges and moments with few-percent precision. Talk given at the 35th International Symposium on Lattice Field Theory, 18 - 24 June 2017, Granada, Spain.

Folding model analyses of 12C-12C and 16O-16O elastic scattering using the density-dependent LOCV-averaged effective interaction

NASA Astrophysics Data System (ADS)

Rahmat, M.; Modarres, M.

2018-03-01

The averaged effective two-body interaction (AEI), which can be generated through the lowest order constrained variational (LOCV) method for symmetric nuclear matter (SNM) with the input [Reid68, Ann. Phys. 50, 411 (1968), 10.1016/0003-4916(68)90126-7] nucleon-nucleon potential, is used as the effective nucleon-nucleon potential in the folding model to describe the heavy-ion (HI) elastic scattering cross sections. The elastic scattering cross sections of 12C-12C and 16O-16O systems are calculated in the above framework. The results are compared with the corresponding calculations coming from the fitting procedures with the input finite range D D M 3 Y 1 -Reid potential and the available experimental data at different incident energies. It is shown that a reasonable description of the elastic 12C-12C and 16O-16O scattering data at the low and medium energies can be obtained by using the above LOCV AEI, without any need to define a parametrized density-dependent function in the effective nucleon-nucleon potential, which is formally considered in the typical D D M 3 Y 1 -Reid interactions.

Nucleon-anti-nucleon intruder state of Dirac equation for nucleon in deep scalar potential well

NASA Astrophysics Data System (ADS)

Kuo, T. T. S.; Kuo, T. K.; Osnes, E.; Shu, S.

We solve the Dirac radial equation for a nucleon in a scalar Woods-Saxon potential well of depth V0 and radius r0. A sequence of values for the depth and radius are considered. For shallow potentials with -1000MeV ≤ V0 < 0 the wave functions for the positive-energy states ψ+(r) are dominated by their nucleon component f(r). But for deeper potentials with V0 ≤ -1500MeV the ψ+(r) s begin to have dominant anti-nucleon component f(r). In particular, a special intruder state enters with wave function ψ1/2(r) and energy E1/2. We have considered several r0 values between 2 and 8fm. For V0 ≤ -2000 MeV and the above r0 values. ψ1/2(r) is the only bound positive-energy state and has its g(r) closely equal to -f(r), both having a narrow wave packet shape centered around r0. The E1/2 of this state is practically independent of V0 for the above V0 range and obeys closely the relation E1/2 = ℏc/r0.

Deriving the nuclear shell model from first principles

NASA Astrophysics Data System (ADS)

Barrett, Bruce R.; Dikmen, Erdal; Vary, James P.; Maris, Pieter; Shirokov, Andrey M.; Lisetskiy, Alexander F.

2014-09-01

The results of an 18-nucleon No Core Shell Model calculation, performed in a large basis space using a bare, soft NN interaction, can be projected into the 0 ℏω space, i.e., the sd -shell. Because the 16 nucleons in the 16O core are frozen in the 0 ℏω space, all the correlations of the 18-nucleon system are captured by the two valence, sd -shell nucleons. By the projection, we obtain microscopically the sd -shell 2-body effective interactions, the core energy and the sd -shell s.p. energies. Thus, the input for standard shell-model calculations can be determined microscopically by this approach. If the same procedure is then applied to 19-nucleon systems, the sd -shell 3-body effective interactions can also be obtained, indicating the importance of these 3-body effective interactions relative to the 2-body effective interactions. Applications to A = 19 and heavier nuclei with different intrinsic NN interactions will be presented and discussed. The results of an 18-nucleon No Core Shell Model calculation, performed in a large basis space using a bare, soft NN interaction, can be projected into the 0 ℏω space, i.e., the sd -shell. Because the 16 nucleons in the 16O core are frozen in the 0 ℏω space, all the correlations of the 18-nucleon system are captured by the two valence, sd -shell nucleons. By the projection, we obtain microscopically the sd -shell 2-body effective interactions, the core energy and the sd -shell s.p. energies. Thus, the input for standard shell-model calculations can be determined microscopically by this approach. If the same procedure is then applied to 19-nucleon systems, the sd -shell 3-body effective interactions can also be obtained, indicating the importance of these 3-body effective interactions relative to the 2-body effective interactions. Applications to A = 19 and heavier nuclei with different intrinsic NN interactions will be presented and discussed. Supported by the US NSF under Grant No. 0854912, the US DOE under Grants Nos. DESC0008485 and DE-FG02-87ER40371, the Higher Education Council of Turkey(YOK), and the Ministry of Education and Science of Russian Fed. under contracts P521 and 14.v37.21.1297.

7Li-induced reaction on natMo: A study of complete versus incomplete fusion

NASA Astrophysics Data System (ADS)

Kumar, Deepak; Maiti, Moumita; Lahiri, Susanta

2017-07-01

Background: Several investigations on the complete-incomplete fusion (CF-ICF) dynamics of α -cluster well-bound nuclei have been contemplated above the Coulomb barrier (˜4 -7 MeV/nucleon) in recent years. It is therefore expected to observe significant ICF over CF in the reactions induced by a weakly bound α -cluster nucleus at slightly above the barrier. Purpose: Study of the CF-ICF dynamics by measuring the populated residues in the weakly bound 7Li+natMo system at energies slightly above the Coulomb barrier to well above it. Method: In order to investigate CF-ICF in the loosely bound system, 7Li beam was bombarded on the natMo foils, separated by the aluminium (Al) catcher foils alternatively, within ˜3 -6.5 MeV/nucleon. Evaporation residues produced in each foil were identified by the off-line γ -ray spectrometry. Measured cross section data of the residues were compared with the theoretical model calculations based on the equilibrium (EQ) and pre-equilibrium (PEQ) reaction mechanisms. Results: The experimental cross section of Rh 101 m,100 ,99 m,97 ,Ru,9597,Tc 99 m,96 ,95 ,94 ,93 m+g , and 93mMo residues measured at various projectile energies were satisfactorily reproduced by the simplified coupled channel approach in comparison to single barrier penetration model calculation. Significant cross section enhancement in the α -emitting channels was observed compared to EQ and PEQ model calculations throughout observed energy region. The ICF process over CF was analyzed by comparing with EMPIRE. The increment of the incomplete fusion fraction was observed with increasing projectile energies. Conclusions: Theoretical model calculations reveal that the compound reaction mechanism is the major contributor to the production of residues in 7Li+natMo reaction. Theoretical evaluations substantiate the contribution of ICF over the CF in α -emitting channels. EMPIRE estimations shed light on its predictive capability of cross sections of the residues from the heavy-ion induced reactions.

Measurement of parity-violating asymmetry in deep inelastic scattering at Jefferson Lab

NASA Astrophysics Data System (ADS)

Zheng, Xiaochao

2015-04-01

Symmetry permeates nature and is fundamental to all laws of physics. One example is mirror symmetry, also called ``parity symmetry''. It implies that flipping left and right does not change the laws of physics. Laws for electromagnetism, gravity and the subatomic strong force respect parity symmetry, but the subatomic weak force does not. Historically, parity violation in electron scattering played a key role in establishing, and now testing, the Standard Model of particle physics. One particular set of the quantities accessible through measurements of parity-violating electron scattering are the vector-electron axial-vector-quark weak couplings, called C2 q's, measured directly only once in the past 40 years. We report here on a new measurement of the parity-violating asymmetry in electron-quark scattering, that has yielded a specific combination 2C2 u -C2 d five times more precise than the earlier result. (Here u and d stand respectively for the up and the down quarks.) These results are the first evidence, at more than the 95% confidence level, that the C2 q's are non-zero as predicted by the electroweak theory. They lead to constraints on new interactions beyond the Standard Model, particularly on those whose laws change when the quark chirality is flipped between left and right. In today's particle physics research that is focused on colliders such as the LHC, our results provide specific chirality information on electroweak theory that is difficult to obtain at high energies. In addition to deep inelastic scattering, we will report on measurement of the asymmetry in the nucleon resonance region. These data exhibit for the first time that the quark-hadron duality may work for electroweak observables at the (10--15)% level throughout the whole resonance region. At the end I will give a brief outlook on the future PVDIS program using the Jefferson Lab 12 GeV beam, which will not only provide more precise measurement of C2 q, but also for sin2 θW and for studying unique features of the nucleon structure and that of the strong interaction. for the Jefferson Lab PVDIS Collaboration.

Effects of the in-medium nucleon-nucleon cross section on collective flow and nuclear stopping in heavy-ion collisions in the Fermi-energy domain

NASA Astrophysics Data System (ADS)

Li, Pengcheng; Wang, Yongjia; Li, Qingfeng; Guo, Chenchen; Zhang, Hongfei

2018-04-01

With the newly updated version of the ultrarelativistic quantum molecular dynamics (UrQMD) model, a systematic investigation of the effects of in-medium nucleon-nucleon (NN ) elastic cross section on the collective flow and the stopping observables in 197Au+197Au collisions at beam energies from 40 to 150 MeV/nucleon is performed. Simulations with the medium correction factors F =σNN in -medium/σNN free=0.2 ,0.3 ,0.5 and the one obtained with the FU3FP1 parametrization which depends on both the density and the momentum are compared to the FOPI and INDRA experimental data. It is found that, to best fit the experimental data of the slope of the directed flow and the elliptic flow at midrapidity as well as the nuclear stopping, the correction factors of F =0.2 and 0.5 are required for reactions at beam energies of 40 and 150 MeV/nucleon, respectively. Whereas calculations with the FU3FP1 parametrization can simultaneously reproduce these experimental data reasonably well. And, the observed increasing nuclear stopping with increasing beam energy in experimental data can also be reproduced by using the FU3FP1 parametrization, whereas the calculated stopping power in Au + Au collisions with beam energies from 40 to 150 MeV /nucleon almost remains constant when taking F equal to a fixed value.

Bino variations: Effective field theory methods for dark matter direct detection

NASA Astrophysics Data System (ADS)

Berlin, Asher; Robertson, Denis S.; Solon, Mikhail P.; Zurek, Kathryn M.

2016-05-01

We apply effective field theory methods to compute bino-nucleon scattering, in the case where tree-level interactions are suppressed and the leading contribution is at loop order via heavy flavor squarks or sleptons. We find that leading log corrections to fixed-order calculations can increase the bino mass reach of direct detection experiments by a factor of 2 in some models. These effects are particularly large for the bino-sbottom coannihilation region, where bino dark matter as heavy as 5-10 TeV may be detected by near future experiments. For the case of stop- and selectron-loop mediated scattering, an experiment reaching the neutrino background will probe thermal binos as heavy as 500 and 300 GeV, respectively. We present three key examples that illustrate in detail the framework for determining weak scale coefficients, and for mapping onto a low-energy theory at hadronic scales, through a sequence of effective theories and renormalization group evolution. For the case of a squark degenerate with the bino, we extend the framework to include a squark degree of freedom at low energies using heavy particle effective theory, thus accounting for large logarithms through a "heavy-light current." Benchmark predictions for scattering cross sections are evaluated, including complete leading order matching onto quark and gluon operators, and a systematic treatment of perturbative and hadronic uncertainties.

Bino variations: Effective field theory methods for dark matter direct detection

DOE PAGES

Berlin, Asher; Robertson, Denis S.; Solon, Mikhail P.; ...

2016-05-10

We apply effective field theory methods to compute bino-nucleon scattering, in the case where tree-level interactions are suppressed and the leading contribution is at loop order via heavy flavor squarks or sleptons. We find that leading log corrections to fixed-order calculations can increase the bino mass reach of direct detection experiments by a factor of 2 in some models. These effects are particularly large for the bino-sbottom coannihilation region, where bino dark matter as heavy as 5–10 TeV may be detected by near future experiments. For the case of stop- and selectron-loop mediated scattering, an experiment reaching the neutrino backgroundmore » will probe thermal binos as heavy as 500 and 300 GeV, respectively. We present three key examples that illustrate in detail the framework for determining weak scale coefficients, and for mapping onto a low-energy theory at hadronic scales, through a sequence of effective theories and renormalization group evolution. For the case of a squark degenerate with the bino, we extend the framework to include a squark degree of freedom at low energies using heavy particle effective theory, thus accounting for large logarithms through a “heavy-light current.” Finally, benchmark predictions for scattering cross sections are evaluated, including complete leading order matching onto quark and gluon operators, and a systematic treatment of perturbative and hadronic uncertainties.« less

Electron Scattering Measurements applied to Neutrino Interactions on Nuclei

NASA Astrophysics Data System (ADS)

Christy, M. Eric

2013-04-01

The extraction of neutrino mass differences and flavor mixing parameters from oscillation experiments requires models of neutrino-nucleus scattering as input. With the reduction of other systematics, the uncertainties stemming from such models are expected to be one of the larger contributions to the systematic uncertainties for next generation oscillation experiments. The neutrino energy range sensitive to oscillations in long baseline experiments is typically the few GeV range, where the interactions with the nucleus and the subsequent production and propagation of hadrons within the nucleus is in the regime studied by nuclear physics experiments at facilities such as Jefferson Lab. While processes such as resonance production have been well studied in electron scattering, there is currently precious little corresponding data from neutrino scattering. Results from electron scattering experiments, therefore, have an important role to play in both building and constraining models for neutrino scattering. On the other hand, the study of nucleon structure via weak probes is very complementary to the program at Jefferson Lab utilizing electromagnetic probes. Neutrino scattering experiments such at MINERvA are expected to provide new experimental information on axial elastic and resonance transition form factors and on medium modifications via the axial coupling. This talk will focus on the application of electron scattering measurements to neutrino interactions on nuclei, but will also touch on where neutrino scattering measurements can add to our understanding of the nucleus.

Projected WIMP Sensitivity of the LUX-ZEPLIN (LZ) Dark Matter Experiment

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

Akerib, D.S.; et al.

LUX-ZEPLIN (LZ) is a next generation dark matter direct detection experiment that will operate 4850 feet underground at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA. Using a two-phase xenon detector with an active mass of 7 tonnes, LZ will search primarily for low-energy interactions with Weakly Interacting Massive Particles (WIMPs), which are hypothesized to make up the dark matter in our galactic halo. In this paper, the projected WIMP sensitivity of LZ is presented based on the latest background estimates and simulations of the detector. For a 1000 live day run using a 5.6 tonne fiducial mass, LZ is projected to exclude at 90% confidence level spin-independent WIMP-nucleon cross sections abovemore » $$1.6 \\times 10^{-48}$$ cm$$^{2}$$ for a 40 $$\\mathrm{GeV}/c^{2}$$ mass WIMP. Additionally, a $$5\\sigma$$ discovery potential is projected reaching cross sections below the existing and projected exclusion limits of similar experiments that are currently operating. For spin-dependent WIMP-neutron(-proton) scattering, a sensitivity of $$2.7 \\times 10^{-43}$$ cm$$^{2}$$ ($$8.1 \\times 10^{-42}$$ cm$$^{2}$$) for a 40 $$\\mathrm{GeV}/c^{2}$$ mass WIMP is expected. With construction well underway, LZ is on track for underground installation at SURF in 2019 and will start collecting data in 2020.« less

Effective nucleon mass and the nuclear caloric curve

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

Shetty, D. V.; Souliotis, G. A.; Galanopoulos, S.

2009-03-15

Assuming a schematic form of the nucleon effective mass as a function of nuclear excitation energy and mass, we provide a simple explanation for understanding the experimentally observed mass dependence of the nuclear caloric curve. It is observed that the excitation energy at which the caloric curve enters into a plateau region could be sensitive to the nuclear mass evolution of the effective nucleon mass.

A Reappraisal of the Mechanism of Pion Exchange and Its Implications for the Teaching of Particle Physics

ERIC Educational Resources Information Center

Dunne, Peter

2002-01-01

The origins of the pion exchange model of nuclear forces are described and the exchange process is reinterpreted in the light of current views on the quark-gluon structure of nucleons. It is suggested that the reinterpretation might provide a picture of cohesive nuclear forces that is more intellectually satisfying than that produced by the…

Pion momentum distributions in the nucleon in chiral effective theory

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

Burkardt, Matthias R.; Hendricks, K. S.; Ji, Cheung Ryong

2013-03-01

We compute the light-cone momentum distributions of pions in the nucleon in chiral effective theory using both pseudovector and pseudoscalar pion--nucleon couplings. For the pseudovector coupling we identifymore » $$\\delta$$-function contributions associated with end-point singularities arising from the pion-nucleon rainbow diagrams, as well as from pion tadpole diagrams which are not present in the pseudoscalar model. Gauge invariance is demonstrated, to all orders in the pion mass, with the inclusion of Weinberg-Tomozawa couplings involving operator insertions at the $$\\pi NN$$ vertex. The results pave the way for phenomenological applications of pion cloud models that are manifestly consistent with the chiral symmetry properties of QCD.« less

Distributions of neutron yields and doses around a water phantom bombarded with 290-MeV/nucleon and 430-MeV/nucleon carbon ions

NASA Astrophysics Data System (ADS)

Satoh, D.; Kajimoto, T.; Shigyo, N.; Itashiki, Y.; Imabayashi, Y.; Koba, Y.; Matsufuji, N.; Sanami, T.; Nakao, N.; Uozumi, Y.

2016-11-01

Double-differential neutron yields from a water phantom bombarded with 290-MeV/nucleon and 430-MeV/nucleon carbon ions were measured at emission angles of 15°, 30°, 45°, 60°, 75°, and 90°, and angular distributions of neutron yields and doses around the phantom were obtained. The experimental data were compared with results of the Monte-Carlo simulation code PHITS. The PHITS results showed good agreement with the measured data. On the basis of the PHITS simulation, we estimated the angular distributions of neutron yields and doses from 0° to 180° including thermal neutrons.

Flavor asymmetry of the nucleon sea and the five-quark components of the nucleons.

PubMed

Chang, Wen-Chen; Peng, Jen-Chieh

2011-06-24

The existence of the five-quark Fock states for the intrinsic charm quark in the nucleons was suggested some time ago, but conclusive evidence is still lacking. We generalize the previous theoretical approach to the light-quark sector and study possible experimental signatures for such five-quark states. In particular, we compare the d-ū and ū + d-s-s data with the calculations based on the five-quark Fock states. The qualitative agreement between the data and the calculations is interpreted as evidence for the existence of the intrinsic light-quark sea in the nucleons. The probabilities for the |uuduū and |uuddd Fock states are also extracted.

Pion Total Cross Section in Nucleon - Nucleon Collisions

NASA Technical Reports Server (NTRS)

Norbury, John W.

2009-01-01

Total cross section parameterizations for neutral and charged pion production in nucleon - nucleon collisions are compared to experimental data over the projectile momentum range from threshold to 300 GeV. Both proton - proton and proton - neutron reactions are considered. Overall excellent agreement between parameterizations and experiment is found, except for notable disagreements near threshold. In addition, the hypothesis that the neutral pion production cross section can be obtained from the average charged pion cross section is checked. The theoretical formulas presented in the paper obey this hypothesis for projectile momenta below 500 GeV. The results presented provide a test of engineering tools used to calculate the pion component of space radiation.

Spin symmetry in the Dirac sea derived from the bare nucleon-nucleon interaction

NASA Astrophysics Data System (ADS)

Shen, Shihang; Liang, Haozhao; Meng, Jie; Ring, Peter; Zhang, Shuangquan

2018-06-01

The spin symmetry in the Dirac sea has been investigated with relativistic Brueckner-Hartree-Fock theory using the bare nucleon-nucleon interaction. Taking the nucleus 16O as an example and comparing the theoretical results with the data, the definition of the single-particle potential in the Dirac sea is studied in detail. It is found that if the single-particle states in the Dirac sea are treated as occupied states, the ground state properties are in better agreement with experimental data. Moreover, in this case, the spin symmetry in the Dirac sea is better conserved and it is more consistent with the findings using phenomenological relativistic density functionals.

Equation of state for nucleonic matter and its quark mass dependence from the nuclear force in lattice QCD.

PubMed

Inoue, Takashi; Aoki, Sinya; Doi, Takumi; Hatsuda, Tetsuo; Ikeda, Yoichi; Ishii, Noriyoshi; Murano, Keiko; Nemura, Hidekatsu; Sasaki, Kenji

2013-09-13

Quark mass dependence of the equation of state (EOS) for nucleonic matter is investigated, on the basis of the Brueckner-Hartree-Fock method with the nucleon-nucleon interaction extracted from lattice QCD simulations. We observe saturation of nuclear matter at the lightest available quark mass corresponding to the pseudoscalar meson mass ≃469  MeV. Mass-radius relation of the neutron stars is also studied with the EOS for neutron-star matter from the same nuclear force in lattice QCD. We observe that the EOS becomes stiffer and thus the maximum mass of neutron star increases as the quark mass decreases toward the physical point.

Chiral symmetry and the nucleon-nucleon interaction

DOE PAGES

Machleidt, Ruprecht

2016-04-20

We review how nuclear forces emerge from low-energy quantum chromodynamics (QCD) via chiral effective field theory (EFT). During the past two decades, this approach has evolved into a powerful tool to derive nuclear two- and many-body forces in a systematic and model-independent way. We then focus on the nucleon-nucleon (NN) interaction and show in detail how, governed by chiral symmetry, the long- and intermediate-range of the NN potential builds up order by order. We proceed up to sixth order in small momenta, where convergence is achieved. Lastly, the final result allows for a full assessment of the validity of themore » chiral EFT approach to the NN interaction.« less

Experimental study of relativistic effects in the dp breakup reaction using the WASA detector

NASA Astrophysics Data System (ADS)

Kłos, B.; Ciepał, I.; Jamróz, B.; Khatri, G.; Kistryn, S.; Kozela, A.; Magiera, A.; Parol, W.; Skwira-Chalot, I.; Stephan, E.

2014-03-01

An experiment to investigate the 1H(overrightarrow d , pp)n breakup reaction at 340 MeV, 360 MeV and 400 MeV deuteron beam energy has been performed at the Cooler Synchrotron COSY-Jülich with the WASA detector. The main goal was to study of various aspects of few-nucleon dynamics in the medium energy region, with a particular emphasis on relativistic effects and their interplay with three nucelon forces. The almost 4π geometry of the WASA detector gives an unique possibility to study the different aspects of nucleon-nucleon dynamics in the three nucleon system. The preliminary analysis of the collected data is presented.

Hard Photodisintegration of 3He

NASA Astrophysics Data System (ADS)

Granados, Carlos

2011-02-01

Large angle photodisintegration of two nucleons from the 3He nucleus is studied within the framework of the hard rescattering model (HRM). In the HRM the incoming photon is absorbed by one nucleon's valence quark that then undergoes a hard rescattering reaction with a valence quark from the second nucleon producing two nucleons emerging at large transverse momentum . Parameter free cross sections for pp and pn break up channels are calculated through the input of experimental cross sections on pp and pn elastic scattering. The calculated cross section for pp breakup and its predicted energy dependency are in good agreement with recent experimental data. Predictions on spectator momentum distributions and helicity transfer are also presented.

Three-cluster dynamics within an ab initio framework

DOE PAGES

Quaglioni, Sofia; Romero-Redondo, Carolina; Navratil, Petr

2013-09-26

In this study, we introduce a fully antisymmetrized treatment of three-cluster dynamics within the ab initio framework of the no-core shell model/resonating-group method. Energy-independent nonlocal interactions among the three nuclear fragments are obtained from realistic nucleon-nucleon interactions and consistent ab initio many-body wave functions of the clusters. The three-cluster Schrödinger equation is solved with bound-state boundary conditions by means of the hyperspherical-harmonic method on a Lagrange mesh. We discuss the formalism in detail and give algebraic expressions for systems of two single nucleons plus a nucleus. Using a soft similarity-renormalization-group evolved chiral nucleon-nucleon potential, we apply the method to amore » 4He+n+n description of 6He and compare the results to experiment and to a six-body diagonalization of the Hamiltonian performed within the harmonic-oscillator expansions of the no-core shell model. Differences between the two calculations provide a measure of core ( 4He) polarization effects.« less

Lattice calculation of electric dipole moments and form factors of the nucleon

NASA Astrophysics Data System (ADS)

Abramczyk, M.; Aoki, S.; Blum, T.; Izubuchi, T.; Ohki, H.; Syritsyn, S.

2017-07-01

We analyze commonly used expressions for computing the nucleon electric dipole form factors (EDFF) F3 and moments (EDM) on a lattice and find that they lead to spurious contributions from the Pauli form factor F2 due to inadequate definition of these form factors when parity mixing of lattice nucleon fields is involved. Using chirally symmetric domain wall fermions, we calculate the proton and the neutron EDFF induced by the C P -violating quark chromo-EDM interaction using the corrected expression. In addition, we calculate the electric dipole moment of the neutron using a background electric field that respects time translation invariance and boundary conditions, and we find that it decidedly agrees with the new formula but not the old formula for F3. Finally, we analyze some selected lattice results for the nucleon EDM and observe that after the correction is applied, they either agree with zero or are substantially reduced in magnitude, thus reconciling their difference from phenomenological estimates of the nucleon EDM.

Spin Physics Experiments at NICA-SPD

NASA Astrophysics Data System (ADS)

Kouznetsov, O.; Savin, I.

2017-01-01

Nuclotron based Ion Collider fAcility (NICA) is a flagship project of the Joint Institute for Nuclear Research which is expected to be operational by 2021. Main tasks of ;NICA Facility; are study of hot and dense baryonic matter, investigation the polarisation phenomena and the nucleon spin structure. The material presented here based on the Letter of Intent (LoI) dedicated to nucleon spin structure studies at NICA. Measurements of asymmetries in the lepton pair (Drell-Yan) production in collisions of non-polarised, longitudinally and transversely polarised proton and deuteron beams to be performed using the specialized Spin Physics Detector (SPD). These measurements can provide an access to all leading twist collinear and Transverse Momentum Dependent Parton Distribution Functions (TMD PDFs) in nucleons. The measurements of asymmetries in production of J/ψ and direct photons, which supply complimentary information on the nucleon structure, will be performed simultaneously. The set of these measurements permits to tests the quark-parton model of nucleons at the QCD twist-2 level with minimal systematic errors.

Lattice QCD evidence that the Λ(1405) resonance is an antikaon-nucleon molecule.

PubMed

Hall, Jonathan M M; Kamleh, Waseem; Leinweber, Derek B; Menadue, Benjamin J; Owen, Benjamin J; Thomas, Anthony W; Young, Ross D

2015-04-03

For almost 50 years the structure of the Λ(1405) resonance has been a mystery. Even though it contains a heavy strange quark and has odd parity, its mass is lower than any other excited spin-1/2 baryon. Dalitz and co-workers speculated that it might be a molecular state of an antikaon bound to a nucleon. However, a standard quark-model structure is also admissible. Although the intervening years have seen considerable effort, there has been no convincing resolution. Here we present a new lattice QCD simulation showing that the strange magnetic form factor of the Λ(1405) vanishes, signaling the formation of an antikaon-nucleon molecule. Together with a Hamiltonian effective-field-theory model analysis of the lattice QCD energy levels, this strongly suggests that the structure is dominated by a bound antikaon-nucleon component. This result clarifies that not all states occurring in nature can be described within a simple quark model framework and points to the existence of exotic molecular meson-nucleon bound states.

Search for dark matter WIMPs using upward through-going muons in Super-Kamiokande

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

Desai, S.; Earl, M.; Kearns, E.

2004-10-15

We present the results of indirect searches for Weakly Interacting Massive Particles (WIMPs), with 1679.6 live days of data from the Super-Kamiokande detector using neutrino-induced upward through-going muons. The search is performed by looking for an excess of high energy muon neutrinos from WIMP annihilations in the Sun, the core of the Earth, and the Galactic Center, as compared to the number expected from the atmospheric neutrino background. No statistically significant excess was seen. We calculate the flux limits in various angular cones around each of the above celestial objects. We obtain conservative model-independent upper limits on the WIMP-nucleon crossmore » section as a function of WIMP mass, and compare these results with the corresponding results from direct dark matter detection experiments.« less

Precison Muon Physics

NASA Astrophysics Data System (ADS)

Hertzog, David

2013-04-01

The worldwide, vibrant experimental program involving precision measurements with muons will be presented. Recent achievements in this field have greatly improved our knowledge of fundamental parameters: Fermi constant (lifetime), weak-nucleon pseudoscalar coupling (μp capture), Michel decay parameters, and the proton charged radius (Lamb shift). The charged-lepton-violating decay μ->eγ sets new physics limits. Updated Standard Model theory evaluations of the muon anomalous magnetic moment has increased the significance beyond 3 σ for the deviation with respect to experiment. Next-generation experiments are mounting, with ambitious sensitivity goals for the muon-to-electron search approaching 10-17 sensitivity and for a 0.14 ppm determination of g-2. The broad physics reach of these efforts involves atomic, nuclear and particle physics communities. I will select from recent work and outline the most important efforts that are in preparation.

Nuclear axial currents in chiral effective field theory

DOE PAGES

Baroni, Alessandro; Girlanda, Luca; Pastore, Saori; ...

2016-01-11

Two-nucleon axial charge and current operators are derived in chiral effective field theory up to one loop. The derivation is based on time-ordered perturbation theory and accounts for cancellations between the contributions of irreducible diagrams and the contributions owing to nonstatic corrections from energy denominators of reducible diagrams. Ultraviolet divergencies associated with the loop corrections are isolated in dimensional regularization. The resulting axial current is finite and conserved in the chiral limit, while the axial charge requires renormalization. As a result, a complete set of contact terms for the axial charge up to the relevant order in the power countingmore » is constructed.« less

Search for nucleon decays with EXO-200

NASA Astrophysics Data System (ADS)

Albert, J. B.; Anton, G.; Badhrees, I.; Barbeau, P. S.; Bayerlein, R.; Beck, D.; Belov, V.; Breidenbach, M.; Brunner, T.; Cao, G. F.; Cen, W. R.; Chambers, C.; Cleveland, B.; Coon, M.; Craycraft, A.; Cree, W.; Daniels, T.; Danilov, M.; Daugherty, S. J.; Daughhetee, J.; Davis, J.; Delaquis, S.; Der Mesrobian-Kabakian, A.; DeVoe, R.; Didberidze, T.; Dilling, J.; Dolgolenko, A.; Dolinski, M. J.; Fairbank, W.; Farine, J.; Feyzbakhsh, S.; Fierlinger, P.; Fudenberg, D.; Gornea, R.; Graham, K.; Gratta, G.; Hall, C.; Hansen, E. V.; Hoessl, J.; Homiller, S.; Hufschmidt, P.; Hughes, M.; Jamil, A.; Jewell, M. J.; Johnson, A.; Johnston, S.; Karelin, A.; Kaufman, L. J.; Koffas, T.; Kravitz, S.; Krücken, R.; Kuchenkov, A.; Kumar, K. S.; Lan, Y.; Leonard, D. S.; Li, G. S.; Li, S.; Licciardi, C.; Lin, Y. H.; MacLellan, R.; Michel, T.; Mong, B.; Moore, D.; Murray, K.; Nelson, R.; Njoya, O.; Odian, A.; Ostrovskiy, I.; Piepke, A.; Pocar, A.; Retière, F.; Robinson, A. L.; Rowson, P. C.; Schmidt, S.; Schubert, A.; Sinclair, D.; Soma, A. K.; Stekhanov, V.; Tarka, M.; Tolba, T.; Tsang, R.; Vogel, P.; Vuilleumier, J.-L.; Wagenpfeil, M.; Waite, A.; Walton, T.; Weber, M.; Wen, L. J.; Wichoski, U.; Wrede, G.; Yang, L.; Yen, Y.-R.; Zeldovich, O. Ya.; Zettlemoyer, J.; Ziegler, T.; EXO-200 Collaboration

2018-04-01

A search for instability of nucleons bound in 136Xe nuclei is reported with 223 kg.yr exposure of 136Xe in the EXO-200 experiment. Lifetime limits of 3.3 ×1023 and 1.9 ×1023 yr are established for nucleon decay to 133Sb and 133Te, respectively. These are the most stringent to date, exceeding the prior decay limits by a factor of 9 and 7, respectively.

Polarized lepton-nucleon scattering

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

Hughes, E.

1994-12-01

The author provides a summary of the proposed and published statistical (systematic) uncertainties from the world experiments on nucleon spin structure function integrals. By the time these programs are complete, there will be a vast resource of data on nucleon spin structure functions. Each program has quite different experimental approaches regarding the beams, targets, and spectrometers thus ensuring systematically independent tests of the spin structure function measurements. Since the field of spin structure function measurements began, there has been a result appearing approximately every five years. With advances in polarized target technology and high polarization in virtually all of themore » lepton beams, results are now coming out each year; this is a true signature of the growth in the field. Hopefully, the experiments will provide a consistent picture of nucleon spin structure at their completion. In summary, there are still many open questions regarding the internal spin structure of the nucleon. Tests of QCD via the investigation of the Bjorken sum rule is a prime motivator for the field, and will continue with the next round of precision experiments. The question of the origin of spin is still a fundamental problem. Researchers hope is that high-energy probes using spin will shed light on this intriguing mystery, in addition to characterizing the spin structure of the nucleon.« less

Disconnected-Sea Quarks Contribution to Nucleon Electromagnetic Form Factors

NASA Astrophysics Data System (ADS)

Sufian, Raza Sabbir

We present comprehensive analysis of the light and strange disconnected-sea quarks contribution to the nucleon electric and magnetic form factors. The lattice QCD estimates of strange quark magnetic moment GsM (0) = -0.064(14)(09) microN and the mean squared charge radius E = -0.0043(16)(14) fm2 are more precise than any existing experimental measurements and other lattice calculations. The lattice QCD calculation includes ensembles across several lattice volumes and lattice spacings with one of the ensembles at the physical pion mass. We have performed a simultaneous chiral, infinite volume, and continuum extrapolation in a global fit to calculate results in the continuum limit. We find that the combined light-sea and strange quarks contribution to the nucleon magnetic moment is -0.022(11)(09) microN and to the nucleon mean square charge radius is -0.019(05)(05) fm 2. The most important outcome of this lattice QCD calculation is that while the combined light-sea and strange quarks contribution to the nucleon magnetic moment is small at about 1%, a negative 2.5(9)% contribution to the proton charge radius and a relatively larger positive 16.3(6.1)% contribution to the neutron charge radius come from the sea quarks in the nucleon. For the first time, by performing global fits, we also give predictions of the light-sea and strange quarks contributions to the nucleon electric and magnetic form factors at the physical point and in the continuum and infinite volume limits in the momentum transfer range of 0 ≤ Q2 ≤ 0.5 GeV2.

Nucleon-deuteron scattering with the JISP16 potential

NASA Astrophysics Data System (ADS)

Skibiński, R.; Golak, J.; Topolnicki, K.; Witała, H.; Volkotrub, Yu.; Kamada, H.; Shirokov, A. M.; Okamoto, R.; Suzuki, K.; Vary, J. P.

2018-01-01

The nucleon-nucleon J -matrix inverse scattering potential JISP16 is applied to elastic nucleon-deuteron scattering and the deuteron breakup process at the laboratory nucleon energies up to 135 MeV. The formalism of the Faddeev equations is used to obtain three-nucleon scattering states. We compare predictions based on the JISP16 force with data and with results based on various two-body interactions, including the CD Bonn, the Argonne AV18, the chiral force with the semilocal regularization at the fifth order of the chiral expansion and with low-momentum interactions obtained from the CD Bonn force as well as with the predictions from the combination of the AV18 NN interaction and the Urbana IX 3 N force. JISP16 provides a satisfactory description of some observables at low energies but strong deviations from data as well as from standard and chiral potential predictions with increasing energy. However, there are also polarization observables at low energies for which the JISP16 predictions differ from those based on the other forces by a factor of two. The reason for such a behavior can be traced back to the P -wave components of the JISP16 force. At higher energies the deviations can be enhanced by an interference with higher partial waves and by the properties of the JISP16 deuteron wave function. In addition, we compare the energy and angular dependence of predictions based on the JISP16 force with the results of the low-momentum interactions obtained with different values of the momentum cutoff parameter. We found that such low-momentum forces can be employed to interpret the nucleon-deuteron elastic scattering data only below some specific energy which depends on the cutoff parameter. Since JISP16 is defined in a finite oscillator basis, it has properties similar to low momentum interactions and its application to the description of nucleon-deuteron scattering data is limited to a low momentum transfer region.

Sea quarks contribution to the nucleon magnetic moment and charge radius at the physical point

NASA Astrophysics Data System (ADS)

Sufian, Raza Sabbir; Yang, Yi-Bo; Liang, Jian; Draper, Terrence; Liu, Keh-Fei; χ QCD Collaboration

2017-12-01

We report a comprehensive analysis of the light and strange disconnected-sea quarks contribution to the nucleon magnetic moment, charge radius, and the electric and magnetic form factors. The lattice QCD calculation includes ensembles across several lattice volumes and lattice spacings with one of the ensembles at the physical pion mass. We adopt a model-independent extrapolation of the nucleon magnetic moment and the charge radius. We have performed a simultaneous chiral, infinite volume, and continuum extrapolation in a global fit to calculate results in the continuum limit. We find that the combined light and strange disconnected-sea quarks contribution to the nucleon magnetic moment is μM(DI )=-0.022 (11 )(09 ) μN and to the nucleon mean square charge radius is ⟨r2⟩E(DI ) =-0.019 (05 )(05 ) fm2 which is about 1 /3 of the difference between the ⟨rp2⟩E of electron-proton scattering and that of a muonic atom and so cannot be ignored in obtaining the proton charge radius in the lattice QCD calculation. The most important outcome of this lattice QCD calculation is that while the combined light-sea and strange quarks contribution to the nucleon magnetic moment is small at about 1%, a negative 2.5(9)% contribution to the proton mean square charge radius and a relatively larger positive 16.3(6.1)% contribution to the neutron mean square charge radius come from the sea quarks in the nucleon. For the first time, by performing global fits, we also give predictions of the light and strange disconnected-sea quarks contributions to the nucleon electric and magnetic form factors at the physical point and in the continuum and infinite volume limits in the momentum transfer range of 0 ≤Q2≤0.5 GeV2 .

Analysis of weak interactions and Eotvos experiments

NASA Technical Reports Server (NTRS)

Hsu, J. P.

1978-01-01

The intermediate-vector-boson model is preferred over the current-current model as a basis for calculating effects due to weak self-energy. Attention is given to a possible violation of the equivalence principle by weak-interaction effects, and it is noted that effects due to weak self-energy are at least an order of magnitude greater than those due to the weak binding energy for typical nuclei. It is assumed that the weak and electromagnetic energies are independent.

Nucleon distribution amplitudes from lattice QCD.

PubMed

Göckeler, Meinulf; Horsley, Roger; Kaltenbrunner, Thomas; Nakamura, Yoshifumi; Pleiter, Dirk; Rakow, Paul E L; Schäfer, Andreas; Schierholz, Gerrit; Stüben, Hinnerk; Warkentin, Nikolaus; Zanotti, James M

2008-09-12

We calculate low moments of the leading-twist and next-to-leading-twist nucleon distribution amplitudes on the lattice using two flavors of clover fermions. The results are presented in the MS[over ] scheme at a scale of 2 GeV and can be immediately applied in phenomenological studies. We find that the deviation of the leading-twist nucleon distribution amplitude from its asymptotic form is less pronounced than sometimes claimed in the literature.

Invited Parallel Talk: Lattice results on nucleon/roper properties

NASA Astrophysics Data System (ADS)

Lin, Huey-Wen

2009-12-01

In this proceeding, I review the attempts to calculate the Nucleon resonance (including Roper as first radially excited state of nucleon and other excited states) using lattice quantum chromodynamics (QCD). The latest preliminary results from Hadron Spectrum Collaboration (HSC) with mπ thickapprox 380 MeV are reported. The Sachs electric form factor of the proton and neutron and their transition with the Roper at large Q2 are also updated in this work.

Complete next-to-leading-order calculation for pion production in nucleon-nucleon collisions at threshold

NASA Astrophysics Data System (ADS)

Hanhart, C.; Kaiser, N.

2002-11-01

Based on a counting scheme that explicitly takes into account the large momentum (Mmπ) characteristic for pion production in nucleon-nucleon collisions we calculate all diagrams for the reaction NN-->NNπ at threshold up to next-to-leading-order. At this order there are no free parameters and the size of the next-to-leading- order contributions is in line with the expectation from power counting. The sum of loop corrections at that order vanishes for the process pp-->ppπ0 at threshold. The total contribution at next-to-leading-order from loop diagrams that include the delta degree of freedom vanishes at threshold in both reaction channels pp-->ppπ0,pnπ+.

Study of prompt D 0 meson production in pPb collisions at √{s_{NN}}=5 TeV

NASA Astrophysics Data System (ADS)

Aaij, R.; Adeva, B.; Adinolfi, M.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Alfonso Albero, A.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Andreassi, G.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Archilli, F.; d'Argent, P.; Arnau Romeu, J.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Babuschkin, I.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baker, S.; Balagura, V.; Baldini, W.; Baranov, A.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Baryshnikov, F.; Baszczyk, M.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Beiter, A.; Bel, L. J.; Beliy, N.; Bellee, V.; Belloli, N.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Beranek, S.; Berezhnoy, A.; Bernet, R.; Berninghoff, D.; Bertholet, E.; Bertolin, A.; Betancourt, C.; Betti, F.; Bettler, M.-O.; van Beuzekom, M.; Bezshyiko, Ia.; Bifani, S.; Billoir, P.; Birnkraut, A.; Bitadze, A.; Bizzeti, A.; Bjoern, M. B.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Boettcher, T.; Bondar, A.; Bondar, N.; Bonivento, W.; Bordyuzhin, I.; Borgheresi, A.; Borghi, S.; Borisyak, M.; Borsato, M.; Borysova, M.; Bossu, F.; Boubdir, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Braun, S.; Britton, T.; Brodzicka, J.; Brundu, D.; Buchanan, E.; Burr, C.; Bursche, A.; Buytaert, J.; Byczynski, W.; Cadeddu, S.; Cai, H.; Calabrese, R.; Calladine, R.; Calvi, M.; Calvo Gomez, M.; Camboni, A.; Campana, P.; Campora Perez, D. H.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; Cavallero, G.; Cenci, R.; Chamont, D.; Charles, M.; Charpentier, Ph.; Chatzikonstantinidis, G.; Chefdeville, M.; Chen, S.; Cheung, S. F.; Chitic, S.-G.; Chobanova, V.; Chrzaszcz, M.; Chubykin, A.; Vidal, X. Cid; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collins, P.; Colombo, T.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombs, G.; Coquereau, S.; Corti, G.; Corvo, M.; Costa Sobral, C. M.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Cruz Torres, M.; Currie, R.; D'Ambrosio, C.; Da Cunha Marinho, F.; Dall'Occo, E.; Dalseno, J.; Davis, A.; De Aguiar Francisco, O.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Serio, M.; De Simone, P.; Dean, C. T.; Decamp, D.; Del Buono, L.; Dembinski, H.-P.; Demmer, M.; Dendek, A.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Nezza, P.; Dijkstra, H.; Dordei, F.; Dorigo, M.; Dosil Suárez, A.; Douglas, L.; Dovbnya, A.; Dreimanis, K.; Dufour, L.; Dujany, G.; Dungs, K.; Durante, P.; Dzhelyadin, R.; Dziewiecki, M.; Dziurda, A.; Dzyuba, A.; Déléage, N.; Easo, S.; Ebert, M.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Farley, N.; Farry, S.; Fay, R.; Fazzini, D.; Federici, L.; Ferguson, D.; Fernandez, G.; Fernandez Declara, P.; Fernandez Prieto, A.; Ferrari, F.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fini, R. A.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fleuret, F.; Fohl, K.; Fontana, M.; Fontanelli, F.; Forshaw, D. C.; Forty, R.; Franco Lima, V.; Frank, M.; Frei, C.; Fu, J.; Funk, W.; Furfaro, E.; Färber, C.; Gabriel, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garcia Martin, L. M.; García Pardiñas, J.; Garra Tico, J.; Garrido, L.; Garsed, P. J.; Gascon, D.; Gaspar, C.; Gavardi, L.; Gazzoni, G.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianì, S.; Gibson, V.; Girard, O. G.; Giubega, L.; Gizdov, K.; Gligorov, V. V.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gorelov, I. V.; Gotti, C.; Govorkova, E.; Grabowski, J. P.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greim, R.; Griffith, P.; Grillo, L.; Gruber, L.; Gruberg Cazon, B. R.; Grünberg, O.; Gushchin, E.; Guz, Yu.; Gys, T.; Göbel, C.; Hadavizadeh, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hamilton, B.; Han, X.; Hancock, T.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; Hasse, C.; Hatch, M.; He, J.; Hecker, M.; Heinicke, K.; Heister, A.; Hennessy, K.; Henrard, P.; Henry, L.; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hombach, C.; Hopchev, P. H.; Huard, Z.-C.; Hulsbergen, W.; Humair, T.; Hushchyn, M.; Hutchcroft, D.; Ibis, P.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jalocha, J.; Jans, E.; Jawahery, A.; Jiang, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Karacson, M.; Kariuki, J. M.; Karodia, S.; Kecke, M.; Kelsey, M.; Kenzie, M.; Ketel, T.; Khairullin, E.; Khanji, B.; Khurewathanakul, C.; Kirn, T.; Klaver, S.; Klimaszewski, K.; Klimkovich, T.; Koliiev, S.; Kolpin, M.; Komarov, I.; Kopecna, R.; Koppenburg, P.; Kosmyntseva, A.; Kotriakhova, S.; Kozeiha, M.; Kravchuk, L.; Kreps, M.; Krokovny, P.; Kruse, F.; Krzemien, W.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kuonen, A. K.; Kurek, K.; Kvaratskheliya, T.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lanfranchi, G.; Langenbruch, C.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Leflat, A.; Lefrançois, J.; Lefèvre, R.; Lemaitre, F.; Lemos Cid, E.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, T.; Li, Y.; Li, Z.; Likhomanenko, T.; Lindner, R.; Lionetto, F.; Liu, X.; Loh, D.; Loi, A.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Lucio Martinez, M.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Lusiani, A.; Lyu, X.; Machefert, F.; Maciuc, F.; Macko, V.; Mackowiak, P.; Maddock, B.; Maddrell-Mander, S.; Maev, O.; Maguire, K.; Maisuzenko, D.; Majewski, M. W.; Malde, S.; Malinin, A.; Maltsev, T.; Manca, G.; Mancinelli, G.; Manning, P.; Marangotto, D.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marinangeli, M.; Marino, P.; Marks, J.; Martellotti, G.; Martin, M.; Martinelli, M.; Martinez Santos, D.; Martinez Vidal, F.; Martins Tostes, D.; Massacrier, L. M.; Massafferri, A.; Matev, R.; Mathad, A.; Mathe, Z.; Matteuzzi, C.; Mauri, A.; Maurice, E.; Maurin, B.; Mazurov, A.; McCann, M.; McNab, A.; McNulty, R.; Mead, J. V.; Meadows, B.; Meaux, C.; Meier, F.; Meinert, N.; Melnychuk, D.; Merk, M.; Merli, A.; Michielin, E.; Milanes, D. A.; Millard, E.; Minard, M.-N.; Minzoni, L.; Mitzel, D. S.; Mogini, A.; Molina Rodriguez, J.; Mombacher, T.; Monroy, I. A.; Monteil, S.; Morandin, M.; Morello, M. J.; Morgunova, O.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Mulder, M.; Mussini, M.; Müller, D.; Müller, J.; Müller, K.; Müller, V.; Naik, P.; Nakada, T.; Nandakumar, R.; Nandi, A.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, T. D.; Nguyen-Mau, C.; Nieswand, S.; Niet, R.; Nikitin, N.; Nikodem, T.; Nogay, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Oldeman, R.; Onderwater, C. J. G.; Ossowska, A.; Otalora Goicochea, J. M.; Owen, P.; Oyanguren, A.; Pais, P. R.; Palano, A.; Palutan, M.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Pappenheimer, C.; Parker, W.; Parkes, C.; Passaleva, G.; Pastore, A.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Pepe Altarelli, M.; Perazzini, S.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Petrov, A.; Petruzzo, M.; Picatoste Olloqui, E.; Pietrzyk, B.; Pikies, M.; Pinci, D.; Pistone, A.; Piucci, A.; Placinta, V.; Playfer, S.; Plo Casasus, M.; Poikela, T.; Polci, F.; Poli Lener, M.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Pomery, G. J.; Ponce, S.; Popov, A.; Popov, D.; Poslavskii, S.; Potterat, C.; Price, E.; Prisciandaro, J.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Pullen, H.; Punzi, G.; Qian, W.; Quagliani, R.; Quintana, B.; Rachwal, B.; Rademacker, J. H.; Rama, M.; Ramos Pernas, M.; Rangel, M. S.; Raniuk, I.; Ratnikov, F.; Raven, G.; Ravonel Salzgeber, M.; Reboud, M.; Redi, F.; Reichert, S.; dos Reis, A. C.; Remon Alepuz, C.; Renaudin, V.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Rodriguez Lopez, J. A.; Rodriguez Perez, P.; Rogozhnikov, A.; Roiser, S.; Rollings, A.; Romanovskiy, V.; Romero Vidal, A.; Ronayne, J. W.; Rotondo, M.; Rudolph, M. S.; Ruf, T.; Ruiz Valls, P.; Ruiz Vidal, J.; Saborido Silva, J. J.; Sadykhov, E.; Sagidova, N.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Gonzalo, D.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santimaria, M.; Santovetti, E.; Sarpis, G.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schael, S.; Schellenberg, M.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schreiner, H. F.; Schubert, K.; Schubiger, M.; Schune, M.-H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sergi, A.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Siddi, B. G.; Silva Coutinho, R.; Silva de Oliveira, L.; Simi, G.; Simone, S.; Sirendi, M.; Skidmore, N.; Skwarnicki, T.; Smith, E.; Smith, I. T.; Smith, J.; Smith, M.; Soares Lavra, l.; Sokoloff, M. D.; Soler, F. J. P.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Stefko, P.; Stefkova, S.; Steinkamp, O.; Stemmle, S.; Stenyakin, O.; Stevens, H.; Stone, S.; Storaci, B.; Stracka, S.; Stramaglia, M. E.; Straticiuc, M.; Straumann, U.; Sun, L.; Sutcliffe, W.; Swientek, K.; Syropoulos, V.; Szczekowski, M.; Szumlak, T.; Szymanski, M.; T'Jampens, S.; Tayduganov, A.; Tekampe, T.; Tellarini, G.; Teubert, F.; Thomas, E.; van Tilburg, J.; Tilley, M. J.; Tisserand, V.; Tobin, M.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Toriello, F.; Tourinho Jadallah Aoude, R.; Tournefier, E.; Traill, M.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tully, A.; Tuning, N.; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagner, A.; Vagnoni, V.; Valassi, A.; Valat, S.; Valenti, G.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vecchi, S.; van Veghel, M.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Venkateswaran, A.; Verlage, T. A.; Vernet, M.; Vesterinen, M.; Viana Barbosa, J. V.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Viemann, H.; Vilasis-Cardona, X.; Vitti, M.; Volkov, V.; Vollhardt, A.; Voneki, B.; Vorobyev, A.; Vorobyev, V.; Voß, C.; de Vries, J. A.; Vázquez Sierra, C.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wang, J.; Ward, D. R.; Wark, H. M.; Watson, N. K.; Websdale, D.; Weiden, A.; Whitehead, M.; Wicht, J.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M. P.; Williams, M.; Williams, T.; Wilson, F. F.; Wimberley, J.; Winn, M. A.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wraight, K.; Wyllie, K.; Xie, Y.; Xu, Z.; Yang, Z.; Yang, Z.; Yao, Y.; Yin, H.; Yu, J.; Yuan, X.; Yushchenko, O.; Zarebski, K. A.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhelezov, A.; Zheng, Y.; Zhu, X.; Zhukov, V.; Zonneveld, J. B.; Zucchelli, S.

2017-10-01

Production of prompt D 0 mesons is studied in proton-lead and lead-proton collisions recorded at the LHCb detector at the LHC. The data sample corresponds to an integrated luminosity of 1 .58±0 .02 nb-1 recorded at a nucleon-nucleon centre-of-mass energy of √{s_{NN}}=5 TeV. Measurements of the differential cross-section, the forward-backward production ratio and the nuclear modification factor are reported using D 0 candidates with transverse momenta less than 10 GeV/c and rapidities in the ranges 1 .5 < y ∗ < 4 .0 and -5 .0 < y ∗ < -2 .5 in the nucleon-nucleon centre-of-mass system. [Figure not available: see fulltext.

Two-Nucleon Systems in a Finite Volume

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

Briceno, Raul

2014-11-01

I present the formalism and methodology for determining the nucleon-nucleon scattering parameters from the finite volume spectra obtained from lattice quantum chromodynamics calculations. Using the recently derived energy quantization conditions and the experimentally determined scattering parameters, the bound state spectra for finite volume systems with overlap with the 3S1-3D3 channel are predicted for a range of volumes. It is shown that the extractions of the infinite-volume deuteron binding energy and the low-energy scattering parameters, including the S-D mixing angle, are possible from Lattice QCD calculations of two-nucleon systems with boosts of |P| <= 2pi sqrt{3}/L in volumes with spatial extentsmore » L satisfying fm <~ L <~ 14 fm.« less

Realistic calculations for c coefficients of the isobaric mass multiplet equation in 1 p 0 f shell nuclei

DOE PAGES

Ormand, W. E.; Brown, B. A.; Hjorth-Jensen, M.

2017-08-01

We present calculations for the c coefficients of the isobaric mass multiplet equation for nuclei from A = 42 to A = 54 based on input from three realistic nucleon-nucleon interactions. We demonstrate that there is a clear dependence on the short-range charge-symmetry-breaking (CSB) part of the strong interaction and that there is significant disagreement in the CSB part between the commonly used CD-Bonn, chiral effective field theory at next-to-next-to-next-to-leading-order, and Argonne V18 nucleon-nucleon interactions. In addition, we show that all three interactions give a CSB contribution to the c coefficient that is too large when compared to experiment.

Realistic calculations for c coefficients of the isobaric mass multiplet equation in 1 p 0 f shell nuclei

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

Ormand, W. E.; Brown, B. A.; Hjorth-Jensen, M.

We present calculations for the c coefficients of the isobaric mass multiplet equation for nuclei from A = 42 to A = 54 based on input from three realistic nucleon-nucleon interactions. We demonstrate that there is a clear dependence on the short-range charge-symmetry-breaking (CSB) part of the strong interaction and that there is significant disagreement in the CSB part between the commonly used CD-Bonn, chiral effective field theory at next-to-next-to-next-to-leading-order, and Argonne V18 nucleon-nucleon interactions. In addition, we show that all three interactions give a CSB contribution to the c coefficient that is too large when compared to experiment.

New aspects in nucleon-nucleus collisions and EAS properties around 10(6) GeV

NASA Technical Reports Server (NTRS)

Capdevielle, J. N.; Gawin, J.

1985-01-01

At energies higher than 2 x 10 to the 5 GeV, very little information exists on detailed properties of nucleon-nucleon collision; the rare elements are coming from jets, and, as nondirect improvements from gamma-ray families. The results exhibit some conflicting features, or, at least, very large fluctuations like copious production of gamma-rays in opposition to Centauro-like events, sometimes suggest that phase transition to quark gluon plasma occurs in nucleus-nucleus collisions and even in nucleon-nucleus collision. The multicluster phenomenological model (MPM) extrapolated for extensive air showers EAS simulation up to 5 x 10 to the 6 GeV to put in evidence some significant deviation between experimental data and prediction.

Chiral EFT based nuclear forces: achievements and challenges

NASA Astrophysics Data System (ADS)

Machleidt, R.; Sammarruca, F.

2016-08-01

During the past two decades, chiral effective field theory has become a popular tool to derive nuclear forces from first principles. Two-nucleon interactions have been worked out up to sixth order of chiral perturbation theory and three-nucleon forces up to fifth order. Applications of some of these forces have been conducted in nuclear few- and many-body systems—with a certain degree of success. But in spite of these achievements, we are still faced with great challenges. Among them is the issue of a proper uncertainty quantification of predictions obtained when applying these forces in ab initio calculations of nuclear structure and reactions. A related problem is the order by order convergence of the chiral expansion. We start this review with a pedagogical introduction and then present the current status of the field of chiral nuclear forces. This is followed by a discussion of representative examples for the application of chiral two- and three-body forces in the nuclear many-body system including convergence issues.

Nuclear reactions from lattice QCD

DOE PAGES

Briceño, Raúl A.; Davoudi, Zohreh; Luu, Thomas C.

2015-01-13

In this study, one of the overarching goals of nuclear physics is to rigorously compute properties of hadronic systems directly from the fundamental theory of strong interactions, Quantum Chromodynamics (QCD). In particular, the hope is to perform reliable calculations of nuclear reactions which will impact our understanding of environments that occur during big bang nucleosynthesis, the evolution of stars and supernovae, and within nuclear reactors and high energy/density facilities. Such calculations, being truly ab initio, would include all two-nucleon and three- nucleon (and higher) interactions in a consistent manner. Currently, lattice QCD provides the only reliable option for performing calculationsmore » of some of the low-energy hadronic observables. With the aim of bridging the gap between lattice QCD and nuclear many-body physics, the Institute for Nuclear Theory held a workshop on Nuclear Reactions from Lattice QCD on March 2013. In this review article, we report on the topics discussed in this workshop and the path planned to move forward in the upcoming years.« less

Testing of multigap Resistive Plate Chambers for Electron Ion Collider Detector Development

NASA Astrophysics Data System (ADS)

Hamilton, Hannah; Phenix Collaboration

2015-10-01

Despite decades of research on the subject, some details of the spin structure of the nucleon continues to be unknown. To improve our knowledge of the nucleon spin structure, the construction of a new collider is needed. This is one of the primary goals of the proposed Electron Ion Collider (EIC). Planned EIC spectrometers will require good particle identification. This can be provided by time of flight (TOF) detectors with excellent timing resolutions of 10 ps. A potential TOF detector that could meet this requirement is a glass multigap resistive plate chamber (mRPC). These mRPCs can provide excellent timing resolution at a low cost. The current glass mRPC prototypes have a total of twenty 0.1 mm thick gas gaps. In order to test the feasibility of this design, a cosmic test stand was assembled. This stand used the coincidence of scintillators as a trigger, and contains fast electronics. The construction, the method of testing, and the test results of the mRPCs will be presented.

Nuclear PDF for neutrino and charged lepton data

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

Kovarik, K.

2011-10-06

Neutrino Deep Inelastic Scattering (DIS) on nuclei is an essential process to constrain the strange quark parton distribution functions (PDF) in the proton. The critical component on the way to using the neutrino DIS data in a proton PDF analysis is understanding the nuclear effects in parton distribution functions. We parametrize these effects by nuclear parton distribution functions (NPDF). Here we compare results from two analysis of NPDF both done at next-to-leading order in QCD. The first uses neutral current charged-lepton (l{sup {+-}A}) Deeply Inelastic Scattering (DIS) and Drell-Yan data for several nuclear targets and the second uses neutrino-nucleon DISmore » data. We compare the nuclear corrections factors (F{sub 2}{sup Fe}/F{sub 2}{sup D}) for the charged-lepton data with other results from the literature. In particular, we compare and contrast fits based upon the charged-lepton DIS data with those using neutrino-nucleon DIS data.« less

New collider scheme at LBL

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

Pugh, H.G.

1984-07-01

This paper presents current ideas from Berkeley concerning a possible new facility for studying the phase transition from hadronic matter to quark matter. The physics ideas have evolved over a period of more than five years, the VENUS concept for a 25 GeV/nucleon colliding beam facility having been presented in 1979. The concept for the Minicollider has been, like that of VENUS, the work of Hermann Grunder and Christoph Leemann.

From quarks and gluons to baryon form factors.

PubMed

Eichmann, Gernot

2012-04-01

I briefly summarize recent results for nucleon and [Formula: see text] electromagnetic, axial and transition form factors in the Dyson-Schwinger approach. The calculation of the current diagrams from the quark-gluon level enables a transparent discussion of common features such as: the implications of dynamical chiral symmetry breaking and quark orbital angular momentum, the timelike structure of the form factors, and their interpretation in terms of missing pion-cloud effects.

A nucleon-pair and boson coexistent description of nuclei

NASA Astrophysics Data System (ADS)

Dai, Lianrong; Pan, Feng; Draayer, J. P.

2017-07-01

We study a mixture of s-bosons and like-nucleon pairs with the standard pairing interaction outside an inert core. Competition between the nucleon-pairs and s-bosons is investigated in this scenario. The robustness of the BCS-BEC coexistence and crossover phenomena are examined through an analysis of pf-shell nuclei with realistic single-particle energies, in which two configurations with Pauli blocking of nucleon-pair orbits due to the formation of the s-bosons is taken into account. When the nucleon-pair orbits are considered to be independent of the s-bosons, the BCS-BEC crossover becomes smooth, with the number of the s-bosons noticeably more than that of the nucleon-pairs near the half-shell point, a feature that is demonstrated in the pf-shell for several values of the standard pairing interaction strength. As a further test of the robustness of the BCS-BEC coexistence and crossover phenomena in nuclei, results are given for values of even-even 102-130Sn with 100Sn taken as a core and valence neutron pairs confined within the 1d 5/2, 0g 7/2, 1d 3/2, 2s 1/2, 1h 11/2 orbits in the nucleon-pair orbit and the s-boson independent approximation. The results indicate that the B(E2) values are reproduced well. Supported by National Natural Science Foundation of China (11375080, 11675071), the U.S. National Science Foundation (OCI-0904874 and ACI-1516338), U. S. Department of Energy (DE-SC0005248), the Southeastern Universities Research Association, the China-U. S. Theory Institute for Physics with Exotic Nuclei (CUSTIPEN) (DE-SC0009971), and the LSU-LNNU joint research program (9961) is acknowledged

Time Dependent Channel Packet Calculation of Two Nucleon Scattering Matrix Elements

DTIC Science & Technology

2010-03-01

solutions, 46 ( ) ( )1 1 11 ( ) cos sinL L L L Lr Akr j kr krψ δ η δ= −   (3.70) Here, A is an arbitrary constant, Lδ is the phase shift...iv AFIT/DS/ENP/10-M03 Abstract A new approach to calculating nucleon-nucleon scattering matrix...elements using a proven atomic time-dependent wave packet technique is investigated. Using this technique, reactant and product wave packets containing

Search for nucleon decays with EXO-200

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

Albert, J. B.; Anton, G.; Badhrees, I.

In this paper, a search for instability of nucleons bound in 136Xe nuclei is reported with 223 kg·yr exposure of 136Xe in the EXO-200 experiment. Lifetime limits of 3.3 × 10 23 and 1.9 × 10 23 yr are established for nucleon decay to 133Sb and 133Te, respectively. These are the most stringent to date, exceeding the prior decay limits by a factor of 9 and 7, respectively.

Reply to comment on ''New limits on intrinsic charm in the nucleon from global analysis of parton distribution''

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

Jimenez-Delgado, Pedro; Hobbs, Timothy J.; Londergan, J. T.

2016-01-05

We reply to the Comment of Brodsky and Gardner on our paper "New limits on intrinsic charm in the nucleon from global analysis of parton distributions" [Phys. Rev. Lett. 114, 082002 (2015)]. We address a number of incorrect claims made about our fitting methodology, and elaborate how global QCD analysis of all available high-energy data provides no evidence for a large intrinsic charm component of the nucleon.

Search for nucleon decays with EXO-200

DOE PAGES

Albert, J. B.; Anton, G.; Badhrees, I.; ...

2018-04-10

In this paper, a search for instability of nucleons bound in 136Xe nuclei is reported with 223 kg·yr exposure of 136Xe in the EXO-200 experiment. Lifetime limits of 3.3 × 10 23 and 1.9 × 10 23 yr are established for nucleon decay to 133Sb and 133Te, respectively. These are the most stringent to date, exceeding the prior decay limits by a factor of 9 and 7, respectively.

Three-particle N π π state contribution to the nucleon two-point function in lattice QCD

NASA Astrophysics Data System (ADS)

Bär, Oliver

2018-05-01

The three-particle N π π state contribution to the QCD two-point function of standard nucleon interpolating fields is computed to leading order in chiral perturbation theory. Using the experimental values for two low-energy coefficients, the impact of this contribution on lattice QCD calculations of the nucleon mass is estimated. The impact is found to be at the per mille level at most and negligible in practice.

Overview of the COMPASS results on the nucleon spin

NASA Astrophysics Data System (ADS)

Franco, Celso; COMPASS Collaboration

2016-04-01

The COMPASS experiment [COMPASS, P. Abbon et al., The COMPASS experiment at CERN, Nucl. Inst. Meth. A577, 455 (2007)] at CERN is one of the leading experiments studying the nucleon spin. These studies are being carried on since 2002, by measuring hadrons produced in deep inelastic scattering (DIS) of 160 GeV/c and 200 GeV/c polarised muons off different polarised targets (NH3 for polarised protons and 6LiD for polarised deuterons). One of the main goals is to determine how the total longitudinal spin projection of the nucleon, 1/2, is distributed among its constituents, quarks and gluons. We review here the recent results on the quark and gluon helicities obtained by COMPASS. The other major goal, whose fulfilment is needed for a complete understanding of the nucleon spin, is the determination of the transverse momentum dependent parton distributions (TMDs). Regarding this topic, the latest results on the Collins and Sivers asymmetries will be shown. The former is sensitive to the transverse spin structure of the nucleon, while the latter reflects the correlations between the quarks transverse momentum and the nucleon spin. This overview will conclude with a summary of the approved plans of COMPASS for the near future: the study of TMDs with a pioneering polarised Drell-Yan experiment and the measurement of generalised parton distributions (GPDs).

The Method of Unitary Clothing Transformations in the Theory of Nucleon-Nucleon Scattering

NASA Astrophysics Data System (ADS)

Dubovyk, I.; Shebeko, O.

2010-12-01

The clothing procedure, put forward in quantum field theory (QFT) by Greenberg and Schweber, is applied for the description of nucleon-nucleon ( N- N) scattering. We consider pseudoscalar ( π and η), vector ( ρ and ω) and scalar ( δ and σ) meson fields interacting with 1/2 spin ( N and {bar{N}}) fermion ones via the Yukawa-type couplings to introduce trial interactions between “bare” particles. The subsequent unitary clothing transformations are found to express the total Hamiltonian through new interaction operators that refer to particles with physical (observable) properties, the so-called clothed particles. In this work, we are focused upon the Hermitian and energy-independent operators for the clothed nucleons, being built up in the second order in the coupling constants. The corresponding analytic expressions in momentum space are compared with the separate meson contributions to the one-boson-exchange potentials in the meson theory of nuclear forces. In order to evaluate the T matrix of the N- N scattering we have used an equivalence theorem that enables us to operate in the clothed particle representation (CPR) instead of the bare particle representation with its large amount of virtual processes. We have derived the Lippmann-Schwinger type equation for the CPR elements of the T-matrix for a given collision energy in the two-nucleon sector of the Hilbert space {mathcal{H}} of hadronic states.

Hard Break-Up of Two-Nucleons and QCD Dynamics of NN Interaction

NASA Astrophysics Data System (ADS)

Sargsian, Misak; Granados, Carlos

2009-05-01

We investigate hard photodisintegration of two nucleons from ^3He nucleus within the framework of hard rescattering model (HRM). In HRM a quark of one nucleon knocked-out by incoming photon rescatters with a quark of the other nucleon leading to the production of two nucleons with high relative momentum. HRM allows to express the amplitude of two-nucleon break-up reaction through the convolution of photon-quark scattering, NN hard scattering amplitude and nuclear spectral function which can be calculated using nonrelativistic ^3He wave function. HRM predicts several specific features for hard break-up reaction. First, the cross section will approximately scale as s-11. Also one predicts comparable or larger cross section for pp break up as compared to that of pn break-up, which is opposite to what is observed in low energy kinematics. Another result is the prediction of different spectator momentum dependencies of pp and pn break-up cross sections. This is due to the fact that same-helicity pp-component is strongly suppressed in the ground state wave function of ^3He. Due to this suppression HRM predicts significantly different asymmetries for the cross section of polarization transfer NN break-up reactions for circularly polarized photons. For the pp break-up this asymmetry is predicted to be zero while for the pn it is close to 23.

Lattice calculation of electric dipole moments and form factors of the nucleon

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

Abramczyk, M.; Aoki, S.; Blum, T.

In this paper, we analyze commonly used expressions for computing the nucleon electric dipole form factors (EDFF)more » $$F_3$$ and moments (EDM) on a lattice and find that they lead to spurious contributions from the Pauli form factor $$F_2$$ due to inadequate definition of these form factors when parity mixing of lattice nucleon fields is involved. Using chirally symmetric domain wall fermions, we calculate the proton and the neutron EDFF induced by the CP-violating quark chromo-EDM interaction using the corrected expression. In addition, we calculate the electric dipole moment of the neutron using a background electric field that respects time translation invariance and boundary conditions, and we find that it decidedly agrees with the new formula but not the old formula for $$F_3$$. In conclusion, we analyze some selected lattice results for the nucleon EDM and observe that after the correction is applied, they either agree with zero or are substantially reduced in magnitude, thus reconciling their difference from phenomenological estimates of the nucleon EDM.« less

Proton-induced knockout reactions with polarized and unpolarized beams

NASA Astrophysics Data System (ADS)

Wakasa, T.; Ogata, K.; Noro, T.

2017-09-01

Proton-induced knockout reactions provide a direct means of studying the single particle or cluster structures of target nuclei. In addition, these knockout reactions are expected to play a unique role in investigations of the effects of the nuclear medium on nucleon-nucleon interactions as well as the properties of nucleons and mesons. However, due to the nature of hadron probes, these reactions can suffer significant disturbances from the nuclear surroundings and the quantitative theoretical treatment of such processes can also be challenging. In this article, we review the experimental and theoretical progress in this field, particularly focusing on the use of these reactions as a spectroscopic tool and as a way to examine the medium modification of nucleon-nucleon interactions. With regard to the former aspect, the review presents a semi-quantitative evaluation of these reactions based on existing experimental data. In terms of the latter point, we introduce a significant body of evidence that suggests, although does not conclusively prove, the existence of medium effects. In addition, this paper also provides information and comments on other related subjects.

Lattice calculation of electric dipole moments and form factors of the nucleon

DOE PAGES

Abramczyk, M.; Aoki, S.; Blum, T.; ...

2017-07-10

In this paper, we analyze commonly used expressions for computing the nucleon electric dipole form factors (EDFF)more » $$F_3$$ and moments (EDM) on a lattice and find that they lead to spurious contributions from the Pauli form factor $$F_2$$ due to inadequate definition of these form factors when parity mixing of lattice nucleon fields is involved. Using chirally symmetric domain wall fermions, we calculate the proton and the neutron EDFF induced by the CP-violating quark chromo-EDM interaction using the corrected expression. In addition, we calculate the electric dipole moment of the neutron using a background electric field that respects time translation invariance and boundary conditions, and we find that it decidedly agrees with the new formula but not the old formula for $$F_3$$. In conclusion, we analyze some selected lattice results for the nucleon EDM and observe that after the correction is applied, they either agree with zero or are substantially reduced in magnitude, thus reconciling their difference from phenomenological estimates of the nucleon EDM.« less

Baryon mass splittings and strong CP violation in SU(3) chiral perturbation theory

DOE PAGES

de Vries, Jordy; Mereghetti, Emanuele; Walker-Loud, Andre P.

2015-10-08

We study SU(3) flavor breaking corrections to the relation between the octet baryon masses and the nucleon-meson CP-violating interactions induced by the QCD theta term. We also work within the framework of SU(3) chiral perturbation theory and work through next-to-next-to-leading order in the SU(3) chiral expansion, which is O(m 2 q). At lowest order, the CP-odd couplings induced by the QCD θ - term are determined by mass splittings of the baryon octet, the classic result of Crewther et al. We show that for each isospin-invariant CP-violating nucleon-meson interaction there exists one relation which is respected by loop corrections upmore » to the order we work, while other leading-order relations are violated. With these relations we extract a precise value of the pion-nucleon coupling g - 0 by using recent lattice QCD evaluations of the proton-neutron mass splitting. Additionally, we derive semi-precise values for CP-violating coupling constants between heavier mesons and nucleons and discuss their phenomenological impact on electric dipole moments of nucleons and nuclei.« less

Lattice QCD spectroscopy for hadronic CP violation

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

de Vries, Jordy; Mereghetti, Emanuele; Seng, Chien -Yeah

Here, the interpretation of nuclear electric dipole moment (EDM) experiments is clouded by large theoretical uncertainties associated with nonperturbative matrix elements. In various beyond-the-Standard Model scenarios nuclear and diamagnetic atomic EDMs are expected to be dominated by CP-violating pion–nucleon interactions that arise from quark chromo-electric dipole moments. The corresponding CP-violating pion–nucleon coupling strengths are, however, poorly known. In this work we propose a strategy to calculate these couplings by using spectroscopic lattice QCD techniques. Instead of directly calculating the pion–nucleon coupling constants, a challenging task, we use chiral symmetry relations that link the pion–nucleon couplings to nucleon sigma terms andmore » mass splittings that are significantly easier to calculate. In this work, we show that these relations are reliable up to next-to-next-to-leading order in the chiral expansion in both SU(2) and SU(3) chiral perturbation theory. We conclude with a brief discussion about practical details regarding the required lattice QCD calculations and the phenomenological impact of an improved understanding of CP-violating matrix elements.« less

Baryon mass splittings and strong CP violation in SU(3) chiral perturbation theory

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

de Vries, Jordy; Mereghetti, Emanuele; Walker-Loud, Andre P.

We study SU(3) flavor breaking corrections to the relation between the octet baryon masses and the nucleon-meson CP-violating interactions induced by the QCD theta term. We also work within the framework of SU(3) chiral perturbation theory and work through next-to-next-to-leading order in the SU(3) chiral expansion, which is O(m 2 q). At lowest order, the CP-odd couplings induced by the QCD θ - term are determined by mass splittings of the baryon octet, the classic result of Crewther et al. We show that for each isospin-invariant CP-violating nucleon-meson interaction there exists one relation which is respected by loop corrections upmore » to the order we work, while other leading-order relations are violated. With these relations we extract a precise value of the pion-nucleon coupling g - 0 by using recent lattice QCD evaluations of the proton-neutron mass splitting. Additionally, we derive semi-precise values for CP-violating coupling constants between heavier mesons and nucleons and discuss their phenomenological impact on electric dipole moments of nucleons and nuclei.« less

Experimental Study of Three-Nucleon Dynamics in the Dp Breakup Collisions Using the WASA Detector

NASA Astrophysics Data System (ADS)

Kłos, B.; Ciepał, I.; Jamróz, B.; Khatri, G.; Kistryn, S.; Kozela, A.; Magiera, A.; Parol, W.; Skwira-Chalot, I.; Stephan, E.

2017-03-01

Until recently, all calculations of breakup observables were carried out in a non-relativistic regime. The relativistic treatment of the breakup reaction in 3 N system is quite a new achievement. The detailed study of various aspects of few-nucleon system dynamics in medium energy region, with a particular emphasis on investigation of relativistic effects and their interplay with three nucleon force (3NF) becomes feasible with increasing available energy in the three nucleon system. Therefore an experiment to investigate the ^1H(d, pp)n breakup cross section using a deuteron beam of 300, 340, 380 and 400 MeV and the WASA detector has been performed at COSY-Jülich. The almost 4π geometry of the WASA detector gives an unique possibility to study variety of kinematic configurations, which reveal different sensitivity to aspects of dynamics of the three nucleon system. The main steps of the analysis, including energy calibration, PID, normalization and efficiency studies, and their impact on the final accuracy of the result, are discussed.

Lattice QCD spectroscopy for hadronic CP violation

DOE PAGES

de Vries, Jordy; Mereghetti, Emanuele; Seng, Chien -Yeah; ...

2017-01-16

Here, the interpretation of nuclear electric dipole moment (EDM) experiments is clouded by large theoretical uncertainties associated with nonperturbative matrix elements. In various beyond-the-Standard Model scenarios nuclear and diamagnetic atomic EDMs are expected to be dominated by CP-violating pion–nucleon interactions that arise from quark chromo-electric dipole moments. The corresponding CP-violating pion–nucleon coupling strengths are, however, poorly known. In this work we propose a strategy to calculate these couplings by using spectroscopic lattice QCD techniques. Instead of directly calculating the pion–nucleon coupling constants, a challenging task, we use chiral symmetry relations that link the pion–nucleon couplings to nucleon sigma terms andmore » mass splittings that are significantly easier to calculate. In this work, we show that these relations are reliable up to next-to-next-to-leading order in the chiral expansion in both SU(2) and SU(3) chiral perturbation theory. We conclude with a brief discussion about practical details regarding the required lattice QCD calculations and the phenomenological impact of an improved understanding of CP-violating matrix elements.« less

Exclusion limits on the WIMP nucleon elastic scattering cross-section from the Cryogenic Dark Matter Search

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

Golwala, Sunil Ramanlal

2000-01-01

Extensive evidence indicates that a large fraction of the matter in the universe is nonluminous, nonbaryonic, and “cold” — nonrelativistic at the time matter began to dominate the energy density of the universe. Weakly Interacting Massive Particles (WIMPs) are an excellent candidate for nonbaryonic, cold dark matter. Minimal supersymmetry provides a natural WIMP candidate in the form of the lightest superpartner, with a typical mass Mδ ~ 100 GeV c-2 . WIMPs are expected to have collapsed into a roughly isothermal, spherical halo within which the visible portion of our galaxy resides. They would scatter off nuclei via the weakmore » interaction, potentially allowingtheir direct detection. The Cryogenic Dark Matter Search (CDMS) employs Ge and Si detectors to search for WIMPs via their elastic-scatteringinteractions with nuclei while discriminatingagainst interactions of background particles. The former yield nuclear recoils while the latter produce electron recoils. The ionization yield (the ratio of ionization production to recoil energy in a semiconductor) of a particle interaction differs greatly for nuclear and electron recoils. CDMS detectors measure phonon and electron-hole-pair production to determine recoil energy and ionization yield for each event and thereby discriminate nuclear recoils from electron recoils. This dissertation reports new limits on the spin-independent WIMP-nucleon elastic-scattering cross section that exclude unexplored parameter space above 10 GeV c-2 WIMP mass and, at > 75% CL, the entire 3σ allowed region for the WIMP signal reported by the DAMA experiment. The experimental apparatus, detector performance, and data analysis are fully described.« less

Collective flows of pions in Au+Au collisions at energies 1.0 and 1.5 GeV/nucleon

NASA Astrophysics Data System (ADS)

Liu, Yangyang; Wang, Yongjia; Li, Qingfeng; Liu, Ling

2018-03-01

Based on the newly updated version of the ultrarelativistic quantum molecular dynamics (UrQMD) model, the pion potentials obtained from the in-medium dispersion relation of the Δ -hole model and from the modified phenomenological approach are further introduced. Both the rapidity y0 and transverse-velocity ut 0 dependence of directed v1 and elliptic v2 flows of π+ and π- charged mesons produced from Au+Au collisions at two beam energies of 1.0 and 1.5 GeV/nucleon and within a large centrality region of 0

Fundamental Neutron Physics: Theory and Analysis

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

Gudkov, Vladimir

The goal of the proposal was to study the possibility of searching for manifestations of new physics beyond the Standard model in fundamental neutron physics experiments. This involves detailed theoretical analyses of parity- and time reversal invariance-violating processes in neutron-induced reactions, properties of neutron β-decay, and the precise description of properties of neutron interactions with nuclei. To describe neutron-nuclear interactions, we use both the effective field theory approach and the theory of nuclear reaction with phenomenological nucleon potentials for the systematic description of parity- and time reversal-violating effects in the consistent way. A major emphasis of our research during themore » funding period has been the study of parity violation (PV) and time reversal invariance violation (TRIV) in few-body systems. We studied PV effects in non-elastic processes in three-nucleon system using both ”DDH-like” and effective field theory (EFT) approaches. The wave functions were obtained by solving three-body Faddeev equations in configuration space for a number of realistic strong potentials. The observed model dependence for the DDH approach indicates intrinsic difficulty in the description of nuclear PV effects, and it could be the reason for the observed discrepancies in the nuclear PV data analysis. It shows that the DDH approach could be a reasonable approach for analysis of PV effects only if exactly the same strong and weak potentials are used in calculating all PV observables in all nuclei. However, the existing calculations of nuclear PV effects were performed using different potentials; therefore, strictly speaking, one cannot compare the existing results of these calculations among themselves.« less

Properties of Nuclei up to A = 16 using Local Chiral Interactions

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

Lonardoni, Diego; Carlson, Joseph; Gandolfi, Stefano

Here, we report accurate quantum Monte Carlo calculations of nuclei up to A = 16 based on local chiral two- and three-nucleon interactions up to next-to-next-to-leading order. We examine the theoretical uncertainties associated with the chiral expansion and the cutoff in the theory, as well as the associated operator choices in the three-nucleon interactions. While in light nuclei the cutoff variation and systematic uncertainties are rather small, in 16O these can be significant for large coordinate-space cutoffs. Overall, we show that chiral interactions constructed to reproduce properties of very light systems and nucleon-nucleon scattering give an excellent description of bindingmore » energies, charge radii, and form factors for all these nuclei, including open-shell systems in A = 6 and 12.« less

Search for nucleon decays induced by GUT magnetic monopoles with the MACRO experiment

NASA Astrophysics Data System (ADS)

Ambrosio, M.; Antolini, R.; Auriemma, G.; Bakari, D.; Baldini, A.; Barbarino, G. C.; Barish, B. C.; Battistoni, G.; Becherini, Y.; Bellotti, R.; Bemporad, C.; Bernardini, P.; Bilokon, H.; Bloise, C.; Bower, C.; Brigida, M.; Bussino, S.; Cafagna, F.; Calicchio, M.; Campana, D.; Carboni, M.; Caruso, R.; Cecchini, S.; Cei, F.; Chiarella, V.; Choudhary, B. C.; Coutu, S.; Cozzi, M.; de Cataldo, G.; Dekhissi, H.; de Marzo, C.; de Mitri, I.; Derkaoui, J.; de Vincenzi, M.; di Credico, A.; Erriquez, O.; Favuzzi, C.; Forti, C.; Fusco, P.; Giacomelli, G.; Giannini, G.; Giglietto, N.; Giorgini, M.; Grassi, M.; Grillo, A.; Guarino, F.; Gustavino, C.; Habig, A.; Hanson, K.; Heinz, R.; Iarocci, E.; Katsavounidis, E.; Katsavounidis, I.; Kearns, E.; Kim, H.; Kyriazopoulou, S.; Lamanna, E.; Lane, C.; Levin, D. S.; Lipari, P.; Longley, N. P.; Longo, M. J.; Loparco, F.; Maaroufi, F.; Mancarella, G.; Mandrioli, G.; Manzoor, S.; Margiotta, A.; Marini, A.; Martello, D.; Marzari-Chiesa, A.; Mazziotta, M. N.; Michael, D. G.; Monacelli, P.; Montaruli, T.; Monteno, M.; Mufson, S.; Musser, J.; Nicolò, D.; Nolty, R.; Orth, C.; Osteria, G.; Palamara, O.; Patera, V.; Patrizii, L.; Pazzi, R.; Peck, C. W.; Perrone, L.; Petrera, S.; Pistilli, P.; Popa, V.; Rainò, A.; Reynoldson, J.; Ronga, F.; Rrhioua, A.; Satriano, C.; Scapparone, E.; Scholberg, K.; Sciubba, A.; Serra, P.; Sioli, M.; Sirri, G.; Sitta, M.; Spinelli, P.; Spinetti, M.; Spurio, M.; Steinberg, R.; Stone, J. L.; Sulak, L. R.; Surdo, A.; Tarlè, G.; Togo, V.; Vakili, M.; Walter, C. W.; Webb, R.

2002-12-01

The interaction of a Grand Unification Magnetic Monopole with a nucleon can lead to a barion-number violating process in which the nucleon decays into a lepton and one or more mesons (catalysis of nucleon decay). In this paper we report an experimental study of the effects of a catalysis process in the MACRO detector. Using a dedicated analysis we obtain new magnetic monopole (MM) flux upper limits at the level of \\char1263\\cdot 10^{-16} cm^{-2} s^{-1} sr^{-1} for 1.1\\cdot 10^{-4} le \\vertβ\\vert le 5\\cdot 10^{-3}, based on the search for catalysis events in the MACRO data. We also analyze the dependence of the MM flux limit on the catalysis cross section.

Scattering calculations and confining interactions

NASA Technical Reports Server (NTRS)

Buck, Warren W.; Maung, Khin M.

1993-01-01

Most of the research work performed under this grant were concerned with strong interaction processes ranging from kaon-nucleon interaction to proton-nucleus scattering calculations. Research performed under this grant can be categorized into three groups: (1) parametrization of fundamental interactions, (2) development of formal theory, and (3) calculations based upon the first two. Parametrizations of certain fundamental interactions, such as kaon-nucleon interaction, for example, were necessary because kaon-nucleon scattering amplitude was needed to perform kaon-nucleus scattering calculations. It was possible to calculate kaon-nucleon amplitudes from the first principle, but it was unnecessary for the purpose of the project. Similar work was also done for example for anti-protons and anti-nuclei. Formal developments to some extent were also pursued so that consistent calculations can be done.

Adiabatic and coupled channels calculations for near barrier fusion of 16O +238U using realistic nucleon-nucleon interaction

NASA Astrophysics Data System (ADS)

Ismail, M.; Seif, W. M.; Botros, M. M.

2016-04-01

We investigate the fusion cross-section and the fusion barrier distribution of 16O +238U at near- and sub-barrier energies. We use an interaction potential generated by the semi-microscopic double folding model-based on density dependent (DD) form of the realistic Michigan-three-Yukawa (M3Y) Reid nucleon-nucleon (NN) interaction. We studied the role of both the static and dynamic deformations of the target nucleus on the fusion process. Rotational and vibrational degrees of freedom of 238U-nucleus are considered. We found that the deformation and the octupole vibrations in 238U enhance its sub-barrier fusion cross-section. The signature of the the octupole vibrational modes of 238U appears clearly in its fusion barrier distribution profile.

Properties of Nuclei up to A = 16 using Local Chiral Interactions

DOE PAGES

Lonardoni, Diego; Carlson, Joseph; Gandolfi, Stefano; ...

2018-03-22

Here, we report accurate quantum Monte Carlo calculations of nuclei up to A = 16 based on local chiral two- and three-nucleon interactions up to next-to-next-to-leading order. We examine the theoretical uncertainties associated with the chiral expansion and the cutoff in the theory, as well as the associated operator choices in the three-nucleon interactions. While in light nuclei the cutoff variation and systematic uncertainties are rather small, in 16O these can be significant for large coordinate-space cutoffs. Overall, we show that chiral interactions constructed to reproduce properties of very light systems and nucleon-nucleon scattering give an excellent description of bindingmore » energies, charge radii, and form factors for all these nuclei, including open-shell systems in A = 6 and 12.« less

Phenomenology of nonperturbative charm in the nucleon

DOE PAGES

Hobbs, T. J.; Londergan, J. T.; Melnitchouk, W.

2014-04-02

We perform a comprehensive analysis of the role of nonperturbative (or intrinsic) charm in the nucleon, generated through Fock state expansions of the nucleon wave function involving five-quark virtual states represented by charmed mesons and baryons. We consider contributions from a variety of charmed meson-baryon states and find surprisingly dominant effects from the D¯ *0 Λ c + configuration. We pay particular attention to the existence and persistence of high-x structure for intrinsic charm, and the x dependence of the c-c¯ asymmetry predicted in meson-baryon models. We discuss how studies of charmed baryons and mesons in hadronic reactions can bemore » used to constrain models, and outline future measurements that could further illuminate the intrinsic charm component of the nucleon.« less

A study of the nucleus-nucleus total reaction cross section of stable systems at intermediate energies: An application to 12C

NASA Astrophysics Data System (ADS)

Hu, Liyuan; Song, Yushou; Hou, Yingwei; Liu, Huilan; Li, Hui

2018-07-01

A semi-microscopic analytical expression of the nucleus-nucleus total reaction cross section (σR) was proposed based on the strong absorption model. It is suitable for stable nuclei at intermediate energies. The matter density distributions of nuclei and the nucleon-nucleon total cross section were both considered. Particularly, the Fermi motion effect of the nucleons in a nucleus was also taken into account. The parametrization of σR was applied to the colliding systems including 12C. The experimental data at energies from 30 to 1000 MeV/nucleon were well reproduced, according to which an approach of deriving σR without adjustable parameters was developed. The necessity of considering the Fermi motion effect in the parametrization was discussed.

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

Krebs, H., E-mail: hermann.krebs@rub.de; Epelbaum, E., E-mail: evgeny.epelbaum@rub.de; Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93016

We present the complete derivation of the nuclear axial charge and current operators as well as the pseudoscalar operators to fourth order in the chiral expansion relative to the dominant one-body contribution using the method of unitary transformation. We demonstrate that the unitary ambiguity in the resulting operators can be eliminated by the requirement of renormalizability and by matching of the pion-pole contributions to the nuclear forces. We give expressions for the renormalized single-, two- and three-nucleon contributions to the charge and current operators and pseudoscalar operators including the relevant relativistic corrections. We also verify explicitly the validity of themore » continuity equation.« less

Proton Distribution Radii of 12-19C Illuminate Features of Neutron Halos

DOE PAGES

Kanungo, R.; Horiuchi, W.; Hagen, Gaute; ...

2016-09-02

We report proton radii of 12-19C densities derived from first accurate charge changing cross section measurements at 900A MeV with a carbon target. A thick neutron surface evolves from ~0.5 fm in 15C to ~1 fm in 19C. Also, the halo radius in 19C is found to be 6.4±0.7 fm as large as 11Li. Ab initio calculations based on chiral nucleon-nucleon and three-nucleon forces reproduce the radii well.

Neutrino-Nucleon Deep Inelastic Scattering in MINERvA

NASA Astrophysics Data System (ADS)

Norrick, Anne; Minerva Collaboration

2015-04-01

Neutrino-Nucleon Deep Inelastic Scattering (DIS) events provide a probe into the structure of the nucleus that cannot be accessed via charged lepton-nucleon interactions. The MINERvA experiment is stationed in the Neutrinos from the Main Injector (NuMI) beam line at Fermi National Accelerator Laboratory. The projected sensitivity of nuclear structure function analyses using MINERvA's suite of nuclear targets (C, CH, Fe and Pb) in the upgraded 6 GeV neutrino energy NuMI beam will be explored, and their impact discussed.

Background field Landau mode operators for the nucleon

NASA Astrophysics Data System (ADS)

Kamleh, Waseem; Bignell, Ryan; Leinweber, Derek B.; Burkardt, Matthias

2018-03-01

The introduction of a uniform background magnetic field breaks threedimensional spatial symmetry for a charged particle and introduces Landau mode effects. Standard quark operators are inefficient at isolating the nucleon correlation function at nontrivial field strengths. We introduce novel quark operators constructed from the twodimensional Laplacian eigenmodes that describe a charged particle on a finite lattice. These eigenmode-projected quark operators provide enhanced precision for calculating nucleon energy shifts in a magnetic field. Preliminary results are obtained for the neutron and proton magnetic polarisabilities using these methods.

NUCLEON Satellite Mission. Status and Plans

NASA Technical Reports Server (NTRS)

Bashindzhagyan, G.; Adams, J.; Bashindzhagyan, P.; Baranova, N.; Christl, M.; Chilingarian, A.; Chupin, I.; Derrickson, J.; Drury, L.; Egorov, N.

2003-01-01

The main objective of the NUCLEON satellite mission is direct measurements of the elemental energy spectra of high-energy (10(exp 11) - 10(exp 15) eV) cosmic rays with Kinematic Lightweight Energy Meter (KLEM) device. The design of the instrument has been corrected to increase geometry factor and improve charge resolution. The special mechanical and electronic systems have been developed for installation of the experimental apparatus in a regular Russian satellite. It is planned to launch the NUCLEON instrument in 2006.

Dark Matter Results from 54-Ton-Day Exposure of PandaX-II Experiment

NASA Astrophysics Data System (ADS)

Cui, Xiangyi; Abdukerim, Abdusalam; Chen, Wei; Chen, Xun; Chen, Yunhua; Dong, Binbin; Fang, Deqing; Fu, Changbo; Giboni, Karl; Giuliani, Franco; Gu, Linhui; Gu, Yikun; Guo, Xuyuan; Guo, Zhifan; Han, Ke; He, Changda; Huang, Di; He, Shengming; Huang, Xingtao; Huang, Zhou; Ji, Xiangdong; Ju, Yonglin; Li, Shaoli; Li, Yao; Lin, Heng; Liu, Huaxuan; Liu, Jianglai; Ma, Yugang; Mao, Yajun; Ni, Kaixiang; Ning, Jinhua; Ren, Xiangxiang; Shi, Fang; Tan, Andi; Wang, Cheng; Wang, Hongwei; Wang, Meng; Wang, Qiuhong; Wang, Siguang; Wang, Xiuli; Wang, Xuming; Wu, Qinyu; Wu, Shiyong; Xiao, Mengjiao; Xie, Pengwei; Yan, Binbin; Yang, Yong; Yue, Jianfeng; Zhang, Dan; Zhang, Hongguang; Zhang, Tao; Zhang, Tianqi; Zhao, Li; Zhou, Jifang; Zhou, Ning; Zhou, Xiaopeng; PandaX-II Collaboration

2017-11-01

We report a new search for weakly interacting massive particles (WIMPs) using the combined low background data sets acquired in 2016 and 2017 from the PandaX-II experiment in China. The latest data set contains a new exposure of 77.1 live days, with the background reduced to a level of 0.8 ×10-3 evt /kg /day , improved by a factor of 2.5 in comparison to the previous run in 2016. No excess events are found above the expected background. With a total exposure of 5.4 ×104 kg day , the most stringent upper limit on the spin-independent WIMP-nucleon cross section is set for a WIMP with mass larger than 100 GeV /c2 , with the lowest 90% C.L. exclusion at 8.6 ×10-47 cm2 at 40 GeV /c2 .

'Tertiary' nuclear burning - Neutron star deflagration?

NASA Technical Reports Server (NTRS)

Michel, F. Curtis

1988-01-01

A motivation is presented for the idea that dense nuclear matter can burn to a new class of stable particles. One of several possibilities is an 'octet' particle which is the 16 baryon extension of alpha particle, but now composed of a pair of each of the two nucleons, (3Sigma, Delta, and 2Xi). Such 'tertiary' nuclear burning (here 'primary' is H-He and 'secondary' is He-Fe) may lead to neutron star explosions rather than collapse to a black hole, analogous to some Type I supernovae models wherein accreting white dwarfs are pushed over the Chandrasekhar mass limit but explode rather than collapse to form neutron stars. Such explosions could possibly give gamma-ray bursts and power quasars, with efficient particle acceleration in the resultant relativistic shocks. The new stable particles themselves could possibly be the sought-after weakly interacting, massive particles (WIMPs) or 'dark' matter.

First results from the Cryogenic Dark Matter Search in the Soudan Underground Laboratory.

PubMed

Akerib, D S; Alvaro-Dean, J; Armel-Funkhouser, M S; Attisha, M J; Baudis, L; Bauer, D A; Beaty, J; Brink, P L; Bunker, R; Burke, S P; Cabrera, B; Caldwell, D O; Callahan, D; Castle, J P; Chang, C L; Choate, R; Crisler, M B; Cushman, P; Dixon, R; Dragowsky, M R; Driscoll, D D; Duong, L; Emes, J; Ferril, R; Filippini, J; Gaitskell, R J; Haldeman, M; Hale, D; Holmgren, D; Huber, M E; Johnson, B; Johnson, W; Kamat, S; Kozlovsky, M; Kula, L; Kyre, S; Lambin, B; Lu, A; Mahapatra, R; Manalaysay, A G; Mandic, V; May, J; McDonald, R; Merkel, B; Meunier, P; Mirabolfathi, N; Morrison, S; Nelson, H; Nelson, R; Novak, L; Ogburn, R W; Orr, S; Perera, T A; Perillo Isaac, M C; Ramberg, E; Rau, W; Reisetter, A; Ross, R R; Saab, T; Sadoulet, B; Sander, J; Savage, C; Schmitt, R L; Schnee, R W; Seitz, D N; Serfass, B; Smith, A; Smith, G; Spadafora, A L; Sundqvist, K; Thompson, J-P F; Tomada, A; Wang, G; Williams, J; Yellin, S; Young, B A

2004-11-19

We report the first results from a search for weakly interacting massive particles (WIMPs) in the Cryogenic Dark Matter Search experiment at the Soudan Underground Laboratory. Four Ge and two Si detectors were operated for 52.6 live days, providing 19.4 kg d of Ge net exposure after cuts for recoil energies between 10 and 100 keV. A blind analysis was performed using only calibration data to define the energy threshold and selection criteria for nuclear-recoil candidates. Using the standard dark-matter halo and nuclear-physics WIMP model, these data set the world's lowest exclusion limits on the coherent WIMP-nucleon scalar cross section for all WIMP masses above 15 GeV/c2, ruling out a significant range of neutralino supersymmetric models. The minimum of this limit curve at the 90% C.L. is 4 x 10(-43) cm2 at a WIMP mass of 60 GeV/c2.

Search for Dark Matter with DEAP-3600

NASA Astrophysics Data System (ADS)

Jillings, Chris; DEAP-3600 Collaboration Collaboration

2017-01-01

DEAP-3600 is a single-phase liquid argon detector, which searches for dark matter particle interactions with 1 tonne fiducial target mass (3.6 tonnes total) contained in an ultra-pure acrylic vessel viewed by 255 high quantum efficiency photomultiplier tubes. It is located 2 km underground at SNOLAB, in Sudbury, Ontario. Radioactive backgrounds are controlled through pulse-shape discrimination in case of electromagnetic backgrounds (demonstrated with a smaller 7-kg prototype DEAP-1) and with a combination of excellent radiopurity, shielding and fiducialization for neutron and alpha backgrounds. The target sensitivity to spin-independent scattering of Weakly Interacting Massive Particles (WIMPs) on nucleons is 10-46 cm2 at 100 GeV/c2. Commissioning of the DEAP-3600 detector is now complete and physics data taking is starting. This talk will present an overview and status of the project, including early results demonstrating the detector performance.

Onset of η-nuclear binding in a pionless EFT approach

NASA Astrophysics Data System (ADS)

Barnea, N.; Bazak, B.; Friedman, E.; Gal, A.

2017-08-01

ηNNN and ηNNNN bound states are explored in stochastic variational method (SVM) calculations within a pionless effective field theory (EFT) approach at leading order. The theoretical input consists of regulated NN and NNN contact terms, and a regulated energy dependent ηN contact term derived from coupled-channel models of the N* (1535) nucleon resonance. A self consistency procedure is applied to deal with the energy dependence of the ηN subthreshold input, resulting in a weak dependence of the calculated η-nuclear binding energies on the EFT regulator. It is found, in terms of the ηN scattering length aηN, that the onset of binding η 3He requires a minimal value of ReaηN close to 1 fm, yielding then a few MeV η binding in η 4He. The onset of binding η 4He requires a lower value of ReaηN, but exceeding 0.7 fm.

Diffractive production of charmed strange mesons by neutrinos and antineutrinos

NASA Astrophysics Data System (ADS)

Asratyan, A. E.; Aderholz, M.; Ammosov, V. V.; Burkot, W.; Clayton, E. F.; Coghen, T.; Erriquez, O.; Gapienko, G. S.; Gapienko, V. A.; Guy, J.; Hantke, D.; Jones, G. T.; Kaftanov, V. S.; Katz, U. F.; Kern, J.; Korotkov, V. A.; Krutchinin, S. P.; Kubantsev, M. A.; Marage, P.; Miller, D. B.; Mobayyen, M. M.; Morrison, D. R. O.; Neveu, M.; Sacton, J.; Schmitz, N.; Varvell, K.; Venus, W.; Wittek, W.; Zaetz, V. G.

1993-03-01

The diffractive production of charmed strange D {s/*} and possibly D s mesons by neutrinos and antineutrinos on nucleons in hydrogen, deuterium and neon targets is observed. The slope parameter of the t distribution is 3.3±0.8 (GeV)-2. The production rate per charged current neutrino interaction with an isoscalar target times the D{s/+}→φτ+ branching fraction is (1.03±0.27)×10-4.

From quarks and gluons to baryon form factors

PubMed Central

Eichmann, Gernot

2012-01-01

I briefly summarize recent results for nucleon and Δ(1232) electromagnetic, axial and transition form factors in the Dyson–Schwinger approach. The calculation of the current diagrams from the quark–gluon level enables a transparent discussion of common features such as: the implications of dynamical chiral symmetry breaking and quark orbital angular momentum, the timelike structure of the form factors, and their interpretation in terms of missing pion-cloud effects. PMID:26766879

Modelling nuclear effects in neutrino scattering

NASA Astrophysics Data System (ADS)

Leitner, T.; Alvarez-Ruso, L.; Mosel, U.

2006-07-01

We have developed a model to describe the interactions of neutrinos with nucleons and nuclei via charged and neutral currents, focusing on the region of the quasielastic and Δ(1232) peaks. For νN collisions a fully relativistic formalism is used. The extension to finite nuclei has been done in the framework of a coupled-channel BUU transport model where we have studied exclusive channels taking into account in-medium effects and final state interactions.

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

Cornelis de Jager

The experimental and theoretical status of elastic electron scattering from the nucleon is reviewed. As a consequence of new experimental facilities, data of unprecedented precision have recently become available for the electromagnetic and the strange form factors of the nucleon.

K- absorption on two nucleons and ppK- bound state search in the Σ0p final state

NASA Astrophysics Data System (ADS)

Vázquez Doce, O.; Fabbietti, L.; Cargnelli, M.; Curceanu, C.; Marton, J.; Piscicchia, K.; Scordo, A.; Sirghi, D.; Tucakovic, I.; Wycech, S.; Zmeskal, J.; Anastasi, A.; Curciarello, F.; Czerwinski, E.; Krzemien, W.; Mandaglio, G.; Martini, M.; Moskal, P.; Patera, V.; Pérez del Rio, E.; Silarski, M.

2016-07-01

We report the measurement of K- absorption processes in the Σ0p final state and the first exclusive measurement of the two nucleon absorption (2NA) with the KLOE detector. The 2NA process without further interactions is found to be 9% of the sum of all other contributing processes, including absorption on three and more nucleons or 2NA followed by final state interactions with the residual nucleons. We also determine the possible contribution of the ppK- bound state to the Σ0p final state. The yield of ppK- /Kstop- is found to be (0.044 ± 0.009stat-0.005+0.004 syst) ṡ10-2 but its statistical significance based on an F-test is only 1σ.

Evidence for solar wind origin of energetic heavy ions in the earth's radiation belt

NASA Technical Reports Server (NTRS)

Hovestadt, D.; Klecker, B.; Scholer, M.; Gloeckler, G.; Ipavich, F. M.; Fan, C. Y.; Fisk, L. A.; Ogallagher, J. J.

1978-01-01

Analysis of data from our energetic ion composition experiment on ISEE-1 has revealed the presence of substantial fluxes of carbon, oxygen, and heavier ions above 400 keV/nucleon at L values between approximately 2.5 and 4 earth radii. The measured C/O ratio varies systematically from 1.3 at 450 keV/nucleon to 4.1 at 1.3 MeV/nucleon, and no iron is observed above 200 keV/nucleon. These results provide strong evidence for a solar wind origin for energetic ions in the outer radiation belt. The absence of iron and the increase of the carbon-to-oxygen ratio with energy suggest that the condition for the validity of the first adiabatic invariant may have a strong influence on the trapping of these particles.

High Energy Break-Up of Few-Nucleon Systems

NASA Astrophysics Data System (ADS)

Sargsian, Misak

2008-03-01

We discus recent developments in theory of high energy two-body break-up reactions of few-nucleon systems. The characteristics of these reactions are such that the hard two-body quasielastic subprocess can be clearly separated from the accompanying soft subprocesses. We discuss in details the hard rescattering model (HRM) in which hard photodisintegration develops in two stages. At first, photon knocks-out an energetic quark which rescatters subsequently with a quark of the other nucleon. The latter provides a mechanism of sharing the initial high momentum of the photon by the outgoing two nucleons. Within HRM we discuss hard break-up reactions involving 2D and 3He targets. Another development of HRM is the prediction of new helicity selection mechanism for hard two-body reactions, which was apparently confirmed in the recent JLab experiment.

Quantum Monte Carlo calculations of light nuclei with local chiral two- and three-nucleon interactions

DOE PAGES

Lynn, J. E.; Tews, I.; Carlson, J.; ...

2017-11-30

Local chiral effective field theory interactions have recently been developed and used in the context of quantum Monte Carlo few- and many-body methods for nuclear physics. In this paper, we go over detailed features of local chiral nucleon-nucleon interactions and examine their effect on properties of the deuteron, paying special attention to the perturbativeness of the expansion. We then turn to three-nucleon interactions, focusing on operator ambiguities and their interplay with regulator effects. We then discuss the nuclear Green's function Monte Carlo method, going over both wave-function correlations and approximations for the two- and three-body propagators. Finally, following this, wemore » present a range of results on light nuclei: Binding energies and distribution functions are contrasted and compared, starting from several different microscopic interactions.« less

The method of unitary clothing transformations in the theory of nucleon-nucleon scattering

NASA Astrophysics Data System (ADS)

Dubovyk, I.; Shebeko, A.

2010-04-01

The clothing procedure, put forward in quantum field theory (QFT) by Greenberg and Schweber, is applied for the description of nucleon-nucleon (N -N) scattering. We consider pseudoscalar (π and η), vector (ρ and ω) and scalar (δ and σ) meson fields interacting with 1/2 spin (N and N) fermion ones via the Yukawa-type couplings to introduce trial interactions between “bare” particles. The subsequent unitary clothing transformations (UCTs) are found to express the total Hamiltonian through new interaction operators that refer to particles with physical (observable) properties, the so-called clothed particles. In this work, we are focused upon the Hermitian and energy-independent operators for the clothed nucleons, being built up in the second order in the coupling constants. The corresponding analytic expressions in momentum space are compared with the separate meson contributions to the one-boson-exchange potentials in the meson theory of nuclear forces. In order to evaluate the T matrix of the N-N scattering we have used an equivalence theorem that enables us to operate in the clothed particle representation (CPR) instead of the bare particle representation (BPR) with its huge amount of virtual processes. We have derived the Lippmann-Schwinger(LS)-type equation for the CPR elements of the T-matrix for a given collision energy in the two-nucleon sector of the Hilbert space H of hadronic states and elaborated a code for its numerical solution in momentum space.

Systematics of α-decay fine structure in odd-mass nuclei based on a finite-range nucleon-nucleon interaction

NASA Astrophysics Data System (ADS)

Adel, A.; Alharbi, T.

2018-07-01

A systematic study on α-decay fine structure is presented for odd-mass nuclei in the range 83 ≤ Z ≤ 92. The α-decay partial half-lives and branching ratios to the ground and excited states of daughter nuclei are calculated in the framework of the Wentzel-Kramers-Brillouin (WKB) approximation with the implementation of the Bohr-Sommerfeld quantization condition. The microscopic α-daughter potential is obtained using the double-folding model with a realistic M3Y-Paris nucleon-nucleon (NN) interaction. The exchange potential, which accounts for the knock-on exchange of nucleons between the interacting nuclei, is calculated using the finite-range exchange NN interaction which is essentially a much better approximation as compared to the zero-range pseudo-potential adopted in the usual double-folding calculations. Our calculations of α-decay fine structure have been improved by considering the preformation factor extracted from the recently proposed cluster formation model on basis of the binding energy difference. The computed partial half-lives and branching ratios are compared with the recent experimental data and they are in good agreement.

Roy-Steiner-equation analysis of pion-nucleon scattering

NASA Astrophysics Data System (ADS)

Hoferichter, Martin; Ruiz de Elvira, Jacobo; Kubis, Bastian; Meißner, Ulf-G.

2016-04-01

We review the structure of Roy-Steiner equations for pion-nucleon scattering, the solution for the partial waves of the t-channel process ππ → N ¯ N, as well as the high-accuracy extraction of the pion-nucleon S-wave scattering lengths from data on pionic hydrogen and deuterium. We then proceed to construct solutions for the lowest partial waves of the s-channel process πN → πN and demonstrate that accurate solutions can be found if the scattering lengths are imposed as constraints. Detailed error estimates of all input quantities in the solution procedure are performed and explicit parameterizations for the resulting low-energy phase shifts as well as results for subthreshold parameters and higher threshold parameters are presented. Furthermore, we discuss the extraction of the pion-nucleon σ-term via the Cheng-Dashen low-energy theorem, including the role of isospin-breaking corrections, to obtain a precision determination consistent with all constraints from analyticity, unitarity, crossing symmetry, and pionic-atom data. We perform the matching to chiral perturbation theory in the subthreshold region and detail the consequences for the chiral convergence of the threshold parameters and the nucleon mass.

Nucleon shadowing effects in Cu + Cu and Au + Au collisions at RHIC within the HIJING code

NASA Astrophysics Data System (ADS)

Abdel-Waged, Khaled; Felemban, Nuha

2018-02-01

The centrality dependence of pseudorapidity density of charged particles ({{{d}}{N}}{{ch}}/{{d}}η ) in Cu + Cu (Au + Au) collisions at Relativistic Heavy Ion Collider energy of \\sqrt{{s}{{NN}}}=22.4, 62.4 and 200 (19.6, 62.4 and 200) GeV, is investigated within an improved HIJING code. The standard HIJING model is enhanced by a prescription for collective nucleon-nucleon (NN) interactions and more modern parton distribution functions. The collective NN-interactions are used to induce both cascade and nucleon shadowing effects. We find collective cascade broadens the pseudorapidity distributions in the tails (at | η | > {y}{beam}) above 25%-30% collision centrality to be consistent with the {{{d}}{N}}{{ch}}/{{d}}η data at \\sqrt{{s}{{NN}}} =19.6,22.4,62.4 {GeV}. The overall contribution of nucleon shadowing is shown to depress the whole shape of {{{d}}{N}}{{ch}}/{{d}}η in the primary interaction region (at | η | < {y}{beam}) for semiperipheral (20%-25%) and peripheral (≥slant 35 % {--}40 % ) Cu + Cu (Au + Au) interactions at \\sqrt{{s}{{NN}}}=200 {GeV}, in accordance with the PHOBOS data.

Helium-3 and helium-4 acceleration by high power laser pulses for hadron therapy

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

Bulanov, S. S.; Esarey, E.; Schroeder, C. B.

The laser driven acceleration of ions is considered a promising candidate for an ion source for hadron therapy of oncological diseases. Though proton and carbon ion sources are conventionally used for therapy, other light ions can also be utilized. Whereas carbon ions require 400 MeV per nucleon to reach the same penetration depth as 250 MeV protons, helium ions require only 250 MeV per nucleon, which is the lowest energy per nucleon among the light ions (heavier than protons). This fact along with the larger biological damage to cancer cells achieved by helium ions, than that by protons, makes thismore » species an interesting candidate for the laser driven ion source. Two mechanisms (magnetic vortex acceleration and hole-boring radiation pressure acceleration) of PW-class laser driven ion acceleration from liquid and gaseous helium targets are studied with the goal of producing 250 MeV per nucleon helium ion beams that meet the hadron therapy requirements. We show that He3 ions, having almost the same penetration depth as He4 with the same energy per nucleon, require less laser power to be accelerated to the required energy for the hadron therapy.« less

Helium-3 and helium-4 acceleration by high power laser pulses for hadron therapy

DOE PAGES

Bulanov, S. S.; Esarey, E.; Schroeder, C. B.; ...

2015-06-24

The laser driven acceleration of ions is considered a promising candidate for an ion source for hadron therapy of oncological diseases. Though proton and carbon ion sources are conventionally used for therapy, other light ions can also be utilized. Whereas carbon ions require 400 MeV per nucleon to reach the same penetration depth as 250 MeV protons, helium ions require only 250 MeV per nucleon, which is the lowest energy per nucleon among the light ions (heavier than protons). This fact along with the larger biological damage to cancer cells achieved by helium ions, than that by protons, makes thismore » species an interesting candidate for the laser driven ion source. Two mechanisms (magnetic vortex acceleration and hole-boring radiation pressure acceleration) of PW-class laser driven ion acceleration from liquid and gaseous helium targets are studied with the goal of producing 250 MeV per nucleon helium ion beams that meet the hadron therapy requirements. We show that He3 ions, having almost the same penetration depth as He4 with the same energy per nucleon, require less laser power to be accelerated to the required energy for the hadron therapy.« less

Nucleon resonance structure in the finite volume of lattice QCD

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

Wu, Jia -Jun; Kamano, H.; Lee, T. -S. H.

An approach for relating the nucleon resonances extracted from πN reaction data to lattice QCD calculations has been developed by using the finite-volume Hamiltonian method. Within models of πN reactions, bare states are introduced to parametrize the intrinsic excitations of the nucleon. We show that the resonance can be related to the probability P N*(E) of finding the bare state, N*, in the πN scattering states in infinite volume. We further demonstrate that the probability P V N*(E) of finding the same bare states in the eigenfunctions of the underlying Hamiltonian in finite volume approaches P N*(E) as the volumemore » increases. Our findings suggest that the comparison of P N*(E) and P V N*(E) can be used to examine whether the nucleon resonances extracted from the πN reaction data within the dynamical models are consistent with lattice QCD calculation. We also discuss the measurement of P V N*(E) directly from lattice QCD. Furthermore, the practical differences between our approach and the approach using the Lüscher formalism to relate LQCD calculations to the nucleon resonance poles embedded in the data are also discussed.« less

Nucleon resonance structure in the finite volume of lattice QCD

DOE PAGES

Wu, Jia -Jun; Kamano, H.; Lee, T. -S. H.; ...

2017-06-19

An approach for relating the nucleon resonances extracted from πN reaction data to lattice QCD calculations has been developed by using the finite-volume Hamiltonian method. Within models of πN reactions, bare states are introduced to parametrize the intrinsic excitations of the nucleon. We show that the resonance can be related to the probability P N*(E) of finding the bare state, N*, in the πN scattering states in infinite volume. We further demonstrate that the probability P V N*(E) of finding the same bare states in the eigenfunctions of the underlying Hamiltonian in finite volume approaches P N*(E) as the volumemore » increases. Our findings suggest that the comparison of P N*(E) and P V N*(E) can be used to examine whether the nucleon resonances extracted from the πN reaction data within the dynamical models are consistent with lattice QCD calculation. We also discuss the measurement of P V N*(E) directly from lattice QCD. Furthermore, the practical differences between our approach and the approach using the Lüscher formalism to relate LQCD calculations to the nucleon resonance poles embedded in the data are also discussed.« less

Iowa State University – Final Report for SciDAC3/NUCLEI

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

Vary, James P

The Iowa State University (ISU) contributions to the NUCLEI project are focused on developing, implementing and running an efficient and scalable configuration interaction code (Many-Fermion Dynamics – nuclear or MFDn) for leadership class supercomputers addressing forefront research problems in low-energy nuclear physics. We investigate nuclear structure and reactions with realistic nucleon-nucleon (NN) and three-nucleon (3N) interactions. We select a few highlights from our work that has produced a total of more than 82 refereed publications and more than 109 invited talks under SciDAC3/NUCLEI.

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

Blunden, P. G.; Melnitchouk, W.

We examine the two-photon exchange corrections to elastic electron-nucleon scattering within a dispersive approach, including contributions from both nucleon and Δ intermediate states. The dispersive analysis avoids off-shell uncertainties inherent in traditional approaches based on direct evaluation of loop diagrams, and guarantees the correct unitary behavior in the high energy limit. Using empirical information on the electromagnetic nucleon elastic and NΔ transition form factors, we compute the two-photon exchange corrections both algebraically and numerically. Finally, results are compared with recent measurements of e + p to e - p cross section ratios from the CLAS, VEPP-3 and OLYMPUS experiments.

First Measurement of the E Double-polarization Observable for the γη to Κ +Σ - with CLAS & a New Forward Tagger Hodoscope for CLAS12

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

Fleming, Jamie

Establishing the excitation spectrum of the nucleon would be a key advance to further our understanding of nucleon structure and Quantum Chromodynamics (QCD). Recent theoretical advances allow predictions of the excitation spectrum of the nucleon and other nucleon properties directly from QCD in the nonperturbative regime, via numerical methods (such as Lattice QCD), complementing existing constituent quark models. There is an ongoing world programme in meson photoproduction from the nucleon, which has already led to a number of nucleon resonances being discovered and established. This advance has largely been made possible by the first accurate measurement of polarisation observables. Availablemore » data has been obtained for proton targets, whereas for a complete picture of meson photoproduction, data from the neutron must also be obtained. This is important, as nucleon resonances can have very different photo-couplings to the proton and neutron. This thesis presents the rst measurement of the E double-polarisation observable for the exclusive γη -> Κ +Σ - reaction using a polarised hydrogendeuterium target from the g14 run period at CLAS. Circularly polarised photons of energies between 1:1 and 2:3 GeV were used, with results shown in 200 MeV bins in E and bins of 0:4 in cosθ C.M./ Κ+ . Further to this, CLAS has undergone a detector upgrade in order to facilitate electrons of up to 12 GeV from Jefferson Lab's upgraded accelerator. Essential to this, is a new system for tagging quasi-real photons by detecting electrons scattered at very small angles. My work includes signi cant contributions to the design, realisation and construction of a hodoscope for this forward photon tagging apparatus. Presented in this thesis is a comprehensive overview of my work in developing and constructing the scintillating hodoscope for the CLAS12 Forward Tagger.« less

Power corrections to the universal heavy WIMP-nucleon cross section

NASA Astrophysics Data System (ADS)

Chen, Chien-Yi; Hill, Richard J.; Solon, Mikhail P.; Wijangco, Alexander M.

2018-06-01

WIMP-nucleon scattering is analyzed at order 1 / M in Heavy WIMP Effective Theory. The 1 / M power corrections, where M ≫mW is the WIMP mass, distinguish between different underlying UV models with the same universal limit and their impact on direct detection rates can be enhanced relative to naive expectations due to generic amplitude-level cancellations at leading order. The necessary one- and two-loop matching calculations onto the low-energy effective theory for WIMP interactions with Standard Model quarks and gluons are performed for the case of an electroweak SU(2) triplet WIMP, considering both the cases of elementary fermions and composite scalars. The low-velocity WIMP-nucleon scattering cross section is evaluated and compared with current experimental limits and projected future sensitivities. Our results provide the most robust prediction for electroweak triplet Majorana fermion dark matter direct detection rates; for this case, a cancellation between two sources of power corrections yields a small total 1 / M correction, and a total cross section close to the universal limit for M ≳ few × 100GeV. For the SU(2) composite scalar, the 1 / M corrections introduce dependence on underlying strong dynamics. Using a leading chiral logarithm evaluation, the total 1 / M correction has a larger magnitude and uncertainty than in the fermionic case, with a sign that further suppresses the total cross section. These examples provide definite targets for future direct detection experiments and motivate large scale detectors capable of probing to the neutrino floor in the TeV mass regime.

Neutrino Production of Opposite Sign Dimuons at the Fnal TEVATRON*.

NASA Astrophysics Data System (ADS)

Foudas, Constantinos

Neutrino-Nucleon (nu-N) interactions with two opposite sign muons (mu ^-mu^+) in the final state have been studied using the CCFR Detector and the Fermilab Quad Triplet Beam (FNAL-E744). In a sample of 670,000 nu-N and 124,000 |nu -N charged-current interactions, a total of 1522 nu-induced and 275 | nu-induced mu^-mu ^+ events have been observed, with 30 GeV < E_{nu} < 600 GeV and P_ {mu} > 9 GeV/c for both muons. The opposite sign dimuon data are consistent with the slow rescaling hypothesis of charm production in nu-N scattering, and within this formalism yield, a value of the charm quark mass parameter m_ c = 1.31_sp{ -0.48}{+0.64} GeV/c^2 . Using the opposite sign dimuon data after background subtraction we measured the strange quark content of the nucleon eta_ s = 0.057 _sp{-0.008}{+0.012} and the Kobayashi-Maskawa (KM) matrix element | V_{cd}| = 0.220_sp{ -0.018}{+0.015}. The nucleon momentum fraction carried by the strange quarks relative to non -strange quarks in the quark sea is kappa = 0.44_sp{-0.07}{+0.11 } which is approximately half that expected for an SU(3) flavor symmetric quark sea, and the strange quark momentum distribution is consistent with that of | u and | d. ftn*Research supported by the National Science Foundation. Submitted in partial fulfillment of the requirement for the degree of Doctor of Philosophy in the Graduate School of Arts and Sciences, Columbia University.

Nucleon measurements at the precision frontier

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

Carlson, Carl E.

We comment on nucleon measurements at the precision frontier. As examples of what can be learned, we concentrate on three topics, which are parity violating scattering experiments, the proton radius puzzle, and the symbiosis between nuclear and atomic physics.

Constraining gluon distributions in nuclei using dijets in proton-proton and proton-lead collisions at $$\\sqrt{s_{_\\mathrm{NN}}} =$$ 5.02 TeV

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

Sirunyan, Albert M; et al.

2018-05-12

The pseudorapidity distributions of dijets as a function of their average transverse momentum (more » $$p_\\mathrm{T}^\\text{ave}$$) are measured in proton-lead (pPb) and proton-proton (pp) collisions. The data samples were collected by the CMS experiment at the CERN LHC, at a nucleon-nucleon center-of-mass energy of 5.02 TeV. A significant modification of the pPb spectra with respect to the pp spectra is observed in all $$p_\\mathrm{T}^\\text{ave}$$ intervals investigated. The ratios of the pPb and pp distributions are compared to next-to-leading order perturbative quantum chromodynamics calculations with unbound nucleon and nuclear parton distribution functions (PDFs). These results give the first evidence that the gluon PDF at large Bjorken $x$ in lead ions is strongly suppressed with respect to the PDF in unbound nucleons.« less

Size of lethality target in mouse immature oocytes determined with accelerated heavy ions.

PubMed

Straume, T; Dobson, R L; Kwan, T C

1989-01-01

Mouse immature oocytes were irradiated in vivo with highly charged, heavy ions from the Bevalac accelerator at the Lawrence Berkeley Laboratory. The particles used were 670-MeV/nucleon Si14+, 570-MeV/nucleon Ar18+, and 450-MeV/nucleon Fe26+. The cross-sectional area of the lethality target in these extremely radiosensitive cells was determined from fluence-response curves and information on energy deposition by delta rays. Results indicate a target cross-section larger than that of the nucleus, one which closely approximates the cross-sectional area of the entire oocyte. For 450-MeV/nucleon Fe26+ particles, the predicted target cross-sectional area is 120 +/- 16 microns2, comparing well with the microscopically determined cross-sectional area of 111 +/- 12 microns2 for these cells. The present results are in agreement with our previous target studies which implicate the oocyte plasma membrane.

Solar cosmic ray composition above 10 MeV/nucleon and its energy dependence in the 4 August 1972 event. [including proton, helium, and Fe-group nuclei fluxes

NASA Technical Reports Server (NTRS)

Bertsch, D. L.; Biswas, S.; Reames, D. V.

1974-01-01

Observations of the proton, helium (C,N,O) and Fe-group nuclei fluxes made during the large 4 August 1972 solar particle event are presented. The results show a small, but significant variation of the composition of multicharged nuclei as a function of energy in the energy region above 10 MeV/nucleon. In particular, the He/(C,N,O) abundance ratio varies by a factor approximately 2 between 10 and 50 MeV/nucleon, and the Fe-group/(C,N,O) ratio suggests a similar variation. Abundance ratios from the 4 August 1972 event are compared as a function of energy with ratios measured in other solar events. At energies approximately greater than 50 MeV/nucleon, the He/(C,N,O) abundance ratio for August 1972 is consistent with all earlier measurements made above that energy.

Photo- and electroproduction of K+Λ with a unitarity-restored isobar model

NASA Astrophysics Data System (ADS)

Skoupil, D.; Bydžovský, P.

2018-02-01

Exploiting the isobar model, kaon photo- and electroproduction on the proton in the resonance region comes under scrutiny. An upgrade of our previous model, comprising higher-spin nucleon and hyperon exchanges in the consistent formalism, was accomplished by implementing energy-dependent widths of nucleon resonances, which leads to a different choice of hadron form factor with much softer values of cutoff parameter for the resonant part. For a reliable description of electroproduction, the necessity of including longitudinal couplings of nucleon resonances to virtual photons was revealed. We present a new model whose free parameters were adjusted to photo- and electroproduction data and which provides a reliable overall description of experimental data in all kinematic regions. The majority of nucleon resonances chosen in this analysis coincide with those selected in our previous analysis and also in the Bayesian analysis with the Regge-plus-resonance model as the states contributing to this process with the highest probability.

Off-shell test of the Moscow potential of nucleon-nucleon interaction on the basis of data on the reaction {gamma}d {sup {yields}} np in the photon-energy region around E{sub {gamma}} {approx_equal} 2 GeV, where this reaction is sensitive to quark effects

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

Knyr, V. A.; Neudatchin, V. G.; Khokhlov, N. A.

Various pieces of evidence in favor of the Moscow potential of nucleon-nucleon interaction are discussed. The formalism of a relativistic potential model as applied to deuteron photodintegration is expounded. The differential cross section calculated for the reaction {gamma}d {sup {yields}} np on the basis of the Moscow potential at incident-photon energies E{sub {gamma}} between 1.5 and 2.5 GeV are quite in accord with present-day experimental data, which are also described well in the literature on the basis of the model of quark-gluon strings. Further steps in testing the Moscow potential and microscopically substantiating it on the basis of quark modelsmore » are indicated.« less

Interacting Boson Model and nucleons

NASA Astrophysics Data System (ADS)

Otsuka, Takaharu

2012-10-01

An overview on the recent development of the microscopic derivation of the Interacting Boson Model is presented with some remarks not found elsewhere. The OAI mapping is reviewed very briefly, including the basic correspondence from nucleon-pair to boson. The new fermionboson mapping method is introduced, where intrinsic states of nucleons and bosons for a wide variation of shapes play an important role. Nucleon intrinsic states are obtained from mean field models, which is Skyrme model in examples to be shown. This method generates IBM-2 Hamiltonian which can describe and predict various situations of quadrupole collective states, including U(5), SU(3), O(6) and E(5) limits. The method is extended so that rotational response (cranking) can be handled, which enables us to describe rotational bands of strongly deformed nuclei. Thus, we have obtained a unified framework for the microscopic derivation of the IBM covering all known situations of quadrupole collectivity at low energy.

Production asymmetry of $$\\Lambda^0$$ and $${\\overline{\\Lambda}}^0$$ in $$\\pi^{\\pm}$$, $$K^{\\pm}$$, p - nucleon collisions at 250 GeV/c (in Portuguese)

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

Nicola, Marcello Santo

Using data from Fermilab xed-target experiment E769, we have measured particleantiparticle production asymmetries for Λ 0 hyperons in π ± - nucleon interactions, K ± - nucleon interactions and p - nucleon interactions at 250 GeV/c. The asymmetries are measured as functions of Feynman-x (x f ) and p T 2 over the ranges 0 ≤ p T 2 ≤ 4(GeV/c) 2 and -0.12 ≤ x F ≤ 0.12 (for positive beam) and 0 ≤ p T 2 ≤ 10(GeV/c) 2 and -0.16 ≤ x F ≤ 0:.0 for the negative beam. We find substantial asymmetries, even at x Fmore » = 0. We also observe leading-particle-type asymmetries which qualitatively agree with theoretical predictions.« less

Δ isobars and nuclear saturation

NASA Astrophysics Data System (ADS)

Ekström, A.; Hagen, G.; Morris, T. D.; Papenbrock, T.; Schwartz, P. D.

2018-02-01

We construct a nuclear interaction in chiral effective field theory with explicit inclusion of the Δ -isobar Δ (1232 ) degree of freedom at all orders up to next-to-next-to-leading order (NNLO). We use pion-nucleon (π N ) low-energy constants (LECs) from a Roy-Steiner analysis of π N scattering data, optimize the LECs in the contact potentials up to NNLO to reproduce low-energy nucleon-nucleon scattering phase shifts, and constrain the three-nucleon interaction at NNLO to reproduce the binding energy and point-proton radius of 4He. For heavier nuclei we use the coupled-cluster method to compute binding energies, radii, and neutron skins. We find that radii and binding energies are much improved for interactions with explicit inclusion of Δ (1232 ) , while Δ -less interactions produce nuclei that are not bound with respect to breakup into α particles. The saturation of nuclear matter is significantly improved, and its symmetry energy is consistent with empirical estimates.

Nucleon electromagnetic form factors using lattice simulations at the physical point

NASA Astrophysics Data System (ADS)

Alexandrou, C.; Constantinou, M.; Hadjiyiannakou, K.; Jansen, K.; Kallidonis, Ch.; Koutsou, G.; Vaquero Aviles-Casco, A.

2017-08-01

We present results for the nucleon electromagnetic form factors using an ensemble of maximally twisted mass clover-improved fermions with pion mass of about 130 MeV. We use multiple sink-source separations and three analysis methods to probe ground-state dominance. We evaluate both the connected and disconnected contributions to the nucleon matrix elements. We find that the disconnected quark loop contributions to the isoscalar matrix elements are small, giving an upper bound of up to 2% of the connected and smaller than its statistical error. We present results for the isovector and isoscalar electric and magnetic Sachs form factors and the corresponding proton and neutron form factors. By fitting the momentum dependence of the form factors to a dipole form or to the z expansion, we extract the nucleon electric and magnetic radii, as well as the magnetic moment. We compare our results to experiment as well as to other recent lattice QCD calculations.

Bonner Prize Address: Measurements of the electromagnetic properties of nucleons and nuclei at short distance scales

NASA Astrophysics Data System (ADS)

Raymond, Arnold

2000-04-01

The talk will present the story of a series of experiments, beginning in 1973 and continuing today, that have measured the internal structure of nuclei and the nucleons using high energy beams of electrons and photons at the Stanford Linear Accelerator Center. These experiments have probed nuclear and nucleon structure in the energy and momentum transfer region where the meson-nucleon description merges with the quark-gluon picture. The experiments have worked at the border between nuclear and particle physics, and were conducted by large collaborative teams. Some were carried out in the context of a special program, called NPAS (Nuclear Physics at SLAC). The early results from these measurements helped stimulate the ideas and helped train and motivate the physicists who went on to build the Jefferson Laboratory. A brief summary of some highlights from the early measurements and updates on recent results will be given.

Leading order relativistic chiral nucleon-nucleon interaction

NASA Astrophysics Data System (ADS)

Ren, Xiu-Lei; Li, Kai-Wen; Geng, Li-Sheng; Long, Bingwei; Ring, Peter; Meng, Jie

2018-01-01

Motivated by the successes of relativistic theories in studies of atomic/molecular and nuclear systems and the need for a relativistic chiral force in relativistic nuclear structure studies, we explore a new relativistic scheme to construct the nucleon-nucleon interaction in the framework of covariant chiral effective field theory. The chiral interaction is formulated up to leading order with covariant power counting and a Lorentz invariant chiral Lagrangian. We find that the relativistic scheme induces all six spin operators needed to describe the nuclear force. A detailed investigation of the partial wave potentials shows a better description of the {}1S0 and {}3P0 phase shifts than the leading order Weinberg approach, and similar to that of the next-to-leading order Weinberg approach. For the other partial waves with angular momenta J≥slant 1, the relativistic results are almost the same as their leading order non-relativistic counterparts. )

Spin-Flavor van der Waals Forces and NN interaction

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

Alvaro Calle Cordon, Enrique Ruiz Arriola

A major goal in Nuclear Physics is the derivation of the Nucleon-Nucleon (NN) interaction from Quantum Chromodynamics (QCD). In QCD the fundamental degrees of freedom are colored quarks and gluons which are confined to form colorless strongly interacting hadrons. Because of this the resulting nuclear forces at sufficiently large distances correspond to spin-flavor excitations, very much like the dipole excitations generating the van der Waals (vdW) forces acting between atoms. We study the Nucleon-Nucleon interaction in the Born-Oppenheimer approximation at second order in perturbation theory including the Delta resonance as an intermediate state. The potential resembles strongly chiral potentials computedmore » either via soliton models or chiral perturbation theory and has a van der Waals like singularity at short distances which is handled by means of renormalization techniques. Results for the deuteron are discussed.« less

Generalized polarizabilities of the nucleon in baryon chiral perturbation theory

NASA Astrophysics Data System (ADS)

Lensky, Vadim; Pascalutsa, Vladimir; Vanderhaeghen, Marc

2017-02-01

The nucleon generalized polarizabilities (GPs), probed in virtual Compton scattering (VCS), describe the spatial distribution of the polarization density in a nucleon. They are accessed experimentally via the process of electron-proton bremsstrahlung (ep→ epγ ) at electron-beam facilities, such as MIT-Bates, CEBAF (Jefferson Lab), and MAMI (Mainz). We present the calculation of the nucleon GPs and VCS observables at next-to-leading order in baryon chiral perturbation theory (Bχ PT), and confront the results with the empirical information. At this order our results are predictions, in the sense that all the parameters are well known from elsewhere. Within the relatively large uncertainties of our calculation we find good agreement with the experimental observations of VCS and the empirical extractions of the GPs. We find large discrepancies with previous chiral calculations - all done in heavy-baryon χ PT (HBχ PT) - and discuss the differences between Bχ PT and HBχ PT responsible for these discrepancies.

Cluster correlation and fragment emission in 12C+12C at 95 MeV/nucleon

NASA Astrophysics Data System (ADS)

Tian, G.; Chen, Z.; Han, R.; Shi, F.; Luo, F.; Sun, Q.; Song, L.; Zhang, X.; Xiao, G. Q.; Wada, R.; Ono, A.

2018-03-01

The impact of cluster correlations has been studied in the intermediate mass fragment (IMF) emission in 12C+12C at 95 MeV/nucleon, using antisymmetrized molecular dynamics (AMD) model simulations. In AMD, the cluster correlation is introduced as a process to form light clusters with A ≤4 in the final states of a collision induced by the nucleon-nucleon residual interaction. Correlations between light clusters are also considered to form light nuclei with A ≤9 . This version of AMD, combined with GEMINI to calculate the decay of primary fragments, reproduces the experimental energy spectra of IMFs well overall with reasonable reproduction of light charged particles when we carefully analyze the excitation energies of primary fragments produced by AMD and their secondary decays. The results indicate that the cluster correlation plays a crucial role for producing fragments at relatively low excitation energies in the intermediate-energy heavy-ion collisions.

CP Violation, Neutral Currents, and Weak Equivalence

DOE R&D Accomplishments Database

Fitch, V. L.

1972-03-23

Within the past few months two excellent summaries of the state of our knowledge of the weak interactions have been presented. Correspondingly, we will not attempt a comprehensive review but instead concentrate this discussion on the status of CP violation, the question of the neutral currents, and the weak equivalence principle.

Dilaton-assisted dark matter.

PubMed

Bai, Yang; Carena, Marcela; Lykken, Joseph

2009-12-31

A dilaton could be the dominant messenger between standard model fields and dark matter. The measured dark matter relic abundance relates the dark matter mass and spin to the conformal breaking scale. The dark matter-nucleon spin-independent cross section is predicted in terms of the dilaton mass. We compute the current constraints on the dilaton from LEP and Tevatron experiments, and the gamma-ray signal from dark matter annihilation to dilatons that could be observed by Fermi Large Area Telescope.

Nucleon decay in non-minimal supersymmetric SO(10)

NASA Astrophysics Data System (ADS)

Macpherson, Alick L.

1996-02-01

Evaluation of nucleon decay modes and branching ratios in a non-minimal supersymmetric SO(10) grand unified theory is presented. The non-minimal GUT considered is the supersymmetrised version of the 'realistic' SO(10) model originally proposed by Harvey, Reiss and Ramond, which is realistic in that it gives acceptable charged fermion and neutrino masses within the context of a phenomenological fit to the low-energy standard model inputs. Despite a complicated Higgs sector, the SO(10) 10 Higgs superfield mass insertion is found to be the sole contribution to the tree-level F-term governing nucleon decay. The resulting dimension-5 operators that mediate nucleon decay give branching ratio predictions parameterised by a single parameter, the ratio of the Yukawa couplings of the 10 to the fermion generations. For parameter values corresponding to a lack of dominance of the third family self-coupling, the dominant nucleon decay modes are p → K + + overlineνμand n → K 0 + overlineνμ as expected. Further, the charged muon decay modes are enhanced by two orders of magnitude over the standard minimal SUSY SU(5) predictions, thus predicting a distinct spectrum of 'visible' modes. These charged muon decay modes, along with p → π + + overlineνμand n → π 0 + overlineνμ, which are moderately enhanced over the SUSY SU(5) prediction, suggest a distinguishing fingerprint of this particular GUT model, and if nucleon decay is observed at Super-KAMIOKANDE the predicted branching ratio spectrum can be used to determine the validity of this 'realistic' SO(10) SUSY GUT model.

Interplay of short-range correlations and nuclear symmetry energy in hard-photon production from heavy-ion reactions at Fermi energies

NASA Astrophysics Data System (ADS)

Yong, Gao-Chan; Li, Bao-An

2017-12-01

Within an isospin- and momentum-dependent transport model for nuclear reactions at intermediate energies, we investigate the interplay of the nucleon-nucleon short-range correlations (SRCs) and nuclear symmetry energy Esym(ρ ) on hard-photon spectra in collisions of several Ca isotopes on 112Sn and 124Sn targets at a beam energy of 45 MeV/nucleon. It is found that over the whole spectra of hard photons studied, effects of the SRCs overwhelm those owing to the Esym(ρ ) . The energetic photons come mostly from the high-momentum tails (HMTs) of single-nucleon momentum distributions in the target and projectile. Within the neutron-proton dominance model of SRCs based on the consideration that the tensor force acts mostly in the isosinglet and spin-triplet nucleon-nucleon interaction channel, there are equal numbers of neutrons and protons, thus a zero isospin asymmetry in the HMTs. Therefore, experimental measurements of the energetic photons from heavy-ion collisions at Fermi energies have the great potential to help us better understand the nature of SRCs without any appreciable influence by the uncertain Esym(ρ ) . These measurements will be complementary to but also have some advantages over the ongoing and planned experiments using hadronic messengers from reactions induced by high-energy electrons or protons. Because the underlying physics of SRCs and Esym(ρ ) are closely correlated, a better understanding of the SRCs will, in turn, help constrain the nuclear symmetry energy more precisely in a broad density range.

Phenomenology of leading nucleon production in e p collisions at HERA in the framework of fracture functions

NASA Astrophysics Data System (ADS)

Shoeibi, Samira; Taghavi-Shahri, F.; Khanpour, Hamzeh; Javidan, Kurosh

2018-04-01

In recent years, several experiments at the e-p collider HERA have collected high precision deep-inelastic scattering (DIS) data on the spectrum of leading nucleon carrying a large fraction of the proton's energy. In this paper, we have analyzed recent experimental data on the production of forward protons and neutrons in DIS at HERA in the framework of a perturbative QCD. We propose a technique based on the fractures functions framework, and extract the nucleon fracture functions (FFs) M2(n /p )(x ,Q2;xL) from global QCD analysis of DIS data measured by the ZEUS Collaboration at HERA. We have shown that an approach based on the fracture functions formalism allows us to phenomenologically parametrize the nucleon FFs. Considering both leading neutron as well as leading proton production data at HERA, we present the results for the separate parton distributions for all parton species, including valence quark densities, the antiquark densities, the strange sea distribution, and the gluon distribution functions. We proposed several parametrizations for the nucleon FFs and open the possibility of these asymmetries. The obtained optimum set of nucleon FFs is accompanied by Hessian uncertainty sets which allow one to propagate uncertainties to other observables interest. The extracted results for the t -integrated leading neutron F2LN (3 )(x ,Q2;xL) and leading proton F2LP (3 )(x ,Q2;xL) structure functions are in good agreement with all data analyzed, for a wide range of fractional momentum variable x as well as the longitudinal momentum fraction xL.

Analysis of nucleon electromagnetic form factors from light-front holographic QCD: The spacelike region

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

Sufian, Raza Sabbir; de Teramond, Guy F.; Brodsky, Stanley J.

We present a comprehensive analysis of the space-like nucleon electromagnetic form factors and their flavor decomposition within the framework of light-front holographic QCD. We show that the inclusion of the higher Fock componentsmore » $$|{qqqq\\bar{q}}$$ has a significant effect on the spin-flip elastic Pauli form factor and almost zero effect on the spin-conserving Dirac form factor. We present light-front holographic QCD results for the proton and neutron form factors at any momentum transfer range, including asymptotic predictions, and show that our results agree with the available experimental data with high accuracy. In order to correctly describe the Pauli form factor we need an admixture of a five quark state of about 30$$\\%$$ in the proton and about 40$$\\%$$ in the neutron. We also extract the nucleon charge and magnetic radii and perform a flavor decomposition of the nucleon electromagnetic form factors. The free parameters needed to describe the experimental nucleon form factors are very few: two parameters for the probabilities of higher Fock states for the spin-flip form factor and a phenomenological parameter $r$, required to account for possible SU(6) spin-flavor symmetry breaking effects in the neutron, whereas the Pauli form factors are normalized to the experimental values of the anomalous magnetic moments. As a result, the covariant spin structure for the Dirac and Pauli nucleon form factors prescribed by AdS$$_5$$ semiclassical gravity incorporates the correct twist scaling behavior from hard scattering and also leads to vector dominance at low energy.« less

Algebraic diagrammatic construction formalism with three-body interactions

NASA Astrophysics Data System (ADS)

Raimondi, Francesco; Barbieri, Carlo

2018-05-01

Background: Self-consistent Green's function theory has recently been extended to the basic formalism needed to account for three-body interactions [Carbone, Cipollone, Barbieri, Rios, and Polls, Phys. Rev. C 88, 054326 (2013), 10.1103/PhysRevC.88.054326]. The contribution of three-nucleon forces has so far been included in ab initio calculations on nuclear matter and finite nuclei only as averaged two-nucleon forces. Purpose: We derive the working equations for all possible two- and three-nucleon terms that enter the expansion of the self-energy up to the third order, thus including the interaction-irreducible (i.e., not averaged) diagrams with three-nucleon forces that have been previously neglected. Methods: We employ the algebraic diagrammatic construction up to the third order as an organization scheme for generating a nonperturbative self-energy, in which ring (particle-hole) and ladder (particle-particle) diagrams are resummed to all orders. Results: We derive expressions of the static and dynamic self-energy up to the third order, by taking into account the set of diagrams required when either the skeleton or nonskeleton expansions of the single-particle propagator are assumed. A hierarchy of importance among different diagrams is revealed, and a particular emphasis is given to a third-order diagram [see Fig. 2(c)] that is expected to play a significant role among those featuring an interaction-irreducible three-nucleon force. Conclusion: A consistent formalism to resum at infinite order correlations induced by three-nucleon forces in the self-consistent Green's function theory is now available and ready to be implemented in the many-body solvers.

Analysis of nucleon electromagnetic form factors from light-front holographic QCD: The spacelike region

DOE PAGES

Sufian, Raza Sabbir; de Teramond, Guy F.; Brodsky, Stanley J.; ...

2017-01-10

We present a comprehensive analysis of the space-like nucleon electromagnetic form factors and their flavor decomposition within the framework of light-front holographic QCD. We show that the inclusion of the higher Fock componentsmore » $$|{qqqq\\bar{q}}$$ has a significant effect on the spin-flip elastic Pauli form factor and almost zero effect on the spin-conserving Dirac form factor. We present light-front holographic QCD results for the proton and neutron form factors at any momentum transfer range, including asymptotic predictions, and show that our results agree with the available experimental data with high accuracy. In order to correctly describe the Pauli form factor we need an admixture of a five quark state of about 30$$\\%$$ in the proton and about 40$$\\%$$ in the neutron. We also extract the nucleon charge and magnetic radii and perform a flavor decomposition of the nucleon electromagnetic form factors. The free parameters needed to describe the experimental nucleon form factors are very few: two parameters for the probabilities of higher Fock states for the spin-flip form factor and a phenomenological parameter $r$, required to account for possible SU(6) spin-flavor symmetry breaking effects in the neutron, whereas the Pauli form factors are normalized to the experimental values of the anomalous magnetic moments. As a result, the covariant spin structure for the Dirac and Pauli nucleon form factors prescribed by AdS$$_5$$ semiclassical gravity incorporates the correct twist scaling behavior from hard scattering and also leads to vector dominance at low energy.« less

Study of generalized parton distributions and deeply virtual compton scattering on the nucleon with the CLAS and CLAS12 detectors at the Jefferson Laboratory

NASA Astrophysics Data System (ADS)

Guegan, Baptiste

The Generalized Parton Distributions (GPDs) provide a new description of the nucleon structure in terms of its elementary constituents, the quarks and the gluons. The GPDs give access to a unified picture of the nucleon, correlating the information obtained from the measurements of the Form Factors and the Parton Distribution Functions. They describe the correlation between the transverse position and the longitudinal momentum fraction of the partons in the nucleon. Deeply Virtual Compton Scattering (DVCS), the electroproduction of a real photon on a single quark of the nucleon eN → eN'gamma , is the most straightforward exclusive process allowing access to the GPDs. The DVCS process interferes with the Bethe-Heitler (BH) process, in which the real photon is emitted by either the incoming or the scattered electron instead of the nucleon. A dedicated experiment to study DVCS with the CLAS detector of Jefferson Lab has been carried out using a 5.883 GeV polarized electron beam and an unpolarized hydrogen target, allowing to collect DVCS events in the widest kinematic range ever explored in the valence region : 1 < Q2 < 4.6 GeV2, 0.1 < xB < 0.58, 0.09 < -t < 3 GeV2. We will present preliminary results on the extraction of the unpolarized and the difference of polarized DVCS cross sections. We will show a preliminary extraction of the GPDs using the latest fitting code procedure on our data, and a preliminary interpretation of the results.

Nucleon and Elastic and Transition Form Factors

NASA Astrophysics Data System (ADS)

Segovia, Jorge; Cloët, Ian C.; Roberts, Craig D.; Schmidt, Sebastian M.

2014-12-01

We present a unified study of nucleon and elastic and transition form factors, and compare predictions made using a framework built upon a Faddeev equation kernel and interaction vertices that possess QCD-like momentum dependence with results obtained using a symmetry-preserving treatment of a vector vector contact-interaction. The comparison emphasises that experiments are sensitive to the momentum dependence of the running couplings and masses in the strong interaction sector of the Standard Model and highlights that the key to describing hadron properties is a veracious expression of dynamical chiral symmetry breaking in the bound-state problem. Amongst the results we describe, the following are of particular interest: possesses a zero at Q 2 = 9.5 GeV2; any change in the interaction which shifts a zero in the proton ratio to larger Q 2 relocates a zero in to smaller Q 2; there is likely a value of momentum transfer above which ; and the presence of strong diquark correlations within the nucleon is sufficient to understand empirical extractions of the flavour-separated form factors. Regarding the -baryon, we find that, inter alia: the electric monopole form factor exhibits a zero; the electric quadrupole form factor is negative, large in magnitude, and sensitive to the nature and strength of correlations in the Faddeev amplitude; and the magnetic octupole form factor is negative so long as rest-frame P- and D-wave correlations are included. In connection with the transition, the momentum-dependence of the magnetic transition form factor, , matches that of once the momentum transfer is high enough to pierce the meson-cloud; and the electric quadrupole ratio is a keen measure of diquark and orbital angular momentum correlations, the zero in which is obscured by meson-cloud effects on the domain currently accessible to experiment. Importantly, within each framework, identical propagators and vertices are sufficient to describe all properties discussed herein. Our analysis and predictions should therefore serve as motivation for measurement of elastic and transition form factors involving the nucleon and its resonances at high photon virtualities using modern electron-beam facilities.

Measurement of νμ charged-current single π0 production on hydrocarbon in the few-GeV region using MINERvA

NASA Astrophysics Data System (ADS)

Altinok, O.; Le, T.; Aliaga, L.; Bellantoni, L.; Bercellie, A.; Betancourt, M.; Bodek, A.; Bravar, A.; Budd, H.; Caceres Vera, G. F. R.; Cai, T.; Carneiro, M. F.; da Motta, H.; Dytman, S. A.; Díaz, G. A.; Felix, J.; Fields, L.; Fine, R.; Gago, A. M.; Galindo, R.; Gallagher, H.; Ghosh, A.; Gran, R.; Han, J. Y.; Harris, D. A.; Kleykamp, J.; Kordosky, M.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; Martinez Caicedo, D. A.; McFarland, K. S.; McGowan, A. M.; Messerly, B.; Miller, J.; Mislivec, A.; Morfín, J. G.; Naples, D.; Nelson, J. K.; Norrick, A.; Nuruzzaman, Paolone, V.; Patrick, C. E.; Perdue, G. N.; Ramirez, M. A.; Ransome, R. D.; Ray, H.; Ren, L.; Rimal, D.; Rodrigues, P. A.; Ruterbories, D.; Schellman, H.; Sobczyk, J. T.; Solano Salinas, C. J.; Sultana, M.; Sánchez Falero, S.; Valencia, E.; Wolcott, J.; Yaeggy, B.

2017-10-01

The semiexclusive channel νμ+CH →μ-π0+nucleon(s ) is analyzed using MINERvA exposed to the low-energy NuMI νμ beam with spectral peak at Eν≃3 GeV . Differential cross sections for muon momentum and production angle, π0 kinetic energy and production angle, and for squared four-momentum transfer are reported, and the cross section σ (Eν) is obtained over the range 1.5 GeV ≤Eν<20 GeV . Results are compared to GENIE and NuWro predictions and to published MINERvA cross sections for charged-current π+(π0) production by νμ(ν¯μ) neutrinos. Disagreements between data and simulation are observed at very low and relatively high values for muon angle and for Q2 that may reflect shortfalls in modeling of interactions on carbon. For π0 kinematic distributions, however, the data are consistent with the simulation and provide support for generator treatments of pion intranuclear scattering. Using signal-event subsamples that have reconstructed protons as well as π0 mesons, the p π0 invariant mass distribution is obtained, and the decay polar and azimuthal angle distributions in the rest frame of the p π0 system are measured in the region of Δ (1232 )+ production, W <1.4 GeV .

Measurement of ν μ charged-current single π 0 production on hydrocarbon in the few-GeV region using MINERvA

DOE PAGES

Altinok, O.; Le, T.; Aliaga, L.; ...

2017-10-01

The semiexclusive channel νμ+CH→μ-π0+nucleon(s) is analyzed using MINERvA exposed to the low-energy NuMI νμ beam with spectral peak at Eν≃3 GeV. Differential cross sections for muon momentum and production angle, π0 kinetic energy and production angle, and for squared four-momentum transfer are reported, and the cross section σ(Eν) is obtained over the range 1.5 GeV≤Eν<20 GeV. Results are compared to GENIE and NuWro predictions and to published MINERvA cross sections for charged-current π+(π0) production by νμ(ν¯μ) neutrinos. Disagreements between data and simulation are observed at very low and relatively high values for muon angle and for Q2 that may reflectmore » shortfalls in modeling of interactions on carbon. For π0 kinematic distributions, however, the data are consistent with the simulation and provide support for generator treatments of pion intranuclear scattering. Using signal-event subsamples that have reconstructed protons as well as π0 mesons, the pπ0 invariant mass distribution is obtained, and the decay polar and azimuthal angle distributions in the rest frame of the pπ0 system are measured in the region of Δ(1232)+ production, W<1.4 GeV.« less

Measurement of ν μ charged-current single π 0 production on hydrocarbon in the few-GeV region using MINERvA

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

Altinok, O.; Le, T.; Aliaga, L.

The semiexclusive channel νμ+CH→μ-π0+nucleon(s) is analyzed using MINERvA exposed to the low-energy NuMI νμ beam with spectral peak at Eν≃3 GeV. Differential cross sections for muon momentum and production angle, π0 kinetic energy and production angle, and for squared four-momentum transfer are reported, and the cross section σ(Eν) is obtained over the range 1.5 GeV≤Eν<20 GeV. Results are compared to GENIE and NuWro predictions and to published MINERvA cross sections for charged-current π+(π0) production by νμ(ν¯μ) neutrinos. Disagreements between data and simulation are observed at very low and relatively high values for muon angle and for Q2 that may reflectmore » shortfalls in modeling of interactions on carbon. For π0 kinematic distributions, however, the data are consistent with the simulation and provide support for generator treatments of pion intranuclear scattering. Using signal-event subsamples that have reconstructed protons as well as π0 mesons, the pπ0 invariant mass distribution is obtained, and the decay polar and azimuthal angle distributions in the rest frame of the pπ0 system are measured in the region of Δ(1232)+ production, W<1.4 GeV.« less

Pions to Quarks

NASA Astrophysics Data System (ADS)

Brown, Laurie Mark; Dresden, Max; Hoddeson, Lillian

2009-01-01

Part I. Introduction; 1. Pions to quarks: particle physics in the 1950s Laurie M Brown, Max Dresden and Lillian Hoddeson; 2. Particle physics in the early 1950s Chen Ning Yang; 3. An historian's interest in particle physics J. L. Heilbron; Part II. Particle discoveries in cosmic rays; 4. Cosmic-ray cloud-chamber contributions to the discovery of the strange particles in the decade 1947-1957 George D. Rochester; 5. Cosmic-ray work with emulsions in the 1940s and 1950s Donald H. Perkins; Part III. High-energy nuclear physics; Learning about nucleon resonances with pion photoproduction Robert L. Walker; 7. A personal view of nucleon structure as revealed by electron scattering Robert Hofstadter; 8. Comments on electromagnetic form factors of the nucleon Robert G. Sachs and Kameshwar C. Wali; Part IV. The new laboratory; 9. The making of an accelerator physicist Matthew Sands; 10. Accelerator design and construction in the 1950s John P. Blewett; 11. Early history of the Cosmotron and AGS Ernest D. Courant; 12. Panel on accelerators and detectors in the 1950s Lawrence W. Jones, Luis W. Alvarez, Ugo Amaldi, Robert Hofstadter, Donald W. Kerst, Robert R. Wilson; 13. Accelerators and the Midwestern Universities Research Association in the 1950s Donald W. Kerst; 14. Bubbles, sparks and the postwar laboratory Peter Galison; 15. Development of the discharge (spark) chamber in Japan in the 1950s Shuji Fukui; 16. Early work at the Bevatron: a personal account Gerson Goldhaber; 17. The discovery of the antiproton Owen Chamberlain; 18. On the antiproton discovery Oreste Piccioni; Part V. The Strange Particles; 19. The hydrogen bubble chamber and the strange resonances Luis W. Alvarez; 20. A particular view of particle physics in the fifties Jack Steinberger; 21. Strange particles William Chinowsky; 22. Strange particles: production by Cosmotron beams as observed in diffusion cloud chambers William B. Fowler; 23. From the 1940s into the 1950s Abraham Pais; Part VI. Detection of the neutrino Frederick Reines; 25. Recollections on the establishment of the weak-interaction notion Bruno M. Pontecorvo; 26. Symmetry and conservation laws in particle physics in the fifties Louis Michel; 27. A connection between the strong and weak interactions Sam B. Treiman; Part VII. Weak interactions and parity nonconservation; 29. The nondiscovery of parity nonconservation Allan Franklin; 30. K-meson decays and parity violation Richard H. Dalitz; 31. An Experimentalist's Perspective Val L. Fitch; 32. The early experiments leading to the V - A interaction Valentine L. Telegdi; 33. Midcentury adventures in particles physics E. C. G. Sudarshan; Part VIII. The particle physics community; 34. The postwar political economy of high-energy physics Robert Seidel; 35. The history of CERN during the early 1950s Edoardo Amaldi; 36. Arguments pro and contra the European laboratory in the participating countries Armin Hermann; 37. Physics and excellences of the life it brings Abdus Salam; 38. Social aspects of Japanese particle physics in the 1950s Michiji Konuma; Part IX. Theories of hadrons; 39. The early S-matrix theory and its propagation (1942-1952) Helmut Rechenberg; 40. From field theory to phenomenology: the history of dispersion relations Andy Pickering; 41. Particles as S-matrix poles: hadron democracy Geoffrey F. Chew; 42. The general theory of quantised fields in the 1950s Arthur S. Wrightman; 43. The classification and structure of hadrons Yuval Ne'eman; 44. Gauge principle, vector-meson dominance and spontaneous symmetry breaking Yoichiro Nambu; Part X. Personal overviews; 45. Scientific impact of the first decade of the Rochester conferences (1950-1960) Robert E. Marshak; 46. Some reflections on the history of particle physics in the 1950s Silvan S. Schweber; 47. Progress in elementary particle theory 1950-1964 Murray Gell-Mann.

Axial, scalar, and tensor charges of the nucleon from 2 + 1 + 1 -flavor lattice QCD

DOE PAGES

Bhattacharya, Tanmoy; Cirigliano, Vincenzo; Cohen, Saul D.; ...

2016-09-19

Here, we present results for the isovector axial, scalar, and tensor charges g u–d A, g u–d S, and g u–d T of the nucleon needed to probe the Standard Model and novel physics. The axial charge is a fundamental parameter describing the weak interactions of nucleons. The scalar and tensor charges probe novel interactions at the TeV scale in neutron and nuclear β-decays, and the flavor-diagonal tensor charges g u T, g d T, and g s T are needed to quantify the contribution of the quark electric dipole moment (EDM) to the neutron EDM. The lattice-QCD calculations weremore » done using nine ensembles of gauge configurations generated by the MILC Collaboration using the highly improved staggered quarks action with 2+1+1 dynamical flavors. These ensembles span three lattice spacings a ≈ 0.06,0.09, and 0.12 fm and light-quark masses corresponding to the pion masses M π ≈ 135, 225, and 315 MeV. High-statistics estimates on five ensembles using the all-mode-averaging method allow us to quantify all systematic uncertainties and perform a simultaneous extrapolation in the lattice spacing, lattice volume, and light-quark masses for the connected contributions. Our final estimates, in the ¯MS scheme at 2 GeV, of the isovector charges are g u–d A = 1.195(33)(20), g u–d S = 0.97(12)(6), and g u–d T = 0.987(51)(20). The first error includes statistical and all systematic uncertainties except that due to the extrapolation Ansatz, which is given by the second error estimate. Combining our estimate for gu–dS with the difference of light quarks masses (m d–m u) QCD = 2.67(35) MeV given by the Flavor Lattice Average Group, we obtain (M N – M P) QCD = 2.59(49) MeV. Estimates of the connected part of the flavor-diagonal tensor charges of the proton are g u T = 0.792(42) and g d T = –0.194(14). Combining our new estimates with precision low-energy experiments, we present updated constraints on novel scalar and tensor interactions, ε S,T, at the TeV scale.« less

Measurement of the νμ charged current quasielastic cross section on carbon with the T2K on-axis neutrino beam

NASA Astrophysics Data System (ADS)

Abe, K.; Adam, J.; Aihara, H.; Andreopoulos, C.; Aoki, S.; Ariga, A.; Assylbekov, S.; Autiero, D.; Barbi, M.; Barker, G. J.; Barr, G.; Bartet-Friburg, P.; Bass, M.; Batkiewicz, M.; Bay, F.; Berardi, V.; Berger, B. E.; Berkman, S.; Bhadra, S.; Blaszczyk, F. d. M.; Blondel, A.; Bolognesi, S.; Bordoni, S.; Boyd, S. B.; Brailsford, D.; Bravar, A.; Bronner, C.; Buchanan, N.; Calland, R. G.; Caravaca Rodríguez, J.; Cartwright, S. L.; Castillo, R.; Catanesi, M. G.; Cervera, A.; Cherdack, D.; Chikuma, N.; Christodoulou, G.; Clifton, A.; Coleman, J.; Coleman, S. J.; Collazuol, G.; Connolly, K.; Cremonesi, L.; Dabrowska, A.; Danko, I.; Das, R.; Davis, S.; de Perio, P.; De Rosa, G.; Dealtry, T.; Dennis, S. R.; Densham, C.; Dewhurst, D.; Di Lodovico, F.; Di Luise, S.; Dolan, S.; Drapier, O.; Duffy, K.; Dumarchez, J.; Dytman, S.; Dziewiecki, M.; Emery-Schrenk, S.; Ereditato, A.; Escudero, L.; Ferchichi, C.; Feusels, T.; Finch, A. J.; Fiorentini, G. A.; Friend, M.; Fujii, Y.; Fukuda, Y.; Furmanski, A. P.; Galymov, V.; Garcia, A.; Giffin, S.; Giganti, C.; Gilje, K.; Goeldi, D.; Golan, T.; Gonin, M.; Grant, N.; Gudin, D.; Hadley, D. R.; Haegel, L.; Haesler, A.; Haigh, M. D.; Hamilton, P.; Hansen, D.; Hara, T.; Hartz, M.; Hasegawa, T.; Hastings, N. C.; Hayashino, T.; Hayato, Y.; Hearty, C.; Helmer, R. L.; Hierholzer, M.; Hignight, J.; Hillairet, A.; Himmel, A.; Hiraki, T.; Hirota, S.; Holeczek, J.; Horikawa, S.; Hosomi, F.; Huang, K.; Ichikawa, A. K.; Ieki, K.; Ieva, M.; Ikeda, M.; Imber, J.; Insler, J.; Irvine, T. J.; Ishida, T.; Ishii, T.; Iwai, E.; Iwamoto, K.; Iyogi, K.; Izmaylov, A.; Jacob, A.; Jamieson, B.; Jiang, M.; Johnson, S.; Jo, J. H.; Jonsson, P.; Jung, C. K.; Kabirnezhad, M.; Kaboth, A. C.; Kajita, T.; Kakuno, H.; Kameda, J.; Kanazawa, Y.; Karlen, D.; Karpikov, I.; Katori, T.; Kearns, E.; Khabibullin, M.; Khotjantsev, A.; Kielczewska, D.; Kikawa, T.; Kilinski, A.; Kim, J.; King, S.; Kisiel, J.; Kitching, P.; Kobayashi, T.; Koch, L.; Koga, T.; Kolaceke, A.; Konaka, A.; Kopylov, A.; Kormos, L. L.; Korzenev, A.; Koshio, Y.; Kropp, W.; Kubo, H.; Kudenko, Y.; Kurjata, R.; Kutter, T.; Lagoda, J.; Lamont, I.; Larkin, E.; Laveder, M.; Lawe, M.; Lazos, M.; Lindner, T.; Lister, C.; Litchfield, R. P.; Longhin, A.; Lopez, J. P.; Ludovici, L.; Magaletti, L.; Mahn, K.; Malek, M.; Manly, S.; Marino, A. D.; Marteau, J.; Martin, J. F.; Martins, P.; Martynenko, S.; Maruyama, T.; Matveev, V.; Mavrokoridis, K.; Mazzucato, E.; McCarthy, M.; McCauley, N.; McFarland, K. S.; McGrew, C.; Mefodiev, A.; Metelko, C.; Mezzetto, M.; Mijakowski, P.; Miller, C. A.; Minamino, A.; Mineev, O.; Missert, A.; Miura, M.; Moriyama, S.; Mueller, Th. A.; Murakami, A.; Murdoch, M.; Murphy, S.; Myslik, J.; Nakadaira, T.; Nakahata, M.; Nakamura, K. G.; Nakamura, K.; Nakayama, S.; Nakaya, T.; Nakayoshi, K.; Nantais, C.; Nielsen, C.; Nirkko, M.; Nishikawa, K.; Nishimura, Y.; Nowak, J.; O'Keeffe, H. M.; Ohta, R.; Okumura, K.; Okusawa, T.; Oryszczak, W.; Oser, S. M.; Ovsyannikova, T.; Owen, R. A.; Oyama, Y.; Palladino, V.; Palomino, J. L.; Paolone, V.; Payne, D.; Perevozchikov, O.; Perkin, J. D.; Petrov, Y.; Pickard, L.; Pinzon Guerra, E. S.; Pistillo, C.; Plonski, P.; Poplawska, E.; Popov, B.; Posiadala-Zezula, M.; Poutissou, J.-M.; Poutissou, R.; Przewlocki, P.; Quilain, B.; Radicioni, E.; Ratoff, P. N.; Ravonel, M.; Rayner, M. A. M.; Redij, A.; Reeves, M.; Reinherz-Aronis, E.; Riccio, C.; Rodrigues, P. A.; Rojas, P.; Rondio, E.; Roth, S.; Rubbia, A.; Ruterbories, D.; Rychter, A.; Sacco, R.; Sakashita, K.; Sánchez, F.; Sato, F.; Scantamburlo, E.; Scholberg, K.; Schoppmann, S.; Schwehr, J.; Scott, M.; Seiya, Y.; Sekiguchi, T.; Sekiya, H.; Sgalaberna, D.; Shah, R.; Shaker, F.; Shaw, D.; Shiozawa, M.; Short, S.; Shustrov, Y.; Sinclair, P.; Smith, B.; Smy, M.; Sobczyk, J. T.; Sobel, H.; Sorel, M.; Southwell, L.; Stamoulis, P.; Steinmann, J.; Still, B.; Suda, Y.; Suzuki, A.; Suzuki, K.; Suzuki, S. Y.; Suzuki, Y.; Tacik, R.; Tada, M.; Takahashi, S.; Takeda, A.; Takeuchi, Y.; Tanaka, H. K.; Tanaka, H. A.; Tanaka, M. M.; Terhorst, D.; Terri, R.; Thompson, L. F.; Thorley, A.; Tobayama, S.; Toki, W.; Tomura, T.; Totsuka, Y.; Touramanis, C.; Tsukamoto, T.; Tzanov, M.; Uchida, Y.; Vacheret, A.; Vagins, M.; Vasseur, G.; Wachala, T.; Wakamatsu, K.; Walter, C. W.; Wark, D.; Warzycha, W.; Wascko, M. O.; Weber, A.; Wendell, R.; Wilkes, R. J.; Wilking, M. J.; Wilkinson, C.; Williamson, Z.; Wilson, J. R.; Wilson, R. J.; Wongjirad, T.; Yamada, Y.; Yamamoto, K.; Yanagisawa, C.; Yano, T.; Yen, S.; Yershov, N.; Yokoyama, M.; Yoo, J.; Yoshida, K.; Yuan, T.; Yu, M.; Zalewska, A.; Zalipska, J.; Zambelli, L.; Zaremba, K.; Ziembicki, M.; Zimmerman, E. D.; Zito, M.; Żmuda, J.; T2K Collaboration

2015-06-01

We report a measurement of the νμ charged current quasielastic cross-sections on carbon in the T2K on-axis neutrino beam. The measured charged current quasielastic cross-sections on carbon at mean neutrino energies of 1.94 GeV and 0.93 GeV are (11.95 ±0.19 (stat)-1.47+1.82(syst))×1 0-39 cm2/neutron , and (10.64 ±0.37 (stat)-1.65+2.03(syst))×1 0-39 cm2/neutron , respectively. These results agree well with the predictions of neutrino interaction models. In addition, we investigated the effects of the nuclear model and the multi-nucleon interaction.

Mars surface radiation exposure for solar maximum conditions and 1989 solar proton events

NASA Technical Reports Server (NTRS)

Simonsen, Lisa C.; Nealy, John E.

1992-01-01

The Langley heavy-ion/nucleon transport code, HZETRN, and the high-energy nucleon transport code, BRYNTRN, are used to predict the propagation of galactic cosmic rays (GCR's) and solar flare protons through the carbon dioxide atmosphere of Mars. Particle fluences and the resulting doses are estimated on the surface of Mars for GCR's during solar maximum conditions and the Aug., Sep., and Oct. 1989 solar proton events. These results extend previously calculated surface estimates for GCR's at solar minimum conditions and the Feb. 1956, Nov. 1960, and Aug. 1972 solar proton events. Surface doses are estimated with both a low-density and a high-density carbon dioxide model of the atmosphere for altitudes of 0, 4, 8, and 12 km above the surface. A solar modulation function is incorporated to estimate the GCR dose variation between solar minimum and maximum conditions over the 11-year solar cycle. By using current Mars mission scenarios, doses to the skin, eye, and blood-forming organs are predicted for short- and long-duration stay times on the Martian surface throughout the solar cycle.

Finite volume effects in the chiral extrapolation of baryon masses

NASA Astrophysics Data System (ADS)

Lutz, M. F. M.; Bavontaweepanya, R.; Kobdaj, C.; Schwarz, K.

2014-09-01

We perform an analysis of the QCD lattice data on the baryon octet and decuplet masses based on the relativistic chiral Lagrangian. The baryon self-energies are computed in a finite volume at next-to-next-to-next-to-leading order (N3LO), where the dependence on the physical meson and baryon masses is kept. The number of free parameters is reduced significantly down to 12 by relying on large-Nc sum rules. Altogether we describe accurately more than 220 data points from six different lattice groups, BMW, PACS-CS, HSC, LHPC, QCDSF-UKQCD and NPLQCD. Values for all counterterms relevant at N3LO are predicted. In particular we extract a pion-nucleon sigma term of 39-1+2 MeV and a strangeness sigma term of the nucleon of σsN=84-4+28 MeV. The flavor SU(3) chiral limit of the baryon octet and decuplet masses is determined with (802±4) and (1103±6) MeV. Detailed predictions for the baryon masses as currently evaluated by the ETM lattice QCD group are made.

Measurement of the Parity-Violating Asymmetries in Electron-Deuteron Scattering in the Nucleon Resonance Region

DOE PAGES

Wang, Diancheng; Pan, Kai; Subedi, Ramesh R.; ...

2013-08-22

We report on parity-violating asymmetries in the nucleon resonance region measured using 5 - 6 GeV longitudinally polarized electrons scattering off an unpolarized deuterium target. These results are the first parity-violating asymmetry data in the resonance region beyond the Δ(1232), and provide a verification of quark-hadron duality in the nucleon electroweak γ Z interference structure functions at the (10-15)% level. The results are of particular interest to models relevant for calculating the γ Z box-diagram corrections to elastic parity-violating electron scattering measurements.

Calculation of the Nucleon Axial Form Factor Using Staggered Lattice QCD

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

Meyer, Aaron S.; Hill, Richard J.; Kronfeld, Andreas S.

The nucleon axial form factor is a dominant contribution to errors in neutrino oscillation studies. Lattice QCD calculations can help control theory errors by providing first-principles information on nucleon form factors. In these proceedings, we present preliminary results on a blinded calculation ofmore » $$g_A$$ and the axial form factor using HISQ staggered baryons with 2+1+1 flavors of sea quarks. Calculations are done using physical light quark masses and are absolutely normalized. We discuss fitting form factor data with the model-independent $z$ expansion parametrization.« less

Stopped nucleons in configuration space

DOE PAGES

Bialas, Andrzej; Bzdak, Adam; Koch, Volker

2017-05-09

In this note, using the colour string model, we study the configuration space distribution of stopped nucleons in heavy-ion collisions. We find that the stopped nucleons from the target and the projectile end up separated from each other by the distance increasing with the collision energy. In consequence, for the center of mass energies larger than 6 or 10 GeV (depending on the details of the model) it appears that the system created is not in thermal and chemical equilibrium, and the net baryon density reached is likely not much higher than that already present in the colliding nuclei.

Charged mediators in dark matter scattering

NASA Astrophysics Data System (ADS)

Stengel, Patrick

2017-11-01

We consider a scenario, within the framework of the MSSM, in which dark matter is bino-like and dark matter-nucleon spin-independent scattering occurs via the exchange of light squarks which exhibit left-right mixing. We show that direct detection experiments such as LUX and SuperCDMS will be sensitive to a wide class of such models through spin-independent scattering. The dominant nuclear physics uncertainty is the quark content of the nucleon, particularly the strangeness content. We also investigate parameter space with nearly degenerate neutralino and squark masses, thus enhancing dark matter annihilation and nucleon scattering event rates.

Neutron matter at next-to-next-to-next-to-leading order in chiral effective field theory.

PubMed

Tews, I; Krüger, T; Hebeler, K; Schwenk, A

2013-01-18

Neutron matter presents a unique system for chiral effective field theory because all many-body forces among neutrons are predicted to next-to-next-to-next-to-leading order (N(3)LO). We present the first complete N(3)LO calculation of the neutron matter energy. This includes the subleading three-nucleon forces for the first time and all leading four-nucleon forces. We find relatively large contributions from N(3)LO three-nucleon forces. Our results provide constraints for neutron-rich matter in astrophysics with controlled theoretical uncertainties.