Science.gov

Sample records for antineutrino nucleon scattering

  1. Single photon production induced by (anti)neutrino neutral current scattering on nucleons and nuclear targets

    SciTech Connect

    Alvarez-Ruso, L.; Nieves, J.; Wang, E.

    2015-10-15

    We review our theoretical approach to neutral current photon emission on nucleons and nuclei in the few-GeV energy region, relevant for neutrino oscillation experiments. These reactions are dominated by the weak excitation of the Δ(1232) resonance but there are also important non-resonant contributions. We have also included terms mediated by nucleon excitations from the second resonance region. On nuclei, Pauli blocking, Fermi motion and the in-medium Δ resonance broadening have been taken into account for both incoherent and coherent reaction channels. With this model, the number and distributions of photon events at the MiniBooNE and T2K experiments have been obtained. We have also compared to the NOMAD upper limit at higher energies. The implications of our findings and future perspectives are discussed.

  2. Measurements of cross-section of charge current inclusive of antineutrino scattering off nucleons using carbon, iron, lead and scintillator at MINER$\

    SciTech Connect

    Rakotondravohitra, Laza

    2015-08-18

    Neutrino physics is one of the most active fields in the domaine of high energy physics during the last century. The need of precise measurement of neutrino-nucleus interactions required by the neutrino oscillation experiments is a an exiting step. These measurements of cross-section are more than essential for neutrino oscillation experiment. Over the year, many measurements from varieties of experiments have been presented. MINERνA is one of the world leaders in measuring cross-section of neutrino and antineutrino -nucleus interactions. MINERνA is a neutrino-nucleus scattering experiment installed in the few-GeV NuMI beam line at Fermilab. In order to study nuclear dependence, MINERνA is endowed with different types of solid nuclear targets as well are liquid targets such as helium and water. This thesis presents measurements of cross-section of antineutrino scattering off nucleons using a variety of solid nuclear targets, carbon, iron, lead and also polystyrene scintillator (CH). The data set of antineutrino used for this analysis was taken between March and July 2010 with a total of 1.60X1020 protons on target. Charged current inclusive interactions were selected by requiring a positive muon and kinematics limitation of acceptance of the muon spectrometer are applied. The analysis requires neutrino energy between 2GeV et 20GeV and the angle of muon θmu < 17degree . The absolute cross-section # as function of neutrino energy and the differential cross-section dσ/ dxbj measured and shown the corresponding systematics for each nuclear targets. Data results are compared with prediction of the models implemented in the neutrino events generators GENIE 2.6.2 used by the experiment.

  3. Quasielastic production of polarized hyperons in antineutrino-nucleon reactions

    NASA Astrophysics Data System (ADS)

    Akbar, F.; Alam, M. Rafi; Athar, M. Sajjad; Singh, S. K.

    2016-12-01

    We have studied the differential cross section as well as the longitudinal and perpendicular components of polarization of the final hyperon (Λ ,Σ ) produced in the antineutrino induced quasielastic charged current reactions on nucleon and nuclear targets. The nucleon-hyperon transition form factors are determined from the experimental data on quasielastic (Δ S =0 ) charged current (anti)neutrino-nucleon scattering and the semileptonic decay of neutron and hyperons assuming G-invariance, T-invariance, and SU(3) symmetry. The vector transition form factors are obtained in terms of nucleon electromagnetic form factors for which various parametrizations available in the literature have been used. A dipole parametrization for the axial vector form factor and the pseudoscalar transition form factor derived in terms of the axial vector form factor assuming PCAC and GT relation extended to the strangeness sector has been used in numerical evaluations. The flux averaged cross section and polarization observables corresponding to the CERN Gargamelle experiment have been calculated for quasielastic hyperon production and found to be in reasonable agreement with the experimental observations. The numerical results for the flux averaged differential cross section d/σ d Q2 and longitudinal (perpendicular) polarization PL(Q2)(PP(Q2)) relevant for the antineutrino fluxes of MINER ν A , MicroBooNE, and T2K experiments have been presented. This will be useful in interpreting future experimental results on production cross sections and polarization observables from the experiments on the quasielastic production of hyperons induced by antineutrinos and exploring the possibility of determining the axial vector and pseudoscalar form factors in the strangeness sector.

  4. Nucleon compositeness and nucleon-nuclei scattering

    NASA Astrophysics Data System (ADS)

    Li, Ming

    1990-04-01

    Large N QCD arguments are used to distinguish phenomenology of nucleon-nuclei scattering based on the Dirac equation with point nucleons and on quark based models with composite nucleons. The Friedberg-Lee soliton model is used as an explicit example.

  5. Hyperon-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Rijken, Th. A.; Maessen, P. M. M.; de Swart, J. J.

    1991-04-01

    The YN-scattering low energy data are analyzed from the perspectives of the recently published Nijmegen soft-core Hyperon-Nucleon potential model. This model is derived from the soft-core Nucleon-Nucleon model using notably SU(3). Differences with the Nijmegen hard-core models D and F are indicated. The predictions of the differential cross section and the Λ-spin observables DNN, DSS, DSL, DLS, and DLL, which could be measured by PILAC, are given for pΛ(lab)=600 MeV/c.

  6. Hyperon-nucleon scattering

    SciTech Connect

    Rijken, T.A.; Maessen, P.M.M.; de Swart, J.J. )

    1991-04-25

    The YN-scattering low energy data are analyzed from the perspectives of the recently published Nijmegen soft-core Hyperon-Nucleon potential model. This model is derived from the soft-core Nucleon-Nucleon model using notably SU(3). Differences with the Nijmegen hard-core models D and F are indicated. The predictions of the differential cross section and the {Lambda}-spin observables {ital D}{sub {ital NN}}, {ital D}{sub {ital SS}}, {ital D}{sub {ital SL}}, {ital D}{sub {ital LS}}, and {ital D}{sub {ital LL}}, which could be measured by PILAC, are given for {ital p}{sub {Lambda}}(lab)=600 MeV/c.

  7. Neutrino and antineutrino CCQE scattering in the SuperScaling Approximation from MiniBooNE to NOMAD energies

    NASA Astrophysics Data System (ADS)

    Megias, G. D.; Amaro, J. E.; Barbaro, M. B.; Caballero, J. A.; Donnelly, T. W.

    2013-08-01

    We compare the predictions of the SuperScaling model for charged-current quasielastic muonic neutrino and antineutrino scattering from 12C with experimental data spanning an energy range up to 100 GeV. We discuss the sensitivity of the results to different parametrizations of the nucleon vector and axial-vector form factors. Finally, we show the differences between electron and muon (anti)neutrino cross sections relevant for the νSTORM facility.

  8. Anti-Neutrino Quasi-Elastic Scattering at MINERvA

    NASA Astrophysics Data System (ADS)

    Maher, Emily

    2012-10-01

    Quasi-elastic neutrino scattering provides a means of measuring the axial form factor of the nucleon, and is a valuable tool for determining the neutrino beam energy in oscillation experiments. There are disagreements between measurements for neutrino energies below 1 GeV on scintillator and those at higher energies. MINERvA provides a bridge between the two regimes. Preliminary results for charge current quasi-elastic scattering results for anti-neutrinos (νμ+ p ->&+circ;+ n) on scintillator will be presented.

  9. The Scattering of Fast Nucleons from Nuclei

    NASA Astrophysics Data System (ADS)

    Kerman, A. K.; McManus, H.; Thaler, R. M.

    2000-04-01

    The formal theory of the scattering of high-energy nucleons by nuclei is developed in terms of the nucleon-nucleon scattering amplitude. The most important approximations necessary to make numerical calculation feasible are then examined. The optical model potential is derived on this basis and compared with the optical model parameters found from experiment. The elastic scattering and polarization of nucleons from light nuclei is predicted and compared with experiment. The effect of nuclear correlations is discussed. The polarization of inelastically scattered nucleons is discussed and predictions compared with experiments. To within the validity of the approximations the experimental data on the scattering of nucleons from nuclei at energies above ˜100 Mev appears to be consistent with the theory.

  10. Neutrino-pair bremsstrahlung from nucleon-nucleon scattering

    DOE PAGES

    Li, Yi; Liou, M. K.; Schreiber, W. M.; ...

    2015-07-22

    Background: Neutrino-pair bremsstrahlung processes from nucleon-nucleon scattering ΝΝνν¯ (nnvv¯, ppvv¯, and npvv¯) have recently attracted attention in studies of neutrino emission in neutron stars, because of the implications for the neutron star cooling. The calculated ΝΝνν¯ emissivities within the neutron star environment are relatively insensitive to the two-nucleon dynamical model used in the calculations, but differ significantly from those obtained using an OPE model. Purpose: To investigate the free ΝΝνν¯ cross sections using a realistic nucleon-nucleon scattering amplitude, comparing the relative sizes of the cross sections for the three processes nnvv¯, ppvv¯, and npvv¯.

  11. Backward pion-nucleon scattering

    SciTech Connect

    F. Huang; Sibirtsev, Alex; Haidenbauer, Johann; Meissner, Ulf-G.

    2010-02-01

    A global analysis of the world data on differential cross sections and polarization asymmetries of backward pion-nucleon scattering for invariant collision energies above 3 GeV is performed in a Regge model. Including the $N_\\alpha$, $N_\\gamma$, $\\Delta_\\delta$ and $\\Delta_\\beta$ trajectories, we reproduce both angular distributions and polarization data for small values of the Mandelstam variable $u$, in contrast to previous analyses. The model amplitude is used to obtain evidence for baryon resonances with mass below 3 GeV. Our analysis suggests a $G_{39}$ resonance with a mass of 2.83 GeV as member of the $\\Delta_{\\beta}$ trajectory from the corresponding Chew-Frautschi plot.

  12. Nucleon-Nucleon Scattering From Fully-Dynamical Lattice QCD

    SciTech Connect

    Konstantinos Orginos; Martin Savage; Paulo Bedaque; Silas Beane

    2006-07-01

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

  13. Covariant formulation of pion-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Lahiff, A. D.; Afnan, I. R.

    A covariant model of elastic pion-nucleon scattering based on the Bethe-Salpeter equation is presented. The kernel consists of s- and u-channel nucleon and delta poles, along with rho and sigma exchange in the t-channel. A good fit is obtained to the s- and p-wave phase shifts up to the two-pion production threshold.

  14. Scattering of dressed nucleons in nuclear matter

    NASA Astrophysics Data System (ADS)

    Dickhoff, W. H.

    1998-11-01

    The scattering of dressed nucleons in nuclear matter is studied. By casting the conventional asymptotic analysis of scattering in free space in the language of the two-body propagator, it becomes possible to develop modifications of this analysis due to the dressing of the scattering nucleons in the medium. While the scattering energy singles out a unique (on-shell) momentum characterizing the relative wave function of free or mean-field nucleons, this uniqueness is no longer maintained for dressed nucleons. The resulting distribution of momenta in the relative wave function leads to a localization in coordinate space of the influence of the scattering process which can be expressed as a healing of the wave function to the noninteracting one. An analytic approximation to the noninteracting propagator of the dressed nucleons is utilized to illustrate these points. The localization of the scattered wave implies that the particles no longer ``remember'' their scattering event beyond some finite distance. This feature suggests that the strict notion of a cross section in the medium is a tenuous concept. Approximate expressions are developed to characterize the strength of the interaction in the medium in terms of phase shifts and cross sections to facilitate comparisons with results of calculations involving mean-field nucleons.

  15. Neutrino-pair bremsstrahlung from nucleon-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Li, Yi; Liou, M. K.; Schreiber, W. M.; Gibson, B. F.

    2015-07-01

    Background: Neutrino-pair bremsstrahlung processes from nucleon-nucleon scattering N N ν ν ¯ (n n ν ν ¯ ,p p ν ν ¯ , and n p ν ν ¯ ) have recently attracted attention in studies of neutrino emission in neutron stars, because of the implications for the neutron star cooling. The calculated N N ν ν ¯ emissivities within the neutron star environment are relatively insensitive to the two-nucleon dynamical model used in the calculations, but differ significantly from those obtained using an one-pion-exchange (OPE) model. Purpose: We investigate the free N N ν ν ¯ cross sections using a realistic nucleon-nucleon scattering amplitude, comparing the relative sizes of the cross sections for the three processes n n ν ν ¯ ,p p ν ν ¯ , and n p ν ν ¯ . Method: We employ a realistic one-boson-exchange (ROBE) model for N N scattering and combine those strong scattering amplitudes with the well-known nucleon weak interaction vertices to construct weak bremsstrahlung amplitudes. Using the resulting N N ν ν ¯ amplitudes we investigate the relative importance of the vector (ΓVμ) , axial vector (ΓAμ) , and tensor (ΓTμ) terms. The ROBE model bremsstrahlung amplitudes are also used as a two-nucleon dynamical model with which we calculate the cross sections d/σ d ω for n n ν ν ¯ ,p p ν ν ¯ , and n p ν ν ¯ . Results: The three free N N ν ν ¯ cross sections d/σ d ω are of similar order of magnitude. Each increases with increasing neutrino-pair energy ω . For the neutrino-pair energy of ω =1 MeV our n n ν ν ¯ results are in quantitative agreement with those previously reported by Timmermans et al. [Phys. Rev. C 65, 064007 (2002), 10.1103/PhysRevC.65.064007], who used the leading-order term of the soft-neutrino-pair bremsstrahlung amplitude to calculate the cross sections. Differences between the n n ν ν ¯ and p p ν ν ¯ cross section are not discernible over the nucleon-nucleon incident energy region considered, due to the

  16. Polarized lepton-nucleon scattering

    SciTech Connect

    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 the 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.

  17. Nucleon-nucleon scattering observables in large- Nc QCD

    NASA Astrophysics Data System (ADS)

    Cohen, Thomas D.; Gelman, Boris A.

    2002-08-01

    Nucleon-nucleon scattering observables are considered in the context of the large Nc limit of QCD for initial states with moderately high momenta ( p∼ Nc). The scattering is studied in the framework of the time-dependent mean-field approximation. We focus on the dependence of those observables on the spin and isospin of the initial state which may be computed using time-dependent mean-field theory. We show that, up to corrections, all such observables must be invariant under simultaneous spin and isospin flips (i.e., rotations through π/2 in both spin and isospin) acting on either particle. All observables of this class obtained from spin unpolarized measurements must be isospin independent up to 1/ Nc corrections. Moreover, it can be shown that the leading correction is of relative order 1/ Nc2 rather than 1/ Nc.

  18. Pion-nucleon scattering and pion production in nucleon-nucleon and nucleus-nucleus collisions

    SciTech Connect

    Dover, C.B.

    1982-01-01

    Lecture notes are presented on the following: (1) basic aspects of ..pi..N interactions (properties of pions and nucleons, SU(3) and SU(6) classification phenomenology of ..pi..N scattering ((3.3) resonance; phase shift analysis, and bag model approach to ..pi..N); (2) pion production and absorption in the two nucleon system (NN ..-->.. NN..pi.. (isobar model) and ..pi..d reversible NN (existence of dibaryon resonances)); (3) pion absorption in complex nuclei (multiparticle aspects and cascade calculations); and (4) pion production with nuclear targets including (a) nucleon-nucleus, (b) nucleus-nucleus (Fermi-averaged 2-body vs thermodynamic models), and (c) ..pi pi.. interoferometry.

  19. Skyrmion recoil in pion-nucleon scattering

    SciTech Connect

    Hughes, J. Physics Department, University of California at Davis, Davis, California 95616 ); Mathews, G.J. )

    1992-08-01

    We calculate the lowest-order recoil corrections to the pion-nucleon scattering matrix in the SU(2) Skyrme model. The corrections result from a direct semiclassical evaluation of path-integral expressions for relevant finite-time transition amplitudes. The {ital S} matrix for pion-nucleon scattering is extracted from these amplitudes by using a configuration-space representation for the asymptotic nucleons; the quanta are treated just as in the vacuum sector. The recoil corrections result from the Skyrmion freely translating between initial and final positions, and are relevant to a kinematical regime opposite to that where the impulse approximation is valid. The form of the corrections is model independent, unchanged for any chiral model with hedgehog solitary wave solutions. Remarkably, new lowest-lying resonances emerge in the {ital p} channels, whereas the {ital s} and {ital d} waves are not noticeably improved.

  20. Low-energy pion-nucleon scattering

    SciTech Connect

    Gibbs, W.R.; Ai, L.; Kaufmann, W.B.

    1998-02-01

    An analysis of low-energy charged pion-nucleon data from recent {pi}{sup {plus_minus}}p experiments is presented. From the scattering lengths and the Goldberger-Miyazawa-Oehme (GMO) sum rule we find a value of the pion-nucleon coupling constant of f{sup 2}=0.0756{plus_minus}0.0007. We also find, contrary to most previous analyses, that the scattering volumes for the P{sub 31} and P{sub 13} partial waves are equal, within errors, corresponding to a symmetry found in the Hamiltonian of many theories. For the potential models used, the amplitudes are extrapolated into the subthreshold region to estimate the value of the {Sigma} term. Off-shell amplitudes are also provided. {copyright} {ital 1998} {ital The American Physical Society}

  1. Low-energy pion-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Gibbs, W. R.; Ai, Li; Kaufmann, W. B.

    1998-02-01

    An analysis of low-energy charged pion-nucleon data from recent π+/-p experiments is presented. From the scattering lengths and the Goldberger-Miyazawa-Oehme (GMO) sum rule we find a value of the pion-nucleon coupling constant of f2=0.0756+/-0.0007. We also find, contrary to most previous analyses, that the scattering volumes for the P31 and P13 partial waves are equal, within errors, corresponding to a symmetry found in the Hamiltonian of many theories. For the potential models used, the amplitudes are extrapolated into the subthreshold region to estimate the value of the Σ term. Off-shell amplitudes are also provided.

  2. Deeply virtual Compton scattering and nucleon structure

    SciTech Connect

    M. Garcon

    2006-11-01

    Deeply Virtual Compton Scattering (DVCS) is the tool of choice to study Generalized Parton Distributions (GPD) in the nucleon. After a general introduction to the subject, a review of experimental results from various facilities is given. Following the first encouraging results, new generation dedicated experiments now allow unprecedented precision and kinematical coverage. Several new results were presented during the conference, showing significant progress in this relatively new field. Prospects for future experiments are presented. The path for the experimental determination of GPDs appears now open.

  3. Quark models of dibaryon resonances in nucleon-nucleon scattering

    SciTech Connect

    Ping, J. L.; Huang, H. X.; Pang, H. R.; Wang Fan; Wong, C. W.

    2009-02-15

    We look for {delta}{delta} and N{delta} resonances by calculating NN scattering phase shifts of two interacting baryon clusters of quarks with explicit coupling to these dibaryon channels. Two phenomenological nonrelativistic chiral quark models giving similar low-energy NN properties are found to give significantly different dibaryon resonance structures. In the chiral quark model (ChQM), the dibaryon system does not resonate in the NNS waves, in agreement with the experimental SP07 NN partial-wave scattering amplitudes. In the quark delocalization and color screening model (QDCSM), the S-wave NN resonances disappear when the nucleon size b falls below 0.53 fm. Both quark models give an IJ{sup P}=03{sup +}{delta}{delta} resonance. At b=0.52 fm, the value favored by the baryon spectrum, the resonance mass is 2390 (2420) MeV for the ChQM with quadratic (linear) confinement, and 2360 MeV for the QDCSM. Accessible from the {sup 3}D{sub 3}{sup NN} channel, this resonance is a promising candidate for the known isoscalar ABC structure seen more clearly in the pn{yields}d{pi}{pi} production cross section at 2410 MeV in the recent preliminary data reported by the CELSIUS-WASA Collaboration. In the isovector dibaryon sector, our quark models give a bound or almost bound {sup 5}S{sub 2}{sup {delta}}{sup {delta}} state that can give rise to a {sup 1}D{sub 2}{sup NN} resonance. None of the quark models used have bound N{delta}P states that might generate odd-parity resonances.

  4. Anti-Neutrino Charged Current Quasi-Elastic Scattering in MINER$\

    SciTech Connect

    Chvojka, Jesse John

    2012-01-01

    The phenomenon of neutrino oscillation is becoming increasingly understood with results from accelerator-based and reactor-based experiments, but unanswered questions remain. The proper ordering of the neutrino mass eigenstates that compose the neutrino avor eigenstates is not completely known. We have yet to detect CP violation in neutrino mixing, which if present could help explain the asymmetry between matter and anti-matter in the universe. We also have not resolved whether sterile neutrinos, which do not interact in any Standard Model interaction, exist. Accelerator-based experiments appear to be the most promising candidates for resolving these questions; however, the ability of present and future experiments to provide answers is likely to be limited by systematic errors. A significant source of this systematic error comes from limitations in our knowledge of neutrino-nucleus interactions. Errors on cross-sections for such interactions are large, existing data is sometimes contradictory, and knowledge of nuclear effects is incomplete. One type of neutrino interaction of particular interest is charged current quasi-elastic (CCQE) scattering, which yields a final state consisting of a charged lepton and nucleon. This process, which is the dominant interaction near energies of 1 GeV, is of great utility to neutrino oscillation experiments since the incoming neutrino energy and the square of the momentum transferred to the final state nucleon, Q2, can be reconstructed using the final state lepton kinematics. To address the uncertainty in our knowledge of neutrino interactions, many experiments have begun making dedicated measurements. In particular, the MINER A experiment is studying neutrino-nucleus interactions in the few GeV region. MINERvA is a fine-grained, high precision, high statistics neutrino scattering experiment that will greatly improve our understanding of neutrino cross-sections and nuclear effects that affect the final state particles

  5. 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.

  6. Exploratory study of nucleon-nucleon scattering lengths in lattice QCD

    SciTech Connect

    Fukugita, M.; Kuramashi, Y.; Mino, H.; Okawa, M.; Ukawa, A. National Laboratory for High Energy Physics , Tsukuba, Ibaraki 305 Faculty of Engineering, Yamanashi University, Kofu 404 Institute of Physics, University of Tsukuba, Tsukuba, Ibaraki 305 )

    1994-10-17

    An exploratory study is made of the nucleon-nucleon [ital s]-wave scattering lengths in quenched lattice QCD with the Wilson quark action. The [pi]-[ital N] and [pi]-[pi] scattering lengths are also calculated for comparison. The calculations are made with heavy quarks corresponding to [ital m][sub [pi

  7. Electromagnetic Form Factors of the Nucleon and Compton Scattering

    SciTech Connect

    Charles Hyde-Wright; Cornelis De Jager

    2004-12-01

    We review the experimental and theoretical status of elastic electron scattering and elastic low-energy photon scattering (with both real and virtual photons) from the nucleon. As a consequence of new experimental facilities and new theoretical insights, these subjects are advancing with unprecedented precision. These reactions provide many important insights into the spatial distributions and correlations of quarks in the nucleon.

  8. Inelastic electron scattering from a moving nucleon

    SciTech Connect

    Kuhn, S.E.; Griffioen, K.

    1994-04-01

    The authors propose to measure inelastically scattered electrons in coincidence with spectator protons emitted backwards relative to the virtual photon direction in the reaction d(e, e{prime}p{sub s})X. In a simple spectator model, the backward proton has equal and opposite momentum to the neutron before it is struck, allowing the authors to study the dependence on kinematics and off-shell behaviour of the electron-nucleon inelastic cross section. If the photon couples to a quark in a 6-quark bag, a different dependence of the cross section on the kinematic variables (x, Q{sup 2}, and p{sub s}) can be observed. This proposed experiment requires large acceptance and beam energies above 6 GeV. It is ideally suited for the CEBAF Large Acceptance Spectrometer (CLAS).

  9. Model independent extraction of the axial mass parameter in CCQE anti neutrino-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Grebe, Heather

    2013-10-01

    Neutrino oscillation studies depend on a consistent value for the axial mass. For this reason, a model-independent extraction of this parameter from quasielastic (anti)neutrino-nucleon scattering data is vital. While most studies employ a model-dependent extraction using the dipole model of the axial form factor, we present a model-independent description using the z expansion of the axial form factor. Quasielastic antineutrino scattering data on C-12 from the MiniBooNE experiment are analyzed using this model-independent description. The value found, mA = 0 .85-0 . 06 + 0 . 13 +/- 0 . 13 GeV, differs significantly from the value utilized by the MiniBooNE Collaboration, mA = 1 . 35 GeV. Advisor: Dr. Gil Paz Wayne State Univerity.

  10. Reconstructing the direction of reactor antineutrinos via electron scattering in Gd-doped water Cherenkov detectors

    SciTech Connect

    Hellfeld, D.; Bernstein, A.; Dazeley, S.; Marianno, C.

    2017-01-01

    The potential of elastic antineutrino-electron scattering (ν¯e + e → ν¯e + e) in a Gd-doped water Cherenkov detector to determine the direction of a nuclear reactor antineutrino flux was investigated using the recently proposed WATCHMAN antineutrino experiment as a baseline model. The expected scattering rate was determined assuming a 13 km standoff from a 3.758 GWt light water nuclear reactor. Background was estimated via independent simulations and by appropriately scaling published measurements from similar detectors. Many potential backgrounds were considered, including solar neutrinos, misidentified reactor-based inverse beta decay interactions, cosmogenic radionuclide and water-borne radon decays, and gamma rays from the photomultiplier tubes, detector walls, and surrounding rock. The detector response was modeled using a GEANT4-based simulation package. The results indicate that with the use of low radioactivity PMTs and sufficient fiducialization, water-borne radon and cosmogenic radionuclides pose the largest threats to sensitivity. The directional sensitivity was then analyzed as a function of radon contamination, detector depth, and detector size. Lastly, the results provide a list of theoretical conditions that, if satisfied in practice, would enable nuclear reactor antineutrino directionality in a Gd-doped water Cherenkov detector approximately 10 km from a large power reactor.

  11. Reconstructing the direction of reactor antineutrinos via electron scattering in Gd-doped water Cherenkov detectors

    NASA Astrophysics Data System (ADS)

    Hellfeld, D.; Bernstein, A.; Dazeley, S.; Marianno, C.

    2017-01-01

    The potential of elastic antineutrino-electron scattering in a Gd-doped water Cherenkov detector to determine the direction of a nuclear reactor antineutrino flux was investigated using the recently proposed WATCHMAN antineutrino experiment as a baseline model. The expected scattering rate was determined assuming a 13-km standoff from a 3.758-GWt light water nuclear reactor and the detector response was modeled using a Geant4-based simulation package. Background was estimated via independent simulations and by scaling published measurements from similar detectors. Background contributions were estimated for solar neutrinos, misidentified reactor-based inverse beta decay interactions, cosmogenic radionuclides, water-borne radon, and gamma rays from the photomultiplier tubes (PMTs), detector walls, and surrounding rock. We show that with the use of low background PMTs and sufficient fiducialization, water-borne radon and cosmogenic radionuclides pose the largest threats to sensitivity. Directional sensitivity was then analyzed as a function of radon contamination, detector depth, and detector size. The results provide a list of experimental conditions that, if satisfied in practice, would enable antineutrino directional reconstruction at 3σ significance in large Gd-doped water Cherenkov detectors with greater than 10-km standoff from a nuclear reactor.

  12. Reconstructing the direction of reactor antineutrinos via electron scattering in Gd-doped water Cherenkov detectors

    DOE PAGES

    Hellfeld, D.; Bernstein, A.; Dazeley, S.; ...

    2016-10-17

    The potential of elastic antineutrino-electron scattering in a Gd-doped water Cherenkov detector to determine the direction of a nuclear reactor antineutrino flux was investigated using the recently proposed WATCHMAN antineutrino experiment as a baseline model. The expected scattering rate was determined assuming a 13 km standoff from a 3.758 GWt light water nuclear reactor and the detector response was modeled using a Geant4-based simulation package. Background was estimated via independent simulations and by scaling published measurements from similar detectors. Background contributions were estimated for solar neutrinos, misidentified reactor-based inverse beta decay interactions, cosmogenic radionuclides, water-borne radon, and gamma rays frommore » the photomultiplier tubes, detector walls, and surrounding rock. We show that with the use of low background PMTs and sufficient fiducialization, water-borne radon and cosmogenic radionuclides pose the largest threats to sensitivity. Directional sensitivity was then analyzed as a function of radon contamination, detector depth, and detector size. Lastly, the results provide a list of experimental conditions that, if satisfied in practice, would enable antineutrino directional reconstruction at 3 sigma significance in large Gd-doped water Cherenkov detectors with greater than 10 km standoff from a nuclear reactor.« less

  13. Reconstructing the direction of reactor antineutrinos via electron scattering in Gd-doped water Cherenkov detectors

    SciTech Connect

    Hellfeld, D.; Bernstein, A.; Dazeley, S.; Marianno, C.

    2016-10-17

    The potential of elastic antineutrino-electron scattering in a Gd-doped water Cherenkov detector to determine the direction of a nuclear reactor antineutrino flux was investigated using the recently proposed WATCHMAN antineutrino experiment as a baseline model. The expected scattering rate was determined assuming a 13 km standoff from a 3.758 GWt light water nuclear reactor and the detector response was modeled using a Geant4-based simulation package. Background was estimated via independent simulations and by scaling published measurements from similar detectors. Background contributions were estimated for solar neutrinos, misidentified reactor-based inverse beta decay interactions, cosmogenic radionuclides, water-borne radon, and gamma rays from the photomultiplier tubes, detector walls, and surrounding rock. We show that with the use of low background PMTs and sufficient fiducialization, water-borne radon and cosmogenic radionuclides pose the largest threats to sensitivity. Directional sensitivity was then analyzed as a function of radon contamination, detector depth, and detector size. Lastly, the results provide a list of experimental conditions that, if satisfied in practice, would enable antineutrino directional reconstruction at 3 sigma significance in large Gd-doped water Cherenkov detectors with greater than 10 km standoff from a nuclear reactor.

  14. Virtual Nucleon Compton Scattering in Perturbative QCD

    NASA Astrophysics Data System (ADS)

    Thomson, Richard; Ji, Chueng-Ryong

    2004-10-01

    Results of perturbative calculation for nucleon Compton scattering are presented. The calculations consider both the case of the incoming photon being real and the case of the incoming photon being virtual. Hard scattering amplitudes are calculated using a software package developed at NC State University footnote[1]A. Pang and C.-R. Ji, Computers in Physics Vol 9 (No. 6), Nov/Dec 1995 p589-593footnote[2]A. Pang and C.-R. Ji, J. Comp. Phys. 115, 267 (1994). The integrations required to calculate total cross section are made following the approach of Kronfeld and Nizicfootnote[3]A. Kronfeld and B. Nizic, Phys. Rev. D 44, 3445 (1991). Poles are split into a real principal part plus an imaginary delta function. The delta functions are evaluated explicitly by hand; principal part integrations are evaluated numerically, after making a variable transformation to render the integrand finite over the range of integration. For the real photon case, there are five previous calculations to consider, each of which produced a different resultfootnote[3]A. Kronfeld and B. Nizic, Phys. Rev. D 44, 3445 (1991)footnote[4]E. Maina and G. Farrar, Phys. Lett. B 206, 120 (1988)footnote[5]G. Farrar and H. Zhang, Phys. Rev. D 41, 3348 (1990)footnote[6]M. Vanderhaeghen, P. Guichon, and J. Van de Wiele, presented at workshop on virtual Compton scattering, Clermont-Ferrand, France, 1996footnote[7]T. Brooks and L. Dixon, Phys. Rev. D 62, 114021 (2000). There is an agreement with the results of Brooks and Dixonfootnote[7]T. Brooks and L. Dixon, Phys. Rev. D 62, 114021 (2000). For the virtual photon case, the new result is compared with that of Farrar and Zhang footnote[5]G. Farrar and H. Zhang, Phys. Rev. D 41, 3348 (1990). Since there are differences, we discuss which result is more believable and why. For the deeply virtual case (DVCS), comparison is made with other non-pertubative methods using GPDs.

  15. Deuteron effects in nucleon-nucleus scattering at intermediate energies

    SciTech Connect

    Arellano, H.F. Departamento de Fisica, Facultad de Ciencias Fisicas y Matematicas, Universidad de Chile, Casilla 487-3, Santiago ); Brieva, F.A. ); Love, W.G. )

    1994-11-01

    We investigate the role of the full dynamical dependence of the free off-shell nucleon-nucleon [ital t] matrix on the optical potential for proton-nucleus elastic scattering in the 100--400 MeV incident energy range within a full-folding model context. Particular emphasis is placed on the effects of deuteron formation by explicitly taking into account pole singularities in the free nucleon-nucleon [ital t] matrix. The full-folding model for the optical potential provides a flexible framework for this purpose as it allows the sampling of the internucleon effective force both off shell and as a function of the energy available in the center of mass for the interacting nucleon pair. A comparison of calculated and measured scattering observables for proton elastic scattering on [sup 40]Ca and [sup 208]Pb leads to the conclusion that the full off-shell free [ital t] matrix is a poor approximation for that part of the nucleon-nucleon effective force required for calculating optical potentials below [similar to]250 MeV. Medium effects and higher order corrections to the optical potential are necessary to improve our understanding of nucleon scattering.

  16. Nucleon-nucleon scattering at small angles, measured at ANKE-COSY

    NASA Astrophysics Data System (ADS)

    Bagdasarian, Z.

    2016-03-01

    The most accepted approach to describe nucleon-nucleon (NN) interaction is the partial wave analysis (PWA), which translates various experimental observables to the common language of the partial waves. The reliable analysis relies not only on the quality experimental data, but also on the measurements of scattering observables over preferably the full angular range. Small angle scattering has been measured for six beam energies between 0.8 and 2.4 GeV using polarized proton beam incident on both proton and deuteron unpolarized targets at COSY-ANKE. This proceeding will report on the published and preliminary results for both pp and pn scattering from this and other recent experiments at ANKE. This study aims to provide the valuable observables to the SAID group in order to improve the phenomenological understanding of the nucleon-nucleon interaction.

  17. Anti-Neutrino Quasi-Elastic Scattering in MINERvA

    NASA Astrophysics Data System (ADS)

    Chvojka, Jesse; Minerva Collaboration

    2011-04-01

    We present recent measurements of anti-neutrino quasi-elastic scattering (nubar_mu+p- >mu+n) at energies of a few GeV which is an important interaction channel and energy range for measuring leptonic CP violation with neutrino oscillation. The interactions were observed in the NuMI beam at Fermilab by the MINERvA detector. We discuss sample selection and reconstruction techniques and show data and simulation comparisons.

  18. 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.c

  19. A precise measurement of the weak mixing angle in neutrino-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Zeller, Geralyn P.

    This dissertation reports a precise determination of the weak mixing angle, sin2 thetaW, from measurement of the ratios of neutral current to charged current neutrino deep inelastic cross sections. High statistics samples of separately collected neutrino and antineutrino events, resulting from exposure to the Fermilab neutrino beam during the period from 1996 to 1997, allowed the reduction of systematic errors associated with charm production and other sources. The final value, sin 2 thetaW(on shell) = 0.2277 +/- 0.0013 (stat) +/- 0.0009 (syst), lies three standard deviations above the standard model prediction. The measurement is currently the most precise determination of sin2 theta W in neutrino-nucleon scattering, surpassing its predecessors by a factor of two in precision. A model independent analysis recasts the same data into a measurement of effective left and right handed neutral current quark couplings.

  20. Electroweak radiative corrections to neutrino-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Park, Kwangwoo

    The main subject of this thesis is to study the impact of electroweak O (alpha) corrections on neutrino-nucleon scattering processes, in particular on the extraction of electroweak parameters at the NuTeV experiment. The Standard Model (SM) represents the best current understanding of electroweak and strong interactions of elementary particles. In recent years it has been impressively confirmed experimentally through the precise determination of W and Z boson properties at the CERN LEP and the Stanford Linear e+e - colliders, and the discovery of the top quark at the Fermilab Tevatron pp collider. The W boson mass (MW) is one of the fundamental parameters in electroweak theory. A precise measurement of MW does not only provide a further precisely known SM input parameter, but significantly improves the indirect limit on the Higgs-boson mass obtained by comparing SM predictions with electroweak precision data. MW is measured directly at the CERN LEP2 e+e- and the Fermilab Tevatron pp colliders. A measurement of MW can also be extracted from a measurement of the sine squared of the weak mixing angle, i.e. sin 2 thetaW, via the well-known relation between the W and Z boson mass, M2W=M2Z (1 - sin2 thetaW). The NuTeV collaboration [20] extracts sin2 theta W, and thus MW, from the ratio of neutral and charged-current neutrino and anti-neutrino cross sections. Their result differs from direct measurements performed at LEP2 and the Fermilab Tevatron by about 3sigma. Much effort both experimental and theoretical has gone into understanding this discrepancy. These efforts include QCD corrections, parton distribution functions, and nuclear structure [21]. However, the effect of electroweak radiative corrections has not been fully studied yet. In the extraction of MW from NuTeV data, only part of the electroweak corrections have been included [20]. Although the complete calculation of these corrections is available in [17] and [18], their impact on the NuTeV measurement of MW

  1. Operator form of the three-nucleon scattering amplitude

    NASA Astrophysics Data System (ADS)

    Topolnicki, Kacper; Golak, Jacek; Skibiński, Roman; Witała, Henryk

    2017-07-01

    To extend the applications of the so-called "three-dimensional" formalism to the description of three-nucleon scattering within the Faddeev formalism, we develop a general form of the three-nucleon scattering amplitude. This form significantly decreases the numerical complexity of the "three-dimensional" calculations by reducing the scattering amplitude to a linear combination of momentum-dependent spin operators and scalar functions of momenta. The number and structure of the spin operators is fixed and the scalar functions can be represented numerically using standard methods such as multidimensional arrays. In this paper, we show that all orders of the iterated Faddeev equation can be written in this general form. We argue that calculations utilizing the three-nucleon force will also conform to the same general form. Additionally, we show how the general form of the scattering amplitude can be used to transform the Faddeev equation to make it suitable for numerical calculations using iterative methods.

  2. Goeppert-Mayer Award Recipient: Electron Scattering and Nucleon Structure

    NASA Astrophysics Data System (ADS)

    Beise, Elizabeth

    1998-04-01

    Electron scattering from hydrogen and light nuclear targets has long been recognized as one of the best tools for understanding the electromagnetic structure of protons, neutrons and few-nucleon systems. In the last decade, considerable progress has been made in the field through advances in polarized beams and polarized targets. Improvements in polarized electron sources has made it feasible to also study the structure of the nucleon through parity-violating electron scattering, where the nucleon's neutral weak structure is probed. In this talk, a summary of the present experimental status of the nucleon's electroweak structure will be presented, with an emphasis on recent results from the MIT-Bates and Jefferson Laboratories.

  3. Parity violation asymmetry in nucleon-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Avishai, Y.; Grangé, P.

    1989-01-01

    We evaluate the helicity dependence of the differential and total cross section for the scattering of longitudinally polarized neutrons on unpolarized neutrons at E = 45 MeV following a SIN experiment and at E = 230 MeV in anticipation of an experiment at TRIUMF. (Both experiments study proton-proton scattering of course, namely overlinep+ p→ p+ p). Calculations are based on the Desplanques, Donoghue and Holstein (DDH) theory for the weak NN interaction and on the Paris potential for the strong NN force. The results can be expressed as a linear combination in the (DDH) weak parameters hρ0, hρ2 and hω0, corresponding to exchanges of isoscalar ρ-, isotensor ρ-, and isoscalar ω- mesons, respectively. For the asymmetry in the total cross section we have found, using DDH suggested "best values", Az (45 MeV) = -2.62 × 10 -7 and Az (230 MeV) = 0.07 × 10 -7. The small value of Az at 230 MeV is due to a sign change in the differential asymmetry. As for the asymmetry in the differential cross section we notice that even at the lower energy E = 45 MeV, the asymmetry in the differential cross section deviates from isotropy, since J > 0 weak amplitudes cannot be neglected.

  4. Partial-wave analysis of nucleon-nucleon elastic scattering data

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

    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. Results are discussed in terms of both partial-wave and direct reconstruction amplitudes.

  5. Neutrino-pair bremsstrahlung from nucleon-α versus nucleon-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Sharma, Rishi; Bacca, Sonia; Schwenk, A.

    2015-04-01

    We study the impact of the nucleon-α P -wave resonances on neutrino-pair bremsstrahlung. Because of the noncentral spin-orbit interaction, these resonances lead to an enhanced contribution to the nucleon spin structure factor for temperatures T ≲4 MeV. If the α -particle fraction is significant and the temperature is in this range, this contribution is competitive with neutron-neutron bremsstrahlung. This may be relevant for neutrino production in core-collapse supernovae or other dense astrophysical environments. Similar enhancements are expected for resonant noncentral nucleon-nucleus interactions.

  6. A study of quasi-elastic muon neutrino and antineutrino scattering in the NOMAD experiment

    NASA Astrophysics Data System (ADS)

    Lyubushkin, V.; Popov, B.; Kim, J. J.; Camilleri, L.; Levy, J.-M.; Mezzetto, M.; Naumov, D.; Alekhin, S.; Astier, P.; Autiero, D.; Baldisseri, A.; Baldo-Ceolin, M.; Banner, M.; Bassompierre, G.; Benslama, K.; Besson, N.; Bird, I.; Blumenfeld, B.; Bobisut, F.; Bouchez, J.; Boyd, S.; Bueno, A.; Bunyatov, S.; Cardini, A.; Cattaneo, P. W.; Cavasinni, V.; Cervera-Villanueva, A.; Challis, R.; Chukanov, A.; Collazuol, G.; Conforto, G.; Conta, C.; Contalbrigo, M.; Cousins, R.; Daniels, D.; Degaudenzi, H.; Del Prete, T.; de Santo, A.; Dignan, T.; di Lella, L.; Do Couto E Silva, E.; Dumarchez, J.; Ellis, M.; Feldman, G. J.; Ferrari, R.; Ferrère, D.; Flaminio, V.; Fraternali, M.; Gaillard, J.-M.; Gangler, E.; Geiser, A.; Geppert, D.; Gibin, D.; Gninenko, S.; Godley, A.; Gomez-Cadenas, J.-J.; Gosset, J.; Gößling, C.; Gouanère, M.; Grant, A.; Graziani, G.; Guglielmi, A.; Hagner, C.; Hernando, J.; Hubbard, D.; Hurst, P.; Hyett, N.; Iacopini, E.; Joseph, C.; Juget, F.; Kent, N.; Kirsanov, M.; Klimov, O.; Kokkonen, J.; Kovzelev, A.; Krasnoperov, A.; Kulagin, S.; Kustov, D.; Lacaprara, S.; Lachaud, C.; Lakić, B.; Lanza, A.; La Rotonda, L.; Laveder, M.; Letessier-Selvon, A.; Ling, J.; Linssen, L.; Ljubičić, A.; Long, J.; Lupi, A.; Marchionni, A.; Martelli, F.; Méchain, X.; Mendiburu, J.-P.; Meyer, J.-P.; Mishra, S. R.; Moorhead, G. F.; Nédélec, P.; Nefedov, Yu.; Nguyen-Mau, C.; Orestano, D.; Pastore, F.; Peak, L. S.; Pennacchio, E.; Pessard, H.; Petti, R.; Placci, A.; Polesello, G.; Pollmann, D.; Polyarush, A.; Poulsen, C.; Rebuffi, L.; Rico, J.; Riemann, P.; Roda, C.; Rubbia, A.; Salvatore, F.; Samoylov, O.; Schahmaneche, K.; Schmidt, B.; Schmidt, T.; Sconza, A.; Seaton, M.; Sevior, M.; Sillou, D.; Soler, F. J. P.; Sozzi, G.; Steele, D.; Stiegler, U.; Stipčević, M.; Stolarczyk, Th.; Tareb-Reyes, M.; Taylor, G. N.; Tereshchenko, V.; Toropin, A.; Touchard, A.-M.; Tovey, S. N.; Tran, M.-T.; Tsesmelis, E.; Ulrichs, J.; Vacavant, L.; Valdata-Nappi, M.; Valuev, V.; Vannucci, F.; Varvell, K. E.; Veltri, M.; Vercesi, V.; Vidal-Sitjes, G.; Vieira, J.-M.; Vinogradova, T.; Weber, F. V.; Weisse, T.; Wilson, F. F.; Winton, L. J.; Wu, Q.; Yabsley, B. D.; Zaccone, H.; Zuber, K.; Zuccon, P.

    2009-10-01

    We have studied the muon neutrino and antineutrino quasi-elastic (QEL) scattering reactions ( ν μ n→ μ - p and bar{ν }_{μ}ptoμ+n ) using a set of experimental data collected by the NOMAD Collaboration. We have performed measurements of the cross-section of these processes on a nuclear target (mainly carbon) normalizing it to the total ν μ ( bar{ν}_{μ} ) charged-current cross section. The results for the flux-averaged QEL cross sections in the (anti)neutrino energy interval 3-100 GeV are < σ_{qel}rangle_{ν_{μ}}=(0.92±0.02(stat)±0.06(syst))×10^{-38} cm2 and <σ_{qel}rangle_{bar{ν}_{μ}}=(0.81±0.05(stat)±0.09(syst))×10^{-38} cm2 for neutrino and antineutrino, respectively. The axial mass parameter M A was extracted from the measured quasi-elastic neutrino cross section. The corresponding result is M A =1.05±0.02(stat)±0.06(syst) GeV. It is consistent with the axial mass values recalculated from the antineutrino cross section and extracted from the pure Q 2 shape analysis of the high purity sample of ν μ quasi-elastic 2-track events, but has smaller systematic error and should be quoted as the main result of this work. Our measured M A is found to be in good agreement with the world average value obtained in previous deuterium filled bubble chamber experiments. The NOMAD measurement of M A is lower than those recently published by K2K and MiniBooNE Collaborations. However, within the large errors quoted by these experiments on M A , these results are compatible with the more precise NOMAD value.

  7. A study of quasi-elastic muon (anti)neutrino scattering in he NOMAD experiment

    NASA Astrophysics Data System (ADS)

    Lyubushkin, Vladimir

    2009-11-01

    We have studied the muon neutrino and antineutrino quasi-elastic (QEL) scattering reactions (vμn→μ-p and v¯μp→μ+n using a set of experimental data collected by the NOMAD collaboration. We have performed measurements of the cross-section of these processes on a nuclear target (mainly Carbon) normalizing it to the total vμ (v¯μ) charged current cross-section. The results for the flux averaged QEL cross-sections in the (anti)neutrino energy interval 3-100 GeV are <σqel>vμ = (0.92±0.02(stat)±0.06(syst))×10-38 cm2 and <σqel>v¯μ = (0.81±0.05(stat)±0.09(syst))×10-38 cm2 for neutrino and antineutrino, respectively. The axial mass parameter MA was extracted from the measured quasi-elastic neutrino cross-section. The corresponding result is MA = 1.05±0.02(stat)±0.06(syst) GeV. It is consistent with the axial mass values recalculated from the antineutrino cross-section and extracted from the pure Q2 shape analysis of the high purity sample of vμ quasi-elastic 2-track events, but has smaller systematic error and should be quoted as the main result of this work. Our measured MA is found to be in good agreement with the world average value obtained in previous deuterium filled bubble chamber experiments. The NOMAD measurement of MA is lower than those recently published by K2K and MiniBooNE collaborations. However, within the large errors quoted by these experiments on MA, these results are compatible with the more precise NOMAD value.

  8. 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 from themore » 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

  9. The one-pion-exchange potential in the three-body model of nucleon-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Garcilazo, Humberto

    1981-02-01

    We derive the one-pion-exchange potential in the three-body model of nucleon-nucleon scattering in which the nucleon is treated as a bound state of a pion and a nucleon, and show that it has the same form as the usual Yukawa OPEP derived from field theory, except that its range is energy dependent and it becomes complex above the pion-production threshold.

  10. Nucleon-nucleon scattering in the 1S0 partial wave in the modified Weinberg approach

    NASA Astrophysics Data System (ADS)

    Gasparyan, A. M.; Epelbaum, E.; Gegelia, J.; Krebs, H.

    2016-03-01

    Nucleon-nucleon scattering in the 1S0 partial wave is considered in chiral effective field theory within the recently suggested renormalizable formulation based on the Kadyshevsky equation. Contact interactions are taken into account beyond the leading-order approximation. The subleading contact terms are included non-perturbatively by means of subtractive renormalization. The dependence of the phase shifts on the choice of the renormalization condition is discussed. Perturbative inclusion of the subleading contact interaction is found to be justified only very close to threshold. The low-energy theorems are reproduced significantly better compared with the leading order results.

  11. Beam normal spin asymmetry in elastic lepton-nucleon scattering

    SciTech Connect

    M. Gorchtein; P.A.M. Guichon; M. Vanderhaeghen

    2004-04-01

    We discuss the two-photon exchange contribution to observables which involve lepton helicity flip in elastic lepton-nucleon scattering. This contribution is accessed through the spin asymmetry for a lepton beam polarized normal to the scattering plane. We estimate this beam normal spin asymmetry at large momentum transfer using a parton model and we express the corresponding amplitude in terms of generalized parton distributions.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Quantum Monte Carlo Calculations of Nucleon-Nucleus Scattering

    NASA Astrophysics Data System (ADS)

    Wiringa, R. B.; Nollett, Kenneth M.; Pieper, Steven C.; Brida, I.

    2009-10-01

    We report recent quantum Monte Carlo (variational and Green's function) calculations of elastic nucleon-nucleus scattering. We are adding the cases of proton-^4He, neutron-^3H and proton-^3He scattering to a previous GFMC study of neutron-^4He scattering [1]. To do this requires generalizing our methods to include long-range Coulomb forces and to treat coupled channels. The two four-body cases can be compared to other accurate four-body calculational methods such as the AGS equations and hyperspherical harmonic expansions. We will present results for the Argonne v18 interaction alone and with Urbana and Illinois three-nucleon potentials. [4pt] [1] K.M. Nollett, S. C. Pieper, R.B. Wiringa, J. Carlson, and G.M. Hale, Phys. Rev. Lett. 99, 022502 (2007)

  17. Meson Productions in Neutrino-Nucleon Scattering

    NASA Astrophysics Data System (ADS)

    Nakamura, Satoshi X.

    A dynamical coupled-channels (DCC) model for neutrino-nucleon reactions in the resonance region is developed. This is an extension of the DCC model that we have previously developed through an analysis of πN, γp → πN, ηN, KΛ, KΣ reaction data for W ≤ 2.1 GeV. The vector current form factors up to Q2 ≤ 3.0 (GeV/c)2 are determined by analyzing electron-induced reaction data for both proton and neutron targets. Within the DCC model, axial-current matrix elements and the πN interactions are related by the Partially Conserved Axial Current (PCAC). As a result, the interference pattern between resonant and non-resonant amplitudes is uniquely fixed. We find that neutrino-induced single-pion production cross sections from the DCC model are consistent with available data. Double-pion production cross sections in the resonance region are also calculated, for the first time, with relevant resonance contributions and channel couplings.

  18. Nucleon polarizabilities: From Compton scattering to hydrogen atom

    NASA Astrophysics Data System (ADS)

    Hagelstein, Franziska; Miskimen, Rory; Pascalutsa, Vladimir

    2016-05-01

    We review the current state of knowledge of the nucleon polarizabilities and of their role in nucleon Compton scattering and in hydrogen spectrum. We discuss the basic concepts, the recent lattice QCD calculations and advances in chiral effective-field theory. On the experimental side, we review the ongoing programs aimed to measure the nucleon (scalar and spin) polarizabilities via the Compton scattering processes, with real and virtual photons. A great part of the review is devoted to the general constraints based on unitarity, causality, discrete and continuous symmetries, which result in model-independent relations involving nucleon polarizabilities. We (re-)derive a variety of such relations and discuss their empirical value. The proton polarizability effects are presently the major sources of uncertainty in the assessment of the muonic hydrogen Lamb shift and hyperfine structure. Recent calculations of these effects are reviewed here in the context of the "proton-radius puzzle". We conclude with summary plots of the recent results and prospects for the near-future work.

  19. Application of multiple scattering theory to lower-energy elastic nucleon-nucleus scattering

    NASA Astrophysics Data System (ADS)

    Chinn, C. R.; Elster, Ch.; Thaler, R. M.; Weppner, S. P.

    1995-03-01

    The optical model potentials for nucleon-nucleus elastic scattering at 65 meV are calculated for 12C, 16O, 28Si, 40Ca, 56Fe, 90Zr, and 208Pb in first-order multiple scattering theory, following the prescription of the spectator expansion, where the only inputs are the free nucleon-nucleon (NN) potentials, the nuclear densities, and the nuclear mean field as derived from microscopic nuclear structure calculations. These potentials are used to predict differential cross sections, analyzing powers, and spin rotation functions for neutron and proton scattering at 65 MeV projectile energy and compared with available experimental data. The theoretical curves are in very good agreement with the data. The modification of the propagator due to the coupling of the struck nucleon to the residual nucleus is seen to be significant at this energy and invariably improves the congruence of theoretical prediction and measurement.

  20. Roy-Steiner equations for pion-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Ditsche, C.; Hoferichter, M.; Kubis, B.; Meissner, U. G.

    Starting from hyperbolic dispersion relations for the invariant amplitudes of pion-nucleon scattering together with crossing symmetry and unitarity, one can derive a closed system of integral equations for the partial waves of both the s-channel (pi N --> pi N) and the t-channel (pi pi --> Nbar N) reaction, called Roy-Steiner equations. After giving a brief overview of the Roy-Steiner system for pi N scattering, we demonstrate that the solution of the t-channel subsystem, which represents the first step in solving the full system, can be achieved by means of Muskhelishvili-Omn\\`es techniques. In particular, we present results for the P-waves featuring in the dispersive analysis of the electromagnetic form factors of the nucleon.

  1. Peripheral nucleon-nucleon scattering at fifth order of chiral perturbation theory

    NASA Astrophysics Data System (ADS)

    Entem, D. R.; Kaiser, N.; Machleidt, R.; Nosyk, Y.

    2015-01-01

    We present the two- and three-pion-exchange contributions to the nucleon-nucleon interaction which occur at next-to-next-to-next-to-next-to-leading order (N4LO , fifth order) of chiral effective field theory and calculate nucleon-nucleon scattering in peripheral partial waves with L ≥3 by using low-energy constants that were extracted from π N analysis at fourth order. While the net three-pion-exchange contribution is moderate, the two-pion exchanges turn out to be sizable and prevailingly repulsive, thus compensating the excessive attraction characteristic for next-to-next-to-leading order and N3LO . As a result, the N4LO predictions for the phase shifts of peripheral partial waves are in very good agreement with the data (with the only exception being the 1F3 wave). We also discuss the issue of the order-by-order convergence of the chiral expansion for the N N interaction.

  2. Kaon-nucleon scattering in three-dimensional technique

    SciTech Connect

    Salam, Agus Fachruddin, Imam

    2016-03-11

    Kaon-nucleon (KN) scattering is formulated in the three-dimensional (3D) momentum space, in which the basis state is not expanded into partial waves. Based on this basis the Lippmann-Schwinger equation for the T-matrix is evaluated. We obtain as final equation for the T-matrix elements a set of two coupled integral equations in two variables, which are the momentum’s magnitude and the scattering angle. Calculations for the differential cross section and some spin observables are shown, for which we employ a hadrons exchange model with the second order contributions only.

  3. Advances in Nucleon-Nucleon Scattering Experiments and Their Theoretical Consequences

    SciTech Connect

    Bekteshi, Sadik; Kabashi, Skender; Kamishi, Burim

    2007-04-23

    An overview of critical analysis of the experimental data obtained from nucleon-nucleon scattering is given and investigated in this work. Comparison of the experimental data with results of recent partial wave analysis of Nijmegen group, VPI/GWU and Saclay is given. Potentials of Nijmegen, Bonn and Argonne group are discussed. Experimental data which lead to the break of charge symmetry, to the break of the charge independence and to the determination of the off-shell tensor force, are particularly emphasized. Disagreements which exist between theoretical calculations related to the contribution of particular mechanism in different reactions are pointed out. In this relation, still open problems to be solved and measurement that should be undertaken in the future are identified, as well.

  4. Nucleon-nucleon correlations and multiquark cluster effects in semi-inclusive deep inelastic lepton scattering off

    SciTech Connect

    Simula, S.

    1994-04-01

    Semi-inclusive deep inelastic lepton scattering off nuclei is investigated assuming that virtual boson absorption occurs on a hadronic cluster which can be either a two-nucleon correlated pair or a six-quark bag. The differences in the energy distribution of nucleons produced in backward and forward directions are analyzed both at x<1 and x>1.

  5. Compton scattering and nucleon polarisabilities in chiral EFT: Status and future

    NASA Astrophysics Data System (ADS)

    Grießhammer, Harald W.; McGovern, Judith A.; Phillips, Daniel R.

    2016-05-01

    We review theoretical progress and prospects for determining the nucleon's static dipole polarisabilities from Compton scattering on few-nucleon targets, including new values; see Refs. [1-5] for details and a more thorough bibliography.

  6. Nucleon Compton scattering in the Dyson-Schwinger approach

    NASA Astrophysics Data System (ADS)

    Eichmann, Gernot; Fischer, Christian S.

    2013-02-01

    We analyze the nucleon’s Compton scattering amplitude in the Dyson-Schwinger/Faddeev approach. We calculate a subset of diagrams that implements the nonperturbative handbag contribution as well as all t-channel resonances. At the quark level, these ingredients are represented by the quark Compton vertex whose analytic properties we study in detail. We derive a general form for a fermion two-photon vertex that is consistent with its Ward-Takahashi identities and free of kinematic singularities, and we relate its transverse part to the on-shell nucleon Compton amplitude. We solve an inhomogeneous Bethe-Salpeter equation for the quark Compton vertex in rainbow-ladder truncation and implement it in the nucleon Compton scattering amplitude. The remaining ingredients are the dressed quark propagator and the nucleon’s bound-state amplitude which are consistently solved from Dyson-Schwinger and covariant Faddeev equations. We verify numerically that the resulting quark Compton vertex and nucleon Compton amplitude both reproduce the πγγ transition form factor when the pion pole in the t channel is approached.

  7. On triplet low-energy parameters of nucleon-nucleon scattering

    SciTech Connect

    Babenko, V. A.; Petrov, N. M.

    2006-09-15

    Triplet low-energy parameters of neutron-proton scattering, including high-order shape parameters, are calculated on the basis of approximating the effective-range function k cot {delta}{sub t} by polynomials and rational functions with the aid of the latest experimental data on phase shifts from the SAID nucleon-nucleon database. With the resulting values of the low-energy parameters, a good description of phase shifts over a broad energy interval is obtained by using the effective-range expansion featuring a small number of terms. The properties of the deuteron that were calculated on the basis of the values found for the triplet low-energy parameters of scattering agree very well with experimental values. The triplet low-energy parameters and the properties of the deuteron that were obtained here by using present-day data from the SAID database differ markedly from the analogous results obtained for data of the Nijmegen group. Possible reasons behind this discrepancy are discussed. Highly precise new approximate formulas for determining the shape parameter v{sub 2} are proposed and are shown to be efficient in calculations. The effective-range expansion for the D wave is considered, and preliminary results of calculations of low-energy scattering parameters for this case are obtained.

  8. Extraction of nuclear spin response functions from spin observables of nucleon quasifree scattering

    SciTech Connect

    Ichimura, M. ); Kawahigashi, K. )

    1992-04-01

    Extraction of spin-longitudinal and -transverse response functions from polarization transfer measurements of nucleon-nucleus quasifree scatterings is discussed. The method proposed by Carey {ital et} {ital al}. is reconsidered and more general formulas are presented. Spin-longitudinal and -transverse interactions are well defined in the nucleon-nucleon scattering {ital t} matrix in the nucleon-nucleon center-of-mass frame. However, observed data are given in the nucleon-nucleus laboratory frame and theoretical analysis based on the distorted-wave and plane-wave impulse approximations is carried out in the nucleon-nucleus center-of-mass system, in which the {ital t} matrix in a certain optimum frame of the nucleon-nucleon system is used. Careful consideration is paid for transformations among these reference frames relativistically.

  9. Measurement of the Antineutrino Double-Differential Charged-Current Quasi-Elastic Scattering Cross Section at MINERvA

    SciTech Connect

    Patrick, Cheryl

    2016-01-01

    Next-generation neutrino oscillation experiments, such as DUNE and Hyper-Kamiokande, hope to measure charge-parity (CP) violation in the lepton sector. In order to do this, they must dramatically reduce their current levels of uncertainty, particularly those due to neutrino-nucleus interaction models. As CP violation is a measure of the difference between the oscillation properties of neutrinos and antineutrinos, data about how the less-studied antineutrinos interact is especially valuable. We present the MINERvA experiment's first double-differential scattering cross sections for antineutrinos on scintillator, in the few-GeV range relevant to experiments such as DUNE and NOvA. We also present total antineutrino-scintillator quasi-elastic cross sections as a function of energy, which we compare to measurements from previous experiments. As well as being useful to help reduce oscillation experiments' uncertainty, our data can also be used to study the prevalence of various cor relation and final-state interaction effects within the nucleus. We compare to models produced by different model generators, and are able to draw first conclusions about the predictions of these models.

  10. Measurement of the antineutrino double-differential charged-current quasi-elastic scattering cross section at MINERvA

    NASA Astrophysics Data System (ADS)

    Patrick, Cheryl Elizabeth

    Next-generation neutrino oscillation experiments, such as DUNE and Hyper-Kamiokande, hope to measure charge-parity (CP) violation in the lepton sector. In order to do this, they must dramatically reduce their current levels of uncertainty, particularly those due to neutrino-nucleus interaction models. As CP violation is a measure of the difference between the oscillation properties of neutrinos and antineutrinos, data about how the less-studied antineutrinos interact is especially valuable. We present the MINERvA experiment's first double-differential scattering cross sections for antineutrinos on scintillator, in the few-GeV range relevant to experiments such as DUNE and NOvA. We also present total antineutrino-scintillator quasi-elastic cross sections as a function of energy, which we compare to measurements from previous experiments. As well as being useful to help reduce oscillation experiments' uncertainty, our data can also be used to study the prevalence of various correlation and final-state interaction effects within the nucleus. We compare to models produced by different model generators, and are able to draw first conclusions about the predictions of these models.

  11. Radiative corrections and parity violating electron-nucleon scattering

    SciTech Connect

    S. Barkanova; A. Aleksejevs; P.G. Blunden

    2002-11-01

    Radiative corrections to the parity-violating asymmetry measured in elastic electron-proton scattering are analyzed in the framework of the Standard Model. We include the complete set of one-loop contributions to one quark current amplitudes. The contribution of soft photon emission to the asymmetry is also calculated, giving final results free of infrared divergences. The one quark radiative corrections, when combines with previous work on many quark effects and recent SAMPLE experimental data, are used to place some new constraints on electroweak form factors of the nucleon.

  12. Compton scattering, meson exchange, and the polarizabilities of bound nucleons

    SciTech Connect

    Feldman, G.; Mellendorf, K.E.; Eisenstein, R.A.; Federspiel, F.J.; Garino, G.; Igarashi, R.; Kolb, N.R.; Lucas, M.A.; MacGibbon, B.E.; Mize, W.K.; Nathan, A.M.; Pywell, R.E.; Wells, D.P. |

    1996-11-01

    Elastic photon scattering cross sections on {sup 16}O have been measured in the energy range 27{endash}108 MeV. These data are inconsistent with a conventional interpretation in which the electric and magnetic polarizabilities of the bound nucleon are unchanged from the free values and the meson-exchange seagull amplitude is taken in the zero-energy limit. Agreement with the data can be achieved by invoking either strongly modified polarizabilities or a substantial energy dependence to the meson-exchange seagull amplitude. It is argued that these seemingly different explanations are experimentally indistinguishable and probably physically equivalent. {copyright} {ital 1996 The American Physical Society.}

  13. Compton scattering, meson exchange, and the polarizabilities of bound nucleons

    NASA Astrophysics Data System (ADS)

    Feldman, G.; Mellendorf, K. E.; Eisenstein, R. A.; Federspiel, F. J.; Garino, G.; Igarashi, R.; Kolb, N. R.; Lucas, M. A.; MacGibbon, B. E.; Mize, W. K.; Nathan, A. M.; Pywell, R. E.; Wells, D. P.

    1996-11-01

    Elastic photon scattering cross sections on 16O have been measured in the energy range 27-108 MeV. These data are inconsistent with a conventional interpretation in which the electric and magnetic polarizabilities of the bound nucleon are unchanged from the free values and the meson-exchange seagull amplitude is taken in the zero-energy limit. Agreement with the data can be achieved by invoking either strongly modified polarizabilities or a substantial energy dependence to the meson-exchange seagull amplitude. It is argued that these seemingly different explanations are experimentally indistinguishable and probably physically equivalent.

  14. Measurement of Neutrino-Nucleon Neutral-Current Elastic Scattering Cross-section at SciBooNE

    SciTech Connect

    Takei, Hideyuki

    2009-02-01

    In this thesis, results of neutrino-nucleon neutral current (NC) elastic scattering analysis are presented. Neutrinos interact with other particles only with weak force. Measurement of cross-section for neutrino-nucleon reactions at various neutrino energy are important for the study of nucleon structure. It also provides data to be used for beam flux monitor in neutrino oscillation experiments. The cross-section for neutrino-nucleon NC elastic scattering contains the axial vector form factor GA(Q2) as well as electromagnetic form factors unlike electromagnetic interaction. GA is propotional to strange part of nucleon spin (Δs) in Q2 → 0 limit. Measurement of NC elastic cross-section with smaller Q2 enables us to access Δs. NC elastic cross-sections of neutrino-nucleon and antineutrino-nucleon were measured earlier by E734 experiment at Brookheaven National Laboratory (BNL) in 1987. In this experiment, cross-sections were measured in Q2 > 0.4 GeV2 region. Result from this experiment was the only published data for NC elastic scattering cross-section published before our experiment. SciBooNE is an experiment for the measurement of neutrino-nucleon scattering cross-secitons using Booster Neutrino Beam (BNB) at FNAL. BNB has energy peak at 0.7 GeV. In this energy region, NC elastic scattering, charged current elastic scattering, charged current pion production, and neutral current pion production are the major reaction branches. SciBar, electromagnetic calorimeter, and Muon Range Detector are the detectors for SciBooNE. The SciBar consists of finely segmented scintillators and 14336 channels of PMTs. It has a capability to reconstruct particle track longer than 8 cm and separate proton from muons and pions using energy deposit information. Signal of NC elastic scattering is a single proton track. In vp → vp process, the recoil proton is detected. On the other hand, most of vn → vn is

  15. Phenomenological models of elastic nucleon scattering and predictions for LHC

    NASA Astrophysics Data System (ADS)

    Kašpar, Jan; Kundrát, Vojtěch; Lokajíček, Miloš; Procházka, Jiří

    2011-02-01

    The hitherto analyses of elastic collisions of charged nucleons involving common influence of Coulomb and hadronic scattering have been based practically on West and Yennie formula. However, this approach has been shown recently to be inadequate from experimental as well as theoretical points of view. The eikonal model enabling to determine physical characteristics in impact parameter space seems to be more pertinent. The contemporary phenomenological models admit, of course, different distributions of collision processes in the impact parameter space and cannot give any definite answer. Nevertheless, some predictions for the planned LHC energy that have been given on their basis may be useful, as well as the possibility of determining the luminosity from elastic scattering.

  16. Pion-nucleon scattering in the P11 channel

    NASA Astrophysics Data System (ADS)

    Morioka, S.; Afnan, I. R.

    1982-09-01

    We present a parametrization of the π-N interaction in the P11 channel in which the amplitude is the sum of a pole part and a non-pole part (t=tpole+tnp) and satisfies two-body unitarity. Here tpole has both the nucleon propagator and the πNN vertex dressed. The final amplitude fits the scattering length and low energy π-N phase shifts (Tlabπ<300 MeV). We study the effect of a resonance in tnp on the phase shifts, πNN coupling constant, and the off-shell behavior of the amplitude. NUCLEAR REACTIONS πN scattering in P11 channel, renormalization, resonance effect.

  17. 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.*

  18. Results for quasi-elastic anti-neutrino scattering on scintillator from the MINERvA experiment

    NASA Astrophysics Data System (ADS)

    Schellman, Heidi; Minerva Collaboration

    2016-09-01

    We present a new preliminary measurement of the charge-current quasi-elastic scattering cross section for anti-neutrinos on scintillator (CH) over the energy range 1.5-10 GeV. The data were taken with the MINERvA detector in the NuMI beamline at Fermilab and cover the energy range of interest for the proposed DUNE long-baseline neutrino oscillation experiment and of JLAB elastic scattering experiments. Of particular interest to the nuclear community are possible signatures for short range correlations and/or meson exchange currents in these data. We present comparisons to a range of nuclear models.

  19. Regularization and the potential of effective field theory in nucleon-nucleon scattering

    SciTech Connect

    Phillips, D.R.

    1998-04-01

    This paper examines the role that regularization plays in the definition of the potential used in effective field theory (EFT) treatments of the nucleon-nucleon interaction. The author considers N N scattering in S-wave channels at momenta well below the pion mass. In these channels (quasi-)bound states are present at energies well below the scale m{sub {pi}}{sup 2}/M expected from naturalness arguments. He asks whether, in the presence of such a shallow bound state, there is a regularization scheme which leads to an EFT potential that is both useful and systematic. In general, if a low-lying bound state is present then cutoff regularization leads to an EFT potential which is useful but not systematic, and dimensional regularization with minimal subtraction leads to one which is systematic but not useful. The recently-proposed technique of dimensional regularization with power-law divergence subtraction allows the definition of an EFT potential which is both useful and systematic.

  20. Low-energy theorems for nucleon-nucleon scattering at unphysical pion masses

    NASA Astrophysics Data System (ADS)

    Baru, V.; Epelbaum, E.; Filin, A. A.; Gegelia, J.

    2015-07-01

    The longest-range part of the nuclear force from the one-pion exchange governs the energy dependence of the scattering amplitude in the near-threshold region and imposes correlations between the coefficients in the effective range expansion. These correlations may be regarded as low-energy theorems and are known to hold to a high accuracy in the neutron-proton 3S1 partial wave. We generalize the low-energy theorems to the case of unphysical pion masses and provide results for the correlations between the coefficients in the effective range expansion in this partial wave for pion masses up to Mπ˜400 MeV . We discuss the implications of our findings for the available and upcoming lattice-quantum-chromodynamics simulations of two-nucleon observables.

  1. Roy-Steiner equations for pion-nucleon scattering

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

    Starting from hyperbolic dispersion relations, we derive a closed system of Roy-Steiner equations for pion-nucleon scattering that respects analyticity, unitarity, and crossing symmetry. We work out analytically all kernel functions and unitarity relations required for the lowest partial waves. In order to suppress the dependence on the high energy regime we also consider once- and twice-subtracted versions of the equations, where we identify the subtraction constants with subthreshold parameters. Assuming Mandelstam analyticity we determine the maximal range of validity of these equations. As a first step towards the solution of the full system we cast the equations for the π π to overline N N partial waves into the form of a Muskhelishvili-Omnès problem with finite matching point, which we solve numerically in the single-channel approximation. We investigate in detail the role of individual contributions to our solutions and discuss some consequences for the spectral functions of the nucleon electromagnetic form factors.

  2. Accessing the nucleon transverse structure in inclusive deep inelastic scattering

    NASA Astrophysics Data System (ADS)

    Accardi, Alberto; Bacchetta, Alessandro

    2017-10-01

    We revisit the standard analysis of inclusive Deep Inelastic Scattering off nucleons taking into account the fact that on-shell quarks cannot be present in the final state, but they rather decay into hadrons - a process that can be described in terms of suitable "jet" correlators. As a consequence, a spin-flip term associated with the invariant mass of the produced hadrons is generated nonperturbatively and couples to the target's transversity distribution function. In inclusive cross sections, this provides an hitherto neglected and large contribution to the twist-3 part of the g2 structure function, that can explain the discrepancy between recent calculations and fits of this quantity. It also provides an extension of the Burkhardt-Cottingham sum rule, providing new information on the transversity function, as well as an extension of the Efremov-Teryaev-Leader sum rule, suggesting a novel way to measure the tensor charge of the proton.

  3. Two-nucleon scattering in a modified Weinberg approach with a symmetry-preserving regularization

    NASA Astrophysics Data System (ADS)

    Behrendt, J.; Epelbaum, E.; Gegelia, J.; Meißner, Ulf-G.; Nogga, A.

    2016-09-01

    We consider the nucleon-nucleon scattering problem by applying time-ordered perturbation theory to the Lorentz-invariant formulation of baryon chiral perturbation theory. We employ a higher-derivative symmetry-preserving regularization to obtain an integral equation for the scattering amplitude, which permits a non-perturbative treatment of subleading contributions to the nucleon-nucleon potential. The resulting formulation is used to quantify finite regulator artefacts in two-nucleon phase shifts as well as in the chiral extrapolations of the S-wave scattering lengths and the deuteron binding energy. Our approach can be straightforwardly extended to analyse few-nucleon systems and processes involving external electroweak sources.

  4. Double Polarized Neutron-Proton Scattering and Meson-Exchange Nucleon-Nucleon Potential Models

    SciTech Connect

    Raichle, B.W.; Gould, C.R.; Haase, D.G.; Seely, M.L.; Walston, J.R.; Tornow, W.; Wilburn, W.S.; Raichle, B.W.; Gould, C.R.; Haase, D.G.; Seely, M.L.; Walston, J.R.; Tornow, W.; Wilburn, W.S.; Penttilae, S.I.; Hoffmann, G.W.

    1999-10-01

    We report on polarized beam{endash}polarized target measurements of the spin-dependent neutron-proton total cross-section differences in longitudinal and transverse geometries ({Delta}{sigma}{sub L} and {Delta}{sigma}{sub T} , respectively) between E{sub n}=5 and 20thinspthinspMeV. Single-parameter phase-shift analyses were performed to extract the phase-shift mixing parameter {var_epsilon}{sub 1} , which characterizes the strength of the nucleon-nucleon tensor interaction at low energies. Consistent with the trend of previous determinations at E{sub n}=25 and 50thinspthinspMeV, our values for {var_epsilon}{sub 1} imply a stronger tensor force than predicted by meson-exchange nucleon-nucleon potential models and nucleon-nucleon phase-shift analyses. {copyright} {ital 1999} {ital The American Physical Society}

  5. Coulomb effects in three- and four-nucleon scattering: A mask of the 3N force

    SciTech Connect

    Deltuva, A.; Fonseca, A. C.; Sauer, P. U.

    2008-04-29

    Recent progress on the solution of ab initio three- and four-nucleon scattering equations in momentum space that include the correct treatment of the Coulomb interaction is reviewed; results for specific observables in reactions initiated by p+d, p+{sup 3}He and n+{sup 3}He indicate that the inclusion of the Coulomb interaction is paramount to validate two- and three-nucleon force models. Three- and four-nucleon force effects in {sup 4}He binding energy and four-nucleon scattering observables are studied for the first time. The effect of the four-nucleon force is found to be much smaller than the effect of the three-nucleon force.

  6. Measurement of Muon Antineutrino Quasielastic Scattering on a Hydrocarbon Target at Eν~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, MA, 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 data at highermore » Q² favor this interpretation over an alternative in which the axial mass is increased.« less

  7. Quark structure of the nucleon and angular asymmetry of proton-neutron hard elastic scattering.

    PubMed

    Granados, Carlos G; Sargsian, Misak M

    2009-11-20

    We investigate an asymmetry in the angular distribution of hard elastic proton-neutron scattering with respect to the 90 degrees center of mass scattering angle and demonstrate that it's magnitude is related to the helicity-isospin symmetry of the quark wave function of the nucleon. Our estimate of the asymmetry within the quark-interchange model of hard scattering demonstrates that the quark wave function of a nucleon based on the exact SU(6) symmetry predicts an angular asymmetry opposite to that of experimental observations. We found that the quark wave function based on the diquark picture of the nucleon produces a correct asymmetry. Comparison with the data allowed us to show that the vector diquarks contribute around 10% in the nucleon wave function and they are in negative phase relative to the scalar diquarks. These observations are essential in constraining QCD models of a nucleon.

  8. 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.

  9. TESLA-N: Polarized electron-nucleon scattering at TESLA

    NASA Astrophysics Data System (ADS)

    Ellinghaus, Frank; Aschenauer, E. C.; Tesla-N Study-Group

    2001-06-01

    Measurements of polarized e-N scattering can be realized at the TESLA linear collider facility with projected luminosities that are about two orders of magnitude higher than those expected of other experiments at comparable energies. Longitudinally polarized electrons, accelerated as a small fraction of the total current in the e+ arm of TESLA, can be directed onto a solid state target that may be longitudinally or transversely polarized. A large variety of polarized parton distribution and fragmentation functions can be determined with unprecedented accuracy, many of them for the first time. A main goal of the experiment is the precise measurement of the x- and Q2-dependence of the unknown transversity distributions that will provide us with the full information on the nucleon's quark spin structure as relevant for high energy processes. The additional possibilities of using unpolarized targets and of experiments with a real photon beam turn TESLA-N into a versatile next-generation facility at the intersection of particle and nuclear physics. .

  10. Relativistic model of 2p-2h meson exchange currents in (anti)neutrino scattering

    NASA Astrophysics Data System (ADS)

    Ruiz Simo, I.; E Amaro, J.; Barbaro, M. B.; De Pace, A.; Caballero, J. A.; Donnelly, T. W.

    2017-06-01

    We develop a model of relativistic, charged meson-exchange currents (MEC) for neutrino-nucleus interactions. The two-body current is the sum of seagull, pion-in-flight, pion-pole and Δ-pole operators. These operators are obtained from the weak pion-production amplitudes for the nucleon derived in the nonlinear σ-model together with weak excitation of the {{Δ }}(1232) resonance and its subsequent decay into Nπ . With these currents we compute the five 2p-2h response functions contributing to ({ν }l,{l}-) and ({\\overline{ν }}l,{l}+) reactions in the relativistic Fermi gas model. The total current is the sum of vector and axial two-body currents. The vector current is related to the electromagnetic MEC operator that contributes to electron scattering. This allows one to check our model by comparison with the results of De Pace et al (2003 Nucl. Phys. A 726 303). Thus, our model is a natural extension of that model to the weak sector with the addition of the axial MEC operator. The dependences of the response functions on several ingredients of the approach are analyzed. Specifically we discuss relativistic effects, quantify the size of the direct-exchange interferences, and the relative importance of the axial versus vector current.

  11. Resonance estimates for single spin asymmetries in elastic electron-nucleon scattering

    SciTech Connect

    Barbara Pasquini; Marc Vanderhaeghen

    2004-07-01

    We discuss the target and beam normal spin asymmetries in elastic electron-nucleon scattering which depend on the imaginary part of two-photon exchange processes between electron and nucleon. We express this imaginary part as a phase space integral over the doubly virtual Compton scattering tensor on the nucleon. We use unitarity to model the doubly virtual Compton scattering tensor in the resonance region in terms of {gamma}* N {yields} {pi} N electroabsorption amplitudes. Taking those amplitudes from a phenomenological analysis of pion electroproduction observables, we present results for beam and target normal single spin asymmetries for elastic electron-nucleon scattering for beam energies below 1 GeV and in the 1-3 GeV region, where several experiments are performed or are in progress.

  12. The pion nucleon scattering lengths from pionic hydrogen and deuterium

    NASA Astrophysics Data System (ADS)

    Schröder, H.-Ch.; Badertscher, A.; Goudsmit, P. F. A.; Janousch, M.; Leisi, H. J.; Matsinos, E.; Sigg, D.; Zhao, Z. G.; Chatellard, D.; Egger, J.-P.; Gabathuler, K.; Hauser, P.; Simons, L. M.; Rusi El Hassani, A. J.

    2001-07-01

    This is the final publication of the ETH Zurich Neuchâtel PSI collaboration on the pionic hydrogen and deuterium precision X-ray experiments. We describe the recent hydrogen 3 p 1 s measurement, report on the determination of the Doppler effect correction to the transition line width, analyze the deuterium shift measurement and discuss implications of the combined hydrogen and deuterium results. From the pionic hydrogen 3 p 1 s transition experiments we obtain the strong-interaction energy level shift \\varepsilon_{1s} = -7.108±0.013 (stat.)±0.034 (syst.) eV and the total decay width Γ_{1s} = 0.868±0.040 (stat.)±0.038 (syst.) eV of the 1s state. Taking into account the electromagnetic corrections we find the hadronic π N s-wave scattering amplitude a_{π-prightarrowπ-p} = 0.0883±0.0008 m_{π}^{-1} for elastic scattering and a_{π-prightarrowπ0n} = -0.128±0.006 m_{π} ^{-1} for single charge exchange, respectively. We then combine the pionic hydrogen results with the 1 s level shift measurement on pionic deuterium and test isospin symmetry of the strong interaction: our data are still compatible with isospin symmetry. The isoscalar and isovector π N scattering lengths (within the framework of isospin symmetry) are found to be b_0 = -0.0001^{+0.0009}_{-0.0021} m_{π}^{-1} and b1 = -0.0885^{+0.0010}_{-0.0021} m_{π} ^{-1}, respectively. Using the GMO sum rule, we obtain from b_1 a new value of the π N coupling constant (g_{π N} = 13.21_{-0.05}^{+0.11}) from which follows the Goldberger Treiman discrepancy Δ_{{GT}} =0.027_{-0.008}^{+0.012}. The new values of b_0 and g_{π N} imply an increase of the nucleon sigma term by at least 9 MeV.

  13. Extra dimensions, SN1987a, and nucleon-nucleon scattering data

    SciTech Connect

    Christoph Hanhart; Daniel R. Phillips; Sanjay Reddy; Martin J. Savage

    2001-02-01

    One of the strongest constraints on the existence of large, compact, ''gravity-only'' dimensions comes from SN1987a. If the rate of energy loss into these putative extra dimensions is too high, then the neutrino pulse from the supernova will differ from that actually seen. The dominant mechanism for the production of Kaluza-Klein gravitons and dilatons in the supernova is via gravistrahlung and dilastrahlung from the nucleon-nucleon system. In this paper we compute the rates for these processes in a model-independent way using low-energy theorems which relate the emissivities to the measured nucleon-nucleon cross section. This is possible because for soft gravitons and dilatons the leading contribution to the energy-loss rate is from graphs in which the gravitational radiation is produced from external nucleon legs. Previous calculations neglected these mechanisms. We re-evaluate the bounds on toroidally-compactified ''gravity-only'' dimensions (GODs), and find that consistency with the observed SN1987a neutrino signal requires that if there are two such dimensions then their radius must be less than 1 micron.

  14. Parity-Violating Electron Scattering and the Electric and Magnetic Strange Form Factors of the Nucleon

    SciTech Connect

    Armstrong, David S.; McKeown, Robert

    2012-11-01

    Measurement of the neutral weak vector form factors of the nucleon provides unique access to the strange quark content of the nucleon. These form factors can be studied using parity-violating electron scattering. A comprehensive program of experiments has been performed at three accelerator laboratories to determine the role of strange quarks in the electromagnetic form factors of the nucleon. This article reviews the remarkable technical progress associated with this program, describes the various methods used in the different experiments, and summarizes the physics results along with recent theoretical calculations.

  15. Sensitivity of nucleon-nucleus scattering to the off-shell behavior of on-shell equivalent {ital NN} potentials

    SciTech Connect

    Arellano, H.F.; Brieva, F.A.; Sander, M.; von Geramb, H.V. |

    1996-11-01

    The sensitivity of nucleon-nucleus elastic scattering to the off-shell behavior of realistic nucleon-nucleon interactions is investigated when on-shell equivalent nucleon-nucleon potentials are used. The study is based on applications of the full-folding optical model potential for an explicit treatment of the off-shell behavior of the nucleon-nucleon effective interaction. Applications were made at beam energies between 40 and 500 MeV for proton scattering from {sup 40}Ca and {sup 208}Pb. We use the momentum-dependent Paris potential and its local on-shell equivalent as obtained with the Gelfand-Levitan and Marchenko inversion formalism for the two nucleon Schr{umlt o}dinger equation. Full-folding calculations for nucleon-nucleus scattering show moderate fluctuations in the corresponding observables. This sets narrow margins within which off-shell features of the nucleon-nucleon interaction can be resolved. Based on these results, inversion potentials were also constructed directly from phenomenological phase shifts (SM94). Their use in nucleon-nucleus scattering at intermediate energies provides an improved description of the data relative to those obtained from current realistic potential models. {copyright} {ital 1996 The American Physical Society.}

  16. Deuteron Analyzing Powers for \\varvec{dp} Elastic Scattering at Intermediate Energies and Three-Nucleon Forces

    NASA Astrophysics Data System (ADS)

    Sekiguchi, K.; Wada, Y.; Watanabe, A.; Eto, D.; Akieda, T.; Kon, H.; Miki, K.; Sakamoto, N.; Sakai, H.; Sasano, M.; Shimizu, Y.; Suzuki, H.; Uesaka, T.; Yanagisawa, Y.; Dozono, M.; Kawase, S.; Kubota, Y.; Lee, C. S.; Yako, K.; Maeda, Y.; Kawakami, S.; Yamamoto, T.; Sakaguchi, S.; Wakasa, T.; Yasuda, J.; Ohkura, A.; Shindo, Y.; Tabata, M.; Milman, E.; Chebotaryov, S.; Okamura, H.; Tang, T. L.

    2017-03-01

    We have measured a complete set of deuteron analyzing powers in deuteron-proton elastic scattering at 190, 250, and 294 MeV/nucleon. The obtained data are compared with the Faddeev calculations based on the modern nucleon-nucleon forces together with the Tucson-Melbourne'99, and UrbanaIX three nucleon forces. The data are also presented with the calculations based on the N4LO NN potentials of the chiral effective field theory.

  17. In-medium full-folding optical model for nucleon-nucleus elastic scattering

    SciTech Connect

    Arellano, H.F.; Brieva, F.A.; Love, W.G. |

    1995-07-01

    We develop an approach for incorporating both medium and off-shell effects in the calculation of full-folding nucleon-nucleus optical potentials for elastic scattering. The approach is based on a flexible scheme for calculating the nucleon-nucleon effective interaction in the nuclear medium. Using this scheme, we calculate a fully off-shell, energy-dependent effective force which includes effects arising from Pauli blocking and the nuclear mean field via an interacting nuclear matter model. Calculations of the elastic scattering observables for {ital p}+{sup 40}Ca and for {ital p}+{sup 208}Pb at energies between 30 and 400 MeV are presented and discussed. We also study total cross sections for neutron scattering off {sup 40}Ca, {sup 90}Zr, and {sup 208}Pb in the 5--400 MeV energy range. The theory gives a reasonable overall description of the data in the energy range under study.

  18. Ab initio many-body calculations of nucleon-nucleus scattering

    NASA Astrophysics Data System (ADS)

    Quaglioni, Sofia; Navrátil, Petr

    2009-04-01

    We develop a new ab initio many-body approach capable of describing simultaneously both bound and scattering states in light nuclei, by combining the resonating-group method with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters. This approach preserves translational symmetry and the Pauli principle. We outline technical details and present phase-shift results for neutron scattering on H3, He4, and Be10 and proton scattering on He3,4, using realistic nucleon-nucleon (NN) potentials. Our A=4 scattering results are compared to earlier ab initio calculations. We find that the CD-Bonn NN potential in particular provides an excellent description of nucleon-He4S-wave phase shifts. In contrast, the experimental nucleon-He4P-wave phase shifts are not well reproduced by any NN potential we use. We demonstrate that a proper treatment of the coupling to the n-Be10 continuum is successful in explaining the parity-inverted ground state in Be11.

  19. Directional Antineutrino Detection

    NASA Astrophysics Data System (ADS)

    Safdi, B. R.; Suerfu, J.

    2014-12-01

    We propose the first truly directional antineutrino detector for antineutrinos near the threshold for the inverse beta decay (IBD) of hydrogen, with potential applications including the spatial mapping of geo-neutrinos, searches for stellar antineutrinos, and the monitoring of nuclear reactors. The detector consists of adjacent and separated target and neutron-capture layers. The IBD events, which result in a neutron and a positron, take place in the target layers. These layers are thin enough so that the neutrons escape without scattering elastically. The neutrons are detected in the thicker neutron-capture layers. The location of the IBD event is determined from the energy deposited by the positron as it slows in the medium and from the two gamma rays that come from the positron annihilation. Since the neutron recoils in the direction of the antineutrino's motion, a line may then be drawn between the IBD event location and the neutron-capture location to approximate the antineutrino's velocity. In some events, we may even measure the positron's velocity, which further increases our ability to reconstruct the antineutrino's direction of motion. Our method significantly improves upon previous methods by allowing the neutron to freely travel a long distance before diffusing and being captured. Moreover, our design is a straightforward modification of existing antineutrino detectors; a prototype could easily be built with existing technology. We verify our design through Monte Carlo simulations in Geant4, using commercially-available boron-loaded plastic scintillators for the target and neutron-capture layer materials. We are able to discriminate from background using multiple coincidence signatures within a short, ~microsecond time interval. We conclude that the detector could likely operate above ground with minimal shielding.

  20. Propagator modifications in elastic nucleon-nucleus scattering within the spectator expansion

    NASA Astrophysics Data System (ADS)

    Chinn, C. R.; Elster, Ch.; Thaler, R. M.; Weppner, S. P.

    1995-10-01

    The theory of the elastic scattering of a nucleon from a nucleus is presented in the form of a spectator expansion of the optical potential. Particular attention is paid to the treatment of the free projectile-nucleus propagator when the coupling of the struck target nucleon to the residual target must be taken into consideration. First order calculations within this framework are shown for neutron total cross sections and for proton scattering for a number of target nuclides at a variety of energies. The calculated values of these observables are in very good agreement with measurement.

  1. Comparison of exact and approximate evaluations of the single-scattering integral in nucleon-deuteron elastic scattering

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.

    1972-01-01

    The exact nucleon-deuteron elastic single scattering integral was calculated numerically in order to evaluate errors in sticking factor approximations. A similar analysis made by using S wave separable potentials concluded that errors for these approximations were negligible except near backward angles where they were found to be about 10 percent.

  2. Meson-induced correlations of nucleons in nuclear Compton scattering

    SciTech Connect

    Huett, M.; Milstein, A.I.

    1998-01-01

    The nonresonant (seagull) contribution to the nuclear Compton amplitude at low energies is strongly influenced by nucleon correlations arising from meson exchange. We study this problem in a modified Fermi gas model, where nuclear correlation functions are obtained with the help of perturbation theory. The dependence of the mesonic seagull amplitude on the nuclear radius is investigated and the influence of a realistic nuclear density on this amplitude is discussed. We found that different form factors appear for the static part (proportional to the enhancement constant {kappa}) of the mesonic seagull amplitude and for the parts, which contain the contribution from electromagnetic polarizabilities. {copyright} {ital 1998} {ital The American Physical Society}

  3. Meson-induced correlations of nucleons in nuclear Compton scattering

    NASA Astrophysics Data System (ADS)

    Hütt, M.-Th.; Milstein, A. I.

    1998-01-01

    The nonresonant (seagull) contribution to the nuclear Compton amplitude at low energies is strongly influenced by nucleon correlations arising from meson exchange. We study this problem in a modified Fermi gas model, where nuclear correlation functions are obtained with the help of perturbation theory. The dependence of the mesonic seagull amplitude on the nuclear radius is investigated and the influence of a realistic nuclear density on this amplitude is discussed. We found that different form factors appear for the static part (proportional to the enhancement constant κ) of the mesonic seagull amplitude and for the parts, which contain the contribution from electromagnetic polarizabilities.

  4. Supersymmetry-generated jost functions and nucleon–nucleon scattering phase shifts

    SciTech Connect

    Bhoi, J. Laha, U.

    2015-10-15

    By exploiting the supersymmetry-inspired factorization method higher partial wave Jost solutions and functions for nuclear Hulthen potential are constructed from the knowledge of the ground state wave function. As a case study the nucleon–nucleon scattering phase shifts are computed for partial waves ℓ = 0, 1, and 2.

  5. Simulation of nucleon elastic scattering in the MARS14 code system

    SciTech Connect

    Igor L Rakhno et al.

    2001-11-26

    Correct modeling of nucleon elastic scattering is of special importance in many applications at high energy accelerators, such as deep penetration, beam loss and collimation studies. In present paper, the work performed to update the MARS elastic scattering model at E < 5 GeV is described. Modern evaluated nuclear data as well as fitting formulae are used in the new model. For protons as projectiles, Coulomb scattering and Coulomb-nuclear interference are taken into account in addition to nuclear elastic scattering. Comparisons with experimental angular distributions and calculations by means of other codes are presented.

  6. Spin effects in pion-nucleon and nucleon-nucleon scattering at high energies and fixed angles

    NASA Astrophysics Data System (ADS)

    Chavleishvili, M. P.

    1989-05-01

    Based on the study of the general structure of helicity amplitudes, obligatory kinematic factors are separated and the so-called dynamic amplitudes are introduced. These factors make conservation laws fulfill and contain all the kinematic singularities of helicity amplitudes. Via the dynamic amplitudes, the observable quantities are expressed in a simple form. Kinematic factors play the role of weighting functions. At high energies and fixed angles these factors turn into small parameters which suppress contributions of some helicity amplitudes, and enhance contributions of others. So we get the kinematic hierarchy for binary processes. As an example we consider πN- and NN-scattering. Predictions are given for some asymmetry parameters which do not coincide with the helicity conservation rules, predicted by QCD.

  7. Solution of the Bethe-Salpeter equation for pion-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Lahiff, A. D.; Afnan, I. R.

    1999-08-01

    A relativistic description of pion-nucleon scattering based on the four-dimensional Bethe-Salpeter equation is presented. The kernel of the equation consists of s- and u-channel nucleon and Δ(1232) pole diagrams, as well as ρ and σ exchange in the t channel. The Bethe-Salpeter equation is solved by means of a Wick rotation, and good fits are obtained to the s- and p-wave πN phase shifts up to 360 MeV pion laboratory energy. The coupling constants determined by the fits are consistent with the commonly accepted values in the literature.

  8. Short-range interactions in an effective field theory approach for nucleon-nucleon scattering

    SciTech Connect

    Scaldeferri, K.A.; Phillips, D.R.; Kao, C.; Cohen, T.D.

    1997-08-01

    We investigate in detail the effect of making the range of the {open_quotes}contact{close_quotes} interaction used in effective field theory (EFT) calculations of NN scattering finite. This is done in both an effective field theory with explicit pions, and one where the pions have been integrated out. In both cases we calculate NN scattering in the {sup 1}S{sub 0} channel using potentials which are second order in the EFT expansion. The contact interactions present in the EFT Lagrangian are made finite by use of a square-well regulator. We find that there is an optimal radius for this regulator, at which second-order corrections to the EFT are identically zero; for radii near optimal these second-order corrections are small. The cutoff EFT{close_quote}s which result from this procedure appear to be valid for momenta up to about 100{endash}150MeV/c. We also find that the radius of the square well cannot be reduced to zero if the theory is to reproduce both the experimental scattering length and effective range. Indeed, we show that, if the NN potential is the sum of a one-pion-exchange piece and a short-range interaction, then the short-range piece must extend out beyond 1.05 fm, regardless of its particular form. {copyright} {ital 1997} {ital The American Physical Society}

  9. The nuclear spin-isospin response to quasifree nucleon scattering

    SciTech Connect

    Taddeucci, T.N.

    1995-12-31

    The Neutron-Time-of-Flight (NTOF) facility at LAMPF has been used to measure complete sets of polarization-transfer coefficients for quasifree ({rvec p},{rvec n}) scattering from {sup 2}H, {sup 12}C, and {sup 40}Ca at 494 MeV and scattering angles of 12.5{degrees}, 18{degrees}, and 27{degrees} (q = 1.2, 1.7, 2.5 fm{sup {minus}1}). These measurements yield separated transverse ({sigma} {times} q) and longitudinal ({sigma}{center_dot}q) isovector spin responses. Comparison of the separated responses to calculations and to electron-scattering responses reveals a strong enhancement in the spin transverse channel. This excess transverse strength masks the effect of pionic correlations in the response ratio.

  10. A relativistic meson-exchange model of pion-nucleon scattering

    SciTech Connect

    Lee, T.S.H.; Hung, C.T.; Yang, S.N.

    1995-08-01

    Pion-nucleon scattering is investigated using the Kadshevsky three-dimensional reduction of the Bethe-Salpeter equation. The resulting potential includes the direct and crossed N and {Delta} terms, and the t-channel {sigma}- and {rho}-exchange terms. The nucleon-pole condition is imposed to define the renormalization of the nucleon mass and the {pi}NN coupling constant. A mixture of the scalar and vector {sigma}{pi}{pi} couplings is introduced to simulate the broad width of the s-wave correlated two-pion exchange mechanism. Good descriptions of the {pi}N phase shifts up to 400 MeV have been obtained in all S- and P-waves. The off-shell behavior for our model differs significantly from that obtained using different reductions. A paper describing our results was published.

  11. {Delta} excitation in inelastic scattering of nucleons on nuclei

    SciTech Connect

    Ramachandran, G.; Vidya, M.S.

    1997-07-01

    We outline an elegant way of deducing the spin structure of any reaction A(a,b)B with arbitrary spins s{sub A},s{sub a},s{sub b},s{sub B} and apply the same to NN{r_arrow}N{Delta}, taking into consideration the Pauli exclusion principle. This method, based on irreducible tensor techniques is then extended to {Delta} excitation in A(N,N{sup {prime}}{pi})B by considering the target excitation process (TDP) as A(N,N{sup {prime}})B{sub {Delta}}{sup {asterisk}} followed by B{sub {Delta}}{sup {asterisk}}{r_arrow}B+{pi} and the projectile excitation process (PDP) as A(N,{Delta})B followed by {Delta}{r_arrow}N{sup {prime}}{pi}. Expressions for the double differential cross section and inelastic nucleon spin observables are given, which are of current experimental interest. {copyright} {ital 1997} {ital The American Physical Society}

  12. Reconciling threshold and subthreshold expansions for pion-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Siemens, D.; Ruiz de Elvira, J.; Epelbaum, E.; Hoferichter, M.; Krebs, H.; Kubis, B.; Meißner, U.-G.

    2017-07-01

    Heavy-baryon chiral perturbation theory (ChPT) at one loop fails in relating the pion-nucleon amplitude in the physical region and for subthreshold kinematics due to loop effects enhanced by large low-energy constants. Studying the chiral convergence of threshold and subthreshold parameters up to fourth order in the small-scale expansion, we address the question to what extent this tension can be mitigated by including the Δ (1232) as an explicit degree of freedom and/or using a covariant formulation of baryon ChPT. We find that the inclusion of the Δ indeed reduces the low-energy constants to more natural values and thereby improves consistency between threshold and subthreshold kinematics. In addition, even in the Δ-less theory the resummation of 1 /mN corrections in the covariant scheme improves the results markedly over the heavy-baryon formulation, in line with previous observations in the single-baryon sector of ChPT that so far have evaded a profound theoretical explanation.

  13. Analytic, non-perturbative, gauge-invariant quantum chromodynamics: Nucleon scattering and binding potentials

    SciTech Connect

    Fried, H.M.; Gabellini, Y.; Grandou, T.; Sheu, Y.-M.

    2013-11-15

    Removal of the quenched approximation in the mechanism which produced an analytic estimate of quark-binding potentials, along with a reasonable conjecture of the color structure of the nucleon formed by such a binding potential, is shown to generate an effective nucleon scattering and binding potential. The mass-scale factor on the order of the pion mass, previously introduced to define the transverse imprecision of quark coordinates, is again used, while the strength of the potential is proportional to the square of a renormalized quantum chromodynamics (QCD) coupling constant. The potential so derived does not include corrections due to spin, angular momentum, nucleon structure, and electroweak interactions; rather, it is qualitative in nature, showing how Nuclear Physics can arise from fundamental QCD. -- Highlights: •Nucleon–nucleon forces are derived qualitatively from basic realistic quantum chromodynamics. •An effective nucleon binding is obtained from the simplest unquenched approximation. •A model deuteron binding energy of −2.2 MeV follows with α{sub s,R}=12.5.

  14. Parity Violating Electron Scattering and Strangeness in the Nucleon

    SciTech Connect

    Maas, Frank E.

    2008-10-13

    A measurement of the weak form factor of the proton allows a flavor separation of the strangeness contribution to the electromagnetic form factors. The weak form factor is accessed experimentally by the measurement of a parity violating (PV) asymmetry in the scattering of polarized electrons on unpolarized protons. An extended experimental program to measure these parity violating asymmetries has been performed and is going on at different accelerators. After the first round of experiments allowing a separation of the strangeness form factors G{sub E}{sup s} and G{sub M}{sup s} at a Q{sup 2}-value of 0.1 (GeV/c){sup 2}, new, preliminary results have been achieved at 0.23 (GeV/c){sup 2}.

  15. Three-body break-up in deuteron-deuteron scattering at 65 MeV/nucleon

    NASA Astrophysics Data System (ADS)

    Ramazani-Moghaddam-Arani, A.; Amir-Ahmadi, H. R.; Bacher, A. D.; Bailey, C. D.; Biegun, A.; Eslamikalantari, M.; Gašparić, I.; Joulaeizadeh, L.; Kalantar-Nayestanaki, N.; Kistryn, St.; Kozela, A.; Mardanpour, H.; Messchendorp, J. G.; Micherdzinska, A. M.; Moeini, H.; Shende, S. V.; Stephan, E.; Stephenson, E. J.; Sworst, R.

    2010-04-01

    We successfully identified several multibody final states in deuteron-deuteron scattering at 65 MeV/nucleon at KVI using a unique and advanced detection system called BINA. This facility enabled us to perform cross sections and polarization measurements with an improved statistical and systematic precision. The analysis procedure and a part of the results of the three-body break-up channel in the deuteron-deuteron scattering at 65 MeV/nucleon are presented.

  16. Halo-independent upper limits on the dark matter scattering cross section with nucleons

    NASA Astrophysics Data System (ADS)

    Wild, Sebastian; Ferrer, Francesc; Ibarra, Alejandro

    2016-05-01

    We present a novel method that allows to derive an upper limit on the scattering cross section of dark matter with nucleons which is independent of the velocity distribution. To this end, we combine null results from direct detection experiments and neutrino telescopes, and use the fact that taken together, these classes of experiments probe the whole range of possible dark matter velocities. The resulting halo-independent upper limits on the dark matter scattering cross section are remarkably strong, and can be used to robustly rule out models of dark matter, without the need to invoke specific assumptions about the local velocity distribution.

  17. Exact expressions and improved approximations for interaction rates of neutrinos with free nucleons in a high-temperature, high-density gas

    NASA Technical Reports Server (NTRS)

    Schinder, Paul J.

    1990-01-01

    The exact expressions needed in the neutrino transport equations for scattering of all three flavors of neutrinos and antineutrinos off free protons and neutrons, and for electron neutrino absorption on neutrons and electron antineutrino absorption on protons, are derived under the assumption that nucleons are noninteracting particles. The standard approximations even with corrections for degeneracy, are found to be poor fits to the exact results. Improved approximations are constructed which are adequate for nondegenerate nucleons for neutrino energies from 1 to 160 MeV and temperatures from 1 to 50 MeV.

  18. Exact expressions and improved approximations for interaction rates of neutrinos with free nucleons in a high-temperature, high-density gas

    NASA Technical Reports Server (NTRS)

    Schinder, Paul J.

    1990-01-01

    The exact expressions needed in the neutrino transport equations for scattering of all three flavors of neutrinos and antineutrinos off free protons and neutrons, and for electron neutrino absorption on neutrons and electron antineutrino absorption on protons, are derived under the assumption that nucleons are noninteracting particles. The standard approximations even with corrections for degeneracy, are found to be poor fits to the exact results. Improved approximations are constructed which are adequate for nondegenerate nucleons for neutrino energies from 1 to 160 MeV and temperatures from 1 to 50 MeV.

  19. Two-Boson Exchange in Electron-Nucleon Scattering

    NASA Astrophysics Data System (ADS)

    Ashworth, Jesse; Melnitchouk, Wally; Blunden, Peter

    2016-09-01

    Researchers are working to determine in-depth information about the proton's substructure. This includes the charge and current distributions of the proton, described by electromagnetic form factors. These quantities can be determined by computing electron-proton scattering cross sections, which have been calculated to first-order expansion in the fine structure constant, α. Experimental discrepancies in the proton's electric-to-magnetic form factor ratio have prompted a need to compute cross sections to second-order expansion in α, involving two-boson exchange (TBE) interactions. Two methods exist for computing TBE contributions: one based on hadronic degrees of freedom (suitable at low Q2) and the other on partonic degrees of freedom (applicable at high Q2). Both methods have been claimed to help account for the form factor discrepancy, but ambiguities exist in the separation of the soft and hard parts of the partonic cross sections. This work aims to resolve such ambiguities and pave the way toward a unified description of TBE effects at all Q2 values. Achieving this goal will further pin down the nature of the proton's interior, and the results in turn can be used to better understand the substructure of the neutron and other hadrons. Thomas Jefferson National Accelerator Facility; Old Dominion University; National Science Foundation.

  20. Pion-nucleon scattering in covariant baryon chiral perturbation theory with explicit Delta resonances

    NASA Astrophysics Data System (ADS)

    Yao, De-Liang; Siemens, D.; Bernard, V.; Epelbaum, E.; Gasparyan, A. M.; Gegelia, J.; Krebs, H.; Meißner, Ulf-G.

    2016-05-01

    We present the results of a third order calculation of the pion-nucleon scattering amplitude in a chiral effective field theory with pions, nucleons and delta resonances as explicit degrees of freedom. We work in a manifestly Lorentz invariant formulation of baryon chiral perturbation theory using dimensional regularization and the extended on-mass-shell renormalization scheme. In the delta resonance sector, the on mass-shell renormalization is realized as a complex-mass scheme. By fitting the low-energy constants of the effective Lagrangian to the S- and P -partial waves a satisfactory description of the phase shifts from the analysis of the Roy-Steiner equations is obtained. We predict the phase shifts for the D and F waves and compare them with the results of the analysis of the George Washington University group. The threshold parameters are calculated both in the delta-less and delta-full cases. Based on the determined low-energy constants, we discuss the pion-nucleon sigma term. Additionally, in order to determine the strangeness content of the nucleon, we calculate the octet baryon masses in the presence of decuplet resonances up to next-to-next-to-leading order in SU(3) baryon chiral perturbation theory. The octet baryon sigma terms are predicted as a byproduct of this calculation.

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

    SciTech Connect

    Hupin, Guillaume; Langhammer, Joachim; Navratil, Petr; Quaglioni, Sofia; Calci, Angelo; Roth, Robert

    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 from 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.

  2. Measurement of Muon Antineutrino Quasielastic Scattering on a Hydrocarbon Target at Eν~3.5 GeV

    SciTech Connect

    Fields, L.; Chvojka, J.; Aliaga, L.; Altinok, O.; Baldin, B.; Baumbaugh, A.; Bodek, A.; Boehnlein, D.; Boyd, S.; Bradford, R.; Brooks, W. K.; Budd, H.; Butkevich, A.; Martinez Caicedo, D. A.; Castromonte, C. M.; Christy, M. E.; Chung, H.; Clark, M.; da Motta, H.; Damiani, D. S.; Danko, I.; Datta, M.; Day, M.; DeMaat, R.; Devan, J.; Draeger, E.; Dytman, S. A.; Díaz, G. A.; Eberly, B.; Edmondson, D. A.; Felix, J.; Fitzpatrick, T.; Fiorentini, G. A.; Gago, A. M.; Gallagher, H.; George, C. A.; Gielata, J. A.; Gingu, C.; Gobbi, B.; Gran, R.; Grossman, N.; Hanson, J.; Harris, D. A.; Heaton, J.; Higuera, A.; Howley, I. J.; Hurtado, K.; Jerkins, M.; Kafka, T.; Kaisen, J.; Kanter, M. O.; Keppel, C. E.; Kilmer, J.; Kordosky, M.; Krajeski, A. H.; Kulagin, S. A.; Le, T.; Lee, H.; Leister, A. G.; Locke, G.; Maggi, G.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; McFarland, K. S.; McGivern, C. L.; McGowan, A. M.; Mislivec, A.; Morfín, J. G.; Mousseau, J.; Naples, D.; Nelson, J. K.; Niculescu, G.; Niculescu, I.; Ochoa, N.; O’Connor, C. D.; Olsen, J.; Osmanov, B.; Osta, J.; Palomino, J. L.; Paolone, V.; Park, J.; Patrick, C. E.; Perdue, G. N.; Peña, C.; Rakotondravohitra, L.; Ransome, R. D.; Ray, H.; Ren, L.; Rodrigues, P. A.; Rude, C.; Sassin, K. E.; Schellman, H.; Schmitz, D. W.; Schneider, R. M.; Schulte, E. C.; Simon, C.; Snider, F. D.; Snyder, M. C.; Sobczyk, J. T.; Solano Salinas, C. J.; Tagg, N.; Tan, W.; Tice, B. G.; Tzanakos, G.; Velásquez, J. P.; Walding, J.; Walton, T.; Wolcott, J.; Wolthuis, B. A.; Woodward, N.; Zavala, G.; Zeng, H. B.; Zhang, D.; Zhu, L. Y.; Ziemer, B. P.

    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, MA, 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 data at higher Q² favor this interpretation over an alternative in which the axial mass is increased.

  3. Antineutrino Neutral Current Interactions in MiniBooNE

    SciTech Connect

    Dharmapalan, Ranjan

    2012-01-01

    This dissertation reports the antineutrino-nucleus neutral current elastic scattering cross section on CH2 measured by the MiniBooNE experiment located in Batavia, IL. The data set consists of 60,605 events passing the selection cuts corresponding to 10.1×1020 POT, which represents the world’s largest sample of antineutrino neutral current elastic scattering events. The final sample is more than one order of magnitude lager that the previous antineutrino NCE scattering cross section measurement reported by the BNL E734 experiment. The measurement presented in this dissertation also spans a wider range in Q2, including the low-Q2 regime where the cross section rollover is clearly visible. A X2-based minimization was performed to determine the best value of the axial mass, MA and the Pauli blocking scaling function, that matches the antineutrino NCE scattering data. However, the best fit values of MA=1.29 GeV and K=1.026 still give a relatively poor X2, which suggests that the underlying nuclear model (based largely on the relativistic Fermi gas model) may not be an accurate representation for this particular interaction. Additionally, we present a measurement of the antineutrino/neutrino-nucleus NCE scattering cross section ratio. The neutrino mode NCE sample used in this study, corresponding to 6.4 × 1020 POT, is also the world’s largest sample (also by an order of magnitude). We have demonstrated that the ratio measurement is robust, as most of the correlated errors cancel, as expected. Furthermore, this ratio also proves to be rather insensitive to variations in the axial mass and the Pauli blocking parameter. This is the first time that this ratio has been experimentally reported. We believe this measurement will aid the theoretical physics community to test various model predictions of neutrino-nucleon/nucleus interactions.

  4. Virtual compton scattering at low energy and the generalized polarizabilities of the nucleon

    SciTech Connect

    Helene Fonvieille

    2003-10-01

    We present a particular kind of (e, e' p) experiments, which has opened a new field of investigation of nucleon structure in the last ten years. The exclusive photon electroproduction process p(e, e' p){gamma} is used to study Virtual Compton Scattering (VCS) off the proton: {gamma}*p {yields} {gamma}p. In the low energy domain, this process gives access to new observables called the Generalized Polarizabilities. They are fundamental properties of the nucleon, characterizing the deformation of its internal structure under an applied electromagnetic field. Dedicated experiments have been performed at MAMI, Jefferson Lab and MIT-Bates. This contribution summarizes the results obtained so far and future prospects in the field.

  5. Neutrino-antineutrino transitions

    SciTech Connect

    Langacker, P.; Wang, J.

    1998-11-01

    We consider transitions between neutrinos and antineutrinos in laboratory experiments in five scenarios. These include the case in which the helicity flips, producing an antineutrino with normal weak interactions, and helicity preserving oscillations into an SU(2) singlet state which only interacts by mixing or new interactions. The ratio of {mu}{sup +} and {mu}{sup {minus}} events for a high energy {nu}{sub {mu}} beam from pion decay rescattered from a nucleon target and the ratio between e{sup +} and e{sup {minus}} events for a rescattered low energy {nu}{sub e} beam are calculated in each case. The upper limit on the ratio is about 10{sup {minus}6}{endash}10{sup {minus}10} for a high energy {nu}{sub {mu}} beam and 10{sup {minus}6}{endash}10{sup {minus}14} for a low energy {nu}{sub e} beam, too small to observe in present experiments. {copyright} {ital 1998} {ital The American Physical Society}

  6. Nucleon-nucleon data

    SciTech Connect

    McNaughton, M.W.; Gulmez, E.; Whitten, C.A.

    1997-10-01

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). This work completes the determination of the nucleon-nucleon (NN) scattering amplitudes from 485 to 800 MeV. The data set is completed by the publication of two papers. These new data have a precision better than 1% and an absolute accuracy about 1%, which is generally an order of magnitude better than previous data. The NN data set is now complete and consistent. The set of spin-dependent NN-scattering amplitudes is now well determined up to 800 MeV.

  7. Elastic pion-nucleon scattering in chiral perturbation theory: A fresh look

    NASA Astrophysics Data System (ADS)

    Siemens, D.; Bernard, V.; Epelbaum, E.; Gasparyan, A.; Krebs, H.; Meißner, Ulf-G.

    2016-07-01

    Elastic pion-nucleon scattering is analyzed in the framework of chiral perturbation theory up to fourth order within the heavy-baryon expansion and a covariant approach based on an extended on-mass-shell renormalization scheme. We discuss in detail the renormalization of the various low-energy constants and provide explicit expressions for the relevant β functions and the finite subtractions of the power-counting breaking terms within the covariant formulation. To estimate the theoretical uncertainty from the truncation of the chiral expansion, we employ an approach which has been successfully applied in the most recent analysis of the nuclear forces. This allows us to reliably extract the relevant low-energy constants from the available scattering data at low energy. The obtained results provide clear evidence that the breakdown scale of the chiral expansion for this reaction is related to the Δ resonance. The explicit inclusion of the leading contributions of the Δ isobar is demonstrated to substantially increase the range of applicability of the effective field theory. The resulting predictions for the phase shifts are in an excellent agreement with the predictions from the recent Roy-Steiner-equation analysis of pion-nucleon scattering.

  8. Strangeness S =-1 hyperon-nucleon scattering in covariant chiral effective field theory

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

    Motivated by the successes of covariant baryon chiral perturbation theory in one-baryon systems and in heavy-light systems, we study relevance of relativistic effects in hyperon-nucleon interactions with strangeness S =-1 . In this exploratory work, we follow the covariant framework developed by Epelbaum and Gegelia to calculate the Y N scattering amplitude at leading order. By fitting the five low-energy constants to the experimental data, we find that the cutoff dependence is mitigated, compared with the heavy-baryon approach. Nevertheless, the description of the experimental data remains quantitatively similar at leading order.

  9. a Phenomenological Determination of the Pion-Nucleon Scattering Lengths from Pionic Hydrogen

    NASA Astrophysics Data System (ADS)

    Ericson, T. E. O.; Loiseau, B.; Wycech, S.

    A model independent expression for the electromagnetic corrections to a phenomenological hadronic pion-nucleon (πN) scattering length ah, extracted from pionic hydrogen, is obtained. In a non-relativistic approach and using an extended charge distribution, these corrections are derived up to terms of order α2 log α in the limit of a short-range hadronic interaction. We infer ahπ ^-p=0.0870(5)m-1π which gives for the πNN coupling through the GMO relation g2π ^± pn/(4π )=14.04(17).

  10. Two-nucleon higher partial-wave scattering from lattice QCD

    NASA Astrophysics Data System (ADS)

    Berkowitz, Evan; Kurth, Thorsten; Nicholson, Amy; Joó, Bálint; Rinaldi, Enrico; Strother, Mark; Vranas, Pavlos M.; Walker-Loud, André

    2017-02-01

    We present a determination of nucleon-nucleon scattering phase shifts for ℓ ≥ 0. The S, P, D and F phase shifts for both the spin-triplet and spin-singlet channels are computed with lattice Quantum ChromoDynamics. For ℓ > 0, this is the first lattice QCD calculation using the Lüscher finite-volume formalism. This required the design and implementation of novel lattice methods involving displaced sources and momentum-space cubic sinks. To demonstrate the utility of our approach, the calculations were performed in the SU (3)-flavor limit where the light quark masses have been tuned to the physical strange quark mass, corresponding to mπ =mK ≈ 800 MeV. In this work, we have assumed that only the lowest partial waves contribute to each channel, ignoring the unphysical partial wave mixing that arises within the finite-volume formalism. This assumption is only valid for sufficiently low energies; we present evidence that it holds for our study using two different channels. Two spatial volumes of V ≈(3.5 fm) 3 and V ≈(4.6 fm) 3 were used. The finite-volume spectrum is extracted from the exponential falloff of the correlation functions. Said spectrum is mapped onto the infinite volume phase shifts using the generalization of the Lüscher formalism for two-nucleon systems.

  11. Longitudinal-Transverse Separation of Deep-Inelastic Scattering at Low Q² on Nucleons and Nuclei

    SciTech Connect

    Tvaskis, Vladas

    2004-12-06

    Since the early experiments at SLAC, which discovered the nucleon substructure and led to the development of the quark parton model, deep inelastic scattering (DIS) has been the most powerful tool to investigate the partonic substructure of the nucleon. After about 30 years of experiments with electron and muon beams the nucleon structure function F2(x,Q2) is known with high precision over about four orders of magnitude in x and Q2. In the region of Q2 > 1 (GeV/c)2 the results of the DIS measurements are interpreted in terms of partons (quarks and gluons). The theoretical framework is provided in this case by perturbative Quantum Chromo Dynamics (pQCD), which includes scaling violations, as described by the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) equations. The description starts to fail when Q2 becomes of the order of 1 (GeV/c)2, where non-perturbative effects (higher-twist effects), which are still not fully understood, become important (non-pQCD). The sensitivity for order-n twist effects increases with decreasing Q2, since they include a factor 1/(Q2n) (n ≥ 1).

  12. Two-nucleon higher partial-wave scattering from lattice QCD

    DOE PAGES

    Berkowitz, Evan; Kurth, Thorsten; Nicholson, Amy; ...

    2016-12-14

    Here, we present a determination of nucleon-nucleon scattering phase shifts for L>0. The S,P,D and F phase shifts for both the spin-triplet and spin-singlet channels are computed for the first time with lattice Quantum ChromoDynamics. This required the design and implementation of novel lattice methods involving displaced sources and momentum-space cubic sinks. In order to demonstrate the utility of our approach, the calculations were performed in the SU(3)-flavor limit where the light quark masses have been tuned to the physical strange quark mass, corresponding to mπ=mK≈800~MeV. Two spatial volumes of V ≈ (3.5 fm)3 and V ≈ (4.6 fm)3 weremore » used. Furthermore, the finite-volume spectrum is extracted from the exponential falloff of the correlation functions. Said spectrum is mapped onto the infinite volume phase shifts using the generalization of the Luscher formalism for two-nucleon systems.« less

  13. 7D-folding integral in a density-dependent microscopic optical model potential for nucleon-nucleus scattering

    SciTech Connect

    Arellano, H. F.

    2011-09-15

    Microscopic optical model potentials, based on density-dependent effective interactions, involve multidimensional integrals to account for the full Fermi motion of the target struck nucleon throughout the nucleus. If a spherical matter distribution is assumed, then each matrix element of the optical potential requires the evaluation of seven-dimensional integrals. In this work we provide a full account of these integrals, retaining the genuine off-shell structure of the nucleon-nucleon effective interaction. The evaluation is based on the asymptotic separation of the optical model potential for nucleon-nucleus scattering in momentum space, where the potential is split into a free t-matrix contribution and another which depends exclusively on the gradient of the density-dependent g matrix. The calculated potentials, based on the Paris nucleon-nucleon (NN) potential, are applied to proton elastic scattering from {sup 16}O and {sup 90}Zr at beam energies between 30 and 65 MeV. The results were compared with two approximations to the unabridged expression, revealing moderate differences among their scattering observables. When comparing with results based on the Argonne v{sub 18} NNpotential, these differences appear smaller than those attainable by the choice of the internucleon potential.

  14. A Lane consistent optical model potential for nucleon scattering on actinide nuclei with extended coupling

    NASA Astrophysics Data System (ADS)

    Quesada, José Manuel; Capote, Roberto; Soukhovitski, Efrem S.; Chiba, Satoshi

    2016-03-01

    An extension for odd-A actinides of a previously derived dispersive coupledchannel optical model potential (OMP) for 238U and 232Th nuclei is presented. It is used to fit simultaneously all the available experimental databases including neutron strength functions for nucleon scattering on 232Th, 233,235,238U and 239Pu nuclei. Quasi-elastic (p,n) scattering data on 232Th and 238U to the isobaric analogue states of the target nucleus are also used to constrain the isovector part of the optical potential. For even-even (odd) actinides almost all low-lying collective levels below 1 MeV (0.5 MeV) of excitation energy are coupled. OMP parameters show a smooth energy dependence and energy independent geometry.

  15. Determination of the pion-nucleon coupling constant and scattering lengths

    NASA Astrophysics Data System (ADS)

    Ericson, T. E.; Loiseau, B.; Thomas, A. W.

    2002-07-01

    We critically evaluate the isovector Goldberger-Miyazawa-Oehme (GMO) sum rule for forward πN scattering using the recent precision measurements of π-p and π-d scattering lengths from pionic atoms. We deduce the charged-pion-nucleon coupling constant, with careful attention to systematic and statistical uncertainties. This determination gives, directly from data, g2c(GMO)/ 4π=14.11+/-0.05(statistical)+/-0.19(systematic) or f2c/4π=0.0783(11). This value is intermediate between that of indirect methods and the direct determination from backward np differential scattering cross sections. We also use the pionic atom data to deduce the coherent symmetric and antisymmetric sums of the pion-proton and pion-neutron scattering lengths with high precision, namely, (aπ-p+aπ-n)/2=[- 12+/-2(statistical)+/-8(systematic)]×10-4 m-1π and (aπ-p-aπ- n)/2=[895+/-3(statistical)+/-13 (systematic)]×10-4 m-1π. For the need of the present analysis, we improve the theoretical description of the pion-deuteron scattering length.

  16. Measurement of the Parity-Violating Asymmetries in Electron-Deuteron Scattering in the Nucleon Resonance Region

    SciTech Connect

    Wang, Diancheng; Pan, Kai; Subedi, Ramesh R.; Deng, Xiaoyan

    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.

  17. Compton Scattering and the Nucleon Polarizabilities in the A2 Collaboration at MAMI

    NASA Astrophysics Data System (ADS)

    Downie, Evangeline; MAMI A2 Collaboration

    2014-09-01

    There has been an upsurge in interest in Compton Scattering experiments as a means to understand the internal structure and dynamics of the nucleon. The new PDG value of β, the proton magnetic polarizability, changed noticeably, with no new data, simply new theoretical treatment of the existing data set. This indicates that the existing data is insufficient to constrain our extraction of these fundamental constants, which are important in areas of physics such as the proton radius determination, and neutron star physics. In the A2 Collaboration of the Institut fuer Kernphysik in Mainz, we use the MAMI accelerator with the Glasgow Mainz Photon Tagger to produce a quasi-monoenergetic, linearly polarized photon beam and apply it to a liquid hydrogen target. The reaction products detected in the Crystal Ball and TAPS large acceptance spectrometer array allow clean separation of the low-cross-section hadronic Compton scattering process. In so doing, we have produced the firs t measurement of the photon asymmetry in Compton scattering on the proton below the pion production threshold. Preliminary results show a demonstrable effect due to the polarizabilities. We will cover the experimental results and future prospects of the A2 polarizability program. There has been an upsurge in interest in Compton Scattering experiments as a means to understand the internal structure and dynamics of the nucleon. The new PDG value of β, the proton magnetic polarizability, changed noticeably, with no new data, simply new theoretical treatment of the existing data set. This indicates that the existing data is insufficient to constrain our extraction of these fundamental constants, which are important in areas of physics such as the proton radius determination, and neutron star physics. In the A2 Collaboration of the Institut fuer Kernphysik in Mainz, we use the MAMI accelerator with the Glasgow Mainz Photon Tagger to produce a quasi-monoenergetic, linearly polarized photon beam and

  18. The Method of Unitary Clothing Transformations in Relativistic Quantum Field Theory: Recent Applications for the Description of Nucleon-Nucleon Scattering and Deuteron Properties

    NASA Astrophysics Data System (ADS)

    Shebeko, A.

    2013-12-01

    The clothing procedure, put forward in quantum field theory by Greenberg and Schweber, is applied for the description of nucleon-nucleon ( N- N) scattering below the pion production threshold and deuteron properties. We consider pseudoscalar ( π and η), vector ( ρ and ω) and scalar ( δ and σ) meson fields interacting with N and 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. 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. We will also show a worked example where the UCTs method is used in the framework of a gauge-independent field-theoretical treatment of electromagnetic interactions of deuterons (bound systems).

  19. Chiral Three-Nucleon Interactions in Light Nuclei, Neutron-α Scattering, and Neutron Matter

    NASA Astrophysics Data System (ADS)

    Lynn, J. E.; Tews, I.; Carlson, J.; Gandolfi, S.; Gezerlis, A.; Schmidt, K. E.; Schwenk, A.

    2016-02-01

    We present quantum Monte Carlo calculations of light nuclei, neutron-α scattering, and neutron matter using local two- and three-nucleon (3 N ) interactions derived from chiral effective field theory up to next-to-next-to-leading order (N2LO ). The two undetermined 3 N low-energy couplings are fit to the 4He binding energy and, for the first time, to the spin-orbit splitting in the neutron-α P -wave phase shifts. Furthermore, we investigate different choices of local 3 N -operator structures and find that chiral interactions at N2LO are able to simultaneously reproduce the properties of A =3 ,4 ,5 systems and of neutron matter, in contrast to commonly used phenomenological 3 N interactions.

  20. Chiral Three-Nucleon Interactions in Light Nuclei, Neutron-α Scattering, and Neutron Matter.

    PubMed

    Lynn, J E; Tews, I; Carlson, J; Gandolfi, S; Gezerlis, A; Schmidt, K E; Schwenk, A

    2016-02-12

    We present quantum Monte Carlo calculations of light nuclei, neutron-α scattering, and neutron matter using local two- and three-nucleon (3N) interactions derived from chiral effective field theory up to next-to-next-to-leading order (N(2)LO). The two undetermined 3N low-energy couplings are fit to the (4)He binding energy and, for the first time, to the spin-orbit splitting in the neutron-α P-wave phase shifts. Furthermore, we investigate different choices of local 3N-operator structures and find that chiral interactions at N(2)LO are able to simultaneously reproduce the properties of A=3,4,5 systems and of neutron matter, in contrast to commonly used phenomenological 3N interactions.

  1. Neutrino-nucleon scattering in supernova matter from the virial expansion

    NASA Astrophysics Data System (ADS)

    Horowitz, C. J.; Caballero, O. L.; Lin, Zidu; O'Connor, Evan; Schwenk, A.

    2017-02-01

    We extend our virial approach to study the neutral-current neutrino response of nuclear matter at low densities. In the long-wavelength limit, the virial expansion makes model-independent predictions for neutrino-nucleon scattering rates and the density SV and spin SA responses. We find that SA is significantly reduced from one even at low densities. We provide a simple fit SAf(n ,T ,Yp) of the axial response as a function of density n , temperature T , and proton fraction Yp, which can be incorporated into supernova simulations in a straightforward manner. This fit reproduces our virial results at low densities and the Burrows and Sawyer random-phase approximation (RPA) model calculations at high densities. Preliminary one-dimensional supernova simulations suggest that the virial reduction in the axial response may enhance neutrino heating rates in the gain region during the accretion phase of a core-collapse supernovae.

  2. Chiral Three-Nucleon Interactions in Light Nuclei, Neutron-α Scattering, and Neutron Matter

    SciTech Connect

    Lynn, J. E.; Tews, I.; Carlson, Joseph Allen; Gandolfi, Stefano; Gezerlis, A.; Schmidt, K. E.; Schwenk, A.

    2016-02-09

    Here we present quantum Monte Carlo calculations of light nuclei, neutron- scattering, and neutron matter using local two- and three-nucleon (3N) interactions derived from chiral e effective fi eld theory up to next-to-next-to-leading order (N2LO). The two undetermined 3N low-energy couplings are fi t to the 4He binding energy and, for the first time, to the spin-orbit splitting in the neutron- P-wave phase shifts. Furthermore, we investigate different choices of local 3N-operator structures and find that chiral interactions at N2LO are able to simultaneously reproduce the properties of A = 3; 4; 5 systems and of neutron matter, in contrast to commonly used phenomenological 3N interactions.

  3. Chiral Three-Nucleon Interactions in Light Nuclei, Neutron-α Scattering, and Neutron Matter

    DOE PAGES

    Lynn, J. E.; Tews, I.; Carlson, Joseph Allen; ...

    2016-02-09

    Here we present quantum Monte Carlo calculations of light nuclei, neutron- scattering, and neutron matter using local two- and three-nucleon (3N) interactions derived from chiral e effective fi eld theory up to next-to-next-to-leading order (N2LO). The two undetermined 3N low-energy couplings are fi t to the 4He binding energy and, for the first time, to the spin-orbit splitting in the neutron- P-wave phase shifts. Furthermore, we investigate different choices of local 3N-operator structures and find that chiral interactions at N2LO are able to simultaneously reproduce the properties of A = 3; 4; 5 systems and of neutron matter, in contrastmore » to commonly used phenomenological 3N interactions.« less

  4. Measurement of sin2θw and ϱ in deep inelastic neutrino-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Reutens, P. G.; Merritt, F. S.; Macfarlane, D. B.; Messner, R. L.; Novikoff, D. B.; Purohit, M. V.; Blair, R. E.; Sciulli, F. J.; Shaevitz, M. H.; Fisk, H. E.; Fukushima, Y.; Jin, B. N.; Kondo, T.; Rapidis, P. A.; Yovanovitch, D. D.; Bodek, A.; Coleman, R. N.; Marsh, W. L.; Fackler, O. D.; Jenkins, K. A.

    1985-03-01

    We describe a high statistics measurement from deep inelastic neutrino-nucleon scattering of the electroweak parameters ϱ and sin2θw, performed in the Fermilab narrow-band neutrino beam. Our measurement uses a radius-dependent cut in y = EH/Ev which reduces the systematic error in sin2θw, and incorporates electromagnetic and electroweak radiative corrections. In a renormalization scheme where sin2θw ≡ 1-m2W/m2Z, a value of sin2θw = 0.242+/-0.011+/-0.005 is obtained fixing ϱ = 1. If both sin2θw and ϱ are allowed to vary in a fit to our data, we measure ϱ = 0.991 +/- 0.025 +/- 0.009. Present address: IBM Thomas J. Watson Research Center, PO Box 218, Yorktown Heights, NY 10598, USA.

  5. Deeply Virtual Compton Scattering on nucleons and nuclei in generalized vector meson dominance model

    SciTech Connect

    Vadim Guzey; Klaus Goeke; Marat Siddikov

    2008-02-01

    We consider Deeply Virtual Compton Scattering (DVCS) on nucleons and nuclei in the framework of generalized vector meson dominance (GVMD) model. We demonstrate that the GVMD model provides a good description of the HERA data on the dependence of the proton DVCS cross section on $Q^2$, $W$ (at $Q^2=4$ GeV$^2$) and $t$. At $Q^2 = 8$ GeV$^2$, the soft $W$-behavior of the GVMD model somewhat underestimates the $W$-dependence of the DVCS cross section due to the hard contribution not present in the GVMD model. We estimate $1/Q^2$ power-suppressed corrections to the DVCS amplitude and the DVCS cross section and find them large. We also make predictions for the nuclear DVCS amplitude and cross section in the kinematics of the future Electron-Ion Collider. We predict significant nuclear shadowing, which matches well predictions of the leading-twist nuclear shadowing in DIS on nuclei.

  6. Pion Production off the Nucleon

    NASA Astrophysics Data System (ADS)

    Rafi Alam, M.; Athar, M. Sajjad; Chauhan, Shikha; Singh, S. K.

    We have studied charged current neutrino/antineutrino induced weak pion production from nucleon. For the present study, contributions from Δ(1232)-resonant term, non-resonant background terms as well as contribution from higher resonances viz. P11(1440), D13(1520), S11(1535), S11(1650), and P13(1720) are taken. To write the hadronic current for the non-resonant background terms, a microscopic approach based on SU(2) non-linear sigma model has been used. The vector form factors for the resonances are obtained from the helicity amplitudes provided by MAID. Axial coupling in the case of Δ(1232) resonance is obtained by fitting the ANL and BNL ν-deuteron reanalyzed scattering data. The results of the cross sections are presented and discussed for all the possible channels of single pion production induced by charged current interaction.

  7. Pion-nucleon scattering in the Roper channel from lattice QCD

    DOE PAGES

    Lang, Christian B.; Leskovec, L.; Padmanath, M.; ...

    2017-01-31

    We present a lattice QCD study ofmore » $$N\\pi$$ scattering in the positive-parity nucleon channel, where the puzzling Roper resonance $N^*(1440)$ resides in experiment. The study is based on the PACS-CS ensemble of gauge configurations with $$N_f=2+1$$ Wilson-clover dynamical fermions, $$m_\\pi \\simeq 156~$$MeV and $$L\\simeq 2.9~$$fm. In addition to a number of $qqq$ interpolating fields, we implement operators for $$N\\pi$$ in $p$-wave and $$N\\sigma$$ in $s$-wave. In the center-of-momentum frame we find three eigenstates below 1.65 GeV. They are dominated by $N(0)$, $$N(0)\\pi(0)\\pi(0)$$ (mixed with $$N(0)\\sigma(0)$$) and $$N(p)\\pi(-p)$$ with $$p\\simeq 2\\pi/L$$, where momenta are given in parentheses. This is the first simulation where the expected multi-hadron states are found in this channel. The experimental $$N\\pi$$ phase-shift would -- in the approximation of purely elastic $$N\\pi$$ scattering -- imply an additional eigenstate near the Roper mass $$m_R\\simeq 1.43~$$GeV for our lattice size. We do not observe any such additional eigenstate, which indicates that $$N\\pi$$ elastic scattering alone does not render a low-lying Roper. Coupling with other channels, most notably with $$N\\pi\\pi$$, seems to be important for generating the Roper resonance, reinforcing the notion that this state could be a dynamically generated resonance. Our results are in line with most of previous lattice studies based just on $qqq$ interpolators, that did not find a Roper eigenstate below $1.65~$GeV. As a result, the study of the coupled-channel scattering including a three-particle decay $$N\\pi\\pi$$ remains a challenge.« less

  8. Effect of the tensor part of Skyrme interaction on the description of elastic nucleon-nucleus scattering on the basis of the optical model

    SciTech Connect

    Kuprikov, V. I.; Pilipenko, V. V.

    2013-01-15

    A microscopic optical nucleon-nucleus potential constructed on the basis of calculating the mass operator for the single-particle Green's function with Skyrme nucleon-nucleon forces was used to study the effect of the tensor part of Skyrme forces on describing differential cross sections for elastic nucleon-nucleus scattering and the structure of nuclei within a self-consistent approach. It was shown that an increase in the tensor terms of nucleon-nucleon forces impaired the description of nucleon-nucleus scattering within the model being considered. The parameters of Skyrme forces were optimized on the basis of an analysis of cross sections for neutron-nucleus scattering, the properties of nuclear matter and the structure of nuclei being tested in doing this. This optimization led to nucleon-nucleon force versions where the tensor part was small or zero and which described satisfactorily the structure of nuclei and cross sections for elastic neutron and proton scattering on nuclei over a broad range of target mass numbers.

  9. Study of photon electroproduction on the nucleon at high and low energy by Virtual Compton Scattering

    NASA Astrophysics Data System (ADS)

    Benali, M.; Mazouz, M.; Fonvieille, H.

    2017-01-01

    Virtual Compton Scattering (VCS) and Deeply Virtual Compton Scattering (DVCS) on the nucleon are two processes accessed via the photon electroproduction reaction ( eN → eγ N). In the first part of this paper we are interested by the DVCS on the neutron. We measured the ( D( e, eγ) X- H( e, e'γ) X) unpolarized cross section and we extracted, for the first time, a non-zero contribution of (neutron-DVCS + coherent- deuteron-DVCS) at Q 2 = 1.75 GeV2 and x B = 36 from Jefferson Lab experiment E08-025. VCS on the proton has been studied at Mainz Microtron MAMI at the four-momentum transfer squared Q 2 = 0.5 GeV2, below the pion production threshold. In the second part of this paper we present our preliminary results of the structure functions ( P LL - ( P TT/ɛ)) and P LT, and the electric and magnetic generalized polarizabilities α E ( Q 2) and β M ( Q 2) extracted from this experiment.

  10. PROBING THE STANDARD MODEL AND NUCLEON STRUCTURE VIA PARITY VIOLATING ELECTRON SCATTERING

    SciTech Connect

    Humensky, T

    2003-10-28

    Parity-violating electron scattering has developed over the last 25 years into a tool to study both the structure of electroweak interactions and the structure of nucleons. Work on two parity-violation experiments is reported in this thesis. They are the Hall A Proton Parity EXperiment (HAPPEX), which ran at Jefferson Laboratory in 1998-1999, and SLAC E-158, which had its first physics running in 2002. HAPPEX measured the parity-violating asymmetry in elastic e-p scattering at a momentum transfer squared of Q{sup 2} = 0.477 GeV{sup 2} and a scattering angle of 12{sup o}. This asymmetry is sensitive to the presence of strange sea quarks in the proton. In particular, it is sensitive to the proton's strange elastic form factors. An asymmetry of A{sub LR}{sup ep} = -15.05 {+-} 0.98 {+-} 0.56 ppm was measured, where the first error is statistical and the second error is systematic. Combining this asymmetry measurement with existing measurements of the electromagnetic form factors of the proton and neutron allowed HAPPEX to set new constraints on the strange elastic form factors of the proton G{sub E}{sup s} + 0.392G{sub M}{sup s} = 0.025 {+-} 0.020 {+-} 0.014, where G{sub E}{sup s} and G{sub M}{sup s} are the strange electric and magnetic form factors of the proton, respectively. The first error is the quadrature sum of the experimental errors and the second error is due to uncertainty in the electromagnetic form factors. This result is consistent with the absence of a contribution from strange quarks. This thesis reports an analysis of the 1999 data set, with a particular focus on the determination of the raw asymmetry and the corrections to the raw asymmetry to account for helicity-correlated asymmetries in properties of the electron beam.

  11. Pion-nucleon scattering in the Roper channel from lattice QCD

    NASA Astrophysics Data System (ADS)

    Lang, C. B.; Leskovec, L.; Padmanath, M.; Prelovsek, S.

    2017-01-01

    We present a lattice QCD study of N π scattering in the positive-parity nucleon channel, where the puzzling Roper resonance N*(1440 ) resides in experiment. The study is based on the PACS-CS ensemble of gauge configurations with Nf=2 +1 Wilson-clover dynamical fermions, mπ≃156 MeV and L ≃2.9 fm . In addition to a number of q q q interpolating fields, we implement operators for N π in p -wave and N σ in s -wave. In the center-of-momentum frame we find three eigenstates below 1.65 GeV. They are dominated by N (0 ), N (0 )π (0 )π (0 ) [mixed with N (0 )σ (0 )] and N (p )π (-p ) with p ≃2 π /L , where momenta are given in parentheses. This is the first simulation where the expected multi-hadron states are found in this channel. The experimental N π phase shift would—in the approximation of purely elastic N π scattering—imply an additional eigenstate near the Roper mass mR≃1.43 GeV for our lattice size. We do not observe any such additional eigenstate, which indicates that N π elastic scattering alone does not render a low-lying Roper. Coupling with other channels, most notably with N π π , seems to be important for generating the Roper resonance, reinforcing the notion that this state could be a dynamically generated resonance. Our results are in line with most of the previous lattice studies based just on q q q interpolators, which did not find a Roper eigenstate below 1.65 GeV. The study of the coupled-channel scattering including a three-particle decay N π π remains a challenge.

  12. Nucleon spin-polarisabilities from polarisation observables in low-energy deuteron Compton scattering

    NASA Astrophysics Data System (ADS)

    Grießhammer, H. W.; Shukla, D.

    2010-11-01

    We investigate the dependence of polarisation observables in elastic deuteron Compton scattering below the pion production threshold on the spin-independent and spin-dependent iso-scalar dipole polarisabilities of the nucleon. The calculation uses Chiral Effective Field Theory ( χ EFT) with dynamical Δ(1232) degrees of freedom in the Small Scale Expansion (SSE) at next-to-leading order. Resummation of the NN intermediate rescattering states and including the Δ induces sizeable effects. The analysis considers cross-sections and the analysing power of linearly polarised photons on an unpolarised target, and cross-section differences and asymmetries of linearly and circularly polarised beams on a vector-polarised deuteron. An intuitive argument helps one to identify kinematics in which one or several polarisabilities do not contribute. Some double-polarised observables are only sensitive to linear combinations of two of the spin-polarisabilities, simplifying a multipole analysis of the data. Spin-polarisabilities can be extracted at photon energies ≳ 100 MeV, after measurements at lower energies of lesssim 70 MeV provide high-accuracy determinations of the spin-independent ones. An interactive Mathematica 7.0 notebook of our findings is available from hgrie@gwu.edu.

  13. Constraints on the virtual Compton scattering on the nucleon in a new dispersive formalism

    NASA Astrophysics Data System (ADS)

    Caprini, Irinel

    2016-04-01

    The dispersive representation of the virtual Compton forward scattering amplitude has been recently reexamined in connection with the evaluation of the Cottingham formula for the proton-neutron electromagnetic mass difference and the proton radius puzzle. The most difficult part of the analysis is related to one of the invariant amplitudes, denoted as T1(ν ,Q2), which requires a subtraction in the standard dispersion relation with respect to the energy ν at fixed photon momentum squared q2=-Q2. We propose an alternative dispersive framework, which implements analyticity and unitarity by combining the Cauchy integral relation at low and moderate energies with the modulus representation of the amplitude at high energies. Using techniques of functional analysis, we derive a necessary and sufficient condition for the consistency with analyticity of the subtraction function S1(Q2)=T1(0 ,Q2) , the cross sections measured at low and moderate energies and the Regge model assumed to be valid at high energies. From this condition we obtain model-independent constraints on the subtraction function, confronting them with the available information on nucleon magnetic polarizabilities and results reported recently in the literature. The formalism can be used also for testing the existence of a fixed pole at J =0 in the angular momentum plane, but more accurate data are necessary for a definite answer.

  14. Predicting the optical observables for nucleon scattering on even-even actinides

    NASA Astrophysics Data System (ADS)

    Martyanov, D. S.; Soukhovitskiĩ, E. Sh.; Capote, R.; Quesada, J. M.; Chiba, S.

    2017-09-01

    The previously derived Lane consistent dispersive coupled-channel optical model for nucleon scattering on 232Th and 238U nuclei is extended to describe scattering on even-even actinides with Z = 90–98. A soft-rotator-model (SRM) description of the low-lying nuclear structure is used, where the SRM Hamiltonian parameters are adjusted to the observed collective levels of the target nucleus. SRM nuclear wave functions (mixed in K quantum number) have been used to calculate the coupling matrix elements of the generalized optical model. The “effective” deformations that define inter-band couplings are derived from the SRM Hamiltonian parameters. Conservation of nuclear volume is enforced by introducing a dynamic monopolar term to the deformed potential, leading to additional couplings between rotational bands. The fitted static deformation parameters are in very good agreement with those derived by Wang and collaborators using the Weizsäcker-Skyrme global mass model (WS4), allowing use of the latter to predict cross sections for nuclei without experimental data. A good description of the scarce “optical” experimental database is achieved. SRM couplings and volume conservation allow a precise calculation of the compound-nucleus formation cross sections, which is significantly different from that calculated with rigid-rotor potentials coupling the ground-state rotational band. The derived parameters can be used to describe both neutron- and proton-induced reactions. Supported by International Atomic Energy Agency, through the IAEA Research Contract 19263, by the Spanish Ministry of Economy and Competitivity under Contracts FPA2014-53290-C2-2-P and FPA2016-77689-C2-1-R.

  15. QCD analysis of nucleon structure functions in deep-inelastic neutrino-nucleon scattering: Laplace transform and Jacobi polynomials approach

    NASA Astrophysics Data System (ADS)

    Nejad, S. Mohammad Moosavi; Khanpour, Hamzeh; Tehrani, S. Atashbar; Mahdavi, Mahdi

    2016-10-01

    We present a detailed QCD analysis of nucleon structure functions x F3(x ,Q2) , based on Laplace transforms and the Jacobi polynomials approach. The analysis corresponds to the next-to-leading order and next-to-next-to-leading order approximations of perturbative QCD. The Laplace transform technique, as an exact analytical solution, is used for the solution of nonsinglet Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations at low- and large-x values. The extracted results are used as input to obtain the x and Q2 evolution of x F3(x ,Q2) structure functions using the Jacobi polynomials approach. In our work, the values of the typical QCD scale ΛMS¯ (nf) and the strong coupling constant αs(MZ2) are determined for four quark flavors (nf=4 ) as well. A careful estimation of the uncertainties shall be performed using the Hessian method for the valence-quark distributions, originating from the experimental errors. We compare our valence-quark parton distribution functions sets with those of other collaborations, in particular with the CT14, MMHT14, and NNPDF sets, which are contemporary with the present analysis. The obtained results from the analysis are in good agreement with those from the literature.

  16. Very low-energy nucleon-16O coupled-channel scattering: Results with a phenomenological vibrational model

    NASA Astrophysics Data System (ADS)

    Svenne, J. P.; Canton, L.; Amos, K.; Fraser, P. R.; Karataglidis, S.; Pisent, G.; van der Knijff, D.

    2017-03-01

    We employ a collective vibration coupled-channel model to describe the nucleon-16O cluster systems, obtaining low-excitation spectra for 17O and 17F. Bound and resonance states of the compound systems have been deduced, showing good agreement with experimental spectra. Low-energy scattering cross sections of neutrons and protons from 16O also have been calculated and the results compare well with available experimental data.

  17. Modern nuclear force predictions for n -3H scattering above the three- and four-nucleon breakup thresholds

    NASA Astrophysics Data System (ADS)

    Lazauskas, Rimantas

    2015-04-01

    Background: Description of the collision process, which includes breakup, is one of the most challenging problems of the quantum mechanics. Recently I have developed a formalism based on the complex-scaling method, which describes accurately nuclear collisions in three- and four-body systems. Purpose: To provide accurate calculations for n -3H scattering above the three- and four-nucleon breakup thresholds. Method: A four-nucleon system is described in configuration space employing Faddeev-Yakubovsky equations. The complex-scaling method is applied to overcome the difficulties related with the complicated boundary conditions. Results: Elastic observables as well as total breakup cross sections are calculated for neutron scattering on tritium at 14.1, 18, and 22.1 MeV using realistic NN interactions. Excellent agreement is found with the pioneering calculations of this process reported by A. Deltuva et al. [Phys. Rev. C 86, 011001 (2012), 10.1103/PhysRevC.86.011001]. Strong correlation of the calculated cross sections is established with model-predicted trinucleon binding energy. The forementioned observables reveal little sensitivity to the short-range details of NN interaction. Conclusion: Reliable and accurate methods are now available to study four-nucleon scattering including the breakup.

  18. Measurement of the antineutrino neutral-current elastic differential cross section

    SciTech Connect

    Aguilar-Arevalo, A.  A.; Brown, B.  C.; Bugel, L.; Cheng, G.; Church, E.  D.; Conrad, J.  M.; Dharmapalan, R.; Djurcic, Z.; Finley, D.  A.; Ford, R.; Garcia, F.  G.; Garvey, G.  T.; Grange, J.; Huelsnitz, W.; Ignarra, C.; Imlay, R.; Johnson, R.  A.; Karagiorgi, G.; Katori, T.; Kobilarcik, T.; Louis, W.  C.; Mariani, C.; Marsh, W.; Mills, G.  B.; Mirabal, J.; Moore, C.  D.; Mousseau, J.; Nienaber, P.; Osmanov, B.; Pavlovic, Z.; Perevalov, D.; Polly, C.  C.; Ray, H.; Roe, B.  P.; Russell, A.  D.; Shaevitz, M.  H.; Spitz, J.; Stancu, I.; Tayloe, R.; Van de Water, R.  G.; Wascko, M.  O.; White, D.  H.; Wickremasinghe, D.  A.; Zeller, G.  P.; Zimmerman, E.  D.

    2015-01-08

    We report the measurement of the flux-averaged antineutrino neutral current elastic scattering cross section (dσν-barN→ν-barN/dQ2) on CH2 by the MiniBooNE experiment using the largest sample of antineutrino neutral current elastic candidate events ever collected. The ratio of the antineutrino to neutrino neutral current elastic scattering cross sections and a ratio of the antineutrino neutral current elastic to antineutrino charged current quasi elastic cross sections are also presented.

  19. Measurement of the antineutrino neutral-current elastic differential cross section

    DOE PAGES

    Aguilar-Arevalo, A.  A.; Brown, B.  C.; Bugel, L.; ...

    2015-01-08

    We report the measurement of the flux-averaged antineutrino neutral current elastic scattering cross section (dσν-barN→ν-barN/dQ2) on CH2 by the MiniBooNE experiment using the largest sample of antineutrino neutral current elastic candidate events ever collected. The ratio of the antineutrino to neutrino neutral current elastic scattering cross sections and a ratio of the antineutrino neutral current elastic to antineutrino charged current quasi elastic cross sections are also presented.

  20. Parity-Violating Electron Scattering from 4He and the Strange Electric Form Factor of the Nucleon

    NASA Astrophysics Data System (ADS)

    Aniol, K. A.; Armstrong, D. S.; Averett, T.; Benaoum, H.; Bertin, P. Y.; Burtin, E.; Cahoon, J.; Cates, G. D.; Chang, C. C.; Chao, Y.-C.; Chen, J.-P.; Choi, Seonho; Chudakov, E.; Craver, B.; Cusanno, F.; Decowski, P.; Deepa, D.; Ferdi, C.; Feuerbach, R. J.; Finn, J. M.; Frullani, S.; Fuoti, K.; Garibaldi, F.; Gilman, R.; Glamazdin, A.; Gorbenko, V.; Grames, J. M.; Hansknecht, J.; Higinbotham, D. W.; Holmes, R.; Holmstrom, T.; Humensky, T. B.; Ibrahim, H.; de Jager, C. W.; Jiang, X.; Kaufman, L. J.; Kelleher, A.; Kolarkar, A.; Kowalski, S.; Kumar, K. S.; Lambert, D.; Laviolette, P.; Lerose, J.; Lhuillier, D.; Liyanage, N.; Margaziotis, D. J.; Mazouz, M.; McCormick, K.; Meekins, D. G.; Meziani, Z.-E.; Michaels, R.; Moffit, B.; Monaghan, P.; Munoz-Camacho, C.; Nanda, S.; Nelyubin, V.; Neyret, D.; Paschke, K. D.; Poelker, M.; Pomatsalyuk, R.; Qiang, Y.; Reitz, B.; Roche, J.; Saha, A.; Singh, J.; Snyder, R.; Souder, P. A.; Subedi, R.; Suleiman, R.; Sulkosky, V.; Tobias, W. A.; Urciuoli, G. M.; Vacheret, A.; Voutier, E.; Wang, K.; Wilson, R.; Wojtsekhowski, B.; Zheng, X.

    2006-01-01

    We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from He4 at an average scattering angle ⟨θlab⟩=5.7° and a four-momentum transfer Q2=0.091GeV2. From these data, for the first time, the strange electric form factor of the nucleon GEs can be isolated. The measured asymmetry of APV=(6.72±0.84(stat)±0.21(syst))×10-6 yields a value of GEs=-0.038±0.042(stat)±0.010(syst), consistent with zero.

  1. Parity-violating electron scattering from 4He and the strange electric form factor of the nucleon.

    PubMed

    Aniol, K A; Armstrong, D S; Averett, T; Benaoum, H; Bertin, P Y; Burtin, E; Cahoon, J; Cates, G D; Chang, C C; Chao, Y-C; Chen, J-P; Choi, Seonho; Chudakov, E; Craver, B; Cusanno, F; Decowski, P; Deepa, D; Ferdi, C; Feuerbach, R J; Finn, J M; Frullani, S; Fuoti, K; Garibaldi, F; Gilman, R; Glamazdin, A; Gorbenko, V; Grames, J M; Hansknecht, J; Higinbotham, D W; Holmes, R; Holmstrom, T; Humensky, T B; Ibrahim, H; de Jager, C W; Jiang, X; Kaufman, L J; Kelleher, A; Kolarkar, A; Kowalski, S; Kumar, K S; Lambert, D; LaViolette, P; LeRose, J; Lhuillier, D; Liyanage, N; Margaziotis, D J; Mazouz, M; McCormick, K; Meekins, D G; Meziani, Z-E; Michaels, R; Moffit, B; Monaghan, P; Munoz-Camacho, C; Nanda, S; Nelyubin, V; Neyret, D; Paschke, K D; Poelker, M; Pomatsalyuk, R; Qiang, Y; Reitz, B; Roche, J; Saha, A; Singh, J; Snyder, R; Souder, P A; Subedi, R; Suleiman, R; Sulkosky, V; Tobias, W A; Urciuoli, G M; Vacheret, A; Voutier, E; Wang, K; Wilson, R; Wojtsekhowski, B; Zheng, X

    2006-01-20

    We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from 4He at an average scattering angle = 5.7 degrees and a four-momentum transfer Q2 = 0.091 GeV2 . From these data, for the first time, the strange electric form factor of the nucleon G(E)s can be isolated. The measured asymmetry of A(PV) = (6.72 +/- 0.84(stat) +/- 0.21(syst) x 10(-6) yields a value of G(E)s = -0.038 +/- 0.042(stat) +/- 0.010(syst), consistent with zero.

  2. Modification of nucleon-nucleon interactions in nuclear medium and neutron densities extracted via proton elastic scattering at intermediate energies

    NASA Astrophysics Data System (ADS)

    Takeda, Hiroyuki

    2003-03-01

    Spin rotation parameters of proton elastic scattering from 58Ni have been measured at Ep=200, 300 and 400 MeV. By combining them with the previously measured cross sections and analyzing powers at the same energies, the series of measurements has become the "complete" experiment. Cross sections and analyzing powers of proton elastic scattering from 58Ni at 250 MeV, those of 120Sn at Ep=200, 250, 300 and 400 MeV and spin rotation parameters of 120Sn at Ep=300 MeV have been also newly measured. The experiment has been performed at Research Center for Nuclear Phyiscs, Osaka University. In order to explain the 58Ni data, it has been necessary to use realistic density distributions deduced from the nuclear charge distribution and to modify coupling constants and masses of σ and ω mesons. For 120Sn, we have assumed the same modification and used the proton distribution deduced from the charge distribution, we have searched the neutron density distribution which has reproduced 120Sn data at 300 MeV. The deduced neutron distribution has an increase at the nuclear center, which seems to be due to wave functions of neutrons in the 3s1/2 orbit. It also explains the 120Sn data at other energies than 300 MeV. Effects of ρ meson modifications on neutron densities are also mentioned.

  3. Nucleon scattering on actinides using a dispersive optical model with extended couplings

    NASA Astrophysics Data System (ADS)

    Soukhovitskiĩ, E. Sh.; Capote, R.; Quesada, J. M.; Chiba, S.; Martyanov, D. S.

    2016-12-01

    The Tamura coupling model [Rev. Mod. Phys. 37, 679 (1965), 10.1103/RevModPhys.37.679] has been extended to consider the coupling of additional low-lying rotational bands to the ground-state band. Rotational bands are built on vibrational bandheads (even-even targets) or single-particle bandheads (odd-A targets) including both axial and nonaxial deformations. These additional excitations are introduced as a perturbation to the underlying axially symmetric rigid-rotor structure of the ground-state rotational band. Coupling matrix elements of the generalized optical model are derived for extended multiband transitions in even-even and odd-A nuclei. Isospin symmetric formulation of the optical model is employed. A coupled-channels optical-model potential (OMP) containing a dispersive contribution is used to fit simultaneously all available optical experimental databases including neutron strength functions for nucleon scattering on 232Th,233,235,238U, and 239Pu nuclei. Quasielastic (p ,n ) scattering data on 232Th and 238U to the isobaric analog states of the target nucleus are also used to constrain the isovector part of the optical potential. Lane consistent OMP is derived for all actinides if corresponding multiband coupling schemes are defined. For even-even (odd-A ) actinides almost all low-lying collective levels below 1 MeV (0.5 MeV) of excitation energy are coupled. OMP parameters show a smooth energy dependence and energy-independent geometry. A phenomenological optical-model potential that couples multiple bands in odd-A actinides is published for a first time. Calculations using the derived OMP potential reproduce measured total cross-section differences between several actinide pairs within experimental uncertainty for incident neutron energies from 50 keV up to 150 MeV. The importance of extended coupling is studied. Multiband coupling is stronger in even-even targets owing to the collective nature of the coupling; the impact of extended coupling on

  4. Density and correlation integrals in deep-inelastic muon-nucleon scattering at 490 GeV

    NASA Astrophysics Data System (ADS)

    Adams, M. R.; Aïd, S.; Anthony, P. L.; Baker, M. D.; Bartlett, J.; Bhatti, A. A.; Botterweck, F.; Braun, H. M.; Busza, W.; Conrad, J. M.; Coutrakon, G.; Davisson, R.; Derado, I.; Dhawan, S. K.; Dougherty, W.; Dreyer, T.; Dziunikowska, K.; Eckardt, V.; Ecker, U.; Erdmann, M.; Eskreys, A.; Figiel, J.; Gebauer, H. J.; Geesaman, D. F.; Gilman, R.; Green, M. C.; Haas, J.; Halliwell, C.; Hanlon, J.; Hantke, D.; Hughes, V. W.; Jackson, H. E.; Jaffe, D. E.; Jancso, G.; Jansen, D. M.; Kadija, K.; Kaufman, S.; Kennedy, R. D.; Kirk, T.; Kobrak, H. G. E.; Krzywdzinski, S.; Kunori, S.; Lord, J. J.; Lubatti, H. J.; McLeod, D.; Magill, S.; Malecki, P.; Manz, A.; Melanson, H.; Michael, D. G.; Mohr, W.; Montgomery, H. E.; Morfin, J. G.; Nickerson, R. B.; O'Day, S.; Olkiewicz, K.; Osborne, L.; Papavassiliou, V.; Pawlik, B.; Pipkin, F. M.; Ramberg, E. J.; Röser, A.; Ryan, J. J.; Salgado, C. W.; Salvarani, A.; Schellman, H.; Schmitt, M.; Schmitz, N.; Schüler, K. P.; Seyerlein, H. J.; Skuja, A.; Snow, G. A.; Söldner-Rembold, S.; Steinberg, P. H.; Stier, H. E.; Stopa, P.; Swanson, R. A.; Talaga, R.; Tentindo-Repond, S.; Trost, H.-J.; Venkataramania, H.; Wilhelm, M.; Wilkes, J.; Wilson, Richard; Wittek, W.; Wolbers, S. A.; Zhao, T.; Fermilab E665 Collaboration

    1994-09-01

    Results on density integrals Fq( Q2) and correlation integrals Kq( Q2) are presented for the first time in muon-nucleon scattering at ∼ 490 GeV, using data from the E665 experiment at the Tevatron of Fermilab. A clear rise of the Fq integrals with decreasing size of the phase-space cells (“intermittency”) is observed for pairs and triplets of negative hadrons whereas the effect is much weaker for mixed charge combinations. From these findings it is concluded that the observed intermittency signal is mainly caused by Bose-Einstein interference. Furthermore, no energy ( W) dependence of F2( Q2) is observed within the W range of the E665 experiment. Finally, the third-order correlation integrals K3( Q2) are found to be significantly different from zero which implies the presence of genuine three-particle correlations in muon-nucleon interactions.

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

    SciTech Connect

    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 Z0 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 Q2 = 0.62 GeV2. The measured asymmetry was used to set new constraints on the contribution of strange quark form factors (GsE,M ) to the nucleon electromagnetic form factors. A value of APV = -23.803±} 0.778 (stat)± 0.359 (syst) ppm resulted in GsE + 0.517GsM = 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 Q2 = 0.009 GeV2. 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 Z0 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.

  6. Three-body break-up in deuteron-deuteron scattering at 65 MeV/nucleon

    NASA Astrophysics Data System (ADS)

    Ramazani-Moghaddam-Arani, A.; Amir-Ahmadi, H. R.; Bacher, A. D.; Bailey, C. D.; Biegun, A.; Eslami-Kalantari, M.; Gašparić, I.; Joulaeizadeh, L.; Kalantar-Nayestanaki, N.; Kistryn, St.; Kozela, A.; Mardanpour, H.; Messchendorp, J. G.; Micherdzinska, A. M.; Moeini, H.; Shende, S. V.; Stephan, E.; Stephenson, E. J.; Sworst, R.

    2011-02-01

    In an experiment with a 65 MeV/nucleon polarized deuteron beam on a liquid-deuterium target at Kernfysisch Versneller Instituut, several multibody final states in deuteron-deuteron scattering were identified. For these measurements, a unique and advanced detection system, called the Big Instrument for Nuclear-polarization Analysis, was utilized. We demonstrate the feasibility of measuring vector and tensor polarization observables of the deuteron break-up reaction leading to a three-body final state. The polarization observables were determined with high precision in a nearly background-free experiment. The analysis procedure and some results are presented.

  7. Nucleon momentum distributions and elastic electron scattering from 19F, 25Mg, 27Al, and 29Si nuclei

    NASA Astrophysics Data System (ADS)

    Al-Rahmani, A.

    2016-04-01

    The nucleon momentum distributions and elastic electron scattering form factors of the ground state for some odd 2 s-1 d shell nuclei, such as 19F, 25Mg, 27Al, and 29Si, have been investigated using the coherent density fluctuation model and expressed in terms of the fluctuation function (weight function) | f( x)|2. The fluctuation function has been related to the nucleon density distribution of the nuclei and determined from the theory. The property of the long-tail manner at high-momentum region of the nucleon momentum distribution has been obtained by theoretical fluctuation function. The calculated form factors F( q) of all nuclei under study are in very good agreement with those of experimental data throughout all values of momentum transfer q. It is concluded that the contributions of the quadrupole form factor F C2( q) in 25Mg and 27Al nuclei, which are characterized by the undeformed 2 s-1 d shell model, are necessary for getting a remarkable agreement between the theoretical and experimental form factors.

  8. Strangeness in the Nucleon, Cold Dark Matter in the Universe, and Neutrino Scattering off Liquid Argon

    SciTech Connect

    Papavassiliou, V.

    2010-03-30

    The strangeness content of the nucleon and the contribution of strange quarks to various nucleon quantum numbers, besides being of fundamental interest, also affects calculations of cross sections of processes that are important in searches for new physics. Here we focus on direct searches for cold dark matter, in the scenario in which the lightest supersymmetric neutral particle dominates the CDM density in the universe and point out that interpretation of searches, as well as the choice of optimal materials for future experiments, are hobbled by uncertainties in the contribution of strange quarks to the nucleon spin. We show how a future low-energy neutrino experiment using a liquid-Ar TPC can make important contributions in determining this quantity with much better precision and reduced theoretical uncertainties.

  9. Parity-Violating Electron Scattering from {sup 4}He and the Strange Electric Form Factor of the Nucleon

    SciTech Connect

    Aniol, Konrad; Armstrong, David; Averett, Todd; Benaoum, Hachemi; Bertin, Pierre; Burtin, Etienne; Cahoon, Jason; Cates, Gordon; Chang, C; Chao, Yu-Chiu; Chen, Jian-Ping; Choi, Seonho; Chudakov, Eugene; Craver, Brandon; Cusanno, Francesco; Decowski, Piotr; Deepa, Deepa; Ferdi, Catherine; Feuerbach, Robert; Finn, John; Frullani, Salvatore; Fuoti, Kirsten; Garibaldi, Franco; Gilman, Ronald; Glamazdin, Oleksandr; Gorbenko, V; Grames, Joseph; Hansknecht, John; Higinbotham, Douglas; Holmes, Richard; Holmstrom, Timothy; Humensky, Thomas; Ibrahim, Hassan; Jager, Cornelis De; Jiang, Xiaodong; Kaufman, Lisa; Kelleher, Aidan; Kolarkar, Ameya; Kowalski, Stanley; Kumar, Krishna; Lambert, Daniel; Laviolette, Peter; LeRose, John; Lhuillier, David; Liyanage, Nilanga; Margaziotis, Demetrius; Mazouz, Malek; McCormick, Kathy; Meekins, David; Meziani, Zein-Eddine; Michaels, Robert; Moffit, Bryan; Monaghan, Peter; Camacho, Carlos Munoz; Nanda, Sirish; Nelyubin, Vladimir; Neyret, Damien; Paschke, Kent; Poelker, Benard; Pomatsalyuk, Roman; Qiang, Yi; Reitz, Bodo; Roche, Julie; Saha, Arunava; Singh, Jaideep; Snyder, Ryan; Souder, Paul; Subedi, Ramesh; Suleiman, Riad; Sulkosky, Vincent; Tobias, William; Urciuoli, Guido; Vacheret, Antonin; Voutier, Eric; Wang, Kebin; Wilson, R; Wojtsekhowski, Bogdan; Zheng, Xiaochao

    2005-06-01

    We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from {sup 4}He at an average scattering angle {theta}{sub lab} = 5.7 degrees and a four-momentum transfer Q{sup 2} = 0.091 GeV{sup 2}. From these data, for the first time, the strange electric form factor of the nucleon G{sub E}{sup s} can be isolated. The measured asymmetry of A{sub PV} = 6.72 {+-} 0.84 (stat) {+-} 0.21 (syst) parts per million yields a value of G{sub E}{sup s} = -0.038 {+-} 0.042 (stat) {+-} 0.010 (syst), consistent with zero.

  10. Quasielastic scattering of 8B and 7Be on 12C at 40 MeV/nucleon

    NASA Astrophysics Data System (ADS)

    Pecina, I.; Anne, R.; Bazin, D.; Borcea, C.; Borrel, V.; Carstoiu, F.; Corre, J. M.; Dlouhy, Z.; Fomitchev, A.; Guillemaud-Mueller, D.; Keller, H.; Kordyasz, A.; Lewitowicz, M.; Lukyanov, S.; Mueller, A. C.; Penionzhkevich, Yu.; Roussel-Chomaz, P.; Saint-Laurent, M. G.; Skobelev, N.; Sorlin, O.; Tarasov, O.

    1995-07-01

    The quasielastic scattering of the exotic nucleus 8B on a 12C target has been studied at an energy of 320 MeV and compared with that of 7Be at the same velocity. The quasielastic scattering of 12C + 12C at 20 MeV/nucleon, also performed as a secondary beam experiment, was used to check the data reduction method. The results are interpreted in terms of a semimicroscopic double folding model and coupled-channels calculation. The difference in the total reaction cross section (8%) between 8B and 7Be is consistent with the measured one proton removal cross section and corresponds to an increase in the interaction radius of 4%. The existence of a substantial proton halo in 8B is not supported by the present data.

  11. Parity-Violating Electron Scattering from {sup 4}He and the Strange Electric Form Factor of the Nucleon

    SciTech Connect

    Aniol, K.A.; Margaziotis, D.J.; Armstrong, D.S.; Averett, T.; Finn, J.M.; Holmstrom, T.; Kelleher, A.; Moffit, B.; Sulkosky, V.; Benaoum, H.; Holmes, R.; Souder, P.A.; Bertin, P.Y.; Ferdi, C.

    2006-01-20

    We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from {sup 4}He at an average scattering angle <{theta}{sub lab}>=5.7 deg. and a four-momentum transfer Q{sup 2}=0.091 GeV{sup 2}. From these data, for the first time, the strange electric form factor of the nucleon G{sub E}{sup s} can be isolated. The measured asymmetry of A{sub PV}=(6.72{+-}0.84{sub (stat)}{+-}0.21{sub (syst)})x10{sup -6} yields a value of G{sub E}{sup s}=-0.038{+-}0.042{sub (stat)}{+-}0.010{sub (syst)}, consistent with zero.

  12. Isospin-violating dark-matter-nucleon scattering via two-Higgs-doublet-model portals

    SciTech Connect

    Drozd, Aleksandra; Grzadkowski, Bohdan; Gunion, John F.; Jiang, Yun

    2016-10-24

    We show that in a multi-Higgs model in which one Higgs fits the LHC 125 GeV state, one or more of the other Higgs bosons can mediate DM-nucleon interactions with maximal DM isospin violation being possible for appropriate Higgs-quark couplings, independent of the nature of DM. We then consider the explicit example of a Type II two-Higgs-doublet model, identifying the h or H as the 125 GeV state while the H or h, respectively, mediates DM-nucleon interactions. Finally, we show that if a stable scalar, S, is added then it can be a viable light DM candidate with correct relic density while obeying all direct and indirect detection limits.

  13. Time Dependent Channel Packet Calculation of Two Nucleon Scattering Matrix Elements

    DTIC Science & Technology

    2010-03-01

    3.2. Feynman Diagram of a Pi Meson Exchange ........................................................... 26 3.3. Centripetal Potential centV... Feynman diagram in Figure 3.2. Figure 3.2. Feynman Diagram of a Pi Meson Exchange between Two Arbitrary Nucleons [9] N N N N π 27...Shultis, J. Kenneth and Richard E. Faw. Fundamentals of Nuclear Science and Engineering. Florida, CRC Press, 2002. pp. 27-35. 56. Bridgman

  14. Double-spin asymmetries in electron-nucleon scattering in Halls B and C at Jlab

    SciTech Connect

    Donald Crabb

    2003-07-15

    Three experiments at JLab have measured the double polarization asymmetries in the nucleon resonance region, using polarized electron beams incident on polarized proton and deuteron targets. The analysis for the first experiment, eg1a in Hall B, is nearly finished and preliminary values of the spin structure function g1(x, Q2) and the first moment (x) have been extracted. The other two experiments, one in Hall B and one in Hall C, are still analyzing data. Some results are presented.

  15. Semi-inclusive polarised lepton-nucleon scattering and the anomalous gluon contribution

    NASA Astrophysics Data System (ADS)

    Güllenstern, St.; Veltri, M.; Górnicki, P.; Mankiewicz, L.; Schäfer, A.

    1993-08-01

    We discuss a new observable for semi-inclusive pion production in polarised lepton-nucleon collisions. This observable is sensitive to the polarised and unpolarised strange quark distribution and the anomalous gluon contribution, provided that their fragmentation functions into pions differ substantially from that of light quarks. From Monte Carlo data generated with our PEPSI code we conclude that HERMES might be able to decide whether the polarized strange quark and gluon distributions are large.

  16. Timelike Compton Scattering off the nucleon: observables and experimental perspectives for JLab at 12 GeV

    SciTech Connect

    Boer, Marie

    2016-03-01

    Hard exclusive processes such as photoproduction or electroproduction of photon or meson off the nucleon provide access to the Generalized Parton Distributions (GPDs), in the regime where the scattering amplitude is factorized into a hard and a soft part. GPDs contain the correlation between the longitudinal momentum fraction and the transverse spatial densities of quarks and gluons in the nucleon. Timelike Compton Scattering (TCS) correspond to the reaction gammaN --> gamma*N --> e+e?N, where the photon is scattered off a quark. It is measured through its interference with the associated Bethe-Heitler process, which has the same final state. TCS allows to access the GPDs and test their universality by comparison to the results obtained with the DVCS process (eN --> e gamma N). Also, results obtained with TCS provide additional independent constrains to the GPDs parameterization. We will present the physical motivations for TCS, with our theoretical predictions for TCS observables and their dependencies. We calculated for JLab 12 GeV energies all the single and double beam and/or target polarization observables off the proton and off the neutron. We will also present the experimental perspectives for the next years at JLab. Two proposals were already accepted at JLab: in Hall B, with the CLAS12 spectrometer, in order to measure the unpolarized cross section and in Hall A, with the SoLID spectrometer, in order to measure the unpolarized cross section and the beam spin asymmetry at high intensity. A Letter Of Intent was also submitted in order to measure the transverse target spin asymmetries in Hall C. We will discuss the merits of this different experiments and present some of the expected results.

  17. Peripheral elastic and inelastic scattering of {sup 17,18}O on light targets at 12 MeV/nucleon

    SciTech Connect

    Carstoiu, F.; Al-Abdullah, T.; Gagliardi, C. A.; Trache, L.

    2015-02-24

    The elastic and inelastic scattering of {sup 17,18}O with light targets has been undertaken at 12 MeV/nucleon in order to determine the optical potentials needed for the transfer reaction {sup 13}C({sup 17}O,{sup 18}O){sup 12}C. Optical potentials in both incoming and outgoing channels have been determined in a single experiment. This transfer reaction was used to infer the direct capture rate to the {sup 17}F(p,γ){sup 18}Ne which is essential to estimate the production of {sup 18}F at stellar energies in ONe novae. We demonstrate the stability of the ANC method and OMP results using good quality elastic and inelastic scattering data with stable beams. The peripherality of our reaction is inferred from a semiclassical decomposition of the total scattering amplitude into barrier and internal barrier components. Comparison between elastic scattering of {sup 17}O, {sup 18}O and {sup 16}O projectiles is made.

  18. Three-nucleon force effects in cross section and spin observables of elastic deuteron-proton scattering at 90 MeV/nucleon

    NASA Astrophysics Data System (ADS)

    Amir-Ahmadi, H. R.; Castelijns, R.; Deltuva, A.; Eslami-Kalantari, M.; Garderen, E. D. Van; Harakeh, M. N.; Kalantar-Nayestanaki, N.; Kiš, M.; Löhner, H.; Mahjour-Shafiei, M.; Mardanpour, H.; Messchendorp, J. G.; Mukherjee, B.; Savran, D.; Sekiguchi, K.; Shende, S. V.; Witała, H.; Wörtche, H. J.

    2007-04-01

    The cross section and several spin-dependent observables have been measured with high precision for the reaction H(d→,p→)d at 90 MeV/nucleon. Several calculations were performed based either purely on two-nucleon potentials or also including three-nucleon potentials (3NP). The cross sections are consistent with all calculations including 3NPs. However, no single calculation reproduces the analyzing powers and spin-transfer coefficients, although some spin observables are reproduced to various degrees by the different calculations. A good understanding of the spin structure of 3NP is still lacking.

  19. Dynamical Coupled-Channel Model of pi-N scattering in te W < 2 GeV Nucleon Resonane Region

    SciTech Connect

    Lee, T S.H.; Julia-diaz, B; Matsuyama, A; Sato, T

    2007-12-01

    As a first step to analyze the electromagnetic meson production reactions in the nucleon resonance region, the parameters of the hadronic interactions of a dynamical coupled-channel model, developed in {\\it Physics Reports 439, 193 (2007)}, are determined by fitting the empirical $\\pi N$ elastic scattering amplitudes of SAID up to 2 GeV. The channels included in the calculations are $\\pi N$, $\\eta N$ and $\\pi\\pi N$ which has $\\pi\\Delta$, $\\rho N$, and $\\sigma N$ resonant components. The non-resonant meson-baryon interactions of the model are derived from a set of Lagrangians by using a unitary transformation method. One or two bare excited nucleon states in each of $S$, $P$, $D$, and $F$ partial waves are included to generate the resonant amplitudes in the fits. The predicted total cross sections of $\\pi N$ reactions and $\\pi N\\rightarrow \\eta N$ reactions are in good agreement with the data. Applications of the constructed model in analyzing the electromagnetic meson production data as well as the future developments are discussed.

  20. Production of neutral strange particles in muon-nucleon scattering at 490 GeV

    NASA Astrophysics Data System (ADS)

    Adams, M. R.; Aderholz, M.; Aïd, S.; Anthony, P. L.; Baker, M. D.; Bartlett, J.; Bhatti, A. A.; Braun, H. M.; Busza, W.; Conrad, J. M.; Coutrakon, G.; Davisson, R.; Derado, I.; Dhawan, S. K.; Dougherty, W.; Dreyer, T.; Dziunikowska, K.; Eckardt, V.; Ecker, U.; Erdmann, M.; Eskreys, A.; Figiel, J.; Gebauer, H. J.; Geesaman, D. F.; Gilman, R.; Green, M. C.; Haas, J.; Halliwell, C.; Hanlon, J.; Hantke, D.; Hughes, V. W.; Jackson, H. E.; Jaffe, D. E.; Jancso, G.; Jansen, D. M.; Kadija, K.; Kaufman, S.; Kennedy, R. D.; Kirk, T.; Kobrak, H. G. E.; Krzywdzinski, S.; Kunori, S.; Lord, J. J.; Lubatti, H. J.; McLeod, D.; Magill, S.; Malecki, P.; Manz, A.; Melanson, H.; Michael, D. G.; Mohr, W.; Montgomery, H. E.; Morfin, J. G.; Nickerson, R. B.; O'Day, S.; Olkiewicz, K.; Osborne, L.; Papavassiliou, V.; Pawlik, B.; Pipkin, F. M.; Ramberg, E. J.; Röser, A.; Ryan, J. J.; Salgado, C. W.; Salvarani, A.; Schellman, H.; Schmitt, M.; Schmitz, N.; Schüler, K. P.; Seyerlein, H. J.; Skuja, A.; Snow, G. A.; Söldner-Rembold, S.; Steinberg, P. H.; Stier, H. E.; Stopa, P.; Swanson, R. A.; Talaga, R.; Tentindo-Repond, S.; Trost, H. J.; Venkataramania, H.; Wilhelm, M.; Wilkes, J.; Wilson, R.; Wittek, W.; Wolbers, S. A.; Zhao, T.

    1994-12-01

    The production of K 0, Λ andbar Λ particles is studied in the E665 muon-nucleon experiment at Fermilab. The average multiplicities and squared transverse momenta are measured as a function of x F and W 2. Most features of the data can be well described by the Lund model. Within this model, the data on the K0/π± ratios and on the average K 0 multiplicity in the forward region favor a strangeness suppression factor s/u in the fragmentation process near 0.20. Clear evidence for QCD effects is seen in the average squared transverse momentum of K 0 and Λ particles.

  1. Radiative effects in scattering of polarized leptons by polarized nucleons and light nuclei

    SciTech Connect

    Igor Akushevich; A. Ilyichev; N. Shumeiko

    2001-07-01

    Recent developments in the field of radiative effects in polarized lepton-nuclear scattering are reviewed. The processes of inclusive, semi-inclusive, diffractive and elastic scattering are considered. The explicit formulae obtained within the covariant approach are discussed. FORTRAN codes POLRAD, RADGEN, HAPRAD, DIFFRAD and MASCARAD created on the basis of the formulae are briefly described. Applications for data analysis of the current experiments on lepton-nuclear scattering at CERN, DESY, SLAC and TJNAF are illustrated by numerical results.

  2. Determination of sin/sup 2/THETA/sub w/ and rho in deep inelastic neutrino-nucleon scattering

    SciTech Connect

    Bogert, D.; Burnstein, R.; Fisk, R.; Fuess, S.; Morfin, J.; Ohska, T.; Stutte, L.; Walker, J.K.; Bofill, J.; Busza, W.

    1985-06-01

    We have determined the electroweak parameters sin/sup 2/THETA/sub w/ and rho by a measurement of deep inelastic neutrino-nucleon scattering using a fine grained neutrino detector exposed to a narrow band neutrino beam at Fermilab. The unique sampling properties of our detector have permitted neutral current and charged current events to be unambiguously identified over a wide kinematic range, thereby allowing a determination of sin/sup 2/THETA/sub w/ and rho to be made with good statistics and small systematic errors. We have found sin/sup 2/THETA/sub w/ = 0.246 +- 0.012 +- 0.013 in a single parameter fit. The details of the experimental and theoretical systematic errors are given. 17 refs., 2 figs., 2 tabs.

  3. Application of a folding-model optical potential to analyzing inelastic pion–nucleus scattering and the in-medium effect on a pion–nucleon amplitude

    SciTech Connect

    Lukyanov, V. K. Zemlyanaya, E. V.; Lukyanov, K. V.; Abdul-Magead, I. A. M.

    2016-11-15

    The folding-model optical potential is generalized in such a way as to apply it to calculating the cross sections for inelastic scattering of π{sup ±}-mesons on {sup 28}Si, {sup 40}Ca, {sup 58}Ni, and {sup 208}Pb nuclei at the energies of 162, 180, 226, and 291 MeV leading to the excitation of the 2{sup +} and 3{sup −} collective states. In doing this, use is made of known nucleon-density distributions in nuclei and the pion–nucleon scattering amplitude whose parameters were obtained previously by fitting the elastic scattering cross sections for the same nuclei. Thus, the values of quadrupole (β{sub 2}) and octupole (β{sub 3}) deformations of nuclei appear here as the only adjustable parameters. The scattering cross section is calculated by solving the relativistic wave equation, whereby effects of relativization and distortion in the entrance and exit scattering channels are taken exactly into account. The cross sections calculated in this way for inelastic scattering are in good agreement with respective experimental data. The importance of the inclusion of in-medium effects in choosing parameters of the pion–nucleon amplitude is emphasized.

  4. Application of a folding-model optical potential to analyzing inelastic pion-nucleus scattering and the in-medium effect on a pion-nucleon amplitude

    NASA Astrophysics Data System (ADS)

    Lukyanov, V. K.; Zemlyanaya, E. V.; Lukyanov, K. V.; Abdul-Magead, I. A. M.

    2016-11-01

    The folding-model optical potential is generalized in such a way as to apply it to calculating the cross sections for inelastic scattering of π ±-mesons on 28Si, 40Ca, 58Ni, and 208Pb nuclei at the energies of 162, 180, 226, and 291 MeV leading to the excitation of the 2+ and 3- collective states. In doing this, use is made of known nucleon-density distributions in nuclei and the pion-nucleon scattering amplitude whose parameters were obtained previously by fitting the elastic scattering cross sections for the same nuclei. Thus, the values of quadrupole ( β 2) and octupole ( β 3) deformations of nuclei appear here as the only adjustable parameters. The scattering cross section is calculated by solving the relativistic wave equation, whereby effects of relativization and distortion in the entrance and exit scattering channels are taken exactly into account. The cross sections calculated in this way for inelastic scattering are in good agreement with respective experimental data. The importance of the inclusion of in-medium effects in choosing parameters of the pion-nucleon amplitude is emphasized.

  5. The two-photon exchange contribution to elastic electron-nucleon scattering at large momentum transfer

    SciTech Connect

    Andrei V. Afanasev; Stanley J. Brodsky; Carl E. Carlson; Yu-Chun Chen; Marc Vanderhaeghen

    2005-01-01

    We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer by using a quark-parton representation of virtual Compton scattering. We thus can relate the two-photon exchange amplitude to the generalized parton distributions which also enter in other wide angle scattering processes. We find that the interference of one- and two-photon exchange contribution is able to substantially resolve the difference between electric form factor measurements from Rosenbluth and polarization transfer experiments.

  6. Quantum preequilibrium multistep direct calculations for nucleon scattering on deformed nuclei: a microscopic approach

    NASA Astrophysics Data System (ADS)

    Dupuis, Marc; Bonneau, Ludovic; Kawano, Toshihiko

    2008-04-01

    An introduction of the different quantum mechanics models is given for the calculation of pre-equilibrium multistep direct process for nucleon induced reaction. A practical application is presented for 238U neutron induced reaction at medium energy (10-20 MeV). The double differential cross-sections are calculated with no adjustable parameter and reproduced the data very well. The cross-sections are expressed as a sum of DWBA transition amplitudes computed with a microscopic two-body interaction. The exited states of the target are expressed as particle-hole excitations built from single particle states obtained with the HF+BCS calculation with a Skyrme force. We also perform a sensitivity study our calculations with respect to the ingredients of the model, namely the two-body interaction which generates the transitions and the target states description.

  7. Quantum preequilibrium multistep direct calculations for nucleon scattering on deformed nuclei: a microscopic approach

    SciTech Connect

    Dupuis, Marc; Kawano, Toshihiko; Bonneau, Ludovic

    2008-04-17

    An introduction of the different quantum mechanics models is given for the calculation of pre-equilibrium multistep direct process for nucleon induced reaction. A practical application is presented for {sup 238}U neutron induced reaction at medium energy (10-20 MeV). The double differential cross-sections are calculated with no adjustable parameter and reproduced the data very well. The cross-sections are expressed as a sum of DWBA transition amplitudes computed with a microscopic two-body interaction. The exited states of the target are expressed as particle-hole excitations built from single particle states obtained with the HF+BCS calculation with a Skyrme force. We also perform a sensitivity study our calculations with respect to the ingredients of the model, namely the two-body interaction which generates the transitions and the target states description.

  8. Charged current antineutrino reactions from {sup 12}C at MiniBooNE energies

    SciTech Connect

    Athar, M. Sajjad; Ahmad, Shakeb; Singh, S. K.

    2007-05-01

    A study of charged current induced antineutrino interactions from nuclei has been done for the intermediate energy antineutrinos and applied to {sup 12}C, relevant for ongoing experiment by MiniBooNE collaboration. The calculations have been done for the quasielastic and inelastic lepton production as well as for the incoherent and the coherent pion production processes. The calculations are done in local density approximation. In the case of the quasielastic reaction the effects of Pauli blocking, Fermi motion effects, renormalization of weak transition strengths in nuclear medium and the Coulomb distortion of the outgoing lepton have been taken into account. For the inelastic processes the calculations have been done in the {delta} dominance model and take into account the effect of Pauli blocking, Fermi motion of the nucleon, and renormalization of {delta} properties in a nuclear medium. The effect of final state interactions of pions is also taken into account. The numerical results for the total cross sections for the charged current quasielastic scattering and incoherent pion production processes are compared with earlier experimental results available in freon and freon-propane. It is found that nuclear medium effects give strong reduction in the cross sections leading to satisfactory agreement with the available data.

  9. Rotational-vibrational Description of Nucleon Scattering on Actinide Nuclei Using a Dispersive Coupled-channel Optical Model

    NASA Astrophysics Data System (ADS)

    Quesada, J. M.; Capote, R.; Soukhovitskiı˜, E. Sh.; Chiba, S.

    2014-04-01

    Tamura's coupling formalism has been extended to consider low-lying rotational bands built on vibrational (single-particle) band heads in well-deformed even-even (odd) actinides. These additional excitations are introduced as a perturbation to the underlying rigid rotor structure that is known to describe well the ground state rotational band of major actinides. Coupling matrix elements needed in extended Tamura's formalism are derived for both even-even and odd actinides. Employed dispersive optical model (DCCOMP) replaces the incident proton energy Ep (for proton induced reactions) by the equivalent Coulomb subtracted energy in all potential terms including both the imaginary and real potentials with the corresponding dispersive corrections. Therefore, the optical potential becomes fully symmetric for protons and neutrons. This potential is used to fit simultaneously all the available optical experimental databases (including neutron strength functions) for nucleon scattering on 238U and 232Th (even even) nuclei. Quasi-elastic (p,n) scattering data to the isobaric analogue states of the target nuclei are also used to constrain the isovector part of the optical potential. Derived Lane-consistent DCCOMP is based on coupling of almost all levels below 1 MeV of excitation energy. The ground state, octupole, beta, gamma and non-axial rotational bands are considered for even nuclei, and rotational bands built on single-particle levels - for odd nuclei. Application of derived potential to odd targets based on a new coupling scheme is foreseen.

  10. Microscopic analysis of K{sup +}-nucleus elastic scattering based on K{sup +}-nucleon phase shifts

    SciTech Connect

    Arellano, H.F.; Geramb, H.V. von

    2005-08-01

    We investigate K{sup +}-nucleus elastic scattering at intermediate energies within a microscopic optical model approach using the current K{sup +}-nucleon (KN) phase shifts from the Center for Nuclear Studies of the George Washington University as primary input. The KN phase shifts are used to generate Gel'fand-Levitan-Marchenko real and local inversion potentials. These potentials are supplemented with a short-range, complex separable term in such a way that the corresponding unitary and nonunitary KN S matrices are exactly reproduced. These KN potentials allow us to calculate all needed on- and off-shell contributions of the t matrix, the driving effective interaction in the full-folding K{sup +}-nucleus optical model potentials reported here. Elastic scattering of positive kaons from {sup 6}Li, {sup 12}C, {sup 28}Si, and {sup 40}Ca are studied at beam momenta in the range 400-1000 MeV/c, leading to a fair description of most differential and total cross section data. To complete the analysis of the full-folding model, three kinds of simpler t{rho} calculations are considered and the results are discussed.

  11. Nucleon-nucleon interactions

    SciTech Connect

    Wiringa, R.B.

    1996-12-31

    Nucleon-nucleon interactions are at the heart of nuclear physics, bridging the gap between QCD and the effective interactions appropriate for the shell model. We discuss the current status of {ital NN} data sets, partial-wave analyses, and some of the issues that go into the construction of potential models. Our remarks are illustrated by reference to the Argonne {ital v}{sub 18} potential, one of a number of new potentials that fit elastic nucleon-nucleon data up to 350 MeV with a {Chi}{sup 2} per datum near 1. We also discuss the related issues of three-nucleon potentials, two-nucleon charge and current operators, and relativistic effects. We give some examples of calculations that can be made using these realistic descriptions of {ital NN} interactions. We conclude with some remarks on how our empirical knowledge of {ital NN} interactions may help constrain models at the quark level, and hence models of nucleon structure.

  12. Axial structure of the nucleon

    SciTech Connect

    Veronique Bernard; Latifa Elouadrhiri; Ulf-G Meissner

    2002-01-01

    We review the current status of experimental and theoretical understanding of the axial nucleon structure at low and moderate energies. Topics considered include (quasi)elastic (anti)neutrino-nucleon scattering, charged pion electroproduction off nucleons and ordinary as well as radiative muon capture on the proton.

  13. Improved input for multi-reaction hadronic analyses from elastic pion-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Revier, Joseph; Roenchen, Deborah; Doering, Michael; Workman`, Ronald

    2017-01-01

    In the search for missing baryonic resonances, many analyses include data from a variety of pion and photon induced reactions. For elastic πN scattering, however, usually the partial waves of the SAID or other groups are fitted, instead of data. We provide the partial-wave covariance matrices needed to perform correlated χ2 fits, in which the obtained χ2 equals the actual χ2 up to non-linear and normalization corrections. For any analysis relying on partial waves extracted from elastic pion scattering, this is a prerequisite to assess the significance of resonance signals and to assign any uncertainty on results. The compilation of the necessary data to improve hadronic analyses is presented in detail. Supported by the U.S. Department of Energy Grant DE-SC0014133, contract DE-AC05-06OR23177, and by the National Science Foundation (CAREER grant No. 1452055, PIF Grant No. 1415459).

  14. Improved Determination of {ital {alpha}}{sub {ital s}} From Neutrino-Nucleon Scattering

    SciTech Connect

    Johnson, R.A.; Vakili, M.; Seligman, W.G.; Arroyo, C.G.; Bazarko, A.O.; Conrad, J.; Kim, J.H.; King, B.J.; Lefmann, W.C.; McNulty, C.; Mishra, S.R.; Quintas, P.Z.; Romosan, A.; Sciulli, F.J.; Shaevitz, M.H.; Spentzouris, P.; Stern, E.G.; Bernstein, R.H.; Lamm, M.J.; Marsh, W.; McFarland, K.S.; Yu, J.; Bolton, T.; Naples, D.; de Barbaro, L.; Schellman, H.; de Barbaro, P.; Bodek, A.; Budd, H.; Harris, D.A.; Sakumoto, W.K.; Yang, U.K.; Kinnel, T.; Smith, W.H.

    1997-08-01

    We present an improved determination of the proton structure functions F{sub 2} and xF{sub 3} from the Columbia-Chicago-Fermilab-Rochester Collaboration {nu}{minus}Fe deep inelastic scattering experiment. Comparisons to corrected high-statistics charged-lepton scattering results for F{sub 2} from the NMC, E665, SLAC, and BCDMS experiments indicate good agreement for x{gt}0.1 but some discrepancy at lower x . The Q{sup 2} evolution of both the F{sub 2} and xF{sub 3} structure functions yields a value of the strong coupling constant at the scale of mass of the Z boson of {alpha}{sub s}(M{sup 2}{sub Z})=0 .119{plus_minus}0.002(expt){plus_minus}0.004( theory) . This is one of the most precise measurements of this quantity. {copyright} {ital 1997} {ital The American Physical Society}

  15. A phenomenological study of photon production in low energy neutrino nucleon scattering

    SciTech Connect

    Jenkins, James P; Goldman, Terry J

    2009-01-01

    Low energy photon production is an important background to many current and future precision neutrino experiments. We present a phenomenological study of t-channel radiative corrections to neutral current neutrino nucleus scattering. After introducing the relevant processes and phenomenological coupling constants, we will explore the derived energy and angular distributions as well as total cross-section predictions along with their estimated uncertainties. This is supplemented throughout with comments on possible experimental signatures and implications. We conclude with a general discussion of the analysis in the context of complimentary methodologies. This is based on a talk presented at the DPF 2009 meeting in Detroit MI.

  16. Microscopic study on proton elastic scattering of helium and lithium isotopes at energy range up to 160 MeV/nucleon.

    NASA Astrophysics Data System (ADS)

    Farag, M. Y. H.; Esmael, E. H.; Maridi, H. M.

    2014-03-01

    The proton elastic scattering data on 4,6,8 He and 6,7,9,11Li nuclei at energies below 160 MeV/nucleon are analyzed using the optical model. The optical potential (OP) is taken microscopically, with few and limited fitting parameters, using the single folding model for the real part and high-energy approximation (HEA) for the imaginary one. Clear dependencies of the volume integrals on energy and rms radii are obtained from the results. The calculated differential and the reaction cross sections are in good agreement with the available experimental data. In general, this OP with few and limited fitting parameters, which have a systematic behavior with incident energy and matter radii, successfully describes the proton elastic scattering data with stable and exotic light nuclei at energies up to 160 MeV/nucleon.

  17. Neutron-proton effective mass splitting in neutron-rich matter at normal density from analyzing nucleon-nucleus scattering data within an isospin dependent optical model

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Hua; Guo, Wen-Jun; Li, Bao-An; Chen, Lie-Wen; Fattoyev, Farrukh J.; Newton, William G.

    2015-04-01

    The neutron-proton effective mass splitting in asymmetric nucleonic matter of isospin asymmetry δ and normal density is found to be mn-p* ≡ (mn* - mp*) / m = (0.41 ± 0.15) δ from analyzing globally 1088 sets of reaction and angular differential cross sections of proton elastic scattering on 130 targets with beam energies from 0.783 MeV to 200 MeV, and 1161 sets of data of neutron elastic scattering on 104 targets with beam energies from 0.05 MeV to 200 MeV within an isospin dependent non-relativistic optical potential model. It sets a useful reference for testing model predictions on the momentum dependence of the nucleon isovector potential necessary for understanding novel structures and reactions of rare isotopes.

  18. Microscopic model analysis of {sup 11}Li+p elastic scattering at 62, 68.4, and 75 MeV/nucleon

    SciTech Connect

    Hassan, M. Y. M.; Farag, M. Y. H.; Esmael, E. H.; Maridi, H. M.

    2009-01-15

    {sup 11}Li+p elastic scattering data at three energies, 62, 68.4, and 75 MeV/nucleon, are analyzed with density-dependent M3Y and KH effective nucleon-nucleon (NN) interactions in the framework of the single folding model. The parameters of the density-dependent term are adjusted to fulfill saturation of nuclear matter. The optical potentials (OP's) and cross sections are calculated using four model densities of {sup 11}Li, G (one-parameter Gaussian), GG (Gaussian-Gaussian), GO (Gaussian- oscillator), and the COSMA (cluster orbital shell model approximation). Comparative studies are performed for real, imaginary, and spin-orbit potentials with the phenomenological and microscopic forms. The microscopic volume and surface imaginary potentials are constructed from both the renormalized folded potentials and their derivatives. The sensitivity of the differential cross section to the four densities is tested. It is found that the {sup 11}Li+p elastic scattering cross sections depend strongly upon the behavior of the corresponding potentials. The GG and GO densities obtained from analyzing the data, using Glauber multiple scattering theory at high energies, give good results at energies below 100 MeV/nucleon in the framework of the folding model. The OP's calculated in the microscopic form using few parameters give good agreement with the data. Thus, it is not necessary to introduce a large number of arbitrary fitting parameters as done in the phenomenological and semimicroscopic OP's. The KH effective interaction successfully describes {sup 11}Li+p elastic scattering as the popular M3Y interaction. The obtained results of the reaction cross section are in good agreement with previous calculations.

  19. Measurement of azimuthal hadron asymmetries in semi-inclusive deep inelastic scattering off unpolarised nucleons

    NASA Astrophysics Data System (ADS)

    Adolph, C.; Akhunzyanov, R.; Alexeev, M. G.; Alexandrov, Yu.; Alexeev, G. D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Austregesilo, A.; Badełek, B.; Balestra, F.; Barth, J.; Baum, G.; Beck, R.; Bedfer, Y.; Berlin, A.; Bernhard, J.; Bertini, R.; Bicker, K.; Bieling, J.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bravar, A.; Bressan, A.; Büchele, M.; Burtin, E.; Capozza, L.; Chiosso, M.; Chung, S. U.; Cicuttin, A.; Crespo, M. L.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S. S.; Dasgupta, S.; Denisov, O. Yu.; Donskov, S. V.; Doshita, N.; Duic, V.; Dünnweber, W.; Dziewiecki, M.; Efremov, A.; Elia, C.; Eversheim, P. D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Filin, A.; Finger, M.; Finger, M.; Fischer, H.; Franco, C.; du Fresne von Hohenesche, N.; Friedrich, J. M.; Frolov, V.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gnesi, I.; Gobbo, B.; Goertz, S.; Gorzellik, M.; Grabmüller, S.; Grasso, A.; Grube, B.; Guskov, A.; Guthörl, T.; Haas, F.; von Harrach, D.; Hahne, D.; Hashimoto, R.; Heinsius, F. H.; Herrmann, F.; Hinterberger, F.; Höppner, Ch.; Horikawa, N.; d'Hose, N.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Jasinski, P.; Joerg, P.; Joosten, R.; Kabuß, E.; Kang, D.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J. H.; Kolosov, V. N.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V. F.; Kotzinian, A. M.; Kouznetsov, O.; Kral, Z.; Krämer, M.; Kroumchtein, Z. V.; Kuchinski, N.; Kunne, F.; Kurek, K.; Kurjata, R. P.; Lednev, A. A.; Lehmann, A.; Levorato, S.; Lichtenstadt, J.; Maggiora, A.; Magnon, A.; Makke, N.; Mallot, G. K.; Marchand, C.; Martin, A.; Marzec, J.; Matousek, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Miyachi, Y.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V. I.; Novy, J.; Nowak, W.-D.; Nunes, A. S.; Orlov, I.; Olshevsky, A. G.; Ostrick, M.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Pesek, M.; Peshekhonov, D.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V. A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Reicherz, G.; Rocco, E.; Rodionov, V.; Rondio, E.; Rychter, A.; Rossiyskaya, N. S.; Ryabchikov, D. I.; Samoylenko, V. D.; Sandacz, A.; Sarkar, S.; Savin, I. A.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schlüter, T.; Schmidt, A.; Schmidt, K.; Schmieden, H.; Schönning, K.; Schopferer, S.; Schott, M.; Shevchenko, O. Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sosio, S.; Sozzi, F.; Srnka, A.; Steiger, L.; Stolarski, M.; Sulc, M.; Sulej, R.; Suzuki, H.; Szableski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; ter Wolbeek, J.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Uhl, S.; Uman, I.; Vandenbroucke, M.; Virius, M.; Vondra, J.; Wang, L.; Weisrock, T.; Wilfert, M.; Windmolders, R.; Wiślicki, W.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.

    2014-09-01

    Spin-averaged asymmetries in the azimuthal distributions of positive and negative hadrons produced in deep inelastic scattering were measured using the CERN SPS longitudinally polarised muon beam at 160 GeV/c and a 6LiD target. The amplitudes of the three azimuthal modulations cos⁡ϕh, cos⁡2ϕh and sin⁡ϕh were obtained binning the data separately in each of the relevant kinematic variables x, z or pTh and binning in a three-dimensional grid of these three variables. The amplitudes of the cos⁡ϕh and cos⁡2ϕh modulations show strong kinematic dependencies both for positive and negative hadrons.

  20. Nucleon Electromagnetic Form Factors

    SciTech Connect

    Kees de Jager

    2004-08-01

    Although nucleons account for nearly all the visible mass in the universe, they have a complicated structure that is still incompletely understood. The first indication that nucleons have an internal structure, was the measurement of the proton magnetic moment by Frisch and Stern (1933) which revealed a large deviation from the value expected for a point-like Dirac particle. The investigation of the spatial structure of the nucleon, resulting in the first quantitative measurement of the proton charge radius, was initiated by the HEPL (Stanford) experiments in the 1950s, for which Hofstadter was awarded the 1961 Nobel prize. The first indication of a non-zero neutron charge distribution was obtained by scattering thermal neutrons off atomic electrons. The recent revival of its experimental study through the operational implementation of novel instrumentation has instigated a strong theoretical interest. Nucleon electro-magnetic form factors (EMFFs) are optimally studied through the exchange of a virtual photon, in elastic electron-nucleon scattering. The momentum transferred to the nucleon by the virtual photon can be selected to probe different scales of the nucleon, from integral properties such as the charge radius to scaling properties of its internal constituents. Polarization instrumentation, polarized beams and targets, and the measurement of the polarization of the recoiling nucleon have been essential in the accurate separation of the charge and magnetic form factors and in studies of the elusive neutron charge form factor.

  1. Stopping power of neutrinos and antineutrinos in polymers

    NASA Technical Reports Server (NTRS)

    Rustgi, M. L.; Leung, P. T.; Long, S. A. T.

    1985-01-01

    The Weinberg-Salam model is applied to quantify the energy loss of antineutrinos and neutrinos encountering polymers. The scattering cross-sectional energy due to encounters with electrons is calculated, along with the probability that an antineutrino will remain the same particle. The energy loss reaches a maximum, i.e., stopping occurs, when the probability is unity. The technique is applied to study the energy losses in kapton, a solid organic insulator used for antennas on spacecraft exposed to solar neutrinos with energies ranging from 0.5-10 MeV. The energy loss is found to be negligible.

  2. Stopping power of neutrinos and antineutrinos in polymers

    NASA Technical Reports Server (NTRS)

    Rustgi, M. L.; Leung, P. T.; Long, S. A. T.

    1985-01-01

    The Weinberg-Salam model is applied to quantify the energy loss of antineutrinos and neutrinos encountering polymers. The scattering cross-sectional energy due to encounters with electrons is calculated, along with the probability that an antineutrino will remain the same particle. The energy loss reaches a maximum, i.e., stopping occurs, when the probability is unity. The technique is applied to study the energy losses in kapton, a solid organic insulator used for antennas on spacecraft exposed to solar neutrinos with energies ranging from 0.5-10 MeV. The energy loss is found to be negligible.

  3. Antineutrino monitoring of thorium reactors

    NASA Astrophysics Data System (ADS)

    Akindele, Oluwatomi A.; Bernstein, Adam; Norman, Eric B.

    2016-09-01

    Various groups have demonstrated that antineutrino monitoring can be successful in assessing the plutonium content in water-cooled nuclear reactors for nonproliferation applications. New reactor designs and concepts incorporate nontraditional fuel types and chemistry. Understanding how these properties affect the antineutrino emission from a reactor can extend the applicability of antineutrino monitoring. Thorium molten salt reactors breed 233U, that if diverted constitute a direct use material as defined by the International Atomic Energy Agency (IAEA). The antineutrino spectrum from the fission of 233U has been estimated for the first time, and the feasibility of detecting the diversion of 8 kg of 233U, within a 30 day timeliness goal has been evaluated. The antineutrino emission from a thorium reactor operating under normal conditions is compared to a diversion scenario by evaluating the daily antineutrino count rate and the energy spectrum of the detected antineutrinos at a 25 m standoff. It was found that the diversion of a significant quantity of 233U could not be detected within the current IAEA timeliness detection goal using either tests. A rate-time based analysis exceeded the timeliness goal by 23 days, while a spectral based analysis exceeds this goal by 31 days.

  4. Antineutrino monitoring of thorium reactors

    SciTech Connect

    Akindele, Oluwatomi A.; Bernstein, Adam; Norman, Eric B.

    2016-09-30

    Various groups have demonstrated that antineutrino monitoring can be successful in assessing the plutonium content in water-cooled nuclear reactors for nonproliferation applications. New reactor designs and concepts incorporate nontraditional fuel types and chemistry. Understanding how these properties affect the antineutrino emission from a reactor can extend the applicability of antineutrino monitoring. Thorium molten salt reactors breed 233U, that if diverted constitute a direct use material as defined by the International Atomic Energy Agency (IAEA). The antineutrino spectrum from the fission of 233U has been estimated for the first time, and the feasibility of detecting the diversion of 8 kg of 233U, within a 30 day timeliness goal has been evaluated. The antineutrino emission from a thorium reactor operating under normal conditions is compared to a diversion scenario by evaluating the daily antineutrino count rate and the energy spectrum of the detected antineutrinos at a 25 m standoff. It was found that the diversion of a significant quantity of 233U could not be detected within the current IAEA timeliness detection goal using either tests. In conclusion, a rate-time based analysis exceeded the timeliness goal by 23 days, while a spectral based analysis exceeds this goal by 31 days.

  5. Antineutrino monitoring of thorium reactors

    DOE PAGES

    Akindele, Oluwatomi A.; Bernstein, Adam; Norman, Eric B.

    2016-09-30

    Various groups have demonstrated that antineutrino monitoring can be successful in assessing the plutonium content in water-cooled nuclear reactors for nonproliferation applications. New reactor designs and concepts incorporate nontraditional fuel types and chemistry. Understanding how these properties affect the antineutrino emission from a reactor can extend the applicability of antineutrino monitoring. Thorium molten salt reactors breed 233U, that if diverted constitute a direct use material as defined by the International Atomic Energy Agency (IAEA). The antineutrino spectrum from the fission of 233U has been estimated for the first time, and the feasibility of detecting the diversion of 8 kg ofmore » 233U, within a 30 day timeliness goal has been evaluated. The antineutrino emission from a thorium reactor operating under normal conditions is compared to a diversion scenario by evaluating the daily antineutrino count rate and the energy spectrum of the detected antineutrinos at a 25 m standoff. It was found that the diversion of a significant quantity of 233U could not be detected within the current IAEA timeliness detection goal using either tests. In conclusion, a rate-time based analysis exceeded the timeliness goal by 23 days, while a spectral based analysis exceeds this goal by 31 days.« less

  6. Antineutrino monitoring of thorium reactors

    SciTech Connect

    Akindele, Oluwatomi A.; Bernstein, Adam; Norman, Eric B.

    2016-09-30

    Various groups have demonstrated that antineutrino monitoring can be successful in assessing the plutonium content in water-cooled nuclear reactors for nonproliferation applications. New reactor designs and concepts incorporate nontraditional fuel types and chemistry. Understanding how these properties affect the antineutrino emission from a reactor can extend the applicability of antineutrino monitoring. Thorium molten salt reactors breed 233U, that if diverted constitute a direct use material as defined by the International Atomic Energy Agency (IAEA). The antineutrino spectrum from the fission of 233U has been estimated for the first time, and the feasibility of detecting the diversion of 8 kg of 233U, within a 30 day timeliness goal has been evaluated. The antineutrino emission from a thorium reactor operating under normal conditions is compared to a diversion scenario by evaluating the daily antineutrino count rate and the energy spectrum of the detected antineutrinos at a 25 m standoff. It was found that the diversion of a significant quantity of 233U could not be detected within the current IAEA timeliness detection goal using either tests. In conclusion, a rate-time based analysis exceeded the timeliness goal by 23 days, while a spectral based analysis exceeds this goal by 31 days.

  7. Antineutrino monitoring of thorium reactors

    SciTech Connect

    Akindele, Oluwatomi A.; Bernstein, Adam; Norman, Eric B.

    2016-09-28

    Various groups have demonstrated that antineutrino monitoring can be successful in assessing the plutonium content in water-cooled nuclear reactors for nonproliferation applications. New reactor designs and concepts incorporate nontraditional fuel types and chemistry. Understanding how these properties affect the antineutrino emission from a reactor can extend the applicability of antineutrino monitoring. Thorium molten salt reactors breed 233U, that if diverted constitute a direct use material as defined by the International Atomic Energy Agency (IAEA). The antineutrino spectrum from the fission of 233U has been estimated for the first time, and the feasibility of detecting the diversion of 8 kg of 233U, within a 30 day timeliness goal has been evaluated. The antineutrino emission from a thorium reactor operating under normal conditions is compared to a diversion scenario by evaluating the daily antineutrino count rate and the energy spectrum of the detected antineutrinos at a 25 m standoff. It was found that the diversion of a significant quantity of 233U could not be detected within the current IAEA timeliness detection goal using either tests. A rate-time based analysis exceeded the timeliness goal by 23 days, while a spectral based analysis exceeds this goal by 31 days.

  8. Antineutrino monitoring of thorium reactors

    DOE PAGES

    Akindele, Oluwatomi A.; Bernstein, Adam; Norman, Eric B.

    2016-09-28

    Various groups have demonstrated that antineutrino monitoring can be successful in assessing the plutonium content in water-cooled nuclear reactors for nonproliferation applications. New reactor designs and concepts incorporate nontraditional fuel types and chemistry. Understanding how these properties affect the antineutrino emission from a reactor can extend the applicability of antineutrino monitoring. Thorium molten salt reactors breed 233U, that if diverted constitute a direct use material as defined by the International Atomic Energy Agency (IAEA). The antineutrino spectrum from the fission of 233U has been estimated for the first time, and the feasibility of detecting the diversion of 8 kg ofmore » 233U, within a 30 day timeliness goal has been evaluated. The antineutrino emission from a thorium reactor operating under normal conditions is compared to a diversion scenario by evaluating the daily antineutrino count rate and the energy spectrum of the detected antineutrinos at a 25 m standoff. It was found that the diversion of a significant quantity of 233U could not be detected within the current IAEA timeliness detection goal using either tests. A rate-time based analysis exceeded the timeliness goal by 23 days, while a spectral based analysis exceeds this goal by 31 days.« less

  9. Segmented scintillation antineutrino detector

    DOEpatents

    Reyna, David

    2017-05-09

    The various technologies presented herein relate to incorporating a wavelength-shifting material in a scintillator to facilitate absorption of a first electromagnetic particle (e.g., a first photon) having a first wavelength and subsequent generation and emission of a second electromagnetic particle (e.g., a second photon) having a second wavelength. The second electromagnetic particle can be emitted isotropically, with a high probability that the direction of emission of the second electromagnetic particle is disparate to the direction of travel of the first electromagnetic particle (and according angle of incidence). Isotropic emission of the second electromagnetic particle enables the second electromagnetic particle to be retained in the scintillator owing to internal reflection. Accordingly, longer length scintillators can be constructed, and accordingly, the scintillator array has a greater area (and volume) over which to detect electromagnetic particles (e.g., antineutrinos) being emitted from a nuclear reaction.

  10. Can one distinguish τ-neutrinos from antineutrinos in neutral-current pion production processes?

    NASA Astrophysics Data System (ADS)

    Hernández, E.; Nieves, J.; Valverde, M.

    2007-04-01

    A potential way to distinguish τ-neutrinos from antineutrinos, below the τ-production threshold, but above the pion production one, is presented. It is based on the different behavior of the neutral-current pion production off the nucleon, depending on whether it is induced by neutrinos or antineutrinos. This procedure for distinguishing τ-neutrinos from antineutrinos neither relies on any nuclear model, nor it is affected by any nuclear effect (distortion of the outgoing nucleon waves, etc.). We show that neutrino-antineutrino asymmetries occur both in the totally integrated cross sections and in the pion azimuthal differential distributions. To define the asymmetries for the latter distributions we just rely on Lorentz-invariance. All these asymmetries are independent of the lepton family and can be experimentally measured by using electron or muon neutrinos, due to the lepton family universality of the neutral-current neutrino interaction. Nevertheless and to estimate their size, we have also used the chiral model of [E. Hernández, J. Nieves, M. Valverde, arxiv:hep-ph/0701149] at intermediate energies. Results are really significant since the differences between neutrino and antineutrino induced reactions are always large in all physical channels.

  11. 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.

  12. Elastic scattering and breakup effect analysis of {sup 11}Be+{sup 12}C at 38.4 MeV/nucleon

    SciTech Connect

    Hassan, M. Y. M.; Farag, M. Y. H.; Esmael, E. H.; Maridi, H. M.

    2009-06-15

    {sup 11}Be+{sup 12}C elastic-scattering data at 38.4 MeV/nucleon has been analyzed using the optical model. The optical potential is calculated in the framework of the double folding model using M3Y effective nucleon-nucleon interaction. Different models of {sup 11}Be density are tested and the model that does not include the halo structure gives poor fitting with data. The breakup effect is studied by introducing a complex dynamical polarization potential (DPP) that is added to the ''bare'' potential. The DPP is taken in different forms that have been obtained from simple phenomenological, semiclassical approximation, and microscopic methods. The simple phenomenological DPP is related to the semiclassical approximation method. The sensitivity of the differential and reaction cross sections to these polarization potentials is tested. The microscopic DPP that has been constructed from the derivative of the folding potential describes the breakup effect well. It gives an explicit justification for the long range of the polarization potential.

  13. Detection of Breeding Blankets Using Antineutrinos

    NASA Astrophysics Data System (ADS)

    Cogswell, Bernadette; Huber, Patrick

    2016-03-01

    The Plutonium Management and Disposition Agreement between the United States and Russia makes arrangements for the disposal of 34 metric tons of excess weapon-grade plutonium. Under this agreement Russia plans to dispose of its excess stocks by processing the plutonium into fuel for fast breeder reactors. To meet the disposition requirements this fuel would be burned while the fast reactors are run as burners, i.e., without a natural uranium blanket that can be used to breed plutonium surrounding the core. This talk discusses the potential application of antineutrino monitoring to the verification of the presence or absence of a breeding blanket. It is found that a 36 kg antineutrino detector, exploiting coherent elastic neutrino-nucleus scattering and made of silicon, could determine the presence of a breeding blanket at a liquid sodium cooled fast reactor at the 95% confidence level within 90 days. Such a detector would be a novel non-intrusive verification tool and could present a first application of coherent elastic neutrino-nucleus scattering to a real-world challenge.

  14. Few-nucleon systems with state-of-the-art chiral nucleon-nucleon forces

    NASA Astrophysics Data System (ADS)

    Binder, S.; Calci, A.; Epelbaum, E.; Furnstahl, R. J.; Golak, J.; Hebeler, K.; Kamada, H.; Krebs, H.; Langhammer, J.; Liebig, S.; Maris, P.; Meißner, Ulf-G.; Minossi, D.; Nogga, A.; Potter, H.; Roth, R.; Skibiński, R.; Topolnicki, K.; Vary, J. P.; Witała, H.; Lenpic Collaboration

    2016-04-01

    We apply improved nucleon-nucleon potentials up to fifth order in chiral effective field theory, along with a new analysis of the theoretical truncation errors to study nucleon-deuteron (N d ) scattering and selected low-energy observables in 3H,4He , and 6Li. Calculations beyond second order differ from experiment well outside the range of quantified uncertainties, providing truly unambiguous evidence for missing three-nucleon forces within the employed framework. The sizes of the required three-nucleon-force contributions agree well with expectations based on Weinberg's power counting. We identify the energy range in elastic N d scattering best suited to study three-nucleon-force effects and estimate the achievable accuracy of theoretical predictions for various observables.

  15. Virtual Compton Scattering and Neutral Pion Electro-production from the Proton in the Nucleon Resonance Region

    SciTech Connect

    Luminita Todor

    2003-05-01

    The experiment (E93-050) at Jefferson Lab measured the ep {yields} ep{gamma} and ep {yields} ep{pi}{sup 0} cross sections in the nucleon resonance region, from the threshold to W = 1.9 GeV at Q{sup 2} = 1 GeV{sup 2} for backward emission of the {gamma} or {pi}{sup 0}.

  16. Semi-inclusive deep-inelastic scattering off few-nucleon systems: Tagging the EMC effect and hadronization mechanisms with detection of slow recoiling nuclei

    SciTech Connect

    Ciofi degli Atti, C.; Kaptari, L. P.

    2011-04-15

    The semi-inclusive deep-inelastic scattering of electrons off {sup 2}H and {sup 3}He with detection of slow protons and deuterons, respectively, i.e., the processes {sup 2}H(e,e{sup '}p)X and {sup 3}He(e,e{sup '}d)X, are calculated within the spectator mechanism, taking into account the final state interaction of the nucleon debris with the detected protons and deuterons. It is shown that by a proper choice of the kinematics the origin of the EMC effect and the details of the interaction between the hadronizing quark and the nuclear medium can be investigated at a level which cannot be reached by inclusive deep-inelastic scattering. A comparison of the results of our calculations, containing no adjustable parameters, with recently available experimental data on the process {sup 2}H(e,e{sup '}p)X shows a good agreement in the backward hemisphere of the emitted nucleons. Theoretical predictions at energies that will be available at the upgraded Thomas Jefferson National Accelerator Facility are presented, and the possibility to investigate the proposed semi-inclusive processes at electron-ion colliders is briefly discussed.

  17. Meson-exchange currents and quasielastic antineutrino cross sections in the superscaling approximation.

    PubMed

    Amaro, J E; Barbaro, M B; Caballero, J A; Donnelly, T W

    2012-04-13

    We evaluate quasielastic double-differential antineutrino cross sections obtained in a phenomenological model based on the superscaling behavior of electron scattering data and estimate the contribution of the vector meson-exchange currents in the two-particle-two-hole sector. We show that the impact of meson-exchange currents for charge-changing antineutrino reactions is much larger than in the neutrino case.

  18. Charm-Quark Production in Deep-Inelastic Neutrino Scattering at Next-to-Next-to-Leading Order in QCD.

    PubMed

    Berger, Edmond L; Gao, Jun; Li, Chong Sheng; Liu, Ze Long; Zhu, Hua Xing

    2016-05-27

    We present a fully differential next-to-next-to-leading order calculation of charm-quark production in charged-current deep-inelastic scattering, with full charm-quark mass dependence. The next-to-next-to-leading order corrections in perturbative quantum chromodynamics are found to be comparable in size to the next-to-leading order corrections in certain kinematic regions. We compare our predictions with data on dimuon production in (anti)neutrino scattering from a heavy nucleus. Our results can be used to improve the extraction of the parton distribution function of a strange quark in the nucleon.

  19. Few-Nucleon Systems

    NASA Astrophysics Data System (ADS)

    Kievsky, A.

    2005-04-01

    Recent advances in the theoretical description of few-nucleon systems are reported. This research activity has been performed under the Italian project FISICA TEORICA DEL NUCLEO E DEI SISTEMI A MOLTI CORPI. Bound and scattering states as well as specific reactions are analyzed in connection with the current experimental activity.

  20. Anti-neutrino imprint in solar neutrino flare

    NASA Astrophysics Data System (ADS)

    Fargion, D.

    2006-10-01

    A future neutrino detector at megaton mass might enlarge the neutrino telescope thresholds revealing cosmic supernova background and largest solar flares (SFs) neutrinos. Indeed the solar energetic (Ep>100 MeV) flare particles (protons, α), while scattering among themselves on solar corona atmosphere must produce prompt charged pions, whose chain decays are source of a solar (electron muon) neutrino 'flare' (at tens or hundreds MeV energy). These brief (minutes) neutrino 'bursts' at largest flare peak may overcome by three to five orders of magnitude the steady atmospheric neutrino noise on the Earth, possibly leading to their detection above detection thresholds (in a full mixed three flavour state). Moreover the birth of anti-neutrinos at a few tens of MeV very clearly flares above a null thermal 'hep' anti-neutrino solar background and also above a tiny supernova relic and atmospheric noise. The largest prompt solar anti-neutrino 'burst' may be well detected in future Super Kamikande (gadolinium implemented) anti-neutrino \\bar\

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

    NASA Astrophysics Data System (ADS)

    Devan, Joshua D.

    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- v method, which relies on the principle that the cross section for interactions with very low recoil energy is nearly constant as a function of neutrino energy. The measured cross section is compared with world data.

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

    SciTech Connect

    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-$\

  3. Dissecting Reactor Antineutrino Flux Calculations.

    PubMed

    Sonzogni, A A; McCutchan, E A; Hayes, A C

    2017-09-15

    Current predictions for the antineutrino yield and spectra from a nuclear reactor rely on the experimental electron spectra from ^{235}U, ^{239}Pu, ^{241}Pu and a numerical method to convert these aggregate electron spectra into their corresponding antineutrino ones. In the present work we investigate quantitatively some of the basic assumptions and approximations used in the conversion method, studying first the compatibility between two recent approaches for calculating electron and antineutrino spectra. We then explore different possibilities for the disagreement between the measured Daya Bay and the Huber-Mueller antineutrino spectra, including the ^{238}U contribution as well as the effective charge and the allowed shape assumption used in the conversion method. We observe that including a shape correction of about +6%  MeV^{-1} in conversion calculations can better describe the Daya Bay spectrum. Because of a lack of experimental data, this correction cannot be ruled out, concluding that in order to confirm the existence of the reactor neutrino anomaly, or even quantify it, precisely measured electron spectra for about 50 relevant fission products are needed. With the advent of new rare ion facilities, the measurement of shape factors for these nuclides, for many of which precise beta intensity data from TAGS experiments already exist, would be highly desirable.

  4. Dissecting Reactor Antineutrino Flux Calculations

    NASA Astrophysics Data System (ADS)

    Sonzogni, A. A.; McCutchan, E. A.; Hayes, A. C.

    2017-09-01

    Current predictions for the antineutrino yield and spectra from a nuclear reactor rely on the experimental electron spectra from 235U, 239Pu, 241Pu and a numerical method to convert these aggregate electron spectra into their corresponding antineutrino ones. In the present work we investigate quantitatively some of the basic assumptions and approximations used in the conversion method, studying first the compatibility between two recent approaches for calculating electron and antineutrino spectra. We then explore different possibilities for the disagreement between the measured Daya Bay and the Huber-Mueller antineutrino spectra, including the 238U contribution as well as the effective charge and the allowed shape assumption used in the conversion method. We observe that including a shape correction of about +6 % MeV-1 in conversion calculations can better describe the Daya Bay spectrum. Because of a lack of experimental data, this correction cannot be ruled out, concluding that in order to confirm the existence of the reactor neutrino anomaly, or even quantify it, precisely measured electron spectra for about 50 relevant fission products are needed. With the advent of new rare ion facilities, the measurement of shape factors for these nuclides, for many of which precise beta intensity data from TAGS experiments already exist, would be highly desirable.

  5. Dissecting Reactor Antineutrino Flux Calculations

    DOE PAGES

    Sonzogni, A. A.; McCutchan, E. A.; Hayes, A. C.

    2017-09-15

    Current predictions for the antineutrino yield and spectra from a nuclear reactor rely on the experimental electron spectra from 235 U , 239 Pu , 241 Pu and a numerical method to convert these aggregate electron spectra into their corresponding antineutrino ones. In our present work we investigate quantitatively some of the basic assumptions and approximations used in the conversion method, studying first the compatibility between two recent approaches for calculating electron and antineutrino spectra. We then explore different possibilities for the disagreement between the measured Daya Bay and the Huber-Mueller antineutrino spectra, including the 238 U contribution as wellmore » as the effective charge and the allowed shape assumption used in the conversion method. Here, we observe that including a shape correction of about + 6 % MeV - 1 in conversion calculations can better describe the Daya Bay spectrum. Because of a lack of experimental data, this correction cannot be ruled out, concluding that in order to confirm the existence of the reactor neutrino anomaly, or even quantify it, precisely measured electron spectra for about 50 relevant fission products are needed. With the advent of new rare ion facilities, the measurement of shape factors for these nuclides, for many of which precise beta intensity data from TAGS experiments already exist, would be highly desirable.« less

  6. 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.

  7. 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.

  8. 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 × 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. Themore » spin-dependent WIMP-neutron limit is the most sensitive constraint to date.« less

  9. Asymptotic behavior of the deuteron form factors in the two-nucleon model and electron scattering experiments at GeV energies at JLab

    SciTech Connect

    Krutov, A. F.; Tsirova, N. A.; Troitsky, V. E.

    2008-10-15

    Using the instant form dynamics of Poincare invariant quantum mechanics and the modified relativistic impulse approximation proposed previously, we calculate asymptotic behavior of electromagnetic form factors for the deuteron considered as a two-nucleon system. We show that today, experimentation on elastic ed scattering has reached the asymptotic regime. We also estimate the possible range of momentum transfer in which the quark degrees of freedom will possibly be seen in future JLab experiments. The explicit relation between the behavior of the deuteron wave function at r=0 and the form factors asymptotic behavior is obtained, and the conditions of wave functions that give the asymptotic behavior predicted by QCD and quark counting rules are formulated.

  10. Nucleon-nucleon scattering at medium energies

    NASA Astrophysics Data System (ADS)

    Afnan, I. R.

    1984-03-01

    A model of the N-N potential, at medium energies, in the frame work of the BB-πBB equations, is presented. The derivation is based on the Cloudy Bag Model Hamiltonian. Recent N-N calculations are reviewed in the frame work of the model. Theoretical methods for the analysis of dibaryon resonances are compared.

  11. Measurements of Polarization Transfers in Real Compton Scattering by a proton target at JLAB. A new source of information on the 3D shape of the nucleon

    SciTech Connect

    Fanelli, Cristiano V.

    2015-03-01

    In this thesis work, results of the analysis of the polarization transfers measured in real Compton scattering (RCS) by the Collaboration E07-002 at the Je fferson Lab Hall-C are presented. The data were collected at large scattering angle (theta_cm = 70deg) and with a polarized incident photon beam at an average energy of 3.8 GeV. Such a kind of experiments allows one to understand more deeply the reaction mechanism, that involves a real photon, by extracting both Compton form factors and Generalized Parton Distributions (GPDs) (also relevant for possibly shedding light on the total angular momentum of the nucleon). The obtained results for the longitudinal and transverse polarization transfers K_LL and K_LT, are of crucial importance, since they confirm unambiguously the disagreement between experimental data and pQCD prediction, as it was found in E99-114 experiment, and favor the Handbag mechanism. The E99-114 and E07-002 results can contribute to attract new interest on the great yield of the Compton scattering by a nucleon target, as demonstrated by the recent approval of an experimental proposal submitted to the Jefferson Lab PAC 42 for a Wide-angle Compton Scattering experiment, at 8 and 10 GeV Photon Energies. The new experiments approved to run with the updated 12 GeV electron beam at JLab, are characterized by much higher luminosities, and a new GEM tracker is under development to tackle the challenging backgrounds. Within this context, we present a new multistep tracking algorithm, based on (i) a Neural Network (NN) designed for a fast and efficient association of the hits measured by the GEM detector which allows the track identification, and (ii) the application of both a Kalman filter and Rauch-Tung-Striebel smoother to further improve the track reconstruction. The full procedure, i.e. NN and filtering, appears very promising, with high performances in terms of both association effciency and reconstruction accuracy, and these preliminary results will

  12. Weak production of strange particles off the nucleon

    SciTech Connect

    Alam, M. Rafi; Athar, M. Sajjad; Simo, I. Ruiz; Alvarez-Ruso, L.; Vacas, M. J. Vicente

    2015-05-15

    The strange particle production off the nucleon induced by neutrinos and antineutrinos is investigated at low and intermediate energies. We develop a microscopic model based on the SU(3) chiral Lagrangian. The studied mechanisms are the main source of single kaon production for (anti)neutrino energies up to 1.5 GeV. Using this model we have also studied the associated production of kaons and hyperons. The cross sections are large enough to be measured by experiments such as MINERνA, T2K and NOνA.

  13. Upper limit on the cross section for elastic neutralino-nucleon scattering in a neutrino experiment at the Baksan Underground Scintillator Telescope

    SciTech Connect

    Suvorova, O. V. Boliev, M. M. Demidov, S. V. Mikheyev, S. P.

    2013-11-15

    The results of a neutrino experiment that involved 24.12 yr of live time of observation of muons from the lower Earth's hemisphere with the aid of the Baksan Underground Scintillator Telescope are presented. In the problem of searches for a signal from the annihilation of dark matter in the Sun, an upper limit on the cross section for the elastic scattering of a weakly interacting massive particle (WIMP) on a nucleon was obtained at a 90% confidence level from an analysis of data accumulated within 21.15 yr of live time of observation. A neutralino in a nonminimal supersymmetric theory was considered for a WIMP. The best limit at the Baksan Underground Scintillator Telescope on the cross section for spin-dependent neutralino interactionwith a proton corresponds to 3 Multiplication-Sign 10{sup -4} pb for the neutralino mass of 210 GeV/c{sup 2}. This limit is three orders of magnitude more stringent than similar limits obtained in experiments that detected directly WIMP scattering on target nuclei.

  14. Reactor antineutrinos and nuclear physics

    NASA Astrophysics Data System (ADS)

    Balantekin, A. B.

    2016-11-01

    Short-baseline reactor neutrino experiments successfully measured the neutrino parameters they set out to measure, but they also identified a shape distortion in the 5-7 MeV range as well as a reduction from the predicted value of the flux. Nuclear physics input into the calculations of reactor antineutrino spectra needs to be better refined if this anomaly is to be interpreted as due to sterile neutrino states.

  15. Nucleon Spin And Structure Studies With COMPASS

    SciTech Connect

    Platchkov, Stephane

    2006-07-11

    The COMPASS experiment at CERN investigates nucleon structure and spectroscopy with high-intensity muon and hadron beams. Between 2002 and 2004 COMPASS has mainly concentrated on the spin structure of the nucleon via deep-inelastic scattering of polarized muons on polarized nucleons. First results include measurements of the gluon contribution to the nucleon spin via charm production and high-pt pairs, {lambda} polarization, vector-meson production, Collins and Sivers asymmetries, inclusive and semi-inclusive deep-inelastic scattering asymmetries and a search for pentaquark states. A short overview of these results is presented.

  16. How low-energy weak reactions can constrain three-nucleon forces and the neutron-neutron scattering length.

    PubMed

    Gårdestig, A; Phillips, D R

    2006-06-16

    We show that chiral symmetry and gauge invariance enforce relations between the short-distance physics that occurs in a number of electroweak and pionic reactions on light nuclei. Within chiral perturbation theory, this is manifested via the appearance of the same axial isovector two-body contact term in pi(-)d --> nngamma, p-wave pion production in NN collisions, tritium beta decay, pp fusion, nud scattering, and the hep reaction. Using a Gamow-Teller matrix element obtained from calculations of pp fusion as input, we compute the neutron spectrum obtained in pi(-)d --> nngamma. With the short-distance physics in this process controlled from pp --> de(=)nu(e), the theoretical uncertainty in the nn scattering length extracted from pi(-)d --> nngamma is reduced by a factor larger than 3, to approximately < or = 0.05 fm.

  17. AGM2015: Antineutrino Global Map 2015

    PubMed Central

    Usman, S.M.; Jocher, G.R.; Dye, S.T.; McDonough, W.F.; Learned, J.G.

    2015-01-01

    Every second greater than 1025 antineutrinos radiate to space from Earth, shining like a faint antineutrino star. Underground antineutrino detectors have revealed the rapidly decaying fission products inside nuclear reactors, verified the long-lived radioactivity inside our planet, and informed sensitive experiments for probing fundamental physics. Mapping the anisotropic antineutrino flux and energy spectrum advance geoscience by defining the amount and distribution of radioactive power within Earth while critically evaluating competing compositional models of the planet. We present the Antineutrino Global Map 2015 (AGM2015), an experimentally informed model of Earth’s surface antineutrino flux over the 0 to 11 MeV energy spectrum, along with an assessment of systematic errors. The open source AGM2015 provides fundamental predictions for experiments, assists in strategic detector placement to determine neutrino mass hierarchy, and aids in identifying undeclared nuclear reactors. We use cosmochemically and seismologically informed models of the radiogenic lithosphere/mantle combined with the estimated antineutrino flux, as measured by KamLAND and Borexino, to determine the Earth’s total antineutrino luminosity at . We find a dominant flux of geo-neutrinos, predict sub-equal crust and mantle contributions, with ~1% of the total flux from man-made nuclear reactors. PMID:26323507

  18. Antineutrino Oscillations in the Atmospheric Sector

    SciTech Connect

    Himmel, Alexander I.

    2011-05-01

    This thesis presents measurements of the oscillations of muon antineutrinos in the atmospheric sector, where world knowledge of antineutrino oscillations lags well behind the knowledge of neutrinos, as well as a search for vμ → $\\bar{v}$μ transitions. Differences between neutrino and antineutrino oscillations could be a sign of physics beyond the Standard Model, including non-standard matter interactions or the violation of CPT symmetry. These measurements leverage the sign-selecting capabilities of the magnetized steel-scintillator MINOS detectors to analyze antineutrinos from the NuMI beam, both when it is in neutrino-mode and when it is in antineutrino-mode. Antineutrino oscillations are observed at |Δ$\\bar{m}$atm 2| = (3.36-0.40+0.46(stat) ± 0.06(syst)) x 10-3 eV2 and sin2(2$\\bar{θ}$23) = 0.860-0.12+0.11(stat) ± 0.01(syst). The oscillation parameters measured for antineutrinos and those measured by MINOS for neutrinos differ by a large enough margin that the chance of obtaining two values as discrepant as those observed is only 2%, assuming the two measurements arise from the same underlying mechanism, with the same parameter values. No evidence is seen for neutrino-to-antineutrino transitions.

  19. AGM2015: Antineutrino Global Map 2015.

    PubMed

    Usman, S M; Jocher, G R; Dye, S T; McDonough, W F; Learned, J G

    2015-09-01

    Every second greater than 10(25) antineutrinos radiate to space from Earth, shining like a faint antineutrino star. Underground antineutrino detectors have revealed the rapidly decaying fission products inside nuclear reactors, verified the long-lived radioactivity inside our planet, and informed sensitive experiments for probing fundamental physics. Mapping the anisotropic antineutrino flux and energy spectrum advance geoscience by defining the amount and distribution of radioactive power within Earth while critically evaluating competing compositional models of the planet. We present the Antineutrino Global Map 2015 (AGM2015), an experimentally informed model of Earth's surface antineutrino flux over the 0 to 11 MeV energy spectrum, along with an assessment of systematic errors. The open source AGM2015 provides fundamental predictions for experiments, assists in strategic detector placement to determine neutrino mass hierarchy, and aids in identifying undeclared nuclear reactors. We use cosmochemically and seismologically informed models of the radiogenic lithosphere/mantle combined with the estimated antineutrino flux, as measured by KamLAND and Borexino, to determine the Earth's total antineutrino luminosity at . We find a dominant flux of geo-neutrinos, predict sub-equal crust and mantle contributions, with ~1% of the total flux from man-made nuclear reactors.

  20. Sterile antineutrino search in the MINOS experiment

    NASA Astrophysics Data System (ADS)

    Chen, Rui; Minos Collaboration

    2017-01-01

    The MINOS experiment is a long-baseline on-axis neutrino oscillation experiment. The two detectors are separated by 734km and optimised for sensitivity to the disappearance of muon neutrinos and antineutrinos delivered by the NuMI beam at Fermilab. The MINOS detectors are magnetised, giving the experiment a unique ability to separate neutrinos and antineutrinos on an event-by-event basis. Thanks to the different possible NuMI beam configurations, MINOS has accumulated 10 . 56 ×1020 POT from a muon neutrino dominated beam and 3 . 36 ×1020 POT from a muon antineutrino enhanced beam. In this talk I will present an analysis of the muon antineutrino interactions collected in both beam configurations. The LSND and MiniBooNE experiments have observed non-standard electron antineutrino appearance in their oscillation analyses. A possible explanation for this is the 3+1 sterile neutrino model where one adds an additional neutrino to the current three-flavour model. MINOS is sensitive to this model through looking at the charged current neutrino and antineutrino energy spectra to probe any deviations from the three-flavour muon neutrino and antineutrino survival probabilities. In this talk, I will present new limits on sterile antineutrinos, using this 3+1 model.

  1. AGM2015: Antineutrino Global Map 2015

    NASA Astrophysics Data System (ADS)

    Usman, S. M.; Jocher, G. R.; Dye, S. T.; McDonough, W. F.; Learned, J. G.

    2015-09-01

    Every second greater than 1025 antineutrinos radiate to space from Earth, shining like a faint antineutrino star. Underground antineutrino detectors have revealed the rapidly decaying fission products inside nuclear reactors, verified the long-lived radioactivity inside our planet, and informed sensitive experiments for probing fundamental physics. Mapping the anisotropic antineutrino flux and energy spectrum advance geoscience by defining the amount and distribution of radioactive power within Earth while critically evaluating competing compositional models of the planet. We present the Antineutrino Global Map 2015 (AGM2015), an experimentally informed model of Earth’s surface antineutrino flux over the 0 to 11 MeV energy spectrum, along with an assessment of systematic errors. The open source AGM2015 provides fundamental predictions for experiments, assists in strategic detector placement to determine neutrino mass hierarchy, and aids in identifying undeclared nuclear reactors. We use cosmochemically and seismologically informed models of the radiogenic lithosphere/mantle combined with the estimated antineutrino flux, as measured by KamLAND and Borexino, to determine the Earth’s total antineutrino luminosity at . We find a dominant flux of geo-neutrinos, predict sub-equal crust and mantle contributions, with ~1% of the total flux from man-made nuclear reactors.

  2. Recovery Act - Measurement of Parity Violation in Deep Inelastic Scattering and Studies of the Nucleon Spin Structure at JLab 6 and 11 GeV

    SciTech Connect

    Zheng, Xiaochao

    2016-03-10

    The program proposed contains two ingredients which aim to address aspects of two of the three research frontiers of nuclear science as identified in the 2007 NSAC Long Range Plan. The first topic, a test of the current Standard Model, is an ongoing project focusing on measurements of the parity-violating asymmetry in ~e-2H deep inelastic scattering (PVDIS). The PVDIS measurement is complementary to other completed or ongoing low- to medium-energy tests of the Standard Model. As the first, exploratory, step, an experiment using a 6 GeV electron beam will be carried out from October to December 2009 at the Thomas Jefferson National Accelerator Facility (JLab). Meanwhile, a program using the upgraded JLab 11 GeV beam is being planned. The PVDIS program as a whole will provide the first precision data on the axial quark neutral-weak coupling constants. This will either put the current Standard Model to a test that has never been done before, or reveal information on where to look for New Physics beyond the current Standard Model. The PVDIS program will also provide results on hadronic physics effects such as charge symmetry violation. The second part of the proposed program uses spin observables to address the research frontier concerning QCD and structure of the nucleon. An experiment using the JLab 6 GeV beam in 2001 showed that, contrary to predictions from perturbative quantum chromodynamics (pQCD), while the valence up quark’s spin is parallel to the nucleon’s spin, the valence down quark’s spin is not. In order to test the limit of QCD in describing the nucleon spin structure to a region beyond the 6 GeV kinematics, this measurement will be extended to a more energetic, “deeper” valence quark region using the upgraded JLab 11 GeV beam with a polarized 3He target. Although the two topics of the proposed program appear to focus on different physics, for the upgraded JLab 11 GeV beam, both will utilize a new, yet-to-be-built large acceptance

  3. Antineutrino geophysics with liquid scintillator detectors

    NASA Astrophysics Data System (ADS)

    Rothschild, Casey G.; Chen, Mark C.; Calaprice, Frank P.

    Detecting the antineutrinos emitted by the decay of radioactive elements in the mantle and crust could provide a direct measurement of the total abundance of uranium and thorium in the Earth. In calculating the antineutrino flux at specific sites, the local geology of the crust and the background from the world's nuclear power reactors are important considerations. Employing a global crustal map, with type and thickness data, and using recent estimates of the uranium and thorium distribution in the Earth, we calculate the antineutrino event rate for two new neutrino detectors. We show that spectral features allow terrestrial antineutrino events to be identified above reactor antineutrino backgrounds and that the uranium and thorium contributions can be separately determined.

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

    SciTech Connect

    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 × 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 cm2p = 2.9 × 10–39 cm2) at 33 GeV/c2. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.

  5. Measurement of the cross section for high-pT hadron production in the scattering of 160-GeV/c muons off nucleons

    NASA Astrophysics Data System (ADS)

    Adolph, C.; Alekseev, M. G.; Alexakhin, V. Yu.; Alexandrov, Yu.; Alexeev, G. D.; Amoroso, A.; Andrieux, V.; Austregesilo, A.; Badełek, B.; Balestra, F.; Barth, J.; Baum, G.; Bedfer, Y.; Berlin, A.; Bernhard, J.; Bertini, R.; Bicker, K.; Bieling, J.; Birsa, R.; Bisplinghoff, J.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bravar, A.; Bressan, A.; Büchele, M.; Burtin, E.; Capozza, L.; Chiosso, M.; Chung, S. U.; Cicuttin, A.; Crespo, M. L.; Dalla Torre, S.; Dasgupta, S. S.; Dasgupta, S.; Denisov, O. Yu.; Donskov, S. V.; Doshita, N.; Duic, V.; Dünnweber, W.; Dziewiecki, M.; Efremov, A.; Elia, C.; Eversheim, P. D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Filin, A.; Finger, M.; Finger, M., Jr.; Fischer, H.; Franco, C.; du Fresne von Hohenesche, N.; Friedrich, J. M.; Frolov, V.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gnesi, I.; Gobbo, B.; Goertz, S.; Grabmüller, S.; Grasso, A.; Grube, B.; Gushterski, R.; Guskov, A.; Guthörl, T.; Haas, F.; von Harrach, D.; Heinsius, F. H.; Herrmann, F.; Heß, C.; Hinterberger, F.; Höppner, Ch.; Horikawa, N.; d'Hose, N.; Huber, S.; Ishimoto, S.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Jasinski, P.; Joosten, R.; Kabuß, E.; Kang, D.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J. H.; Kolosov, V. N.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V. F.; Kotzinian, A. M.; Kouznetsov, O.; Krämer, M.; Kroumchtein, Z. V.; Kuchinski, N.; Kunne, F.; Kurek, K.; Kurjata, R. P.; Lednev, A. A.; Lehmann, A.; Levorato, S.; Lichtenstadt, J.; Maggiora, A.; Magnon, A.; Makke, N.; Mallot, G. K.; Mann, A.; Marchand, C.; Martin, A.; Marzec, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Miyachi, Y.; Morreale, A.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V. I.; Novakova, C.; Novy, J.; Nowak, W.-D.; Nunes, A. S.; Olshevsky, A. G.; Ostrick, M.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Pesek, M.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V. A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Reicherz, G.; Rocco, E.; Rodionov, V.; Rondio, E.; Rossiyskaya, N. S.; Ryabchikov, D. I.; Samoylenko, V. D.; Sandacz, A.; Sapozhnikov, M. G.; Sarkar, S.; Savin, I. A.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schlüter, T.; Schmidt, A.; Schmidt, K.; Schmïden, H.; Schmitt, L.; Schönning, K.; Schopferer, S.; Schott, M.; Shevchenko, O. Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sosio, S.; Sozzi, F.; Srnka, A.; Steiger, L.; Stolarski, M.; Sulc, M.; Sulej, R.; Suzuki, H.; Sznajder, P.; Takekawa, S.; Ter Wolbeek, J.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Uhl, S.; Uman, I.; Vandenbroucke, M.; Virius, M.; Vondra, J.; Wang, L.; Weisrock, T.; Wilfert, M.; Windmolders, R.; Wiślicki, W.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Zhuravlev, N.; Ziembicki, M.

    2013-11-01

    The differential cross section for the production of charged hadrons with high transverse momenta in the scattering of 160GeV/c muons off nucleons at low photon virtualities has been measured at the COMPASS experiment at CERN. The results, which cover transverse momenta from 1.1GeV/c to 3.6GeV/c, are compared to a perturbative quantum chromodynamics (pQCD) calculation, in order to evaluate the applicability of pQCD to this process in the kinematic domain of the experiment. The shape of the calculated differential cross section as a function of transverse momentum is found to be in good agreement with the experimental data, but the absolute scale is underestimated by next-to-leading order pQCD. The inclusion of all-order resummation of large logarithmic threshold corrections reduces the discrepancy from a factor of 3 to 4 to a factor of 2. The dependence of the cross section on the pseudorapidity and on the virtual photon energy fraction is investigated. Finally the dependence on the charge of the hadrons is discussed.

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

    SciTech Connect

    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 × 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 cm2p = 2.9 × 10–39 cm2) at 33 GeV/c2. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.

  7. Weak η production off the nucleon

    NASA Astrophysics Data System (ADS)

    Alam, M. Rafi; Alvarez-Ruso, L.; Athar, M. Sajjad; Vacas, M. J. Vicente

    2015-05-01

    The weak η-meson production off the nucleon induced by (anti)neutrinos is studied at low and intermediate energies, the range of interest for several ongoing and future neutrino experiments. We consider Born diagrams and the excitation of N* (1535)S11 and N* (1650)S11 resonances. The vector part of the N-S11 transition form factors has been obtained from the MAID helicity amplitudes while the poorly known axial part is constrained with the help of the partial conservation of the axial current (PCAC) and assuming the pion-pole dominance of the pseudoscalar form factor.

  8. Weak η production off the nucleon

    SciTech Connect

    Alam, M. Rafi; Athar, M. Sajjad; Alvarez-Ruso, L.; Vacas, M. J. Vicente

    2015-05-15

    The weak η-meson production off the nucleon induced by (anti)neutrinos is studied at low and intermediate energies, the range of interest for several ongoing and future neutrino experiments. We consider Born diagrams and the excitation of N{sup *} (1535)S{sub 11} and N{sup *} (1650)S{sub 11} resonances. The vector part of the N-S{sub 11} transition form factors has been obtained from the MAID helicity amplitudes while the poorly known axial part is constrained with the help of the partial conservation of the axial current (PCAC) and assuming the pion-pole dominance of the pseudoscalar form factor.

  9. Neutrino and antineutrino inclusive charged-current cross section measurement with the MINOS near detector

    SciTech Connect

    Bhattacharya, Debdatta

    2009-01-01

    This thesis presents the measurement of energy dependence of the neutrino-nucleon inclusive charged current cross section on an isoscalar target in the range 3-50 GeV for neutrinos and 5-50 GeV energy range for antineutrinos. The data set was collected with the MINOS Near Detector using the wide band NuMI beam at Fermilab. The size of the charged current sample is 1.94 x 106 neutrino events and 1.60 x 105 antineutrino events. The flux has been extracted using a low hadronic energy sub-sample of the charged current events. The energy dependence of the cross section is obtained by dividing the charged current sample with the extracted flux. The neutrino and antineutrino cross section exhibits a linear dependence on energy at high energy but shows deviations from linear behavior at low energy. We also present a measurement of the ratio of antineutrino to neutrino inclusive cross section.

  10. Spin Structure of the Nucleon

    NASA Astrophysics Data System (ADS)

    Nezza, Pasquale Di

    2006-02-01

    HERMES is a second generation experiment to study the spin structure of the nucleon, in which measurements of the spin dependent properties of semi-inclusive deep-inelastic lepton scattering are emphasized. The first experimental results from measurements of single-spin asymmetries for pions and kaons in deep-inelastic scattering with transverse target polarization are discussed. Longitudinally polarized beam and target data provide information on the flavor decomposition of the polarized quark distributions in the nucleon and a first glimpse of the gluon polarization. Moreover, first preliminary results for the unpolarized ep → enπ+ total cross section are presented and compared to Generalized Parton Distribution calculations.

  11. Two Nucleons on a Lattice

    SciTech Connect

    S.R. Beane; P.F.Bedaque; A. Parreno; M.J. Savage

    2004-04-01

    The two-nucleon sector is near an infrared fixed point of QCD and as a result the S-wave scattering lengths are unnaturally large compared to the effective ranges and shape parameters. It is usually assumed that a lattice QCD simulation of the two-nucleon sector will require a lattice that is much larger than the scattering lengths in order to extract quantitative information. In this paper we point out that this does not have to be the case: lattice QCD simulations on much smaller lattices will produce rigorous results for nuclear physics.

  12. Is Deuterium Nuclear Fusion Catalyzed by Antineutrinos?

    NASA Astrophysics Data System (ADS)

    Shomer, Isaac

    2010-02-01

    The hypothesis of Fischbach and Jenkins that neutrinos emitted from the sun accelerate radioactive decay is noted. It is thought that neutrinos accelerate beta decay by reacting with neutron-rich nuclides to form a beta particle and a daughter product, with no antineutrino emitted. Conversely, it is proposed that antineutrinos can react with proton-rich nuclides to cause positron decay, with no neutrino emitted. It is also proposed that the nuclear fusion of the hydrogen bomb is triggered not only by the energy of the igniting fission bomb, but by the antineutrinos created by the rapid beta decay of the daughter products in the fission process. The contemplated mechanism for antineutrino initiated fusion is the following: 1. The antineutrinos from the fission daughter products cause positron decay of deuterium by the process outlined above. 2. In a later fusion step, these positrons subsequently react with neutrons in deuterium to create antineutrinos. Electrons are unavailable to annihilate positrons in the plasma of the hydrogen bomb. 3. These antineutrinos thereafter react with more deuterium to form positrons, thereby propagating a chain reaction. )

  13. Reactor monitoring and safeguards using antineutrino detectors

    SciTech Connect

    Bowden, N S

    2008-09-07

    Nuclear reactors have served as the antineutrino source for many fundamental physics experiments. The techniques developed by these experiments make it possible to use these very weakly interacting particles for a practical purpose. The large flux of antineutrinos that leaves a reactor carries information about two quantities of interest for safeguards: the reactor power and fissile inventory. Measurements made with antineutrino detectors could therefore offer an alternative means for verifying the power history and fissile inventory of a reactors, as part of International Atomic Energy Agency (IAEA) and other reactor safeguards regimes. Several efforts to develop this monitoring technique are underway across the globe.

  14. 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.

  15. Search for muon antineutrino disappearance due to sterile antineutrino oscillations with the MINOS experiment

    NASA Astrophysics Data System (ADS)

    Chen, R.; Todd, J.; Poonthottathil, N.; Sousa, A.; Evans, J.; MINOS/MINOS+ Collaboration

    2017-09-01

    Three-flavour neutrino mixing has successfully explained a wide range of neutrino oscillation data. However, results such as the electron antineutrino appearance excesses seen by LSND and MiniBooNE can be explained in terms of neutrino oscillations adding a sterile neutrino at a larger mass scale than the existing three flavour mass states. MINOS is a two-detector, long-baseline neutrino oscillation experiment that uses magnetized tracker-calorimeter detectors to measure the energy and composition of the NuMI neutrino beam. These magnetized detectors give MINOS a unique ability to be able to separate muon neutrino and antineutrino interactions. Using data taken with the NuMI beam configured in antineutrino mode, MINOS is able to search for sterile antineutrinos by looking for the disappearance of muon antineutrinos over its 734 km baseline. The sterile antineutrino signature would be seen as modulations at high energy in the charged-current muon antineutrino spectrum. We present the first MINOS results constraining 3+1 sterile antineutrino oscillations, using a combination of 3.36×1020 protons-on-target (POT) of antineutrino-enhanced beam data, and 10.56×1020 protons-on-target (POT) of neutrino-dominated beam data. These results are compared with existing constraints and future improvements to the searches are discussed.

  16. Electromagnetic Form Factors of the Nucleon

    SciTech Connect

    Kees de Jager

    2004-06-01

    The experimental and theoretical status of elastic electron scattering from the nucleon is reviewed. As a consequence of new experimental facilities and new theoretical insights, this subject is advancing with unprecedented precision.

  17. Nucleon measurements at the precision frontier

    SciTech Connect

    Carlson, Carl E.

    2013-11-07

    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.

  18. Strangeness contributions to nucleon form factors

    SciTech Connect

    Ross Young

    2006-09-11

    We review a recent theoretical determination of the strange quark content of the electromagnetic form factors of the nucleon. These are compared with a global analysis of current experimental measurements in parity-violating electron scattering.

  19. Model-independent analysis of Airy structures in the {sup 16}O+{sup 12}C and {sup 16}O+{sup 16}O elastic scattering differential cross sections at 13-22 MeV/nucleon

    SciTech Connect

    Korda, V. Yu.; Molev, A. S.; Klepikov, V. F.; Korda, L. P.

    2009-02-15

    We present the results of the model-independent analysis of Airy structures in the {sup 16}O+{sup 12}C and {sup 16}O+{sup 16}O elastic scattering differential cross sections at 13-22 MeV/nucleon. The analysis has been performed with help of a procedure based on the application of the evolutionary algorithm, which enables us to extract the nuclear part of the scattering matrix S{sub N}(l) as a complex function of angular momentum directly from the scattering data. Contrary to the commonly used model approaches, our procedure gives the better fits and leads to the S{sub N}(l) representations defined by the moduli and the nuclear phases exhibiting smooth monotonic dependencies on l.

  20. Total nucleon-nucleon cross sections in large Nc QCD

    NASA Astrophysics Data System (ADS)

    Cohen, Thomas D.; Gelman, Boris A.

    2012-02-01

    We use contracted spin-flavor symmetry which emerges in the large Nc limit of QCD to obtain relations between proton-proton and proton-neutron total cross sections for both polarized and unpolarized scattering. The formalism used is valid in the semiclassical regime in which the relative momentum of the incident nucleons is much larger than the inverse size of the nucleon, provided that certain technical assumptions are met. The relations should be phenomenologically useful provided that Nc=3 is sufficiently large so that the large Nc results have at least semiquantitative predictive power. The relations are model independent in the sense that they depend on properties of large Nc QCD only and not on any particular model-dependent details of the nucleon-nucleon interaction. We compare these model-independent results to the experimental data. We find the relation for spin-unpolarized scattering works well empirically. For the case of polarized scattering, the data are consistent with the relations, but the cross sections are too small to make sharp predictions.

  1. Antineutrino induced Λ (1405 ) production off the proton

    NASA Astrophysics Data System (ADS)

    Ren, Xiu-Lei; Oset, E.; Alvarez-Ruso, L.; Vicente Vacas, M. J.

    2015-04-01

    We have studied the strangeness-changing antineutrino-induced reactions ν¯lp →l+ϕ B , with ϕ B =K-p , K¯0n , π0Λ , π0Σ0 , η Λ , η Σ0 , π+Σ- , π-Σ+ , K+Ξ- , and K0Ξ0 , using a chiral unitary approach. These ten coupled channels are allowed to interact strongly, using a kernel derived from the chiral Lagrangians. This interaction generates two Λ (1405 ) poles, leading to a clear single peak in the π Σ invariant mass distributions. At backward scattering angles in the center-of-mass frame, ν¯μp →μ+π0Σ0 is dominated by the Λ (1405 ) state at around 1420 MeV while the lighter state becomes relevant as the angle decreases, leading to an asymmetric line shape. In addition, there are substantial differences in the shape of π Σ invariant mass distributions for the three charge channels. If observed, these differences would provide valuable information on a claimed isospin I =1 , strangeness S =-1 baryonic state around 1400 MeV. Integrated cross sections have been obtained for the π Σ and K ¯N channels and the impact of unitarization in the results has been investigated. The number of events with Λ (1405 ) excitation in ν¯μp collisions in the recent antineutrino run at the Main Injector Experiment for ν -A (MINERνA) has also been obtained. We find that this reaction channel is relevant enough to be investigated experimentally and to be taken into account in the simulation models of future experiments with antineutrino beams.

  2. Impact of nucleon-nucleon bremsstrahlung rates beyond one-pion exchange

    NASA Astrophysics Data System (ADS)

    Bartl, A.; Bollig, R.; Janka, H.-T.; Schwenk, A.

    2016-10-01

    Neutrino-pair production and annihilation through nucleon-nucleon bremsstrahlung is included in current supernova simulations by rates that are based on the one-pion-exchange approximation. Here we explore the consequences of bremsstrahlung rates based on modern nuclear interactions for proto-neutron star cooling and the corresponding neutrino emission. We find that despite a reduction of the bremsstrahlung emission by a factor of 2-5 in the neutrinospheric region, models with the improved treatment exhibit only ≲5 % changes of the neutrino luminosities and an increase of ≲0.7 MeV of the average energies of the radiated neutrino spectra, with the largest effects for the antineutrinos of all flavors and at late times. Overall, the proto-neutron star cooling evolution is slowed down modestly by ≲0.5 - 1 s .

  3. Terrestrial and Reactor Antineutrinos in Borexino

    NASA Astrophysics Data System (ADS)

    Chen, M. C.; Calaprice, F. P.; Rothschild, C. G.

    1998-10-01

    The Earth is an abundant source of antineutrinos coming from the decay of radioactive elements in the mantle and crust. Detecting these antineutrinos is a challenge due to their small cross section and low energies. The Borexino solar neutrino experiment will also be an excellent detector for barν_e. With 300 tons of ultra-low-background liquid scintillator, surrounded by an efficient muon veto, the inverse-β-decay reaction: barνe + p arrow e^+ + n (Q = 1.8 MeV), can be exploited to detect terrestrial antineutrinos from the uranium and thorium decay chains, with little background. A direct measurement of the total uranium and thorium abundance would establish important geophysical constraints on the heat generation and thermal history of the Earth. Starting with the most recent uranium and thorium distribution and abundance data, and employing a global map of crustal type and thickness, we calculated the antineutrino fluxes for several sites. We estimate a terrestrial antineutrino event rate in Borexino of 10 events per year. This small signal can be distinguished over the neutrino background from the world's nuclear power reactors by measuring the positron energy spectrum from the barνe events. The possibility to perform a long-baseline oscillation experiment, reaching Δ m^2 ≈ 10-6 eV^2, using the nuclear reactors in Europe will also be discussed.

  4. Weak charged and neutral current induced one pion production off the nucleon

    NASA Astrophysics Data System (ADS)

    Rafi Alam, M.; Sajjad Athar, M.; Chauhan, S.; Singh, S. K.

    2016-02-01

    We present a study of neutrino/antineutrino induced charged current (CC) and neutral current (NC) single pion production (SPP) off the nucleon. For this, we have considered P33(1232) resonance, nonresonant background (NRB) terms, other higher resonances like P11(1440), S11(1535), D13(1520), S11(1650) and P13(1720). For the NRB terms a microscopic approach based on SU(2) nonlinear sigma model has been used. The vector form factors for the resonances are obtained by using the relationship between the electromagnetic resonance form factors and helicity amplitudes provided by MAID. Axial coupling C5A(0) in the case of P33(1232) resonance is obtained by fitting the ANL and BNL ν-deuteron reanalyzed scattering data. The results are presented with and without deuteron effect for the total scattering cross-sections for all possible channels, viz. νl(ν¯l)+N → l-(l+)+N‧+πi and νl(ν¯l)+N → νl(ν¯l)+N‧ + πi, where N,N‧ = p,n, πi = π± or π0 and l = e,μ.

  5. A Direction-Sensitive Detector for Electron Antineutrinos

    SciTech Connect

    Brooks, F. D.; Drosg, M.; Smit, F. D.

    2011-12-13

    A modular design is proposed for an electron antineutrino detector based on boron-doped liquid scintillator. Tests have been carried out on small detector systems using neutrons to simulate the antineutrino detection signature. Results from these tests are reported, and the possibility of using a larger system of similar design to detect reactor antineutrinos is discussed.

  6. Some measurements for determining strangeness matrix elements in the nucleon

    SciTech Connect

    Henley, E.M.; Pollock, S.J.; Ying, S.; Frederico, T.; Krein,; Williams, A.G.

    1991-12-31

    Some experiments to measure strangeness matrix elements of the proton are proposed. Two of these suggestions are described in some detail, namely electro-production of phi mesons and the difference between neutrino and antineutrino scattering for isospin zero targets such as deuterium.

  7. Some measurements for determining strangeness matrix elements in the nucleon

    SciTech Connect

    Henley, E.M.; Pollock, S.J.; Ying, S. ); Frederico, T. , Sao Jose dos Campos, SP . Inst. de Estudos Avancados); Krein, . Inst. de Fisica Teorica); Williams, A.G. )

    1991-01-01

    Some experiments to measure strangeness matrix elements of the proton are proposed. Two of these suggestions are described in some detail, namely electro-production of phi mesons and the difference between neutrino and antineutrino scattering for isospin zero targets such as deuterium.

  8. Nucleon-nucleon theory and phenomenology

    SciTech Connect

    Signell, P.

    1981-03-01

    This project involves five inter-related subprojects: (1) derivation of the intermediate range nucleon-nucleon interaction using a new method that utilizes much shorter and simpler analytic continuation through the unphysical region that lies between the ..pi..N and ..pi pi.. physical regions of the N anti N ..-->.. ..pi pi.. amplitude (with significantly improved accuracy for the nucleon-nucleon interaction); (2) construction of a short range phenomenological potential that, with the theoretical part mentioned above, gives a precise fit to the nucleon-nucleon data and is parameterized for easy use in nucleon calculations; (3) phase shift analyses of the world data below 400 MeV, especially the large amount of very precise data below 20 MeV and the new data near 55 MeV that have never been analyzed properly; (4) the introduction of a K-matrix formulation of the Optimal Polynomial Expansion in order to accelerate convergence of the partial wave series at LAMPF energies; and (5) setting up of a cooperatively evaluated permanent nucleon-nucleon data bank in the 0-1200 MeV range that can be used by all nucleon-nucleon reseachers.

  9. Recent Developments in Neutrino/Antineutrino-Nucleus Interactions

    SciTech Connect

    Morfín, Jorge G.; Nieves, Juan; Sobczyk, Jan T.

    2012-01-01

    Recent experimental results and developments in the theoretical treatment of neutrino-nucleus interactions in the energy range of 1–10 GeV are discussed. Difficulties in extracting neutrino-nucleon cross sections from neutrino-nucleus scattering data are explained and significance of understanding nuclear effects for neutrino oscillation experiments is stressed. Detailed discussions of the status of two-body current contribution in the kinematic region dominated by quasielastic scattering and specific features of partonic nuclear effects in weak DIS scattering are presented.

  10. Recent Developments in Neutrino/Antineutrino-Nucleus Interactions

    DOE PAGES

    Morfín, Jorge G.; Nieves, Juan; Sobczyk, Jan T.

    2012-01-01

    Recent experimental results and developments in the theoretical treatment of neutrino-nucleus interactions in the energy range of 1–10 GeV are discussed. Difficulties in extracting neutrino-nucleon cross sections from neutrino-nucleus scattering data are explained and significance of understanding nuclear effects for neutrino oscillation experiments is stressed. Detailed discussions of the status of two-body current contribution in the kinematic region dominated by quasielastic scattering and specific features of partonic nuclear effects in weak DIS scattering are presented.

  11. Chiral perturbation theory with nucleons

    SciTech Connect

    Meissner, U.G.

    1991-09-01

    I review the constraints posed on the interactions of pions, nucleons and photons by the spontaneously broken chiral symmetry of QCD. The framework to perform these calculations, chiral perturbation theory, is briefly discussed in the meson sector. The method is a simultaneous expansion of the Greens functions in powers of external moments and quark masses around the massless case, the chiral limit. To perform this expansion, use is made of a phenomenological Lagrangian which encodes the Ward-identities and pertinent symmetries of QCD. The concept of chiral power counting is introduced. The main part of the lectures of consists in describing how to include baryons (nucleons) and how the chiral structure is modified by the fact that the nucleon mass in the chiral limit does not vanish. Particular emphasis is put on working out applications to show the strengths and limitations of the methods. Some processes which are discussed are threshold photopion production, low-energy compton scattering off nucleons, {pi}N scattering and the {sigma}-term. The implications of the broken chiral symmetry on the nuclear forces are briefly described. An alternative approach, in which the baryons are treated as very heavy fields, is touched upon.

  12. Hybrid method to resolve the neutrino mass hierarchy by supernova (anti)neutrino induced reactions

    SciTech Connect

    Vale, D.; Rauscher, T.; Paar, N. E-mail: Thomas.Rauscher@unibas.ch

    2016-02-01

    We introduce a hybrid method to determine the neutrino mass hierarchy by simultaneous measurements of responses of at least two detectors to antineutrino and neutrino fluxes from accretion and cooling phases of core-collapse supernovae. The (anti)neutrino-nucleus cross sections for {sup 56}Fe and {sup 208}Pb are calculated in the framework of the relativistic nuclear energy density functional and weak interaction Hamiltonian, while the cross sections for inelastic scattering on free protons p(ν-bar {sub e},e{sup +})n are obtained using heavy-baryon chiral perturbation theory. The modelling of (anti)neutrino fluxes emitted from a protoneutron star in a core-collapse supernova include collective and Mikheyev-Smirnov-Wolfenstein effects inside the exploding star. The particle emission rates from the elementary decay modes of the daughter nuclei are calculated for normal and inverted neutrino mass hierarchy. It is shown that simultaneous use of (anti)neutrino detectors with different target material allows to determine the neutrino mass hierarchy from the ratios of ν{sub e}- and ν-bar {sub e}-induced particle emissions. This hybrid method favors neutrinos from the supernova cooling phase and the implementation of detectors with heavier target nuclei ({sup 208}Pb) for the neutrino sector, while for antineutrinos the use of free protons in mineral oil or water is the appropriate choice.

  13. IceCube PeV cascade events initiated by electron-antineutrinos at Glashow resonance

    NASA Astrophysics Data System (ADS)

    Barger, Vernon; Learned, John; Pakvasa, Sandip

    2013-02-01

    We propose an interpretation of the two neutrino initiated cascade events with PeV energies observed by IceCube: Ultrahigh energy cosmic ray protons (or Fe nuclei) scatter on cosmic microwave background photons through the Delta-resonance (the Berezinsky-Zatsepin process) yielding charged pions and neutrons. The neutron decays give electron-antineutrinos which undergo neutrino oscillations to populate all antineutrino flavors, but the electron-antineutrino flux remains dominant. At 6.3 PeV electron-antineutrino energy their annihilation on electrons in the IceCube detector is enhanced by the Glashow resonance (the W-boson) whose decays can give the PeV showers observed in the IceCube detector. The two observed showers with ˜1PeV energies would need to be from W leptonic decays to electrons and taus. An order of magnitude higher event rate of showers at 6.3 PeV is predicted from W to hadron decays. This interpretation can be tested in the near term. It has significant physics implications on the origin of the highest energy cosmic rays, since neutrino events and cosmic ray events likely share a common origin.

  14. Neutrino-Nucleon Interactions and Lattice QCD

    NASA Astrophysics Data System (ADS)

    Hill, Richard; Kronfeld, Andreas; Meyer, Aaron

    2016-03-01

    We address techniques to make the theoretical underpinning of neutrino-nucleon scattering more robust. We see this foundation as a necessary step to disentangle fundamental physics (such as neutrino oscillation parameters) from nuclear effects. We address a reanalysis of old experiments with elementary targets, model-independent parametrizations of nucleon form factors based on analyticity, and lattice QCD calculations of the form factors. speaker.

  15. Reactor antineutrino fluxes – Status and challenges

    DOE PAGES

    Huber, Patrick

    2016-04-22

    Here, we describe the current understanding of reactor antineutrino fluxes and point out some recent developments. This is not intended to be a complete review of this vast topic but merely a selection of observations and remarks, which despite their incompleteness, will highlight the status and the challenges of this field.

  16. Antineutrino flux and spectrum calculation for spent nuclear fuel for the Daya Bay antineutrino experiment

    NASA Astrophysics Data System (ADS)

    Ma, X. B.; Zhao, Y. F.; Chen, Y. X.; Zhong, W. L.; An, F. P.

    2017-10-01

    The antineutrino flux from spent nuclear fuel (SNF) is an important source of uncertainty when making estimates of a reactor neutrino flux. However, to determine the contribution from SNF, sufficient data is needed such as the amount of spent fuel in the pool, the time after discharged from the reactor core, the burnup of each assembly, and the antineutrino spectrum of each isotope in the SNF. A method to calculate this contribution is proposed. A reactor simulation code verified against experimental data has been used to simulate fuel depletion by taking into account more than 2000 isotopes and fission products, the quantity of SNF in each of the six spent fuel pools, and the time variation of the antineutrino spectra after SNF discharging from the core. Results show that the SNF contribution to the total antineutrino flux is about 0.26%-0.34%, and the shutdown impact is about 20%. The SNF spectrum alters the softer part of the antineutrino spectra, and the maximum contribution from the SNF is about 3.0%. Nevertheless, there is an 18% difference between the line evaluate method and under evaluate method. In addition, non-equilibrium effects are also discussed, and the results are compatible considering the uncertainties.

  17. Cooperative Monitoring of Reactors with Antineutrino Detectors

    NASA Astrophysics Data System (ADS)

    Keefer, Greg

    2010-11-01

    The current state-of-the-art in antineutrino detection is such that it is now possible to monitor the operational status, power levels and fissile content of nuclear reactors in real-time at standoff distances of a few tens of meters, well outside of the reactor containment. This has been demonstrated at civilian power reactors in both Russia and the United States. In the last few years, the International Atomic Energy Agency has begun to consider the potential of this technology for its reactor safeguards regime. In this talk, I describe the state of the art for this application, and emphasize the natural overlap with ongoing efforts in fundamental physics to measure the oscillations of antineutrinos using reactor sources.

  18. Antineutrino and gamma emission from the OSIRIS research reactor

    NASA Astrophysics Data System (ADS)

    Giot, Lydie; Fallot, Muriel

    2017-09-01

    For the first time, the summation method has been coupled with a complete reactor model, in order to predict the antineutrino emission of a research reactor. This work, discussed in the first part of this paper, allows us to predict the low energy part of the antineutrino spectrum, evidencing the important contribution of actinides to the antineutrino emission. Experimental conditions at short distance from research reactors are challenging, because the reactor itself produces huge gamma background that induce accidental and correlated backgrounds in an antineutrino target. The understanding of this background is of utmost importance and triggered the second part of the work presented here.

  19. Reactor antineutrino detector iDREAM.

    NASA Astrophysics Data System (ADS)

    Gromov, M. B.; Lukyanchenko, G. A.; Novikova, G. J.; Obinyakov, B. A.; Oralbaev, A. Y.; Skorokhvatov, M. D.; Sukhotin, S. V.; Chepurnov, A. S.; Etenko, A. V.

    2017-09-01

    Industrial Detector for Reactor Antineutrino Monitoring (iDREAM) is a compact (≈ 3.5m 2) industrial electron antineutrino spectrometer. It is dedicated for remote monitoring of PWR reactor operational modes by neutrino method in real-time. Measurements of antineutrino flux from PWR allow to estimate a fuel mixture in active zone and to check the status of the reactor campaign for non-proliferation purposes. LAB-based gadolinium doped scintillator is exploited as a target. Multizone architecture of the detector with gamma-catcher surrounding fiducial volume and plastic muon veto above and below ensure high efficiency of IBD detection and background suppression. DAQ is based on Flash ADC with PSD discrimination algorithms while digital trigger is programmable and flexible due to FPGA. The prototype detector was started up in 2014. Preliminary works on registration Cerenkov radiation produced by cosmic muons were established with distilled water inside the detector in order to test electronic and slow control systems. Also in parallel a long-term measurements with different scintillator samples were conducted.

  20. Nucleon-nucleon interaction: A typical/concise review

    NASA Astrophysics Data System (ADS)

    Naghdi, M.

    2014-09-01

    Nearly a recent century of work is divided to Nucleon-Nucleon ( NN) interaction issue. We review some overall perspectives of NN interaction with a brief discussion about deuteron, general structure and symmetries of NN Lagrangian as well as equations of motion and solutions. Meanwhile, the main NN interaction models, as frameworks to build NN potentials, are reviewed concisely. We try to include and study almost all well-known potentials in a similar way, discuss more on various commonly used plain forms for two-nucleon interaction with an emphasis on the phenomenological and meson-exchange potentials as well as the constituent-quark potentials and new ones based on chiral effective field theory and working in coordinate-space mostly. The potentials are constructed in a way that fit NN scattering data, phase shifts, and are also compared in this way usually. An extra goal of this study is to start comparing various potentials forms in a unified manner. So, we also comment on the advantages and disadvantages of the models and potentials partly with reference to some relevant works and probable future studies.

  1. Future directions for probing two and three nucleon short-range correlations at high energies

    SciTech Connect

    Frankfurt, Leonid; Sargsian, Misak; Strikman, Mark

    2008-10-13

    We summarize recent progress in the studies of the short-rang correlations (SRC) in nuclei in high energy electron and hadron nucleus scattering and suggest directions for the future high energy studies aimed at establishing detailed structure of two-nucleon SRCs, revealing structure of three nucleon SRC correlations and discovering non-nucleonic degrees of freedom in nuclei.

  2. Mapping High x Structure of the Nucleon: which data is missing?

    SciTech Connect

    Smirnov, G.I.

    2005-02-10

    The analysis of numerous experiments on lepton-nucleon and lepton-nucleus deep inelastic scattering reveals several non-trivial features of the nucleon structure, which are particularly interesting in the range of large Bjorken x (x > 0.8). It is shown that new data form the lightest nuclei can provide decisive information needed for the understanding of the nucleon structure.

  3. Elastic scattering phenomenology

    NASA Astrophysics Data System (ADS)

    Mackintosh, R. S.

    2017-04-01

    We argue that, in many situations, fits to elastic scattering data that were historically, and frequently still are, considered "good", are not justifiably so describable. Information about the dynamics of nucleon-nucleus and nucleus-nucleus scattering is lost when elastic scattering phenomenology is insufficiently ambitious. It is argued that in many situations, an alternative approach is appropriate for the phenomenology of nuclear elastic scattering of nucleons and other light nuclei. The approach affords an appropriate means of evaluating folding models, one that fully exploits available empirical data. It is particularly applicable for nucleons and other light ions.

  4. Borexino's search for low-energy neutrino and antineutrino signals correlated with gamma-ray bursts

    NASA Astrophysics Data System (ADS)

    Agostini, M.; Altenmüller, K.; Appel, S.; Atroshchenko, V.; Bellini, G.; Benziger, J.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Calaprice, F.; Caminata, A.; Carlini, M.; Cavalcante, P.; Chepurnov, A.; Choi, K.; D'Angelo, D.; Davini, S.; de Kerret, H.; Derbin, A.; Di Noto, L.; Drachnev, I.; Etenko, A.; Fomenko, K.; Franco, D.; Gabriele, F.; Galbiati, C.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Gromov, M.; Hagner, C.; Hungerford, E.; Ianni, Aldo; Ianni, Andrea; Jany, A.; Jedrzejczak, K.; Jeschke, D.; Kobychev, V.; Korablev, D.; Korga, G.; Kryn, D.; Laubenstein, M.; Lehnert, B.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Manuzio, G.; Marcocci, S.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Montuschi, M.; Mosteiro, P.; Muratova, V.; Neumair, B.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Roncin, R.; Rossi, N.; Schönert, S.; Semenov, D.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Thurn, J.; Toropova, M.; Unzhakov, E.; Vishneva, A.; Vogelaar, R. B.; von Feilitzsch, F.; Wang, H.; Weinz, S.; Winter, J.; Wojcik, M.; Wurm, M.; Yokley, Z.; Zaimidoroga, O.; Zavatarelli, S.; Zuber, K.; Zuzel, G.

    2017-01-01

    A search for neutrino and antineutrino events correlated with 2350 gamma-ray bursts (GRBs) is performed with Borexino data collected between December 2007 and November 2015. No statistically significant excess over background is observed. We look for electron antineutrinos (νbare) that inverse beta decay on protons with energies from 1.8 MeV to 15 MeV and set the best limit on the neutrino fluence from GRBs below 8 MeV. The signals from neutrinos and antineutrinos from GRBs that scatter on electrons are also searched for, a detection channel made possible by the particularly radio-pure scintillator of Borexino. We obtain currently the best limits on the neutrino fluence of all flavors and species below 7 MeV. Finally, time correlations between GRBs and bursts of events are investigated. Our analysis combines two semi-independent data acquisition systems for the first time: the primary Borexino readout optimized for solar neutrino physics up to a few MeV, and a fast waveform digitizer system tuned for events above 1 MeV.

  5. Uncertainty analysis of fission fraction for reactor antineutrino experiments

    NASA Astrophysics Data System (ADS)

    Ma, X. B.; Lu, F.; Wang, L. Z.; Chen, Y. X.; Zhong, W. L.; An, F. P.

    2016-06-01

    Reactor simulation is an important source of uncertainties for a reactor neutrino experiment. Therefore, how to evaluate the antineutrino flux uncertainty results from reactor simulation is an important question. In this study, a method of the antineutrino flux uncertainty result from reactor simulation was proposed by considering the correlation coefficient. In order to use this method in the Daya Bay antineutrino experiment, the open source code DRAGON was improved and used for obtaining the fission fraction and correlation coefficient. The average fission fraction between DRAGON and SCIENCE code was compared and the difference was less than 5% for all the four isotopes. The uncertainty of fission fraction was evaluated by comparing simulation atomic density of four main isotopes with Takahama-3 experiment measurement. After that, the uncertainty of the antineutrino flux results from reactor simulation was evaluated as 0.6% per core for Daya Bay antineutrino experiment.

  6. Strange nucleon form-factors

    NASA Astrophysics Data System (ADS)

    Maas, F. E.; Paschke, K. D.

    2017-07-01

    A broad program measuring parity-violation in electron-nuclear scattering has now provided a large set of precision data on the weak-neutral-current form-factors of the proton. Under comparison with well-measured electromagnetic nucleon form-factors, these measurements reveal the role of the strange quark sea on the low-energy interactions of the proton through the strange-quark-flavor vector form-factors. This review will describe the experimental program and the implications of the global data for the strange-quark vector form-factors. We present here a new fit to the world data.

  7. Personal History of Nucleon Polarization Experiments

    DOE R&D Accomplishments Database

    Chamberlain, O.

    1984-09-01

    The history of nucleon scattering experiments is reviewed, starting with the observation of large proton polarizations in scattering from light elements such as carbon, and ending with the acceleration of polarized proton beams in high-energy synchrotrons. Special mention is made about significant contributions made by C.L. Oxley, L. Wolfenstein, R.D. Tripp, T. Ypsilantis, A. Abragam, M. Borghini, T. Niinikoski, Froissart, Stora, A.D. Krisch, and L.G. Ratner.

  8. Four nucleon systems: a zoom to the open problems in nuclear interaction

    SciTech Connect

    Lazauskas, R.

    2005-05-06

    Faddeev-Yakubovski equations in configuration space are used to solve four nucleon problem for bound and scattering states. Different realistic interaction models are tested, elucidating open problems in the description of nuclear interaction. On one hand, by example of nonlocal Doleschall potential, we reveal possibility of reducing three-nucleon force. On the other hand we disclose discrepancies in describing n+3H resonance, which seems to be hardly related with off-shell structure of nucleon-nucleon interaction.

  9. Compton scattering by nuclei

    NASA Astrophysics Data System (ADS)

    Hütt, M.-Th.; L'vov, A. I.; Milstein, A. I.; Schumacher, M.

    2000-01-01

    The concept of Compton scattering by even-even nuclei from giant-resonance to nucleon-resonance energies and the status of experimental and theoretical researches in this field are outlined. The description of Compton scattering by nuclei starts from different complementary approaches, namely from second-order S-matrix and from dispersion theories. Making use of these, it is possible to incorporate into the predicted nuclear scattering amplitudes all the information available from other channels, viz. photon-nucleon and photon-meson channels, and to efficiently make use of models of the nucleon, the nucleus and the nucleon-nucleon interaction. The total photoabsorption cross section constrains the nuclear scattering amplitude in the forward direction. The specific information obtained from Compton scattering therefore stems from the angular dependence of the nuclear scattering amplitude, providing detailed insight into the dynamics of the nuclear and nucleon degrees of freedom and into the interplay between them. Nuclear Compton scattering in the giant-resonance energy-region provides information on the dynamical properties of the in-medium mass of the nucleon. Most prominently, the electromagnetic polarizabilities of the nucleon in the nuclear medium can be extracted from nuclear Compton scattering data obtained in the quasi-deuteron energy-region. In our description of this latter process special emphasis is laid upon the exploration of many-body and two-body effects entering into the nuclear dynamics. Recent results are presented for two-body effects due to the mesonic seagull amplitude and due to the excitation of nucleon internal degrees of freedom accompanied by meson exchanges. Due to these studies the in-medium electromagnetic polarizabilities are by now well understood, whereas the understanding of nuclear Compton scattering in the Δ-resonance range is only at the beginning. Furthermore, phenomenological methods how to include retardation effects in the

  10. Measurement of the antineutrino to neutrino charged-current interaction cross section ratio in MINERvA

    DOE PAGES

    Ren, L.; Aliaga, L.; Altinok, O.; ...

    2017-04-14

    Here, we present measurements of the neutrino and antineutrino total charged-current cross sections on carbon and their ratio using the MINERvA scintillator-tracker. The measurements span the energy range 2-22 GeV and were performed using forward and reversed horn focusing modes of the Fermilab low-energy NuMI beam to obtain large neutrino and antineutrino samples. The flux is obtained using a sub-sample of charged-current events at low hadronic energy transfer along with precise higher energy external neutrino cross section data overlapping with our energy range between 12-22 GeV. We also report on the antineutrino-neutrino cross section ratio, Rcc, which does not rely on external normalization information. Our ratio measurement, obtained within the same experiment using the same technique, benefits from the cancellation of common sample systematic uncertainties and reaches a precision of 5% at low energy. Our results for the antineutrino-nucleus scattering cross section and for Rcc are the most precise to date in the energy rangemore » $$E_{\

  11. Measurement of the antineutrino to neutrino charged-current interaction cross section ratio in MINERvA

    NASA Astrophysics Data System (ADS)

    Ren, L.; Aliaga, L.; Altinok, O.; Bellantoni, L.; Bercellie, A.; Betancourt, M.; Bodek, A.; Bravar, A.; Budd, H.; Cai, T.; Carneiro, M. F.; da Motta, H.; Devan, J.; Dytman, S. A.; Díaz, G. A.; Eberly, B.; Endress, E.; Felix, J.; Fields, L.; Fine, R.; Gago, A. M.; Galindo, R.; Gallagher, H.; Ghosh, A.; Golan, T.; Gran, R.; Han, J. Y.; Harris, D. A.; Hurtado, K.; Kiveni, M.; Kleykamp, J.; Kordosky, M.; Le, T.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; Martinez Caicedo, D. A.; McFarland, K. S.; McGivern, C. L.; McGowan, A. M.; Messerly, B.; Miller, J.; Mislivec, A.; Morfín, J. G.; Mousseau, J.; Naples, D.; Nelson, J. K.; Norrick, A.; Nuruzzaman, Paolone, V.; Park, J.; Patrick, C. E.; Perdue, G. N.; Ramírez, M. A.; Ransome, R. D.; Ray, H.; Rimal, D.; Rodrigues, P. A.; Ruterbories, D.; Schellman, H.; Solano Salinas, C. J.; Sultana, M.; Sánchez Falero, S.; Valencia, E.; Walton, T.; Wolcott, J.; Wospakrik, M.; Yaeggy, B.; MinerνA Collaboration

    2017-04-01

    We present measurements of the neutrino and antineutrino total charged-current cross sections on carbon and their ratio using the MINERvA scintillator-tracker. The measurements span the energy range 2-22 GeV and were performed using forward and reversed horn focusing modes of the Fermilab low-energy NuMI beam to obtain large neutrino and antineutrino samples. The flux is obtained using a subsample of charged-current events at low hadronic energy transfer along with precise higher energy external neutrino cross section data overlapping with our energy range between 12-22 GeV. We also report on the antineutrino-neutrino cross section ratio, RCC , which does not rely on external normalization information. Our ratio measurement, obtained within the same experiment using the same technique, benefits from the cancellation of common sample systematic uncertainties and reaches a precision of ˜5 % at low energy. Our results for the antineutrino-nucleus scattering cross section and for RCC are the most precise to date in the energy range Eν<6 GeV .

  12. Sensitivity of the halo nuclei-12C elastic scattering at incident nucleon energy 800 MeV to the halo density distribution

    NASA Astrophysics Data System (ADS)

    Hassan, M. A. M.; Nour El-Din, M. S. M.; Ellithi, A.; Hosny, H.; Salama, T. N. E.

    2017-10-01

    In the framework of Glauber optical limit approximation where Coulomb effect is taken into account, the elastic scattering differential cross section for halo nuclei with {}^{12}{C} at 800 MeV/N has been calculated. Its sensitivity to the halo densities and the root mean square of the core and halo is the main goal of the current study. The projectile nuclei are taken to be one-neutron and two-neutron halo. The calculations are carried out for Gaussian-Gaussian, Gaussian-Oscillator and Gaussian-2 s phenomenological densities for each considered projectile in the mass number range 6-29. Also included a comparison between the obtained results of phenomenological densities and the results within the microscopic densities LSSM of {}6{He} and {}^{11}{Li} and microscopic densities GCM of {}^{11}{Be} where the density of the target nucleus {}^{12}{C} obtained from electron-{}^{12}{C} scattering is used. The zero range approximation is considered in the calculations. We found that the sensitivity of elastic scattering differential cross section to the halo density is clear if the nucleus appears as two clear different clusters, core and halo.

  13. 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.

  14. Measurement of muon neutrino and antineutrino induced single neutral pion production cross sections

    SciTech Connect

    Anderson, Colin E.

    2011-05-01

    flux-averaged, total cross sections for NC 1π0 production on CH2 to be (4.76 ± 0.05stat ± 0.76sys) x 10-40 cm2/nucleon at ν> = 808 MeV for neutrino induced production and (1.48 ± 0.05stat ± 0.23sys) x 10-40 cm2/nucleon at ν> = 664 MeV for antineutrino induced production.

  15. Long Distance Reactor Antineutrino Flux Monitoring

    NASA Astrophysics Data System (ADS)

    Dazeley, Steven; Bergevin, Marc; Bernstein, Adam

    2015-10-01

    The feasibility of antineutrino detection as an unambiguous and unshieldable way to detect the presence of distant nuclear reactors has been studied. While KamLAND provided a proof of concept for long distance antineutrino detection, the feasibility of detecting single reactors at distances greater than 100 km has not yet been established. Even larger detectors than KamLAND would be required for such a project. Considerations such as light attenuation, environmental impact and cost, which favor water as a detection medium, become more important as detectors get larger. We have studied both the sensitivity of water based detection media as a monitoring tool, and the scientific impact such detectors might provide. A next generation water based detector may be able to contribute to important questions in neutrino physics, such as supernova neutrinos, sterile neutrino oscillations, and non standard electroweak interactions (using a nearby compact accelerator source), while also providing a highly sensitive, and inherently unshieldable reactor monitoring tool to the non proliferation community. In this talk I will present the predicted performance of an experimental non proliferation and high-energy physics program. Lawrence Livermore National Laboratory is operated by Lawrence Livermore National Security, LLC, for the U.S. Department of Energy, National Nuclear Security Administration under Contract DE-AC52-07NA27344. Release number LLNL-ABS-674192.

  16. Neutral pion production by charged-current antineutrino-nucleus interactions in MINERvA

    NASA Astrophysics Data System (ADS)

    Le, Trung; Minerva Collaboration

    2013-10-01

    MINERvA is a neutrino scattering experiment at the NuMI beamline of FNAL. It is a high resolution, fully active detector designed to study the interaction of neutrinos with nuclei. In addition to plastic scintillator, there are several other nuclear targets such as 4He, Fe, Pb, C, and H20 which allow detailed studies of the A dependence of neutrino cross sections. We present the preliminary results of the measurement of single neutral pion production by charged-current interactions of anti-neutrinos in plastic scintillator.

  17. About Hydrotechnical Laboratory, Professor Smorodinsky, and Nucleon-Nucleon Scattering

    NASA Astrophysics Data System (ADS)

    Ryndin, R. M.

    2013-06-01

    Yakov Abramovich Smorodinsky... memory brings me back to those far-off days when we first met in March 1952. We saw each other for the first time at the Hydrotechnical Laboratory (GTL) of the Academy of Sciences of the USSR, , where I obtained a position after graduation from The Physics Department of Leningrad State University. Already a well known professor, Yakov Abramovich (Ya.A.) was only eleven years older than me, a beginning physicist. Today, I would say that we were almost of the same age. We immediately liked each other, and worked closely together for 18 years until I moved back to St. Petersburg, at that time Leningrad, of course. I learned a lot from Ya.A. during those years: his intrinsic desire and ability to share his knowledge was a peculiarity of his talent...

  18. Study of Generalized Parton Distributions and Deeply Virtual Compton Scattering on the nucleon with the CLAS and CLAS12 detectors at the Jefferson Laboratory

    SciTech Connect

    Guegan, Baptiste

    2012-11-01

    The exclusive leptoproduction of a real photon is considered to be the "cleanest" way to access the Generalized Parton Distribution (GPD). This process is called Deeply Virtual Compton Scattering (DVCS) lN {yields} lN{gamma} , and is sensitive to all the four GPDs. Measuring the DVCS cross section is one of the main goals of this thesis. In this thesis, we present the work performed to extract on a wide phase-space the DVCS cross-section from the JLab data at a beam energy of 6 GeV.

  19. Neutrino-antineutrino correlations in dense anisotropic media

    NASA Astrophysics Data System (ADS)

    Serreau, Julien; Volpe, Cristina

    2014-12-01

    We derive the most general evolution equations describing in-medium (anti)neutrino propagation in the mean-field approximation. In particular, we consider various types of neutrino-antineutrino mixing, for both Dirac and Majorana fields, resulting either from nontrivial pair correlations or from helicity coherence due to the nonvanishing neutrino masses. We show that, unless the medium is spatially homogeneous and isotropic, these correlations are sourced by the usual neutrino and antineutrino densities. This may be of importance in astrophysical environments such as core-collapse supernovae.

  20. Parton and valon distributions in the nucleon

    SciTech Connect

    Hwa, R.C.; Sajjad Zahir, M.

    1981-06-01

    Structure functions of the nucleon are analyzed in the valon model in which a nucleon is assumed to be a bound state of three valence quark clusters (valons). At high Q/sup 2/ the structure of the valons is described by leading-order results in the perturbative quantum chromodynamics. From the experimental data on deep-inelastic scattering off protons and neutrons, the flavor-dependent valon distributions in the nucleon are determined. Predictions for the parton distributions are then made for high Q/sup 2/ without guesses concerning the quark and gluon distributions at low Q/sup 2/. The sea-quark and gluon distributions are found to have a sharp peak at very small x. Convenient parametrization is provided which interpolates between different numbers of flavors.

  1. Sea Quark Contribution to the Nucleon Spin

    NASA Astrophysics Data System (ADS)

    Benmokhtar, Fatiha

    2015-10-01

    The widespread belief is that proton and neutron, commonly known as nucleons, are each composed of three elementary particles called quarks. But in the last two decades experiments showed that the mass, momentum, spin and electromagnetic properties of the three quarks do not add up to the known proprieties of the nucleon. Theory predicts that a ``sea'' of virtual pairs of quarks and anti-quarks, along with the strong force carrier particles called gluons, should account for the difference. I will present ongoing work on the preparation of an experiment to isolate the contributions of the sea to the nucleon spin using semi-inclusive deep inelastic scattering technique at the Thomas Jefferson National Accelerator Facility.

  2. Evaluation of the Antiproton Flux from the Antineutrino Electron Scattering

    NASA Astrophysics Data System (ADS)

    Alekseev, V. V.; Belotsky, K. M.; Bogomolov, Yu V.; Budaev, R. I.; Dunaeva, O. A.; Kirillov, A. A.; Kuznetsov, A. V.; Laletin, M. N.; Lukyanov, A. D.; Malakhov, V. V.; Mayorov, A. G.; Mayorova, M. A.; Mosichkin, A. F.; Okrugin, A. A.; Rodenko, S. A.; Shitova, A. M.

    2016-02-01

    Recent experiments in high enegry cosmic ray physics, PAMELA and AMS-02, excite a new interest to the mechanisms of generation of galactic antiparticles. In spite of the fact that global picture coincides with the predictions of the standard model, there are some black spots stimulating scientists to involve into research a particularly new physics like dark matter. In the present work, we make an attempt to estimate the impact of standard neutrino processes into the total flux of secondary antiprotons detected by contemporary experiments.

  3. Estimating terrestrial uranium and thorium by antineutrino flux measurements

    PubMed Central

    Dye, Stephen T.; Guillian, Eugene H.

    2008-01-01

    Uranium and thorium within the Earth produce a major portion of terrestrial heat along with a measurable flux of electron antineutrinos. These elements are key components in geophysical and geochemical models. Their quantity and distribution drive the dynamics, define the thermal history, and are a consequence of the differentiation of the Earth. Knowledge of uranium and thorium concentrations in geological reservoirs relies largely on geochemical model calculations. This article describes the methods and criteria to experimentally determine average concentrations of uranium and thorium in the continental crust and in the mantle by using site-specific measurements of the terrestrial antineutrino flux. Optimal, model-independent determinations involve significant exposures of antineutrino detectors remote from nuclear reactors at both a midcontinental and a midoceanic site. This would require major, new antineutrino detection projects. The results of such projects could yield a greatly improved understanding of the deep interior of the Earth. PMID:18172211

  4. Estimating terrestrial uranium and thorium by antineutrino flux measurements.

    PubMed

    Dye, Stephen T; Guillian, Eugene H

    2008-01-08

    Uranium and thorium within the Earth produce a major portion of terrestrial heat along with a measurable flux of electron antineutrinos. These elements are key components in geophysical and geochemical models. Their quantity and distribution drive the dynamics, define the thermal history, and are a consequence of the differentiation of the Earth. Knowledge of uranium and thorium concentrations in geological reservoirs relies largely on geochemical model calculations. This article describes the methods and criteria to experimentally determine average concentrations of uranium and thorium in the continental crust and in the mantle by using site-specific measurements of the terrestrial antineutrino flux. Optimal, model-independent determinations involve significant exposures of antineutrino detectors remote from nuclear reactors at both a midcontinental and a midoceanic site. This would require major, new antineutrino detection projects. The results of such projects could yield a greatly improved understanding of the deep interior of the Earth.

  5. First direct observation of muon antineutrino disappearance

    DOE PAGES

    Adamson, P.

    2011-07-05

    This letter reports the first direct observation of muon antineutrino disappearance. The MINOS experiment has taken data with an accelerator beam optimized for ν¯μ production, accumulating an exposure of 1.71 x 1020 protons on target. In the Far Detector, 97 charged current ν¯μ events are observed. The no-oscillation hypothesis predicts 156 events and is excluded at 6.3σ. The best fit to oscillation yields |Δm¯2| = (3.36-0.40 +0.46(stat.) ± 0.06(syst.)) x 10-3 eV2, sin2(2 θ¯) = 0.86-0.12+0.11 (stat.) ± 0.01(syst.). The MINOS νμ and ν¯μ measurements are consistent at the 2.0% confidence level, assuming identical underlying oscillation parameters.

  6. Geoneutrinos and reactor antineutrinos at SNO+

    NASA Astrophysics Data System (ADS)

    Baldoncini, M.; Strati, V.; Wipperfurth, S. A.; Fiorentini, G.; Mantovani, F.; McDonough, W. F.; Ricci, B.

    2016-05-01

    In the heart of the Creighton Mine near Sudbury (Canada), the SNO+ detector is foreseen to observe almost in equal proportion electron antineutrinos produced by U and Th in the Earth and by nuclear reactors. SNO+ will be the first long baseline experiment to measure a reactor signal dominated by CANDU cores (~55% of the total reactor signal), which generally burn natural uranium. Approximately 18% of the total geoneutrino signal is generated by the U and Th present in the rocks of the Huronian Supergroup-Sudbury Basin: the 60% uncertainty on the signal produced by this lithologic unit plays a crucial role on the discrimination power on the mantle signal as well as on the geoneutrino spectral shape reconstruction, which can in principle provide a direct measurement of the Th/U ratio in the Earth.

  7. Neutrino-antineutrino pair production by hadronic bremsstrahlung

    NASA Astrophysics Data System (ADS)

    Bacca, Sonia

    2016-09-01

    I will report on recent calculations of neutrino-antineutrino pair production from bremsstrahlung processes in hadronic collisions and consider temperature conditions relevant for core collapse supernovae. Earlier studies on bremsstrahlung from neutron-neutron collisions showed that the approximation used in typical supernova simulation to model this process differs by about a factor of 2 from predictions based on chiral effective field theory, where the chiral expansion of two-body forces is considered up to the next-to-next-to-next-to-leading order. When the density of neutrons is large enough this process may compete with other non-hadronic reactions in the production of neutrinos, in particular in the case of μ and τ neutrinos, which are not generated by charged-current reactions. A natural question to ask is then: what is the effect of neutrino pair production from collisions of neutrons with finite nuclei? To tackle this question, we recently have addressed the case of neutron- α collisions, given that in the P-wave channels the neutron- α scattering features a resonance near 1 MeV. We find that the resonance leads to an enhanced contribution in the neutron spin structure function at temperatures in the range of 0 . 1 - 4 MeV. For significant density fractions of α in this temperature range, this process is competitive with contributions from neutron-neutron scattering. TRIUMF receives federal funding via a contribution agreement with the National Research Council of Canada. This work was supported in parts by the Natural Sciences and Engineering Research Council (Grant Number SAPIN-2015-0003).

  8. Few-Nucleon Systems

    NASA Astrophysics Data System (ADS)

    Viviani, Michele

    The recent theoretical advances in the study of the statical and dynamical properties of few-nucleon systems are here reported, with particular attention to the research activities performed under the Italian MURST-PRIN project FISICA DEL NUCLEO E DEI SISTEMI A PIÙ CORPI. The latter studies also include the development of methods for dealing with pionic degrees of freedom, the determination of static properties of light nuclei, and the computation of few-nucleon reaction observables, including electroweak processes.

  9. 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.

  10. Antineutrino analysis for continuous monitoring of nuclear reactors: Sensitivity study

    SciTech Connect

    Stewart, Christopher; Erickson, Anna

    2015-10-28

    This paper explores the various contributors to uncertainty on predictions of the antineutrino source term which is used for reactor antineutrino experiments and is proposed as a safeguard mechanism for future reactor installations. The errors introduced during simulation of the reactor burnup cycle from variation in nuclear reaction cross sections, operating power, and other factors are combined with those from experimental and predicted antineutrino yields, resulting from fissions, evaluated, and compared. The most significant contributor to uncertainty on the reactor antineutrino source term when the reactor was modeled in 3D fidelity with assembly-level heterogeneity was found to be the uncertainty on the antineutrino yields. Using the reactor simulation uncertainty data, the dedicated observation of a rigorously modeled small, fast reactor by a few-ton near-field detector was estimated to offer reduction of uncertainty on antineutrino yields in the 3.0–6.5 MeV range to a few percent for the primary power-producing fuel isotopes, even with zero prior knowledge of the yields.

  11. Antineutrino analysis for continuous monitoring of nuclear reactors: Sensitivity study

    NASA Astrophysics Data System (ADS)

    Stewart, Christopher; Erickson, Anna

    2015-10-01

    This paper explores the various contributors to uncertainty on predictions of the antineutrino source term which is used for reactor antineutrino experiments and is proposed as a safeguard mechanism for future reactor installations. The errors introduced during simulation of the reactor burnup cycle from variation in nuclear reaction cross sections, operating power, and other factors are combined with those from experimental and predicted antineutrino yields, resulting from fissions, evaluated, and compared. The most significant contributor to uncertainty on the reactor antineutrino source term when the reactor was modeled in 3D fidelity with assembly-level heterogeneity was found to be the uncertainty on the antineutrino yields. Using the reactor simulation uncertainty data, the dedicated observation of a rigorously modeled small, fast reactor by a few-ton near-field detector was estimated to offer reduction of uncertainty on antineutrino yields in the 3.0-6.5 MeV range to a few percent for the primary power-producing fuel isotopes, even with zero prior knowledge of the yields.

  12. Multiple scattering expansion with distortion

    NASA Astrophysics Data System (ADS)

    Tandy, P. C.; Thaler, R. M.

    1980-12-01

    A multiple scattering description of elastic scattering is formulated in terms of impulsive scatterings from single target nucleons and pairs of target nucleons. In this description, distortion effects on the projectile from the residual medium are also described by multiple scattering in terms of the same single and pair amplitudes. At the level of single scattering, this procedure yields the first order optical potential result of Kerman, McManus, and Thaler. When scattering from both single nucleons and pairs of nucleons is included, the method leads to a one-body integral equation which requires the physical projectile-nucleon and projectile-pair transition amplitudes as input. This input is similar, but not exactly equivalent to that required by the spectator expansion for the optical potential truncated at second order. A principal advantage of the present formulation is that there need be no explicit dependence upon the projection operator Q which projects off the target ground state. This feature introduces a scaling which appears to be a direct extension of the first order Kerman, McManus, and Thaler type of scaling. We follow up suggestions arising in the foregoing to show that the exact optical potential to second order in the spectator expansion can also be cast into a form having no explicit dependence upon Q, and requiring physical projectile-nucleon and projectile-pair transition amplitudes as input. NUCLEAR REACTIONS Multiple scattering from single nucleons, pairs of nucleons in nucleus. Distortion from residual medium. Optical potential. spectator expansion.

  13. 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.

  14. Nucleon spin structure at Jefferson Lab

    SciTech Connect

    Angela Biselli

    2011-10-01

    In the past decade an extensive experimental program to measure the spin structure of the nucleon has been carried out in the three halls at Jefferson Lab. Using a longitudinally polarized beam scattering off longitudinally or transversely polarized 3He, NH3 and ND3 targets, the double spin asymmetries A|| and A[perpendicular] were measured, providing data of impressively high precision that gives a better understanding of the structure of the nucleon in the deep inelastic scattering and the valence quarks regions. The virtual photon asymmetries A1,2 and polarized structure functions g1,2 were also extracted for the proton, neutron and deuteron over large kinematic ranges, allowing the extraction of first moments and the testing of sum rules and duality.

  15. Nucleon Form Factors - A Jefferson Lab Perspective

    SciTech Connect

    John Arrington, Kees de Jager, Charles F. Perdrisat

    2011-06-01

    The charge and magnetization distributions of the proton and neutron are encoded in their elastic electromagnetic form factors, which can be measured in elastic electron--nucleon scattering. By measuring the form factors, we probe the spatial distribution of the proton charge and magnetization, providing the most direct connection to the spatial distribution of quarks inside the proton. For decades, the form factors were probed through measurements of unpolarized elastic electron scattering, but by the 1980s, progress slowed dramatically due to the intrinsic limitations of the unpolarized measurements. Early measurements at several laboratories demonstrated the feasibility and power of measurements using polarization degrees of freedom to probe the spatial structure of the nucleon. A program of polarization measurements at Jefferson Lab led to a renaissance in the field of study, and significant new insight into the structure of matter.

  16. Strange quark contribution to the nucleon form factor

    NASA Astrophysics Data System (ADS)

    Baunack, S.

    PoS(Confinement8)078 According to QCD, the nucleon is made up of valence quarks, sea quarks and gluons. Concern- ing the quark sea, also strange quarks can contribute to the nucleon properties. Parity violating electron scattering offers a tool to investigate the strange quark contribution to the nucleon form factors parameterized by the strange form factors GE and Gs . The theoretical framework to ac- s M cess these strange form factors is outlined here and an overview of the existing world data is given. The measurements performed by the A4 collaboration at the electron accelerator facility MAMI are described here in more details and preliminary results are reported.

  17. The low-energy structure of the nucleon-nucleon interaction: statistical versus systematic uncertainties

    NASA Astrophysics Data System (ADS)

    Navarro Pérez, R.; Amaro, J. E.; Ruiz Arriola, E.

    2016-11-01

    We analyze the low-energy nucleon-nucleon (NN) interaction by confronting statistical versus systematic uncertainties. This is carried out with the help of model potentials fitted to the Granada-2013 database where a statistically meaningful partial wave analysis comprising a total of 6713 np and pp published scattering data below 350 MeV from 1950 till 2013 has been made. We extract threshold parameter uncertainties from the coupled-channel effective range expansion up to j≤slant 5. We find that for threshold parameters systematic uncertainties are generally at least an order of magnitude larger than statistical uncertainties. Similar results are found for np phase shifts and amplitude parameters.

  18. Relativistic Treatments of the Nucleon-Nucleon System

    NASA Astrophysics Data System (ADS)

    Beachey, David Joseph

    The relativistically minimalist Breit equation is used to study the two-nucleon system. Generally, the equation is noncovariant and its realm of applicability is limited. It is not a field-theoretical equation but, at low energy, it was thought to be a promising candidate to explore the scheme of repulsive vector and attractive scalar interactions as the dominant ingredient of the two -nucleon interaction. In the ^1S_0 singlet case, the equation does indeed seem viable. Dynamically sound interactions and a reasonable fit of the scattering data arise. In a specific application, the discrepancy between the ^1S_0 isovector scattering lengths of the p-p and n -n interactions is explored. This novel charge -symmetry-breaking (CSB) mechanism enlarges the discrepancy between the two lengths, implying a still larger correction is required by other documented (CSB) mechanisms. An all-encompassing model of the ^3S _1-^3D_1 state is, on the other hand, not achieved. Models which best fit the experimental deuteron and elastic scattering data, are unphysical. The vector coupling is driven strongly negative and a dominant interference mechanism arises involving the entirely phenomenological short range OPEP. It was hoped that this parametrized short range OPEP would remain benign while the scalar/vector interference scheme took a lead role. Instead the constraint of avoiding Klein paradox difficulties defeats this picture and achieves the short-range repulsion in the N-N force by ramping up the phenomenological OPEP. It is finally argued that the Breit framework almost certainly does not lend itself to an adequate description of the N-N system. It does, however, point to novel relativistic elements which may ultimately resolve celebrated outstanding problems such as the a_ {t}-r_{m} discrepancy. The triplet scattering length a_ {t} and deuteron matter-radius r _{m} are tightly correlated and resistant to simultaneous fitting in conventional models. The p-wave amplitudes of the

  19. 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.

  20. Renormalization of the Brazilian chiral nucleon-nucleon potential

    SciTech Connect

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

    2013-03-25

    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.

  1. Electromagnetic nucleon form factors

    SciTech Connect

    Bender, A.; Roberts, C.D.; Frank, M.R.

    1995-08-01

    The Dyson-Schwinger equation framework is employed to obtain expressions for the electromagnetic nucleon form factor. In generalized impulse approximation the form factor depends on the dressed quark propagator, the dressed quark-photon vertex, which is crucial to ensuring current conservation, and the nucleon Faddeev amplitude. The approach manifestly incorporates the large space-like-q{sup 2} renormalization group properties of QCD and allows a realistic extrapolation to small space-like-q{sup 2}. This extrapolation allows one to relate experimental data to the form of the quark-quark interaction at small space-like-q{sup 2}, which is presently unknown. The approach provides a means of unifying, within a single framework, the treatment of the perturbative and nonperturbative regimes of QCD. The wealth of experimental nucleon form factor data, over a large range of q{sup 2}, ensures that this application will provide an excellent environment to test, improve and extend our approach.

  2. Neutrino mass hierarchy determination using reactor antineutrinos

    NASA Astrophysics Data System (ADS)

    Ghoshal, Pomita; Petcov, S. T.

    2011-03-01

    Building on earlier studies, we investigate the possibility to determine the type of neutrino mass spectrum (i.e., "the neutrino mass hierarchy") in a high statistics reactor {bar{ν }_e} experiment with a relatively large KamLAND-like detector and an optimal baseline of 60 Km. We analyze systematically the Fourier Sine and Cosine Transforms (FST and FCT) of simulated reactor antineutrino data with reference to their specific mass hierarchy-dependent features discussed earlier in the literature. We perform also a binned χ 2 analysis of the sensitivity of simulated reactor {bar{ν }_e} event spectrum data to the neutrino mass hierarchy, and determine, in particular, the characteristics of the detector and the experiment (energy resolution, visible energy threshold, exposure, systematic errors, binning of data, etc.), which would allow us to get significant information on, or even determine, the type of the neutrino mass spectrum. We find that if sin2 2 θ 13 is sufficiently large, sin2 2 θ 13 ≳ 0 .02, the requirements on the set-up of interest are very challenging, but not impossible to realize.

  3. Bolometric Bounds on the Antineutrino Mass

    NASA Astrophysics Data System (ADS)

    Arnaboldi, C.; Brofferio, C.; Cremonesi, O.; Fiorini, E.; Lo Bianco, C.; Martensson, L.; Nucciotti, A.; Pavan, M.; Pessina, G.; Pirro, S.; Previtali, E.; Sisti, M.; Giuliani, A.; Margesin, B.; Zen, M.

    2003-10-01

    High statistics calorimetric measurements of the β spectrum of 187Re are being performed with arrays of silver perrhenate crystals operated at low temperature. After a substantial modification of the experimental setup, a new measurement with ten silver perrhenate microbolometers has been running since July 2002. The crystals have masses around 300 μg and their average FWHM energy resolution is of 28.3eV at the β end point. The Kurie plot collected during 4485 h×mg effective running time has an end-point energy of 2466.1±0.8stat±1.5syst eV, while the half lifetime of the decay is found to be 43.2±0.2stat±0.1syst Gy. These values are the most precise obtained so far for 187Re. The best fit value for m2ν¯e is 147±237stat±90syst eV2, which corresponds to an upper limit for the electron antineutrino mass mν¯e≤21.7 eV at 90%C.L.

  4. First direct observation of muon antineutrino disappearance

    SciTech Connect

    Adamson, P.

    2011-07-05

    This letter reports the first direct observation of muon antineutrino disappearance. The MINOS experiment has taken data with an accelerator beam optimized for ν¯μ production, accumulating an exposure of 1.71 x 1020 protons on target. In the Far Detector, 97 charged current ν¯μ events are observed. The no-oscillation hypothesis predicts 156 events and is excluded at 6.3σ. The best fit to oscillation yields |Δm¯2| = (3.36-0.40 +0.46(stat.) ± 0.06(syst.)) x 10-3 eV2, sin2(2 θ¯) = 0.86-0.12+0.11 (stat.) ± 0.01(syst.). The MINOS νμ and ν¯μ measurements are consistent at the 2.0% confidence level, assuming identical underlying oscillation parameters.

  5. A novel segmented-scintillator antineutrino detector

    NASA Astrophysics Data System (ADS)

    Abreu, Y.; Amhis, Y.; Arnold, L.; Ban, G.; Beaumont, W.; Bongrand, M.; Boursette, D.; Buhour, J. M.; Castle, B. C.; Clark, K.; Coupé, B.; Cucoanes, A. S.; Cussans, D.; De Roeck, A.; D'Hondt, J.; Durand, D.; Fallot, M.; Fresneau, S.; Ghys, L.; Giot, L.; Guillon, B.; Guilloux, G.; Ihantola, S.; Janssen, X.; Kalcheva, S.; Kalousis, L. N.; Koonen, E.; Labare, M.; Lehaut, G.; Mermans, J.; Michiels, I.; Moortgat, C.; Newbold, D.; Park, J.; Petridis, K.; Piñera, I.; Pommery, G.; Popescu, L.; Pronost, G.; Rademacker, J.; Reynolds, A.; Ryckbosch, D.; Ryder, N.; Saunders, D.; Shitov, Yu. A.; Schune, M.-H.; Scovell, P. R.; Simard, L.; Vacheret, A.; Van Dyck, S.; Van Mulders, P.; van Remortel, N.; Vercaemer, S.; Waldron, A.; Weber, A.; Yermia, F.

    2017-04-01

    The next generation of very-short-baseline reactor experiments will require compact detectors operating at surface level and close to a nuclear reactor. This paper presents a new detector concept based on a composite solid scintillator technology. The detector target uses cubes of polyvinyltoluene interleaved with 6LiF:ZnS(Ag) phosphor screens to detect the products of the inverse beta decay reaction. A multi-tonne detector system built from these individual cells can provide precise localisation of scintillation signals, making efficient use of the detector volume. Monte Carlo simulations indicate that a neutron capture efficiency of over 70 % is achievable with a sufficient number of 6LiF:ZnS(Ag) screens per cube and that an appropriate segmentation enables a measurement of the positron energy which is not limited by γ-ray leakage. First measurements of a single cell indicate that a very good neutron-gamma discrimination and high neutron detection efficiency can be obtained with adequate triggering techniques. The light yield from positron signals has been measured, showing that an energy resolution of 14%/√E(MeV) is achievable with high uniformity. A preliminary neutrino signal analysis has been developed, using selection criteria for pulse shape, energy, time structure and energy spatial distribution and showing that an antineutrino efficiency of 40% can be achieved. It also shows that the fine segmentation of the detector can be used to significantly decrease both correlated and accidental backgrounds.

  6. Progress Towards Deployable Antineutrino Detectors for Reactor Safeguards

    SciTech Connect

    Bowden, N; Bernstein, A; Dazeley, S; Keefer, G; Reyna, D; Cabrera-Palmer, B; Kiff, S

    2010-04-05

    Fission reactors emit large numbers of antineutrinos and this flux may be useful for the measurement of two quantities of interest for reactor safeguards: the reactor's power and plutonium inventory throughout its cycle. The high antineutrino flux and relatively low background rates means that simple cubic meter scale detectors at tens of meters standoff can record hundreds or thousands of antineutrino events per day. Such antineutrino detectors would add online, quasi-real-time bulk material accountancy to the set of reactor monitoring tools available to the IAEA and other safeguards agencies with minimal impact on reactor operations. Between 2003 and 2008, our LLNL/SNL collaboration successfully deployed several prototype safeguards detectors at a commercial reactor in order to test both the method and the practicality of its implementation in the field. Partially on the strength of the results obtained from these deployments, an Experts Meeting was convened by the IAEA Novel Technologies Group in 2008 to assess current antineutrino detection technology and examine how it might be incorporated into the safeguards regime. Here we present a summary of our previous deployments and discuss current work that seeks to provide expanded capabilities suggested by the Experts Panel, in particular aboveground detector operation.

  7. Yale High Energy Physics Research: Precision Studies of Reactor Antineutrinos

    SciTech Connect

    Heeger, Karsten M.

    2014-09-13

    This report presents experimental research at the intensity frontier of particle physics with particular focus on the study of reactor antineutrinos and the precision measurement of neutrino oscillations. The experimental neutrino physics group of Professor Heeger and Senior Scientist Band at Yale University has had leading responsibilities in the construction and operation of the Daya Bay Reactor Antineutrino Experiment and made critical contributions to the discovery of non-zero$\\theta_{13}$. Heeger and Band led the Daya Bay detector management team and are now overseeing the operations of the antineutrino detectors. Postdoctoral researchers and students in this group have made leading contributions to the Daya Bay analysis including the prediction of the reactor antineutrino flux and spectrum, the analysis of the oscillation signal, and the precision determination of the target mass yielding unprecedented precision in the relative detector uncertainty. Heeger's group is now leading an R\\&D effort towards a short-baseline oscillation experiment, called PROSPECT, at a US research reactor and the development of antineutrino detectors with advanced background discrimination.

  8. Determining Reactor Fuel Type from Continuous Antineutrino Monitoring

    NASA Astrophysics Data System (ADS)

    Jaffke, Patrick; Huber, Patrick

    2017-09-01

    We investigate the ability of an antineutrino detector to determine the fuel type of a reactor. A hypothetical 5-ton antineutrino detector is placed 25 m from the core and measures the spectral shape and rate of antineutrinos emitted by fission fragments in the core for a number of 90-d periods. Our results indicate that four major fuel types can be differentiated from the variation of fission fractions over the irradiation time with a true positive probability of detection at approximately 95%. In addition, we demonstrate that antineutrinos can identify the burnup at which weapons-grade mixed-oxide (MOX) fuel would be reduced to reactor-grade MOX, on average, providing assurance that plutonium-disposition goals are met. We also investigate removal scenarios where plutonium is purposefully diverted from a mixture of MOX and low-enriched uranium fuel. Finally, we discuss how our analysis is impacted by a spectral distortion around 6 MeV observed in the antineutrino spectrum measured from commercial power reactors.

  9. 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 ~12GeV2 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

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    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 the 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˜12 GeV2 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.

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

    SciTech Connect

    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 the 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 ~12GeV2 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.

  12. Two-Nucleon Systems in a Finite Volume

    SciTech Connect

    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 extents L satisfying fm <~ L <~ 14 fm.

  13. Instantons and the spin of the nucleon

    NASA Astrophysics Data System (ADS)

    Schäfer, T.; Zetocha, V.

    2004-05-01

    Motivated by measurements of the flavor singlet axial coupling constant of the nucleon in polarized deep inelastic scattering we study the contribution of instantons to Okubo-Zweig-Iizuka rule (OZI) violation in the axial-vector channel. We consider, in particular, the f1-a1 meson splitting, the flavor singlet and triplet axial coupling of a constituent quark, and the axial coupling constant of the nucleon. We show that instantons provide a short distance contribution to OZI violating correlation functions which is repulsive in the f1 meson channel and adds to the flavor singlet three-point function of a constituent quark. We also show that the sign of this contribution is determined by positivity arguments. We compute long distance contributions using numerical simulations of the instanton liquid. We find that the isovector axial coupling constant of a constituent quark is (g3A)Q=0.9 and that of a nucleon is g3A=1.28, in good agreement with experiment. The flavor singlet coupling of a quark is close to one, while that of a nucleon is suppressed, g0A=0.77. However, this number is larger than the experimental value g0A=(0.28-0.41).

  14. Nucleon Spin Structure: Longitudinal and Transverse

    SciTech Connect

    Jian-Ping Chen

    2011-02-01

    Inclusive Deep-Inelastic Scattering (DIS) experiments have provided us with the most extensive information on the unpolarized and longitudinal polarized parton (quark and gluon) distributions in the nucleon. It has becoming clear that transverse spin and transverse momentum dependent distributions (TMDs) study are crucial for a more complete understanding of the nucleon structure and the dynamics of the strong interaction. The transverse spin structure and the TMDs are the subject of increasingly intense theoretical and experimental study recently. With a high luminosity electron beam facility, JLab has played a major role in the worldwide effort to study both the longitudinal and transverse spin structure. Highlights of recent results will be presented. With 12-GeV energy upgrade, JLab will provide the most precise measurements in the valence quark region to close a chapter in longitudinal spin study. JLab will also perform a multi-dimensional mapping of the transverse spin structure and TMDs in the valence quark region through Semi-Inclusive DIS (SIDIS) experiments, providing a 3-d partonic picture of the nucleon in momentum space and extracting the u and d quark tensor charges of the nucleon. The precision mapping of TMDs will also allow a detailed study of the quark orbital motion and its dynamics.

  15. Scattering Of Light Nuclei

    SciTech Connect

    Quaglioni, S; Navratil, P; Roth, R

    2009-12-15

    The exact treatment of nuclei starting from the constituent nucleons and the fundamental interactions among them has been a long-standing goal in nuclear physics. Above all nuclear scattering and reactions, which require the solution of the many-body quantum-mechanical problem in the continuum, represent an extraordinary theoretical as well as computational challenge for ab initio approaches.We present a new ab initio many-body approach which derives from the combination of the ab initio no-core shell model with the resonating-group method [4]. By complementing a microscopic cluster technique with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters, this approach is capable of describing simultaneously both bound and scattering states in light nuclei. We will discuss applications to neutron and proton scattering on sand light p-shell nuclei using realistic nucleon-nucleon potentials, and outline the progress toward the treatment of more complex reactions.

  16. Data acquisition system for segmented reactor antineutrino detector

    NASA Astrophysics Data System (ADS)

    Hons, Z.; Vlášek, J.

    2017-01-01

    This paper describes the data acquisition system used for data readout from the PMT channels of a segmented detector of reactor antineutrinos with active shielding. Theoretical approach to the data acquisition is described and two possible solutions using QDCs and digitizers are discussed. Also described are the results of the DAQ performance during routine data taking operation of DANSS. DANSS (Detector of the reactor AntiNeutrino based on Solid Scintillator) is a project aiming to measure a spectrum of reactor antineutrinos using inverse beta decay (IBD) in a plastic scintillator. The detector is located close to an industrial nuclear reactor core and is covered by passive and active shielding. It is expected to have about 15000 IBD interactions per day. Light from the detector is sensed by PMT and SiPM.

  17. Monitoring nuclear reactors for safeguards purposes using anti-neutrinos

    NASA Astrophysics Data System (ADS)

    Carroll, J.; Coleman, J.; Lockwood, M.; Metelko, C.; Murdoch, M.; Touramanis, C.; Davies, G.; Roberts, A.

    2015-04-01

    Preventing nuclear proliferation is a high priority for the international community. Monitoring of nuclear facilities to detect unauthorised removal of fissile materials from operational cores is central to this. Neutrino detection devices can be used to remotely monitor the core of operating reactors in a safe, reliable manner. Technology developed for the T2K experiment can be adapted to make a small footprint, reliable, anti-neutrino detector. Through, characterisation of the anti-neutrino spectrum there is a possibility to provide core material accountancy. A prototype of such a device has been developed and demonstrated at the University of Liverpool. Based on the design of the T2K Near Detector Calorimeter, the device will detect anti-neutrinos through the distinctive delayed coincidence signal of inverse beta decay interactions. This poster presented data from detector commissioning. The detector is currently deployed at Wylfa power station, UK for field testing.

  18. Solar antineutrinos from fluctuating magnetic fields at Kamiokande

    NASA Astrophysics Data System (ADS)

    Torrente-Lujan, E.

    1998-11-01

    We consider the effect of a strongly chaotic magnetic field at the narrow bottom of the convective zone of the Sun together with resonant matter oscillations on the production of electron Majorana antineutrinos. Even for moderate levels of noise, we show that it is possible to obtain a small but significant probability for νe-->ν¯e conversions (1-3%) at the energy range 2-10 MeV for large regions of the mixing parameter space while still satisfying present (Super)-Kamiokande antineutrino bounds and observed total rates. In the other hand it would be possible to obtain information about the solar magnetic internal field if antineutrino bounds reach the 1% level and a particle physics solution to the SNP is assumed. The mechanism presented here has the advantage of being independent of the largely unknown magnetic profile of the Sun and the intrinsic neutrino magnetic moment.

  19. 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-Q2 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.

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

    SciTech Connect

    Fomin, N.; Arrington, J.; Asaturyan, R.; Benmokhtar, F.; Boeglin, W.; Bosted, P.; Bruell, A.; Bukhari, M. H. S.; Christy, M. E.; Chudakov, E.; Clasie, B.; Connell, S. H.; Dalton, M. M.; Daniel, A.; Day, D. B.; Dutta, D.; Ent, R.; El Fassi, L.; Fenker, H.; Filippone, B. W.; Garrow, K.; Gaskell, D.; Hill, C.; Holt, R. J.; Horn, T.; Jones, M. K.; Jourdan, J.; Kalantarians, N.; Keppel, C. E.; Kiselev, D.; Kotulla, M.; Lindgren, R.; Lung, A. F.; Malace, S.; Markowitz, P.; McKee, P.; Meekins, D. G.; Mkrtchyan, H.; Navasardyan, T.; Niculescu, G.; Opper, A. K.; Perdrisat, C.; Potterveld, D. H.; Punjabi, V.; Qian, X.; Reimer, P. E.; Roche, J.; Rodriguez, V. M.; Rondon, O.; Schulte, E.; Seely, J.; Segbefia, E.; Slifer, K.; Smith, G. R.; Solvignon, P.; Tadevosyan, V.; Tajima, S.; Tang, L.; Testa, G.; Trojer, R.; Tvaskis, V.; Vulcan, W. F.; Wasko, C.; Wesselmann, F. R.; Wood, S. A.; Wright, J.; Zheng, X.

    2012-02-01

    We present new, high-Q2 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.

  1. Spectral structure of electron antineutrinos from nuclear reactors.

    PubMed

    Dwyer, D A; Langford, T J

    2015-01-09

    Recent measurements of the positron energy spectrum obtained from inverse beta decay interactions of reactor electron antineutrinos show an excess in the 4 to 6 MeV region relative to current predictions. First-principles calculations of fission and beta decay processes within a typical pressurized water reactor core identify prominent fission daughter isotopes as a possible origin for this excess. These calculations also predict percent-level substructures in the antineutrino spectrum due to Coulomb effects in beta decay. Precise measurement of these substructures can elucidate the nuclear processes occurring within reactors. These substructures can be a systematic issue for measurements utilizing the detailed spectral shape.

  2. Evidence for new nucleon resonances from electromagnetic meson production

    SciTech Connect

    Volker Burkert

    2012-12-01

    The study of nucleon resonances in electromagnetic meson production with the CLAS detector is discussed. The electromagnetic interaction is complementary to pion scattering in the exploration of the nucleon excitation spectrum. Higher mass states often decouple from the N{pi} channel and are not seen in {pi} N --> {pi} N. Photoproduction of mesons, such as K {Lambda}, {omega} p and {eta}' p may be more sensitive to many of these states. The CLAS detector, combined with the use of energy-tagged polarized photons and polarized electrons, as well as po- larized targets and the measurement of recoil polarization, are the tools needed for a comprehensive nucleon resonance program. Some of the recently published high statistics data sets had significant impact on further clarifying the nucleon excitation spectrum.

  3. Momentum and coordinate space three-nucleon potentials

    SciTech Connect

    Coon, S.A.; Pena, M.T.

    1993-06-10

    In this paper we give explicit formulae in momentum and coordinate space for the three-nucleon potentials due to {rho} and {pi} meson exchange, derived from off-mass-shell meson-nucleon scattering amplitudes which are constrained by the symmetries of QCD and by the experimental data. Those potentials have already been applied to nuclear matter calculations. Here we display additional terms which appear to be the most important for nuclear structure. The potentials are decomposed in a way that separates the contributions of different physical mechanisms involved in the meson-nucleon amplitudes. The same type of decomposition is presented for the {pi} {minus} {pi} TM force: The {Delta} isobar, the chiral symmetry breaking and the nucleon pair terms are isolated.

  4. From Extraction of Nucleon Resonances to LQCD

    SciTech Connect

    Lee, T.-S. H.; Wu, Jia-jun; Kamano, Hiroyuki

    2016-06-09

    The intrinsic difficulties in extracting the hadron resonances from reaction data are illustrated by using several exactly soluble ππ ππ scattering models. The finite-volume Hamiltonian method is applied to predict spectra using two meson-exchange Hamiltonians of πN πN reactions. Within a three-channel model with πN πN , πΔ πΔ and σN σN channels, we show the advantage of the finite-volume Hamiltonian method over the approach using the Lüscher formula to test Lattice QCD calculations aimed at predicting nucleon resonances. We discuss the necessary steps for using the ANL-Osaka eight-channel Hamiltonian to predict the spectra for testing the LQCD calculations for determining the excited nucleon states up to invariant mass W=2 W=2 GeV.

  5. Spin and angular momentum in the nucleon

    SciTech Connect

    Franz Gross, Gilberto Ramalho, Teresa Pena

    2012-05-01

    Using the covariant spectator theory (CST), we present the results of a valence quark-diquark model calculation of the nucleon structure function f(x) measured in unpolarized deep inelastic scattering (DIS), and the structure functions g1(x) and g2(x) measured in DIS using polarized beams and targets. Parameters of the wave functions are adjusted to fit all the data. The fit fixes both the shape of the wave functions and the relative strength of each component. Two solutions are found that fit f(x) and g1(x), but only one of these gives a good description of g2(x). This fit requires the nucleon CST wave functions contain a large D-wave component (about 35%) and a small P-wave component (about 0.6%). The significance of these results is discussed.

  6. From Extraction of Nucleon Resonances to LQCD

    NASA Astrophysics Data System (ADS)

    Lee, T.-S. H.; Wu, Jia-jun; Kamano, Hiroyuki

    2016-10-01

    The intrinsic difficulties in extracting the hadron resonances from reaction data are illustrated by using several exactly soluble π π scattering models. The finite-volume Hamiltonian method is applied to predict spectra using two meson-exchange Hamiltonians of π N reactions. Within a three-channel model with π N, π Δ and σ N channels, we show the advantage of the finite-volume Hamiltonian method over the approach using the Lüscher formula to test Lattice QCD calculations aimed at predicting nucleon resonances. We discuss the necessary steps for using the ANL-Osaka eight-channel Hamiltonian to predict the spectra for testing the LQCD calculations for determining the excited nucleon states up to invariant mass W= 2 GeV.

  7. THE SPIN STRUCTURE OF THE NUCLEON.

    SciTech Connect

    VOGELSANG, W.

    2005-05-23

    For many years now, spin has played a very prominent role in QCD. The field of QCD spin physics has been carried by the hugely successful experimental program of polarized deeply-inelastic lepton-nucleon scattering (DIS), and by a simultaneous tremendous progress in theory. A new milestone has now been reached with the advent of RHIC, the world's first polarized proton-proton collider. RHIC is poised to help answer many of the important question pertaining to the spin structure of the nucleon. Recently, it has also been proposed to study spin phenomena in transversely polarized {bar p}p collisions at the planned GSI-FAIR facility. This talk describes some of the opportunities provided by RHIC and the proposed GSI experiments.

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

    SciTech Connect

    Skorodumina, Iu. A.; Burkert, V. D.; Golovach, E. N.; Gothe, R. W.; Isupov, E. L.; Ishkhanov, B. S.; Mokeev, V. I.; Fedotov, G. V.

    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.

  9. Deformed chiral nucleons

    NASA Astrophysics Data System (ADS)

    Price, C. E.; Shepard, J. R.

    1991-04-01

    We compute properties of the nucleon in a hybrid chiral model based on the linear σ-model with quark degrees of freedom treated explicity. In contrast to previous calculations, we do not use the hedgehog ansatz. Instead we solve self-consistently for a state with well defined spin and isospin projections. We allow this state to be deformed and find that, although d- and g-state admixtures in the predominantly s-state single quark wave functions are not large, they have profound effects on many nucleon properties including magnetic moments and gA. Our best fit parameters provide excellent agreement with experiment but are much different from those determined in hedgehog calculations.

  10. Probing of the neutrino magnetic moment at the level of 10{sup -22} μ{sub B} with an intense tritium source of (anti)neutrino and helium target (project)

    SciTech Connect

    Martemyanov, V.P.; Aleshin, V.I.; Tarasenko, V.G.; Tsinoev, V.G.; Sabelnikov, A.A.; Yukhimchuk, A.A.; Popov, V.V.; Baluev, V.V.; Golubkov, A.N.; Klevtsov, V.G.; Kuryakin, A.V.; Sitdikov, D.T.; Bogdanova, L.N.

    2015-03-15

    We present research results of the preparation project for the experimental measurement of the (anti)neutrino magnetic moment at the level of 10{sup -12} μ{sub B} using an intense tritium source of antineutrinos and a liquid helium scintillation detector. The neutrino detection in the scintillation detector is based on the scattering of neutrinos by the electrons of the helium atoms that produces fast electrons able to ionize and exciting helium atoms. The detection of the atomic radiation emitted during the relaxation process of the helium atoms and the knowledge of its parameters will allow us to conclude on the neutrino properties.

  11. Search for electron antineutrino appearance at the deltam(2) approximately 1 eV(2) Scale.

    PubMed

    Aguilar-Arevalo, A A; Anderson, C E; Brice, S J; Brown, B C; Bugel, L; Conrad, J M; Djurcic, Z; Fleming, B T; Ford, R; Garcia, F G; Garvey, G T; Gonzales, J; Grange, J; Green, C; Green, J A; Imlay, R; Johnson, R A; Karagiorgi, G; Katori, T; Kobilarcik, T; Linden, S K; Louis, W C; Mahn, K B M; Marsh, W; Mauger, C; McGary, V T; Metcalf, W; Mills, G B; Moore, C D; Mousseau, J; Nelson, R H; Nienaber, P; Nowak, J A; Osmanov, B; Pavlovic, Z; Perevalov, D; Polly, C C; Ray, H; Roe, B P; Russell, A D; Shaevitz, M H; Sorel, M; Spitz, J; Stancu, I; Stefanski, R J; Tayloe, R; Tzanov, M; Van de Water, R G; Wascko, M O; White, D H; Wilking, M J; Zeller, G P; Zimmerman, E D

    2009-09-11

    The MiniBooNE Collaboration reports initial results from a search for nu(mu)-->nu(e) oscillations. A signal-blind analysis was performed using a data sample corresponding to 3.39x10(20) protons on target. The data are consistent with background prediction across the full range of neutrino energy reconstructed assuming quasielastic scattering, 200antineutrino oscillations suggested by data from the Liquid Scintillator Neutrino Detector at Los Alamos National Laboratory.

  12. Neutron Capture and the Antineutrino Yield from Nuclear Reactors.

    PubMed

    Huber, Patrick; Jaffke, Patrick

    2016-03-25

    We identify a new, flux-dependent correction to the antineutrino spectrum as produced in nuclear reactors. The abundance of certain nuclides, whose decay chains produce antineutrinos above the threshold for inverse beta decay, has a nonlinear dependence on the neutron flux, unlike the vast majority of antineutrino producing nuclides, whose decay rate is directly related to the fission rate. We have identified four of these so-called nonlinear nuclides and determined that they result in an antineutrino excess at low energies below 3.2 MeV, dependent on the reactor thermal neutron flux. We develop an analytic model for the size of the correction and compare it to the results of detailed reactor simulations for various real existing reactors, spanning 3 orders of magnitude in neutron flux. In a typical pressurized water reactor the resulting correction can reach ∼0.9% of the low energy flux which is comparable in size to other, known low-energy corrections from spent nuclear fuel and the nonequilibrium correction. For naval reactors the nonlinear correction may reach the 5% level by the end of cycle.

  13. Electron Neutrino and Antineutrino Appearance in the MINOS Detector

    SciTech Connect

    Schreckenberger, Adam Paul

    2013-04-01

    The Main Injector Neutrino Oscillation Search (MINOS) is a long-baseline neutrino experiment that utilizes a particle beam and two steel-scintillator calorimeters designed to determine the parameters associated with muon neutrino disappearance. Analysis methods developed by the MINOS νe group have facilitated the placement of limits upon the mixing angle associated with νμ → νe oscillations. Since the polarity of the focusing horns can be switched, we can perform a similar analysis with an antineutrino-enriched beam to select electron antineutrino appearance candidates. Using 3.34e20 POT (protons on target) in the antineutrino mode, we exclude θ13 = 0 at the 80% C.L. A joint fit of the 3.34e20 POT antineutrino and 10.6e20 POT neutrino samples excluded θ13 = 0 at the 96% C.L. In addition, the combined data were used to produce exclusions regarding the CP-violating phase.

  14. Monitoring of spent nuclear fuel with antineutrino detectors

    NASA Astrophysics Data System (ADS)

    Brdar, Vedran

    2017-09-01

    We put forward the possibility of employing antineutrino detectors in order to control the amounts of spent nuclear fuel in repositories or, alternatively, to precisely localize the underground sources of nuclear material. For instance, we discuss the applicability in determining a possible leakage of stored nuclear material which would aid in preventing environmental problems. The long-term storage facilities are also addressed.

  15. Calculation of relativistic nucleon-nucleon potentials in three dimensions

    NASA Astrophysics Data System (ADS)

    Hadizadeh, M. R.; Radin, M.

    2017-02-01

    In this paper, we have applied a three-dimensional approach for the calculation of the relativistic nucleon-nucleon potential. The quadratic operator relation between the non-relativistic and the relativistic nucleon-nucleon interactions is formulated as a function of relative two-nucleon momentum vectors, which leads to a three-dimensional integral equation. The integral equation is solved by the iteration method, and the matrix elements of the relativistic potential are calculated from non-relativistic ones. The spin-independent Malfliet-Tjon potential is employed in the numerical calculations, and the numerical tests indicate that the two-nucleon observables calculated by the relativistic potential are preserved with high accuracy.

  16. Nucleon-nucleon interaction and large Nc QCD

    NASA Astrophysics Data System (ADS)

    Banerjee, Manoj K.; Cohen, Thomas D.; Gelman, Boris A.

    2002-03-01

    The nature of the nonrelativistic nucleon-nucleon potential in the large-Nc limit is discussed. In particular, we address the consistency of the meson-exchange picture of nucleon interactions. It is shown that the nonrelativistic nucleon-nucleon potential extracted from the Feynmann graphs up to and including two-meson-exchange diagrams satisfies the spin-flavor counting rules of Kaplan and Savage and of Kaplan and Manohar, provided the nucleon momenta is of order N0c. The key to this is a cancellation of the retardation effect of the box graphs against the contributions of the crossed-box diagram. The consistency requires including Δ as an intermediate state.

  17. Measuring Antineutrino Oscillations with the MINOS Experiment

    SciTech Connect

    Evans, Justin John

    2008-09-01

    MINOS is a long baseline neutrino oscillation experiment. A manmade beam of predominantly muon neutrinos is detected both 1 km and 735 km from the production point by two functionally identical detectors. A comparison of the energy spectra measured by the two detectors shows the energy-dependent disappearance of muon neutrinos characteristic of oscillations and allows a measurement of the parameters governing the oscillations. This thesis presents work leading to measurements of disappearance in the 6% $\\bar{v}$μ background in that beam. A calibration is developed to correct for time-dependent changes in the responses of both detectors, reducing the corresponding uncertainty on hadronic energy measurements from 1.8% to 0.4% in the near detector and from 0.8% to 0.4% in the far detector. A method of selecting charged current $\\bar{v}$μ events is developed, with purities (efficiencies) of 96.5% (74.4%) at the near detector, and 98.8% (70.9%) at the far detector in the region below 10 GeV reconstructed antineutrino energy. A method of using the measured near detector neutrino energy spectrum to predict that expected at the far detector is discussed, and developed for use in the $\\bar{v}$μ analysis. Sources of systematic uncertainty contributing to the oscillation measurements are discussed. In the far detector, 32 charged current $\\bar{v}$μ events are observed below a reconstructed energy of 30 GeV, compared to an expectation of 47.8 for Δ$\\bar{m}$atm2 = Δ$\\bar{m}$atm2, sin2(2$\\bar{θ}$23) = sin2(2θ23). This deficit, in such a low-statistics sample, makes the result difficult to interpret in the context of an oscillation parameter measurement. Possible sources for the discrepancy are discussed, concluding that considerably more data are required for a definitive solution. Running MINOS with a dedicated $\\bar

  18. Probing the nucleon structure with SIDIS at Jefferson Lab

    SciTech Connect

    Pereira, Sergio Anafalos

    2013-01-01

    In recent years, measurements of azimuthal moments of polarized hadronic cross sections in hard processes have emerged as a powerful tool to probe nucleon structure. Many experiments worldwide are currently trying to pin down various effects related to nucleon structure through Semi-Inclusive Deep-Inelastic Scattering (SIDIS). Azimuthal distributions of final-state particles in semi-inclusive deep inelastic scattering, in particular, are sensitive to the orbital motion of quarks and play an important role in the study of Transverse Momentum Dependent parton distribution functions (TMDs) of quarks in the nucleon. The CLAS spectrometer, installed in Hall-B at Jefferson Lab, has collected semi-inclusive data using the CEBAF 6 GeV polarized electron beam on polarized solid NH{sub 3} and ND{sub 3} targets. An overview of these measurements is presented.

  19. Parity-Violating Effects in Two-Nucleon Systems

    SciTech Connect

    R. Schiavilla; J. Carlson; M. Paris

    2002-10-01

    We report recent results obtained for the parity-violating (PV) asymmetries in pp elastic scattering, np radiative capture at thermal neutron energies, and deuteron electro-disintegration in quasi-elastic kinematics. The available data on the pp longitudinal asymmetry are used to put constraints on some of the P V vector-meson couplings occurring in the DDH model for the PV nucleon-nucleon interaction. In the np capture, we show that a measurement of the associated asymmetry will lead to an essentially model-independent determination of the PV pion coupling to the nucleon. Finally, in quasi-elastic electron scattering as demonstrate that the asymmetry induced by hadronic weak interactions (and associated currents) is two orders of magnitude smaller than that originating from interference of the 7- and Z-exchange amplitudes.

  20. Three-Body Antikaon-Nucleon Systems

    NASA Astrophysics Data System (ADS)

    Shevchenko, N. V.

    2017-01-01

    The paper contains a review of the exact or accurate results achieved in the field of the three-body antikaon-nucleon physics. Different states and processes in bar{K}NN and bar{K}bar{K}N systems are considered. In particular, quasi-bound states in K^- pp and K^- K^- p systems were investigated together with antikaonic deuterium atom. Near-threshold scattering of antikaons on deuteron, including the K^- d scattering length, and applications of the scattering amplitudes are also discussed. All exact three-body results were calculated using some form of Faddeev equations. Different versions of bar{K}N, {\\varSigma }N, bar{K}bar{K}, and NN potentials, specially constructed for the calculations, allowed investigation of the dependence of the three-body results on the two-body input. Special attention is paid to the antikaon-nucleon interaction, being the most important for the three-body systems. Approximate calculations, performed additionally to the exact ones, demonstrate accuracy of the commonly used approaches.

  1. Nucleon-antinucleon annihilation in chiral soliton model

    SciTech Connect

    Musakhanov, M.M. . Inst. for Nuclear Theory Tashkentskij Gosudarstvennyj Univ., Tashkent . Dept. of Theoretical Physics); Musatov, I.V. . Research Inst. of Applied Physics)

    1991-09-07

    We investigate annihilation process of nucleons in the chiral soliton model by the path integral method. A soliton-antisoliton pair is shown to decay into mesons at range of about 1fm, defined by the S{bar S} potential. Contribution of the annihilation channel to the elastic scattering is discussed.

  2. Four-nucleon potential due to exchange of pions

    SciTech Connect

    Robilotta, M.R.

    1985-03-01

    A four-body force due to the exchange of pions has been derived by means of It includes effects corresponding to pion-pion scattering, pion production, and pion-nucleon rescattering. The strength parameters of this four-body potential are typically one order of magnitude smaller than those of the two-pion-exchange three-body force.

  3. A letter of intent for a neutrino scattering experiment on the booster neutrino meanline: FINeSSE

    SciTech Connect

    Fleming, B.T.; Tayloe, R.; /Indiana U. /Yale U.

    2005-03-01

    The experiment described in this Letter of Intent provides a decisive measurement of {Delta}s, the spin of the nucleon carried by strange quarks. This is crucial as, after more than thirty years of study, the spin contribution of strange quarks to the nucleon is still not understood. The interpretation of {Delta}s measurements from inclusive Deep Inelastic Scattering (DIS) experiments using charged leptons suffers from two questionable techniques; an assumption of SU(3)-flavor symmetry, and an extrapolation into unmeasured kinematic regions, both of which provide ample room for uncertain theoretical errors in the results. The results of recent semi-inclusive DIS data from HERMES paint a somewhat different picture of the contribution of strange quarks to the nucleon spin than do the inclusive results, but since HERMES does not make use of either of the above-mentioned techniques, then the results are somewhat incomparable. What is required is a measurement directly probing the spin contribution of the strange quarks in the nucleon. Neutrino experiments provide a theoretically clean and robust method of determining {Delta}s by comparing the neutral current interaction, which is isoscalar plus isovector, to the charged current interaction, which is strictly isovector. A past experiment, E734, performed at Brookhaven National Laboratory, has pioneered this effort. Building on what they have learned, we present an experiment which achieves a measurement to {+-} 0.025 using neutrino scattering, and {+-} 0.04 using anti-neutrino scattering, significantly better than past measurements. The combination of the neutrino and anti-neutrino data, when combined with the results of the parity-violating electron-nucleon scattering data, will produce the most significant result for {Delta}s. This experiment can also measure neutrino cross sections in the energy range required for accelerator-based precision oscillation measurements. Accurate measurements of cross sections have been

  4. Electromagnetic studies of nucleon and nuclear structure

    SciTech Connect

    Heisenberg, J.H.; Calarco, J.R.; Hersman, F.W.; Dawson, J.F.

    1993-06-01

    Important objectives of the group are the study of subatomic structure through experimental measurements and the interpretation of the data through modeling. The common theme that unifies the studies of strong interactions and hadronic systems is the effort to determine the electromagnetic response as completely as possible. The general approach is coincidence detection of exclusive final states and determination of the dependence on the spin variables using polarized beams and targets and outgoing nucleon polarimetry. Direct reaction and giant resonance studies of electron quasi-elastic scattering on {sup 12}C and {sup 16}O are reported, as well as work on nuclear structure models and instrumentation development.

  5. NN inversion potentials intermediate energy proton-nucleus elastic scattering

    SciTech Connect

    Arellano, H.F.; Brieva, F.A.; Love, W.G.; Geramb, H.V. von

    1995-10-01

    Recently developed nucleon-nucleon interactions using the quantum inverse scattering method shed new fight on the off-shell properties of the internucleon effective force for nucleon-nucleus scattering. Calculations of proton elastic scattering from {sup 40}Ca and {sup 208}Pb in the 500 MeV region show that variations in off-shell contributions are determined to a great extent by the accuracy with which the nucleon-nucleon phase shifts are reproduced. The study is based on the full-folding approach to the nucleon-nucleus optical potential which allows a deep understanding of the interplay between on- and off-shell effects in nucleon scattering. Results and the promising extension offered by the inversion potentials beyond the range of validity of the low-energy internucleon forces will be discussed.

  6. Experimental Studies of Nuclear Interactions in Few-Nucleon Systems

    NASA Astrophysics Data System (ADS)

    Stephan, E.; Kistryn, St.; Kalantar-Nayestanaki, N.; Kozela, A.

    2017-03-01

    Systems of three nucleons (3N) can be treated as a testing ground for modern approaches to describe nuclear interactions. At intermediate energies, observables for 3N systems are sensitive to subtle effects of the dynamics beyond the pairwise nucleon-nucleon force, so-called 3N-force (3NF). For years the search for 3NF has been motivating precise measurements of observables of elastic nucleon-deuteron scattering and for the deuteron breakup reaction. Breakup of a deuteron in collision with a proton leads to the final state of three free nucleons, with variety of possible kinematic configurations, revealing locally enhanced sensitivity to particular aspects of the interaction dynamics, like 3NF, Coulomb force between protons, or relativistic effects. This feature makes the breakup reaction a very versatile tool for validation of the theoretical description. Reactions involving four nucleons pose immense challenges with regard to exact theoretical calculations for such systems. Nonetheless, they attract attention due to expected enhanced sensitivity to certain aspects of the nuclear dynamics, manifesting themselves in various channels and configurations. The most important results of recent experimental studies of 3N and 4N systems at intermediate energies are discussed. A brief survey of the ongoing projects is given.

  7. The two-nucleon system at next-to-next-to-next-to-leading order

    SciTech Connect

    Evgeny Epelbaum; Walter Gloeckle; Ulf-G. Meissner

    2005-01-01

    We consider the two-nucleon system at next-to-next-to-next-to-leading order (N{sup 3}LO) in chiral effective field theory. The two--nucleon potential at N{sup 3}LO consists of one-, two- and three-pion exchanges and a set of contact interactions with zero, two and four derivatives. In addition, one has to take into account various isospin--breaking and relativistic corrections. We employ spectral function regularization for the multi--pion exchanges. Within this framework, it is shown that the three-pion exchange contribution is negligibly small. The low--energy constants (LECs) related to pion-nucleon vertices are taken consistently from studies of pion-nucleon scattering in chiral perturbation theory. The total of 26 four--nucleon LECs has been determined by a combined fit to some np and pp phase shifts from the Nijmegen analysis together with the nn scattering length.

  8. Flavor changing nucleon decay

    NASA Astrophysics Data System (ADS)

    Maekawa, Nobuhiro; Muramatsu, Yu

    2017-04-01

    Recent discovery of neutrino large mixings implies the large mixings in the diagonalizing matrices of 5 bar fields in SU (5) grand unified theory (GUT), while the diagonalizing matrices of 10 fields of SU (5) are expected to have small mixings like Cabibbo-Kobayashi-Maskawa matrix. We calculate the predictions of flavor changing nucleon decays (FCND) in SU (5), SO (10), and E6 GUT models which have the above features for mixings. We found that FCND can be the main decay mode and play an important role to test GUT models.

  9. Nucleon Resonance Physics

    SciTech Connect

    Burkert, Volker D.

    2016-07-25

    Recent results of meson photo-production at the existing electron machines with polarized real photon beams and the measurement of polarization observables of the final state baryons have provided high precision data that led to the discovery of new excited nucleon and $\\Delta$ states using multi-channel partial wave analyses procedures. The internal structure of several prominent excited states has been revealed employing meson electroproduction processes. On the theoretical front, lattice QCD is now predicting the baryon spectrum with very similar characteristics as the constituent quark model, and continuum QCD, such as is represented in the Dyson-Schwinger Equations approach and in light front relativistic quark models, describes the non-perturbative behavior of resonance excitations at photon virtuality of $Q^2 > 1.5GeV^2$. In this talk I discuss the need to continue a vigorous program of nucleon spectroscopy and the study of the internal structure of excited states as a way to reveal the effective degrees of freedom underlying the excited states and their dependence on the distance scale probed.

  10. Nucleon Resonance Physics

    NASA Astrophysics Data System (ADS)

    Burkert, Volker D.

    2016-10-01

    Recent results of meson photo-production at the existing electron machines with polarized real photon beams and the measurement of polarization observables of the final state baryons have provided high precision data that led to the discovery of new excited nucleon and Δ states using multi-channel partial wave analyses procedures. The internal structure of several prominent excited states has been revealed employing meson electroproduction processes. On the theoretical front, lattice QCD is now predicting the baryon spectrum with very similar characteristics as the constituent quark model, and continuum QCD, such as is represented in the Dyson-Schwinger equations approach and in light front relativistic quark models, describes the non-perturbative behavior of resonance excitations at photon virtuality of Q^2 > 1.5 GeV^2. In this talk I discuss the need to continue a vigorous program of nucleon spectroscopy and the study of the internal structure of excited states as a way to reveal the effective degrees of freedom underlying the excited states and their dependence on the distance scale probed.

  11. Single-nucleon experiments

    SciTech Connect

    Deur, Alexandre

    2009-12-01

    We discuss the Jefferson Lab low momentum transfer data on moments of the nucleon spin structure functions $g_1$ and $g_2$ and on single charged pion electroproduction off polarized proton and polarized neutron. A wealth of data is now available, while more is being analyzed or expected to be taken in the upcoming years. Given the low momentum transfer selected by the experiments, these data can be compared to calculations from Chiral Perturbation theory, the effective theory of strong force that should describe it at low momentum transfer. The data on various moments and the respective calculations do not consistently agree. In particular, experimental data for higher moments disagree with the calculations.The absence of contribution from the $\\Delta$ resonance in the various observables was expected to facilitate the calculations and hence make the theory predictions either more robust or valid over a larger $Q^2$ range. Such expectation is verified only for the Bjorken sum, but not for other observables in which the $\\Delta$ is suppressed. Preliminary results on pion electroproduction off polarized nucleons are also presented and compared to phenomenological models for which contributions from different resonances are varied. Chiral Perturbation calculations of these observables, while not yet available, would be valuable and, together with these data, would provide an extensive test of the effective theory.

  12. Time-correlated coincidences at the sudbury neutrino observatory: An antineutrino search

    NASA Astrophysics Data System (ADS)

    Shokair, Timothy Milad

    This dissertation presents a search for antineutrinos in all three phases of data from the Sudbury Neutrino Observatory. This work presents a new method for detecting time correlated coincidences in water detectors. There are two separate searches: an outside search for the inverse beta decay of antineutrinos on protons and an inside search for the inverse beta decay of antineutrinos on deuterons. The inside search found 3 antineutrino candidates in Phase I with an expected background of 3.83+0.71-0.72 events, 28 antineutrino candidates in Phase II with an expected background of 21.25+3.72-3.75 events, 4 antineutrino candidates in Phase III with an expected background of 6.06 +/- 1.14 events. The outside search found 4 antineutrino candidates in Phase I with an expected background of 1.21+0.14-0.17 events, 8 antineutrino candidates in Phase II with an expected background of 9.77+1.06-1.34 events, 0 antineutrino candidates in Phase III with an expected background of 0.46 +/- 0.29 events. Including the expected contribution of antineutrinos from nuclear reactors after oscillations, a limit on the solar antineutrino flux is computed to be F8Bn¯ ≤ 2.5 x 103 cm-2s -1. Taking the flux limit and the measured 8B solar neutrino flux, a limit on the neutrino to antineutrino conversion probability of P(nu → nu) ≤ 5.0 x 10-4. These limits are the best limits from a water detector.

  13. Simulation and Prediction of SONGS Reactor Antineutrino Flux Using the DRAGON Code

    NASA Astrophysics Data System (ADS)

    Jones, Christopher; Conrad, Janet; Bernstein, Adam

    2010-02-01

    We present a comparison of the predicted antineutrino flux from the San Onofre Nuclear Generating Station (SONGS) PWR reactor with the determinstic lattice code, DRAGON. This simulation will be used to benchmark the DRAGON code for use in predicting an antineutrino flux for the Double Chooz experiment. We can also make a comparison between DRAGON and ORIGEN-ARP, another code used to model the antineutrino flux. )

  14. Hylogenesis and annihilation of nucleons by dark matter

    SciTech Connect

    Davoudiasl, Hooman

    2014-06-24

    In this talk, we briefly present hylogenesis - a unified scenario for simultaneous generation of asymmetric dark matter (ADM) and visible baryons in the early Universe - and some of its experimental implications. A particularly interesting signature of hylogenesis is induced nucleon decay (IND), that is the possibility of baryon destruction in scattering from ADM. For some motivated range of parameters, IND can result in potentially observable signals in nucleon decay experiments. We also briefly discuss other signals of hylogenesis, including collider physics and astrophysical implications of IND.

  15. Three pion nucleon coupling constants

    NASA Astrophysics Data System (ADS)

    Ruiz Arriola, E.; Amaro, J. E.; Navarro Pérez, R.

    2016-08-01

    There exist four pion nucleon coupling constants, fπ0pp, - fπ0nn, fπ+pn/2 and fπ-np/2 which coincide when up and down quark masses are identical and the electron charge is zero. While there is no reason why the pion-nucleon-nucleon coupling constants should be identical in the real world, one expects that the small differences might be pinned down from a sufficiently large number of independent and mutually consistent data. Our discussion provides a rationale for our recent determination fp2 = 0.0759(4),f 02 = 0.079(1),f c2 = 0.0763(6), based on a partial wave analysis of the 3σ self-consistent nucleon-nucleon Granada-2013 database comprising 6713 published data in the period 1950-2013.

  16. Development of an advanced antineutrino detector for reactor monitoring

    DOE PAGES

    Classen, T.; Bernstein, A.; Bowden, N. S.; ...

    2014-11-05

    We present the development of a compact antineutrino detector for the purpose of nuclear reactor monitoring, improving upon a previously successful design. Our paper will describe the design improvements of the detector which increases the antineutrino detection efficiency threefold over the previous effort. There are two main design improvements over previous generations of detectors for nuclear reactor monitoring: dual-ended optical readout and single volume detection mass. The dual-ended optical readout eliminates the need for fiducialization and increases the uniformity of the detector's optical response. The containment of the detection mass in a single active volume provides more target mass permore » detector footprint, a key design criteria for operating within a nuclear power plant. This technology could allow for real-time monitoring of the evolution of a nuclear reactor core, independent of reactor operator declarations of fuel inventories, and may be of interest to the safeguards community.« less

  17. Development of an advanced antineutrino detector for reactor monitoring

    SciTech Connect

    Classen, T.; Bernstein, A.; Bowden, N. S.; Cabrera-Palmer, B.; Ho, A.; Jonkmans, G.; Kogler, L.; Reyna, D.; Sur, B.

    2014-11-05

    We present the development of a compact antineutrino detector for the purpose of nuclear reactor monitoring, improving upon a previously successful design. Our paper will describe the design improvements of the detector which increases the antineutrino detection efficiency threefold over the previous effort. There are two main design improvements over previous generations of detectors for nuclear reactor monitoring: dual-ended optical readout and single volume detection mass. The dual-ended optical readout eliminates the need for fiducialization and increases the uniformity of the detector's optical response. The containment of the detection mass in a single active volume provides more target mass per detector footprint, a key design criteria for operating within a nuclear power plant. This technology could allow for real-time monitoring of the evolution of a nuclear reactor core, independent of reactor operator declarations of fuel inventories, and may be of interest to the safeguards community.

  18. Development of an advanced antineutrino detector for reactor monitoring

    NASA Astrophysics Data System (ADS)

    Classen, T.; Bernstein, A.; Bowden, N. S.; Cabrera-Palmer, B.; Ho, A.; Jonkmans, G.; Kogler, L.; Reyna, D.; Sur, B.

    2015-01-01

    Here we present the development of a compact antineutrino detector for the purpose of nuclear reactor monitoring, improving upon a previously successful design. This paper will describe the design improvements of the detector which increases the antineutrino detection efficiency threefold over the previous effort. There are two main design improvements over previous generations of detectors for nuclear reactor monitoring: dual-ended optical readout and single volume detection mass. The dual-ended optical readout eliminates the need for fiducialization and increases the uniformity of the detector's optical response. The containment of the detection mass in a single active volume provides more target mass per detector footprint, a key design criteria for operating within a nuclear power plant. This technology could allow for real-time monitoring of the evolution of a nuclear reactor core, independent of reactor operator declarations of fuel inventories, and may be of interest to the safeguards community.

  19. Calibration and Reconstruction of the Daya Bay Antineutrino Detector

    NASA Astrophysics Data System (ADS)

    Hu, Bei-Zhen; Daya Bay Collaboration

    2017-09-01

    The Daya Bay Reactor Neutrino Experiment has produced the most precise measurements to date of the mixing angle θ 13 and the mass-squared difference |Δ {m}ee2| in the electron antineutrino disappearance channel. In addition, the experiment has published a precision measurement of the reactor antineutrino flux and spectrum. Energy calibration and reconstruction are crucial to all of these measurements. Various approaches are used to understand the detector non-linearity, non-uniformity, energy scale and the related systematic uncertainties. The uncertainty of the detector-uncorrelated energy scale and the absolute energy response are less than 0.2% and 1%, respectively. Nevertheless, these uncertainties are among the leading contributors to the overall systematic uncertainties leading contributors of the systematic uncertainties and will continue to be studied.

  20. The Daya Bay Reactor Electron Anti-neutrino Oscillation Experiment

    NASA Astrophysics Data System (ADS)

    Liu, Jianglai

    2007-10-01

    The phenomenon of neutrino flavor oscillations is now well-established. Mixing among the three flavors is characterized by three mixing angles, with θ13 being the only presently unknown angle. A precise measurement of θ13 using nuclear reactors as a source of electron anti-neutrinos requires high electron anti-neutrino flux, ˜2 km baselines, as well as good shielding to reduce cosmogenic backgrounds. The Daya Bay nuclear reactor complex located in south China is an ideal site to perform such a measurement. We have proposed an experiment at Daya Bay utilizing multiple baselines (between 0.3 and 2 km) and multiple liquid scintillator detector modules. Since the formal physics proposal in 2006, much progress has been made by the collaboration in the design of the experiment. The civil construction of the experiment will begin this year. In this talk, I will give an overview of the experiment, and report on the recent progress and the project status.

  1. Inverse-square law violation and reactor antineutrino anomaly

    NASA Astrophysics Data System (ADS)

    Naumov, D. V.; Naumov, V. A.; Shkirmanov, D. S.

    2017-01-01

    We discuss a possibility that the so-called reactor antineutrino anomaly can be, at least in part, explained by applying a quantum field-theoretical approach to neutrino oscillations, which in particular predicts a small deviation from the classical inverse-square law at short but macroscopic distances between the neutrino source and detector. An extensive statistical analysis of the reactor data is performed to examine this speculation.

  2. Uncertainties in the Anti-neutrino Production at Nuclear Reactors

    SciTech Connect

    Djurcic, Zelimir; Detwiler, Jason A.; Piepke, Andreas; Foster Jr., Vince R.; Miller, Lester; Gratta, Giorgio

    2008-08-06

    Anti-neutrino emission rates from nuclear reactors are determined from thermal power measurements and fission rate calculations. The uncertainties in these quantities for commercial power plants and their impact on the calculated interaction rates in {bar {nu}}{sub e} detectors is examined. We discuss reactor-to-reactor correlations between the leading uncertainties, and their relevance to reactor {bar {nu}}{sub e} experiments.

  3. Nucleon and Deuteron Form Factors from BLAST

    SciTech Connect

    Hasell, D. K.

    2009-12-17

    The BLAST experiment was designed to study in a systematic manner the spin-dependent, electromagnetic interaction on hydrogen and deuterium. Measuring only asymmetries in electron scattering with respect to the beam helicity, target spin, or both; the BLAST experiment was able to extract information on nucleon and deuteron form factors independent of beam intensity or target density. By further forming 'super-ratios' of asymmetries, measurements were possible independent of beam and target polarization thus reducing uncertainties due to these quantities as well. Some of the form factor results from BLAST will be briefly presented here. Also, in response to observed discrepancies between polarization measurements and those obtained using traditional Rosenbluth separation techniques a proposed experiment, OLYMPUS, which will use the BLAST detector to measure the two photon contribution to elastic electron scattering will also be presented.

  4. On the Convergence of Finite Range Expansions in 3-nucleon Systems

    NASA Astrophysics Data System (ADS)

    Shepard, James; McNeil, James

    2008-10-01

    We examine the convergence properties of the Effective Range Expansion based on Effective Theories (ET-ERE) of the 2-nucleon scattering amplitude in 3-nucleon applications in the context of a simple rank-1 separable 2-body potential where the finite range effects can be tracked explicitly. To illustrate the approach in a simple context we consider the bound and scattering properties of the ^3S1 and ^4S3/2 2- and 3-nucleon systems. We find that the poor convergence of the 3-nucleon scattering amplitude using the ET-ERE can be traced to its poor account of finite range effects that soften the momentum dependence of the deuteron propagator in the Faddeev kernel. In contrast, a simple separable potential with dipole form factors works remarkably well and forms the leading term of a systematic controlled approximation expansion.

  5. Recent Improvements in the Summation Calculation of Antineutrino Spectra

    NASA Astrophysics Data System (ADS)

    Sonzogni, Alejandro; Johnson, Timothy; McCutchan, Elizabeth; Dimitriou, Paraskevi

    2016-09-01

    The antineutrino spectrum following the fission of an actinide nucleus can be calculated using a comprehensive set of fission yields and decay data, an approach known as the summation method. We have recently updated our databases to incorporate newly published results as well as to perform some corrections and updates. These summation calculations are now in better agreement with those from the conversion method. The advantage of the summation method is that one can understand the rich correlations between the different radiation types - gammas, electrons, neutrons and antineutrinos - as well as study the time dependence of the radiation intensity in a variety of situations. Additionally, we have performed a sensitivity study to identify different elements of the input nuclear data which have an important impact in the calculation of antineutrino spectra and which would benefit from a precise measurement. Work at Brookhaven National Laboratory was sponsored by the Office of Nuclear Physics, Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-98CH10886.

  6. A quark transport theory to describe nucleon-nucleon collisions

    NASA Astrophysics Data System (ADS)

    Kalmbach, U.; Vetter, T.; Biró, T. S.; Mosel, U.

    1993-11-01

    On the basis of the Friedberg-Lee model we formulate a semiclassical transport theory to describe the phase-space evolution of nucleon-nucleon collisions on the quark level. The time evolution is given by a Vlasov equation for the quark phase-space distribution and a Klein-Gordon equation for the mean-field describing the nucleon as a soliton bag. The Vlasov equation is solved numerically using an extended test-particle method. We test the confinement mechanism and mean-field effects in (1 + 1)-dimensional simulations.

  7. Neutron Measurements and the Weak Nucleon-Nucleon Interaction

    PubMed Central

    Snow, W. M.

    2005-01-01

    The weak interaction between nucleons remains one of the most poorly-understood sectors of the Standard Model. A quantitative description of this interaction is needed to understand weak interaction phenomena in atomic, nuclear, and hadronic systems. This paper summarizes briefly what is known about the weak nucleon-nucleon interaction, tries to place this phenomenon in the context of other studies of the weak and strong interactions, and outlines a set of measurements involving low energy neutrons which can lead to significant experimental progress. PMID:27308120

  8. 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.

  9. The nucleon sigma term

    SciTech Connect

    Banerjee, S; Tandy, P.C.

    1995-04-01

    The explicit chiral symmetry breaking component of the nucleon mass generated by the bare quark mass is extracted from a mean field treatment of chiral meson modes produced by a QCD-based model field theory. Because of the underlying finite range gluon propagator, bosonization produces a distributed dynamics of dressed quarks and finite size chiral meson fields that is totally determined by the amplitude functions of the quark propagator. The authors take the latter from a recent confining representation constrained by soft chiral meson physics. The sigma term is generated consistently from that level. A hedgehog format facilitates the mean field solution. New contributions to the sigma term arise which are not present in the point-coupling limit and the resulting value will be presented.

  10. Nucleon Electromagnetic Form Factors

    SciTech Connect

    Marc Vanderhaeghen; Charles Perdrisat; Vina Punjabi

    2007-10-01

    There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has greatly improved by performing double polarization experiments, in comparison with previous unpolarized data. Here we review the experimental data base in view of the new results for the proton, and neutron, obtained at JLab, MAMI, and MIT-Bates. The rapid evolution of phenomenological models triggered by these high-precision experiments will be discussed, including the recent progress in the determination of the valence quark generalized parton distributions of the nucleon, as well as the steady rate of improvements made in the lattice QCD calculations.

  11. 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.

  12. News on Compton Scattering γX → γX in Chiral EFT

    NASA Astrophysics Data System (ADS)

    Grießhammer, Harald W.; McGovern, Judith A.; Phillips, Daniel R.

    2016-03-01

    We review theoretical progress and prospects to understand the nucleon's static dipole polarisabilities from Compton scattering on few-nucleon targets, including new values; see Refs. [1-5] for details and a more thorough bibliography.

  13. Experimental studies of nucleon-nucleon and pion-nucleus interactions at intermediate energies

    SciTech Connect

    Not Available

    1990-10-01

    This report summarizes the work on experimental research in intermediate energy nuclear and particle physics carried out by New Mexico State University in 1988--91. Most of these studies have involved investigations of neutron-proton and pion-nucleus interactions. The neutron-proton research is part of a program of studies of interactions between polarized nucleons that we have been involved with for more than ten years. Its purpose has been to help complete the determination of the full set of ten complex nucleon-nucleon amplitudes at energies up to 800 MeV, as well as to continue investigating the possibility of the existence of dibaryon resonances. The give complex isospin-one amplitudes have been fairly well determined, partly as a result of this work. Our work in this period has involved measurements and analysis of data on elastic scattering and total cross sections for polarized neutrons on polarized protons. The pion-nucleus research continues our studies of this interaction in regions where it has not been well explored. One set of experiments includes studies of pion elastic and double-charge-exchange scattering at energies between 300 and 550 MeV, where our data is unique. Another involves elastic and single-charge-exchange scattering of pions from polarized nuclear targets, a new field of research which will give the first extensive set of information on spin-dependent pion-nucleus amplitudes. Still another involves the first set of detailed studies of the kinematic correlations among particles emitted following pion absorption in nuclei.

  14. Soft two-pion-exchange nucleon-nucleon potentials

    SciTech Connect

    Rijken, Th.A. )

    1991-06-01

    Two-pion-exchange nucleon-nucleon potentials are derived for the pseudo-vector pion-nucleon interaction, assuming strong dynamical pair-suppression. At the pion-nucleon vertices the authors include Gaussian form factors, which are incorporated into the relativistic two-body framework by using a dispersion representation for the one-pion-exchange amplitude. The Fourier transformations are performed using a factorization technique for the energy denominators. This leads to analytic expressions for the TPE-potentials containing at most one-dimensional integrals. The TPE-potentials are calculated up to orders {line integral}{sup 4} and (m/M){line integral}{sup 4}. The terms of order {line integral}{sup 4} come from the adiabatic contributions of the parallel and crossed three-dimensional momentum-space TPE-diagrams, and from the non-adiabatic contributions of the OPE-iteration. The (m/M)-corrections are due to the 1/M-terms in the non-adiabatic expansion of the nucleon energies in the intermediate states, and the 1/M-terms in the pion-nucleon vertices. The latter are typical for the PV-coupling and would be absent for the PS-coupling. The Gaussian form factors lead to soft TPE-potentials. These potentials can readily be exploited in NN-calculations in combination with, e.g., the Nijmegen soft-core OBE-model, and in nuclear (matter) calculations.

  15. Symmetry energy of cold nucleonic matter within a relativistic mean field model encapsulating effects of high-momentum nucleons induced by short-range correlations

    NASA Astrophysics Data System (ADS)

    Cai, Bao-Jun; Li, Bao-An

    2016-01-01

    It is well known that short-range nucleon-nucleon correlations (SRC) from the tensor components and/or the repulsive core of nuclear forces lead to a high- (low-)momentum tail (depletion) in the single-nucleon momentum distribution above (below) the nucleon Fermi surface in cold nucleonic matter. Significant progress was made recently in constraining the isospin-dependent parameters characterizing the SRC-modified single-nucleon momentum distribution in neutron-rich nucleonic matter using both experimental data and microscopic model calculations. Using the constrained single-nucleon momentum distribution in a nonlinear relativistic mean field (RMF) model, we study the equation of state (EOS) of asymmetric nucleonic matter (ANM), especially the density dependence of nuclear symmetry energy Esym(ρ ) . First, as a test of the model, the average nucleon kinetic energy extracted recently from electron-nucleus scattering experiments using a neutron-proton dominance model is well reproduced by the RMF model incorporating effects of the SRC-induced high-momentum nucleons, while it is significantly under predicted by the RMF model using a step function for the single-nucleon momentum distribution as in free Fermi gas (FFG) models. Second, consistent with earlier findings within nonrelativistic models, the kinetic symmetry energy of quasinucleons is found to be Esymkin(ρ0) =-16.94 ±13.66 MeV which is dramatically different from the prediction of Esymkin(ρ0) ≈12.5 MeV by FFG models at nuclear matter saturation density ρ0=0.16 fm-3 . Third, comparing the RMF calculations with and without the high-momentum nucleons using two sets of model parameters both reproducing identically all empirical constraints on the EOS of symmetric nuclear matter (SNM) and the symmetry energy of ANM at ρ0, the SRC-modified single-nucleon momentum distribution is found to make the Esym(ρ ) more concave around ρ0 by softening it significantly at both subsaturation and suprasaturation

  16. 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).

  17. Symmetry relations in nucleon decay

    NASA Astrophysics Data System (ADS)

    Hurlbert, Anya; Wilczek, Frank

    1980-05-01

    Some experimental consequences of the structure of the effective hamiltonian for nucleon decay are presented. New results concern relations among inclusive decay rates, a striking test of the kinship hypothesis involving μ+ polarization, and soft π theorems.

  18. Antineutrino Oscillations and a Search for Non-standard Interactions with the MINOS

    SciTech Connect

    Isvan, Zeynep

    2012-01-01

    MINOS searches for neutrino oscillations using the disappearance of muon neutrinos from the NuMI beam at Fermilab between two detectors. The Near Detector, located near the source, measures the beam composition before flavor change occurs. The energy spectrum is measured again at the Far Detector after neutrinos travel a distance. The mixing angle and mass splitting between the second and third mass states are extracted from the energy dependent difference between the spectra at the two detectors. NuMI is able to produce an antineutrino-enhanced beam as well as a neutrino-enhanced beam. Collecting data in antineutrino-mode allows the direct measurement of antineutrino oscillation parameters. From the analysis of the antineutrino mode data we measure $|\\Delta\\bar{m}^{2}_{\\text{atm}}| = 2.62^{+0.31}_{-0.28}\\times10^{-3}\\text{eV}^{2}$ and $\\sin^{2}(2\\bar{\\theta})_{23} = 0.95^{+0.10}_{-0.11}$, which is the most precise measurement of antineutrino oscillation parameters to date. A difference between neutrino and antineutrino oscillation parameters may indicate new physics involving interactions that are not part of the Standard Model, called non-standard interactions, that alter the apparent disappearance probability. Collecting data in neutrino and antineutrino mode independently allows a direct search for non-standard interactions. In this dissertation non-standard interactions are constrained by a combined analysis of neutrino and antineutrino datasets and no evidence of such interactions is found.

  19. The isospin dependent nucleon-nucleon inelastic cross section in the nuclear medium

    NASA Astrophysics Data System (ADS)

    Li, Qingfeng; Li, Zhuxia

    2017-10-01

    The calculation of the energy-, density-, and isospin-dependent Δ production cross sections in nucleon-nucleon (NN) scattering σNN→ NΔ * has been performed within the framework of the relativistic BUU approach. The NΔ cross sections are calculated in Born approximation taking into account the effective mass splitting of the nucleons and Δs in asymmetric matter. Due to the different mass splitting for neutron, proton and differently charged Δs, it is shown that, similar to the NN elastic ones, the reductions of NΔ inelastic cross sections in isospin-asymmetric nuclear medium are different from each other for all the individual channels and the effect is largest and of opposite sign for the Δ++ and Δ- states. This approach is also compared to calculations without effective mass splitting and with splitting derived from Dirac-Brueckerner (DB) calculations. The isospin dependence of the NΔ cross sections is expected to influence the production of π+ and π- mesons as well as their yield ratio, and thus affect the use of the latter quantity as a probe of the stiffness of the symmetry energy at supranormal densities.

  20. Nucleon structure and the high energy interactions

    NASA Astrophysics Data System (ADS)

    Selyugin, O. V.

    2015-06-01

    On the basis of the representation of the generalized structure of nucleons a new model of the hadron interaction at high energies is presented. A new t dependence of the generalized parton distributions is obtained from the comparative analysis of different sets of the parton distribution functions, based on the description of the entire set of experimental data for the electromagnetic form factors of the proton and neutron. Taking into account the different moments of the generalized parton distributions of the hadron, quantitative descriptions of all existing experimental data of the proton-proton and proton-antiproton elastic scatterings from √{s }=9.8 GeV to 8 TeV, including the Coulomb range and large momentum transfers up to -t =15 GeV2 , are obtained with a few free high-energy fitting parameters. The real part of the hadronic elastic scattering amplitude is determined only through the complex s that satisfies the dispersion relations. The negligible contributions of the hard Pomeron and the presence of the non-small contributions of the maximal Odderon are obtained. The non-dying form of the spin-flip amplitude is examined as well. The structures of the Born term and unitarized scattering amplitude are analyzed. It is shown that the black disk limit for the elastic scattering amplitude is not reached at LHC energies. Predictions for LHC energies are made.

  1. Impact of low-energy nuclear excitations on neutrino-nucleus scattering at MiniBooNE and T2K kinematics

    NASA Astrophysics Data System (ADS)

    Pandey, V.; Jachowicz, N.; Martini, M.; González-Jiménez, R.; Ryckebusch, J.; Van Cuyck, T.; Van Dessel, N.

    2016-11-01

    Background: Meticulous modeling of neutrino-nucleus interactions is essential to achieve the unprecedented precision goals of present and future accelerator-based neutrino-oscillation experiments. Purpose: Confront our calculations of charged-current quasielastic cross sections with the measurements of MiniBooNE and T2K, and to quantitatively investigate the role of nuclear-structure effects, in particular, low-energy nuclear excitations in forward muon scattering. Method: The model takes the mean-field approach as the starting point, and solves Hartree-Fock (HF) equations using a Skyrme (SkE2) nucleon-nucleon interaction. Long-range nuclear correlations are taken into account by means of the continuum random-phase approximation (CRPA) framework. Results: We present our calculations on flux-folded double differential, and flux-unfolded total cross sections off 12C and compare them with MiniBooNE and (off-axis) T2K measurements. We discuss the importance of low-energy nuclear excitations for the forward bins. Conclusions: The HF and CRPA predictions describe the gross features of the measured cross sections. They underpredict the data (more in the neutrino than in the antineutrino case) because of the absence of processes beyond pure quasielastic scattering in our model. At very forward muon scattering, low-energy HF-CRPA nuclear excitations (ω <50 MeV) account for nearly 50% of the flux-folded cross section. This extra low-energy strength is a feature of the detailed microscopic nuclear model used here, that is not accessed in a Fermi-gas based approach.

  2. Microscopic optical potentials for He4 scattering

    NASA Astrophysics Data System (ADS)

    Egashira, Kei; Minomo, Kosho; Toyokawa, Masakazu; Matsumoto, Takuma; Yahiro, Masanobu

    2014-06-01

    We present a reliable double-folding (DF) model for He4-nucleus scattering, using the Melbourne g-matrix nucleon-nucleon interaction that explains nucleon-nucleus scattering with no adjustable parameter. In the DF model, only the target density is taken as the local density in the Melbourne g matrix. For He4 elastic scattering from Ni58 and Pb208 targets in a wide range of incident energies from 20 to 200 MeV/nucleon, the DF model with the target-density approximation (TDA) yields much better agreement with the experimental data than the usual DF model with the frozen-density approximation in which the sum of projectile and target densities is taken as the local density. We also discuss the relation between the DF model with the TDA and the conventional folding model in which the nucleon-nucleus potential is folded with the He4 density.

  3. The Detection of Reactor Antineutrinos for Reactor Core Monitoring: an Overview

    NASA Astrophysics Data System (ADS)

    Fallot, M.

    2014-06-01

    There have been new developments in the field of applied neutrino physics during the last decade. The International Atomic Energy Agency (IAEA) has expressed interest in the potentialities of antineutrino detection as a new tool for reactor monitoring and has created an ad hoc Working Group in late 2010 to follow the associated research and development. Several research projects are ongoing around the world to build antineutrino detectors dedicated to reactor monitoring, to search for and develop innovative detection techniques, or to simulate and study the characteristics of the antineutrino emission of actual and innovative nuclear reactor designs. We give, in these proceedings, an overview of the relevant properties of antineutrinos, the possibilities of and limitations on their detection, and the status of the development of a variety of compact antineutrino detectors for reactor monitoring.

  4. The physics of antineutrinos in DUNE and determination of octant and δCP

    NASA Astrophysics Data System (ADS)

    Nath, Newton; Ghosh, Monojit; Goswami, Srubabati

    2016-12-01

    The octant of the leptonic mixing angle θ23 and the CP phase δCP are the two major unknowns (apart from neutrino mass hierarchy) in neutrino oscillation physics. It is well known that the precise determination of octant and δCP is interlinked through the octant-δCP degeneracy. In this paper we study the proficiency of the DUNE experiment to determine these parameters scrutinizing, in particular, the role played by the antineutrinos, the broadband nature of the beam and the matter effect. It is well known that for Pμe and P μ bar e bar the octant-δCP degeneracy occurs at different values of δCP, combination of neutrino and antineutrino runs help to resolve this. However, in regions where neutrinos do not have octant degeneracy adding antineutrino data is expected to decrease the sensitivity because of the degeneracy and reduced statistics. However we find that in case of DUNE baseline, the antineutrino runs help even in parameter space where the antineutrino probabilities suffer from degeneracies. We explore this point in detail and point out that this happens because of the (i) broad-band nature of the beam so that even if there is degeneracy at a particular energy bin, over the whole spectrum the degeneracy may not be there; (ii) the enhanced matter effect due to the comparatively longer baseline which creates an increased tension between the neutrino and the antineutrino probabilities which raises the overall χ2 in case of combined runs. This feature is more prominent for IH since the antineutrino probabilities in this case are much higher than the neutrino probabilities due to matter effects. The main role of antineutrinos in enhancing CP sensitivity is their ability to remove the octant-δCP degeneracy. However even if one assumes octant to be known the addition of antineutrinos can give enhanced CP sensitivity in some parameter regions due to the tension between the neutrino and antineutrino χ2s.

  5. Calculation of the nd Scattering Lengths by a Realistic Nonlocal Gaussian Potential

    SciTech Connect

    Fukukawa, K.; Fujiwara, Y.

    2010-05-12

    We apply a quark-model nucleon-nucleon interaction to the neutron-deuteron (nd) scattering. We solve the Alt-Grassberger-Sandhas equation in the momentum space. The doublet and quartet nd scattering lengths ({sup 2}a{sub nd} and {sup 4}a{sub nd}) are calculated. We re-confirm the pole structure in the doublet scattering length. The experimental data are well reproduced without three-nucleon forces. This result seems to be related to the off-shell properties of the quark-model nucleon-nucleon interaction.

  6. The SoLid anti-neutrino detector's readout system

    NASA Astrophysics Data System (ADS)

    Arnold, L.; Beaumont, W.; Cussans, D.; Newbold, D.; Ryder, N.; Weber, A.

    2017-02-01

    The SoLid collaboration have developed an intelligent readout system to reduce their 3200 silicon photomultiplier detector's data rate by a factor of 10000 whilst maintaining high efficiency for storing data from anti-neutrino interactions. The system employs an FPGA-level waveform characterisation to trigger on neutron signals. Following a trigger, data from a space-time region of interest around the neutron will be read out using the IPbus protocol. In these proceedings the design of the readout system is explained and results showing the performance of a prototype version of the system are presented.

  7. The muon system of the Daya Bay Reactor antineutrino experiment

    NASA Astrophysics Data System (ADS)

    An, F. P.; Balantekin, A. B.; Band, H. R.; Beriguete, W.; Bishai, M.; Blyth, S.; Brown, R. E.; Butorov, I.; Cao, G. F.; Cao, J.; Carr, R.; Chan, Y. L.; Chang, J. F.; Chang, L.; Chang, Y.; Chasman, C.; Chen, H. S.; Chen, H. Y.; Chen, Q. Y.; Chen, S. J.; Chen, S. M.; Chen, X. C.; Chen, X. H.; Chen, Y.; Chen, Y. X.; Cheng, Y. P.; Cherwinka, J. J.; Chu, M. C.; Cummings, J. P.; Dale, E.; de Arcos, J.; Deng, Z. Y.; Ding, Y. Y.; Diwan, M. V.; Draeger, E.; Du, X. F.; Dwyer, D. A.; Edwards, W. R.; Ely, S. R.; Fu, J. Y.; Ge, L. Q.; Gill, R.; Goett, J.; Gonchar, M.; Gong, G. H.; Gong, H.; Gu, W. Q.; Guan, M. Y.; Guo, X. H.; Hackenburg, R. W.; Han, G. H.; Hans, S.; He, M.; He, Q.; Heeger, K. M.; Heng, Y. K.; Hinrichs, P.; Hor, Y. K.; Hsiung, Y. B.; Hu, B. Z.; Hu, L. J.; Hu, L. M.; Hu, T.; Hu, W.; Huang, E. C.; Huang, H. X.; Huang, H. Z.; Huang, X. T.; Huber, P.; Hussain, G.; Isvan, Z.; Jaffe, D. E.; Jaffke, P.; Jetter, S.; Ji, X. L.; Ji, X. P.; Jiang, H. J.; Jiao, J. B.; Johnson, R. A.; Kang, L.; Kebwaro, J. M.; Kettell, S. H.; Kramer, M.; Kwan, K. K.; Kwok, M. W.; Kwok, T.; Lai, W. C.; Lai, W. H.; Lau, K.; Lebanowski, L.; Lee, J.; Lei, R. T.; Leitner, R.; Leung, A.; Leung, J. K. C.; Lewis, C. A.; Li, D. J.; Li, F.; Li, G. S.; Li, Q. J.; Li, W. D.; Li, X. N.; Li, X. Q.; Li, Y. Z. B.; Liang, H.; Lin, C. J.; Lin, G. L.; Lin, P. Y.; Lin, S. K.; Link, J. M.; Littenberg, L.; Littlejohn, B. R.; Liu, D. W.; Liu, H.; Liu, J. C.; Liu, J. L.; Liu, S. S.; Liu, Y. B.; Lu, C.; Lu, H. Q.; Luk, K. B.; Ma, Q. M.; Ma, X. B.; Ma, X. Y.; Ma, Y. Q.; McDonald, K. T.; McFarlane, M. C.; McKeown, R. D.; Meng, Y.; Mitchell, I.; Mohapatra, D.; Morgan, J. E.; Nakajima, Y.; Napolitano, J.; Naumov, D.; Naumova, E.; Nemchenok, I.; Newsom, C.; Ngai, H. Y.; Ngai, W. K.; Ning, Z.; Ochoa-Ricoux, J. P.; Olshevski, A.; Patton, S.; Pec, V.; Pearson, C. E.; Peng, J. C.; Piilonen, L. E.; Pinsky, L.; Pun, C. S. J.; Qi, F. Z.; Qi, M.; Qian, X.; Raper, N.; Ren, B.; Ren, J.; Rosero, R.; Roskovec, B.; Ruan, X. C.; Shao, B. B.; Steiner, H.; Sun, G. X.; Sun, J. L.; Tam, Y. H.; Tang, X.; Themann, H.; Tsang, K. V.; Tsang, R. H. M.; Tull, C. E.; Tung, Y. C.; Viren, B.; Virostek, S.; Vorobel, V.; Wang, C. H.; Wang, L. S.; Wang, L. Y.; Wang, L. Z.; Wang, M.; Wang, N. Y.; Wang, R. G.; Wang, W.; Wang, W. W.; Wang, X.; Wang, Y. F.; Wang, Z.; Wang, Z.; Wang, Z. M.; Webber, D. M.; Wei, H. Y.; Wei, Y. D.; Wen, L. J.; Whisnant, K.; White, C. G.; Whitehead, L.; Wilhelmi, J.; Wise, T.; Wong, H. L. H.; Wong, S. C. F.; Worcester, E.; Wu, Q.; Xia, D. M.; Xia, J. K.; Xia, X.; Xing, Z. Z.; Xu, G. H.; Xu, J.; Xu, J. L.; Xu, J. Y.; Xu, Y.; Xue, T.; Yan, J.; Yang, C. G.; Yang, L.; Yang, M. S.; Yang, M. T.; Ye, M.; Yeh, M.; Yeh, Y. S.; Young, B. L.; Yu, G. Y.; Yu, J. Y.; Yu, Z. Y.; Zang, S. L.; Zhan, L.; Zhang, C.; Zhang, F. H.; Zhang, J. W.; Zhang, K.; Zhang, Q. M.; Zhang, S. H.; Zhang, Y. H.; Zhang, Y. M.; Zhang, Y. X.; Zhang, Z. J.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, J.; Zhao, Q. W.; Zhao, Y.; Zhao, Y. B.; Zheng, L.; Zhong, W. L.; Zhou, L.; Zhou, Z. Y.; Zhuang, H. L.; Zou, J. H.

    2015-02-01

    The Daya Bay experiment consists of functionally identical antineutrino detectors immersed in pools of ultrapure water in three well-separated underground experimental halls near two nuclear reactor complexes. These pools serve both as shields against natural, low-energy radiation, and as water Cherenkov detectors that efficiently detect cosmic muons using arrays of photomultiplier tubes. Each pool is covered by a plane of resistive plate chambers as an additional means of detecting muons. Design, construction, operation, and performance of these muon detectors are described.

  8. Development and Prototyping of the PROSPECT Antineutrino Detector

    NASA Astrophysics Data System (ADS)

    Commeford, Kelley; Prospect Collaboration

    2017-01-01

    The PROSPECT experiment will make the most precise measurement of the 235U reactor antineutrino spectrum as well as search for sterile neutrinos using a segmented Li-loaded liquid scintillator neutrino detector. Several prototype detectors of increasing size, complexity, and fidelity have been constructed and tested as part of the PROSPECT detector development program. The challenges to overcome include the efficient rejection of cosmogenic background and collection of optical photons in a compact volume. Design choices regarding segment structure and layout, calibration source deployment, and optical collection methods are discussed. Results from the most recent multi-segment prototype, PROSPECT-50, will also be shown.

  9. The Muon System of the Daya Bay Reactor Antineutrino Experiment

    DOE PAGES

    An, F. P.; Hackenburg, R. W.; Brown, R. E.; ...

    2014-10-05

    The Daya Bay experiment consists of functionally identical antineutrino detectors immersed in pools of ultrapure water in three well-separated underground experimental halls near two nuclear reactor complexes. These pools serve both as shields against natural, low-energy radiation, and as water Cherenkov detectors that efficiently detect cosmic muons using arrays of photomultiplier tubes. Each pool is covered by a plane of resistive plate chambers as an additional means of detecting muons. Design, construction, operation, and performance of these muon detectors are described. (auth)

  10. The Muon System of the Daya Bay Reactor Antineutrino Experiment

    SciTech Connect

    An, F. P.; Hackenburg, R. W.; Brown, R. E.; Chasman, C.; Dale, E.; Diwan, M. V.; Gill, R.; Hans, S.; Isvan, Z.; Jaffe, D. E.; Kettell, S. H.; Littenberg, L.; Pearson, C. E.; Qian, X.; Theman, H.; Viren, B.; Worcester, E.; Yeh, M.; Zhang, C.

    2014-10-05

    The Daya Bay experiment consists of functionally identical antineutrino detectors immersed in pools of ultrapure water in three well-separated underground experimental halls near two nuclear reactor complexes. These pools serve both as shields against natural, low-energy radiation, and as water Cherenkov detectors that efficiently detect cosmic muons using arrays of photomultiplier tubes. Each pool is covered by a plane of resistive plate chambers as an additional means of detecting muons. Design, construction, operation, and performance of these muon detectors are described. (auth)

  11. Flavor Analysis of Nucleon, Δ , and Hyperon Electromagnetic Form Factors

    NASA Astrophysics Data System (ADS)

    Rohrmoser, Martin; Choi, Ki-Seok; Plessas, Willibald

    2017-03-01

    By the analysis of the world data base of elastic electron scattering on the proton and the neutron (for the latter, in fact, on ^2H and ^3He) important experimental insights have recently been gained into the flavor compositions of nucleon electromagnetic form factors. We report on testing the Graz Goldstone-boson-exchange relativistic constituent-quark model in comparison to the flavor contents in low-energy nucleons, as revealed from electron-scattering phenomenology. It is found that a satisfactory agreement is achieved between theory and experiment for momentum transfers up to Q^2˜ 4 GeV^2, relying on three-quark configurations only. Analogous studies have been extended to the Δ and the hyperon electromagnetic form factors. For them we here show only some sample results in comparison to data from lattice quantum chromodynamics.

  12. Hard QCD rescattering in few nucleon systems

    NASA Astrophysics Data System (ADS)

    Maheswari, Dhiraj; Sargsian, Misak

    2017-01-01

    The theoretical framework of hard QCD rescattering mechanism (HRM) is extended to calculate the high energy γ3 He -> pd reaction at 900 center of mass angle. In HRM model , the incoming high energy photon strikes a quark from one of the nucleons in the target which subsequently undergoes hard rescattering with the quarks from the other nucleons generating hard two-body baryonic system in the final state of the reaction. Based on the HRM, a parameter free expression for the differential cross section for the reaction is derived, expressed through the 3 He -> pd transition spectral function, hard pd -> pd elastic scattering cross section and the effective charge of the quarks being interchanged in the hard rescattering process. The numerical estimates obtained from this expression for the differential cross section are in a good agreement with the data recently obtained at the Jefferson Lab experiment, showing the energy scaling of cross section with an exponent of s-17, also consistent with the quark counting rule. The angular and energy dependences of the cross section are also predicted within HRM which are in good agreement with the preliminary data of these distributions. Research is supported by the US Department of Energy.

  13. Neutrino Exclusive Charged Current Quasi-Elastic Scattering in MINERvA

    NASA Astrophysics Data System (ADS)

    Walton, Tammy

    2012-10-01

    MINERvA part 3. The MINERvA experiment will measure neutrino and antineutrino quasi-elastic scattering on helium, water, carbon, iron, and lead for neutrinos in the few GeV range. We will present an overview and status of the analysis for neutrino exclusive charged current quasi-elastic scattering on lead, iron, and carbon.

  14. Neutrino Exclusive Charged Current Quasi-Elastic Scattering in MINERvA

    NASA Astrophysics Data System (ADS)

    Walton, Tammy

    2012-03-01

    The MINERvA experiment will measure neutrino and antineutrino quasi-elastic scattering on helium, water, carbon, iron, and lead for neutrinos in the few GeV range. We will present an overview of MINERvA analysis plan for neutrino exclusive charged current quasi-elastic scattering on lead, iron, and carbon.

  15. Kaon-nucleus scattering

    NASA Technical Reports Server (NTRS)

    Hong, Byungsik; Maung, Khin Maung; Wilson, John W.; Buck, Warren W.

    1989-01-01

    The derivations of the Lippmann-Schwinger equation and Watson multiple scattering are given. A simple optical potential is found to be the first term of that series. The number density distribution models of the nucleus, harmonic well, and Woods-Saxon are used without t-matrix taken from the scattering experiments. The parameterized two-body inputs, which are kaon-nucleon total cross sections, elastic slope parameters, and the ratio of the real to the imaginary part of the forward elastic scattering amplitude, are presented. The eikonal approximation was chosen as our solution method to estimate the total and absorptive cross sections for the kaon-nucleus scattering.

  16. Electroexcitation of nucleon resonances

    SciTech Connect

    Inna Aznauryan, Volker D. Burkert

    2012-01-01

    We review recent progress in the investigation of the electroexcitation of nucleon resonances, both in experiment and in theory. The most accurate results have been obtained for the electroexcitation amplitudes of the four lowest excited states, which have been measured in a range of Q2 up to 8 and 4.5 GeV2 for the Delta(1232)P33, N(1535)S11 and N(1440)P11, N(1520)D13, respectively. These results have been confronted with calculations based on lattice QCD, large-Nc relations, perturbative QCD (pQCD), and QCD-inspired models. The amplitudes for the Delta(1232) indicate large pion-cloud contributions at low Q2 and don't show any sign of approaching the pQCD regime for Q2<7 GeV2. Measured for the first time, the electroexcitation amplitudes of the Roper resonance, N(1440)P11, provide strong evidence for this state as a predominantly radial excitation of a three-quark (3q) ground state, with additional non-3-quark contributions needed to describe the low Q2 behavior of the amplitudes. The longitudinal transition amplitude for the N(1535)S11 was determined and has become a challenge for quark models. Explanations may require large meson-cloud contributions or alternative representations of this state. The N(1520)D13 clearly shows the rapid changeover from helicity-3/2 dominance at the real photon point to helicity-1/2 dominance at Q2 > 0.5 GeV2, confirming a long-standing prediction of the constituent quark model. The interpretation of the moments of resonance transition form factors in terms of transition transverse charge distributions in infinite momentum frame is presented.

  17. Electron antineutrino detection from simulated supernovae

    NASA Astrophysics Data System (ADS)

    Luoma, Steffon Jon

    Supernova 1987A demonstrated that neutrinos from a nearby supernova could be detected terrestrially. The partition of events between the neutrino flavours generated by stellar collapse can provide details about supernova dynamics and by using Monte Carlo simulations we can prepare for the analysis of data from the next such supernova. Through its sensitivity to the charged current, neutral current and elastic scattering interactions in both the heavy and light waters, the Sudbury Neutrino Observatory (SNO) is able to measure this partition. The unique signal of the charged current [Special characters omitted.] interactions with deuterium nuclei ([Special characters omitted.] + d [arrow right] n + n + e + ) allows a direct count of the number of [Special characters omitted.] 's to be made. With the addition of NaCl to the heavy water the efficiency of detecting neutrons was increased, which in turn increased the sensitivity for the detection of [Special characters omitted.] 's. This work explores methods of identifying [Special characters omitted.] 's in the high flux environment of a modeled supernova source in SNO during the salt phase. The differences in energy spectrum and in PMT hit pattern of positrons and neutrons allow for distinction between the two, and thus permits classification. Association of these particles to the [Special characters omitted.] interaction is made possible by measuring the time and space between detection of the positron and each neutron generated from the same [Special characters omitted.] . A [Special characters omitted.] is considered to be identified when the correct final state particles generated from the interaction with a deuterium nucleus are associated with each other. Because the expected data rate may be very high and may have a large dynamic range, causing some improper particle association, a pivotal component of this analysis is understanding the rate dependencies. To accomplish this, datasets were generated at several

  18. Translation invariance and antisymmetry in the theory of the nucleon optical model

    NASA Astrophysics Data System (ADS)

    Johnson, R. C.

    2017-06-01

    The first step in any formalism that aims to connect a many-nucleon theory of nucleon-nucleus scattering and the concept of an optical model potential in the sense pioneered by Feshbach is to explain what is meant by the optical model wave function. By definition, this is a function of a single space coordinate plus a set of single-nucleon internal variables. This article gives a critique of the definition as it is frequently expressed in second quantization language and suggests a new definition which is more consistent with the requirements of antisymmetry and translational invariance. A modification of the time-dependent Green's function formalism is suggested.

  19. Unpolarized nucleon structure studies utilizing polarized electromagnetic probes.

    SciTech Connect

    Arrington, J.; Physics

    2009-08-15

    By the mid-1980s, measurements of the nucleon form factors had reached a stage where only slow, incremental progress was possible using unpolarized electron scattering. The development of high quality polarized beams, polarized targets, and recoil polarimeters led to a renaissance in the experimental program. I provide an overview of the changes in the field in the last ten years, which were driven by the dramatically improved data made possible by a new family of tools to measure polarization observables.

  20. Nucleon Transfer Reactions in Few-Body Nuclear Systems

    NASA Astrophysics Data System (ADS)

    Deltuva, A.

    2017-03-01

    Three- and four-body scattering is described solving Faddeev-Yakubovsky or equivalent Alt-Grassberger-Sandhas integral equations for transition operators in momentum-space. Several realistic nuclear interaction models are used; the Coulomb force between charged particles is taken into account via the screening and renormalization method. Differential cross sections and spin observables for various nucleon transfer reactions are calculated and compared with experimental data.

  1. The gluon contribution to nucleon spin

    SciTech Connect

    Antje Bruell

    2006-04-06

    EIC is the ideal machine to finally determine the contribution of the gluons to the nucleon spin. Measurements of G{sub 1} will allow: (1) a determination of {Delta}G/G from its scaling violation and (2) a statistically very precise determination of the Bjorken Sum (systematics due to uncertainty in proton beam polarization). Measurements of charm cross section asymmetries will provide a precise determination of {Delta}G/G for 0.003 < x < 0.5 at a fixed value of Q{sup 2} of {approx} GeV{sup 2} provided they can measure the scattered electron at extremely small angles; separate the primary and secondary vertex with sufficient precision; and control the contribution of resolved photons. More work is needed to define the necessary detector requirements.

  2. From nucleons to nuclei to fusion reactions

    NASA Astrophysics Data System (ADS)

    Quaglioni, S.; Navrátil, P.; Roth, R.; Horiuchi, W.

    2012-12-01

    Nuclei are prototypes of many-body open quantum systems. Complex aggregates of protons and neutrons that interact through forces arising from quantum chromo-dynamics, nuclei exhibit both bound and unbound states, which can be strongly coupled. In this respect, one of the major challenges for computational nuclear physics, is to provide a unified description of structural and reaction properties of nuclei that is based on the fundamental underlying physics: the constituent nucleons and the realistic interactions among them. This requires a combination of innovative theoretical approaches and high-performance computing. In this contribution, we present one of such promising techniques, the ab initio no-core shell model/resonating-group method, and discuss applications to light nuclei scattering and fusion reactions that power stars and Earth-base fusion facilities.

  3. From Nucleons To Nuclei To Fusion Reactions

    SciTech Connect

    Quaglioni, S; Navratil, P; Roth, R; Horiuchi, W

    2012-02-15

    Nuclei are prototypes of many-body open quantum systems. Complex aggregates of protons and neutrons that interact through forces arising from quantum chromo-dynamics, nuclei exhibit both bound and unbound states, which can be strongly coupled. In this respect, one of the major challenges for computational nuclear physics, is to provide a unified description of structural and reaction properties of nuclei that is based on the fundamental underlying physics: the constituent nucleons and the realistic interactions among them. This requires a combination of innovative theoretical approaches and high-performance computing. In this contribution, we present one of such promising techniques, the ab initio no-core shell model/resonating-group method, and discuss applications to light nuclei scattering and fusion reactions that power stars and Earth-base fusion facilities.

  4. Nucleon spin decomposition and orbital angular momentum in the nucleon

    NASA Astrophysics Data System (ADS)

    Wakamatsu, Masashi

    2014-09-01

    To get a complete decomposition of nucleon spin is a fundamentally important homework of QCD. In fact, if our researches end up without accomplishing this task, a tremendous efforts since the 1st discovery of the nucleon spin crisis would end in the air. We now have a general agreement that there are at least two physically inequivalent gauge-invariant decompositions of the nucleon. In these two decompositions, the intrinsic spin parts of quarks and gluons are just common. What discriminate these two decompositions are the orbital angular momentum (OAM) parts. The OAMs of quarks and gluons appearing in the first decomposition are the so-called ``mechanical'' OAMs, while those appearing in the second decomposition are the generalized (gauge-invariant) ``canonical'' ones. By this reason, these decompositions are broadly called the ``mechanical'' and ``canonical'' decompositions of the nucleon spin. Still, there remains several issues, which have not reached a complete consensus among the experts. (See the latest recent). In the present talk, I will mainly concentrate on the practically most important issue, i.e. which decomposition is more favorable from the observational viewpoint. There are two often-claimed advantages of canonical decomposition. First, each piece of this decomposition satisfies the SU(2) commutation relation or angular momentum algebra. Second, the canonical OAM rather than the mechanical OAM is compatible with free partonic picture of constituent orbital motion. In the present talk, I will show that both these claims are not necessarily true, and push forward a viewpoint that the ``mechanical'' decomposition is more physical in that it has more direct connection with observables. I also emphasize that the nucleon spin decomposition accessed by the lattice QCD analyses is the ``mechanical'' decomposition not the ``canonical'' one. The recent lattice QCD studies of the nucleon spin decomposition are also briefly overviewed.

  5. Time Dependent Nuclear Scattering Calculations

    NASA Astrophysics Data System (ADS)

    Weeks, David

    2005-04-01

    A new time dependent method for calculating scattering matrix elements of two and three body nuclear collisions below 50 Mev is being developed. The procedure closely follows the channel packet method (CPM) used to compute scattering matrix elements for non-adiabatic molecular reactions.ootnotetextT.A.Niday and D.E.Weeks, Chem. Phys. Letters 308 (1999) 106 Currently, one degree of freedom calculations using a simple square well have been completed and a two body scattering calculation using the Yukawa potential is anticipated. To perform nuclear scattering calculations with the CPM that will incorporate the nucleon-nucleon tensor force, we plan to position initial reactant and product channel packets in the asymptotic limit on single coupled potential energy surfaces labeled by the spin, isospin, and total angular momentum of the reactant nucleons. The wave packets will propagated numerically using the split operator method augmented by a coordinate dependant unitary transformation used to diagonalize the potential. Scattering matrix elements will be determined by the Fourier transform of the correlation function between the evolving reactant and product wave packets. A brief outline of the Argonne v18 nucleon-nucleon potentialootnotetextR.B.Wiringa, V.G.J.Stoks, and R.Schiavilla, Physical Review C 51(1995) 38 and the proposed wave packet calculations will be presented.

  6. Systematics of meson-Skyrmion scattering

    SciTech Connect

    Mattis, M.P.

    1986-02-01

    The S-matrix characterizing the scattering of pions from nucleons is calculated in the context of skyrmion models of the nucleon. These are models in which the nucleon is considered a soliton in the field of pions. The spectrum of nucleon and delta resonances in the Skyrme model is calculated and found to be in overall good agreement with Nature. Model-independent sum rules between amplitudes in the same partial wave are derived and examined. An extension of the formalism to the case of three light flavors is presented. 31 refs., 26 figs., 6 tabs.

  7. Nucleon spin structure studies at COMPASS

    SciTech Connect

    Marchand, Claude

    2006-02-11

    One of the main goal of the COMPASS experiment at CERN is the study of the spin structure of the nucleon in DIS, by scattering 160 GeV polarized muon beam on a longitudinally (or transversely) polarized 6LiD target. Besides the scattered muon, the particles produced in the deep inelastic scattering are detected by a two stage magnetic spectrometer equipped with state of the art tracking and particle ID detectors.The emphasis of COMPASS muon program is the direct determination of the gluon polarization {delta}G/G, accessed via asymmetries involving photon-gluon fusion mechanism (PGF). Both open charm production (detecting D0's), as well as production of height pT hadron pairs are used to tag PGF. Preliminary results for {delta}G/G based on the analysis of 2002 and 2003 data are shown. In addition, improved measurement of the deuteron structure function g{sub 1}{sup d} at small x, as well as studies of transverse distribution functions in the deuteron by measuring Collins and Sivers azimuthal asymmetries, are reported.

  8. Parameterizations of Pion Energy Spectrum in Nucleon-Nucleon Collisions

    NASA Technical Reports Server (NTRS)

    Cucinotta, Franics A.; Wilson, John W.; Norbury, John W.

    1998-01-01

    The effects of pion (PI) production are expected to play an important role in radiation exposures in the upper atmosphere or on the Martian surface. Nuclear databases for describing pion production are developed for radiation transport codes to support these studies. We analyze the secondary energy spectrum of pions produced in nucleon-nucleon (NN) collisions in the relativistic one-pion exchange model. Parametric formulas of the isospin cross sections for one-pion production channels are discussed and are used to renormalize the model spectrum. Energy spectra for the deuteron related channels (NN yields dPi) are also described.

  9. Above-ground Antineutrino Detection for Nuclear Reactor Monitoring

    DOE PAGES

    Sweany, Melinda; Brennan, James S.; Cabrera-Palmer, Belkis; ...

    2014-08-01

    Antineutrino monitoring of nuclear reactors has been demonstrated many times, however the technique has not as of yet been developed into a useful capability for treaty verification purposes. The most notable drawback is the current requirement that detectors be deployed underground, with at least several meters-water-equivalent of shielding from cosmic radiation. In addition, the deployment of liquid-based detector media presents a challenge in reactor facilities. We are currently developing a detector system that has the potential to operate above ground and circumvent deployment problems associated with a liquid detection media: the system is composed of segments of plastic scintillator surroundedmore » by 6LiF/ZnS:Ag. ZnS:Ag is a radio-luminescent phosphor used to detect the neutron capture products of lithium-6. Because of its long decay time compared to standard plastic scintillators, pulse-shape discrimination can be used to distinguish positron and neutron interactions resulting from the inverse beta decay (IBD) of antineutrinos within the detector volume, reducing both accidental and correlated backgrounds. Segmentation further reduces backgrounds by identifying the positron’s annihilation gammas, which are absent for most correlated and uncorrelated backgrounds. This work explores different configurations in order to maximize the size of the detector segments without reducing the intrinsic neutron detection efficiency. We believe this technology will ultimately be applicable to potential safeguards scenarios such as those recently described.« less

  10. Above-ground Antineutrino Detection for Nuclear Reactor Monitoring

    SciTech Connect

    Sweany, Melinda; Brennan, James S.; Cabrera-Palmer, Belkis; Kiff, Scott D.; Reyna, David; Throckmorton, Daniel J.

    2014-08-01

    Antineutrino monitoring of nuclear reactors has been demonstrated many times, however the technique has not as of yet been developed into a useful capability for treaty verification purposes. The most notable drawback is the current requirement that detectors be deployed underground, with at least several meters-water-equivalent of shielding from cosmic radiation. In addition, the deployment of liquid-based detector media presents a challenge in reactor facilities. We are currently developing a detector system that has the potential to operate above ground and circumvent deployment problems associated with a liquid detection media: the system is composed of segments of plastic scintillator surrounded by 6LiF/ZnS:Ag. ZnS:Ag is a radio-luminescent phosphor used to detect the neutron capture products of lithium-6. Because of its long decay time compared to standard plastic scintillators, pulse-shape discrimination can be used to distinguish positron and neutron interactions resulting from the inverse beta decay (IBD) of antineutrinos within the detector volume, reducing both accidental and correlated backgrounds. Segmentation further reduces backgrounds by identifying the positron’s annihilation gammas, which are absent for most correlated and uncorrelated backgrounds. This work explores different configurations in order to maximize the size of the detector segments without reducing the intrinsic neutron detection efficiency. We believe this technology will ultimately be applicable to potential safeguards scenarios such as those recently described.

  11. Weak production of strange particles and η mesons off the nucleon

    SciTech Connect

    Alam, M. Rafi; Athar, M. Sajjad; Simo, I. Ruiz; Alvarez-Ruso, L.; Vacas, M. J. Vicente

    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{sub 11}(1650) resonances are included.

  12. Sensitivity of the Antineutrino Emission from Reactors to the Fuel Content

    SciTech Connect

    Hayes-Sterbenz, Anna C

    2012-06-25

    We investigated the antineutrino signals for several reactor core designs. In all cases we found that the antineutrino signals are distinct. The signals are distinguishable by the combination of their magnitudes and their rate of change with fuel burn-up. If the thermal power of the reactor is known, the overall uncertainty in the antineutrino flux emitted from the reactor is about 5%. The quoted uncertainty in the number of antineutrinos per fission for {sup 235}U, {sup 239}Pu, and {sup 241}Pu is less than 3% and for {sup 238}U is 8%. When folded with the uncertainty in the thermal power measurement and the uncertainty in converting the thermal power to a fission rate, the total antineutrino flux is typically quoted with an accuracy of 3-5%. This overall uncertainty in the antineutrino flux, together with the calculations presented here, suggests that the differences in fuels for the class of reactor designed considered would be detectable using antineutrino monitoring.

  13. 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.

  14. Nucleon Structure from Lattice QCD

    SciTech Connect

    Haegler, Philipp

    2011-10-24

    Hadron structure calculations in lattice QCD have seen substantial progress during recent years. We illustrate the achievements that have been made by discussing latest lattice results for a limited number of important observables related to nucleon form factors and generalized parton distributions. A particular focus is placed on the decomposition of the nucleon spin 1/2 in terms of quark spin and orbital angular momentum contributions. Results and limitations of the necessary chiral extrapolations based on ChPT will be briefly discussed.

  15. The hyperon-nucleon interaction

    NASA Astrophysics Data System (ADS)

    Haidenbauer, J.

    2007-11-01

    Results of two recent hyperon-nucleon interaction potentials, both developed by the Bonn-Jülich group, are presented that are derived either in the conventional meson-exchange picture or within leading order chiral effective field theory. The chiral potential consists of one-pseudoscalar-meson exchanges and non-derivative four-baryon contact terms. The most salient feature of the new meson-exchange hyperon-nucleon model is that the contributions in the scalar-isoscalar (σ) and vector-isovector (ρ) exchange channels are constrained by a microscopic model of correlated ππ and KK¯ exchange.

  16. Antineutrinos for Reactor Safeguards: Effect of Fuel Loading and Burnup on the Signal

    NASA Astrophysics Data System (ADS)

    Erickson, Anna; Bernstein, Adam; Bowden, Nathaniel

    2014-02-01

    Various types of nuclear reactor related information, including relative power level and fuel evolution parameters, can be inferred remotely using antineutrino detectors. We show that it is possible to verify assembly-level burnup using information derived from an antineutrino detector if the nominal reactor fuel loading is known. Alternatively, if the core power is measured using an independent method, for example, a thermal hydraulic element, and the nominal core behavior is known, the antineutrino detector has a capability to determine previously unknown MOX loading in the core.

  17. Search for differences in oscillation parameters for atmospheric neutrinos and antineutrinos at Super-Kamiokande.

    PubMed

    Abe, K; Hayato, Y; Iida, T; Ikeda, M; Iyogi, K; Kameda, J; Koshio, Y; Kozuma, Y; Miura, M; Moriyama, S; Nakahata, M; Nakayama, S; Obayashi, Y; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takenaga, Y; Takeuchi, Y; Ueno, K; Ueshima, K; Watanabe, H; Yamada, S; Yokozawa, T; Ishihara, C; Kaji, H; Lee, K P; Kajita, T; Kaneyuki, K; McLachlan, T; Okumura, K; Shimizu, Y; Tanimoto, N; Martens, K; Vagins, M R; Labarga, L; Magro, L M; Dufour, F; Kearns, E; Litos, M; Raaf, J L; Stone, J L; Sulak, L R; Goldhaber, M; Bays, K; Kropp, W R; Mine, S; Regis, C; Smy, M B; Sobel, H W; Ganezer, K S; Hill, J; Keig, W E; Jang, J S; Kim, J Y; Lim, I T; Albert, J B; Scholberg, K; Walter, C W; Wendell, R; Wongjirad, T M; Tasaka, S; Learned, J G; Matsuno, S; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Nishikawa, K; Nishino, H; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Suzuki, A T; Minamino, A; Nakaya, T; Fukuda, Y; Itow, Y; Mitsuka, G; Tanaka, T; Jung, C K; Taylor, I; Yanagisawa, C; Ishino, H; Kibayashi, A; Mino, S; Mori, T; Sakuda, M; Toyota, H; Kuno, Y; Kim, S B; Yang, B S; Ishizuka, T; Okazawa, H; Choi, Y; Nishijima, K; Koshiba, M; Yokoyama, M; Totsuka, Y; Chen, S; Heng, Y; Yang, Z; Zhang, H; Kielczewska, D; Mijakowski, P; Connolly, K; Dziomba, M; Wilkes, R J

    2011-12-09

    We present a search for differences in the oscillations of antineutrinos and neutrinos in the Super-Kamiokande-I, -II, and -III atmospheric neutrino sample. Under a two-flavor disappearance model with separate mixing parameters between neutrinos and antineutrinos, we find no evidence for a difference in oscillation parameters. Best-fit antineutrino mixing is found to be at (Δm2,sin2 2θ)=(2.0×10(-3)  eV2, 1.0) and is consistent with the overall Super-K measurement.

  18. Total Absorption Spectroscopy Study of (92)Rb Decay: A Major Contributor to Reactor Antineutrino Spectrum Shape.

    PubMed

    Zakari-Issoufou, A-A; Fallot, M; Porta, A; Algora, A; Tain, J L; Valencia, E; Rice, S; Bui, V M; Cormon, S; Estienne, M; Agramunt, J; Äystö, J; Bowry, M; Briz, J A; Caballero-Folch, R; Cano-Ott, D; Cucoanes, A; Elomaa, V-V; Eronen, T; Estévez, E; Farrelly, G F; Garcia, A R; Gelletly, W; Gomez-Hornillos, M B; Gorlychev, V; Hakala, J; Jokinen, A; Jordan, M D; Kankainen, A; Karvonen, P; Kolhinen, V S; Kondev, F G; Martinez, T; Mendoza, E; Molina, F; Moore, I; Perez-Cerdán, A B; Podolyák, Zs; Penttilä, H; Regan, P H; Reponen, M; Rissanen, J; Rubio, B; Shiba, T; Sonzogni, A A; Weber, C

    2015-09-04

    The antineutrino spectra measured in recent experiments at reactors are inconsistent with calculations based on the conversion of integral beta spectra recorded at the ILL reactor. (92)Rb makes the dominant contribution to the reactor antineutrino spectrum in the 5-8 MeV range but its decay properties are in question. We have studied (92)Rb decay with total absorption spectroscopy. Previously unobserved beta feeding was seen in the 4.5-5.5 region and the GS to GS feeding was found to be 87.5(25)%. The impact on the reactor antineutrino spectra calculated with the summation method is shown and discussed.

  19. Nuclear effects on neutrino emissivities from nucleon-nucleon bremsstrahlung

    NASA Astrophysics Data System (ADS)

    Stoica, S.; Paun, V. P.; Negoita, A. G.

    2004-06-01

    The rates of neutrino pair emission by nucleon-nucleon (NN) bremsstrahlung are calculated with the inclusion of the full contribution from a nuclear one pion exchange potential (OPEP). We compute the contributions from the neutron-neutron (nn), proton-proton (pp), and neutron-proton (np) processes for physical conditions encountered in supernovae and neutron stars, both in the degenerate (D) and nondegenerate (ND) limits. We find a significant reduction of these rates, especially for the nn and pp processes, in comparison with the case when the whole nuclear contribution was replaced by constants, representing the high-momentum limits of the expressions of the nuclear potential. Furthermore, we also perform the calculations by including contributions due to the ρ meson exchange between nucleons, in the OPEP. This may be relevant for processes produced in the inner core of neutron stars, where the density may exceed several times the standard nuclear density, and the short-range part of the NN interaction should be taken into account. These corrections lead to an additional suppression of the neutrino emission rates between (8 and 36)%, depending on the process [nn (pp) or np] and physical conditions (temperature and degeneracy of the nucleons).

  20. Recent lattice QCD results on nucleon structure

    SciTech Connect

    Konstantinos Orginos

    2006-07-01

    I review recent developments in lattice calculations of nucleon structure. In particular, I cover the calculations of nucleon matrix elements related to generalized parton distribution functions, structure functions and form factors.

  1. Exploring Three Nucleon Forces in Lattice QCD

    SciTech Connect

    Doi, Takumi

    2011-10-21

    We study the three nucleon force in N{sub f} = 2 dynamical clover fermion lattice QCD, utilizing the Nambu-Bethe-Salpeter wave function of the three nucleon system. Since parity-odd two nucleon potentials are not available in lattice QCD at this moment, we develop a new formulation to extract the genuine three nucleon force which requires only the information of parity-even two nucleon potentials. In order to handle the extremely expensive calculation cost, we consider a specific three-dimensional coordinate configuration for the three nucleons. We find that the linear setup is advantageous, where nucleons are aligned linearly with equal spacings. The lattice calculation is performed with 16{sup 3}x32 configurations at {beta} = 1.95, m{sub {pi}} = 1.13 GeV generated by CP-PACS Collaboration, and the result of the three nucleon force in triton channel is presented.

  2. Nucleon resonance structure in the finite volume of lattice QCD

    NASA Astrophysics Data System (ADS)

    Wu, Jia-Jun; Kamano, H.; Lee, T.-S. H.; Leinweber, D. B.; Thomas, A. W.

    2017-06-01

    An approach for relating the nucleon resonances extracted from π N reaction data to lattice QCD calculations has been developed by using the finite-volume Hamiltonian method. Within models of π N reactions, bare states are introduced to parametrize the intrinsic excitations of the nucleon. We show that the resonance can be related to the probability PN*(E) of finding the bare state, N*, in the π N scattering states in infinite volume. We further demonstrate that the probability PN*V(E) of finding the same bare states in the eigenfunctions of the underlying Hamiltonian in finite volume approaches PN*(E) as the volume increases. Our findings suggest that the comparison of PN* (E) and PN*V(E) can be used to examine whether the nucleon resonances extracted from the π N reaction data within the dynamical models are consistent with lattice QCD calculation. We also discuss the measurement of PN*V(E) directly from lattice QCD. 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.

  3. Stylized features of single-nucleon momentum distributions

    NASA Astrophysics Data System (ADS)

    Ryckebusch, Jan; Vanhalst, Maarten; Cosyn, Wim

    2015-05-01

    Nuclear short-range correlations (SRC) typically manifest themselves in the tail parts of the single-nucleon momentum distributions. We propose an approximate practical method for computing those SRC contributions to the high-momentum parts. The framework adopted in this work is applicable throughout the nuclear mass table and corrects mean-field models for central, spin-isospin and tensor correlations by shifting the complexity induced by the SRC from the wave functions to the operators. It is argued that the expansion of these modified operators can be truncated to a low order. The proposed model can generate the SRC-related high-momentum tail of the single-nucleon momentum distribution. These are dominated by correlation operators acting on mean-field pairs with vanishing relative radial and angular-momentum quantum numbers. The proposed method explains the dominant role of proton-neutron pairs in generating the SRC and accounts for the magnitude and mass dependence of SRC as probed in inclusive electron scattering. It also provides predictions for the ratio of the amount of correlated proton-proton to proton-neutron pairs which are in line with the observations. In asymmetric nuclei, the correlations make the average kinetic energy for the minority nucleons larger than for the majority nucleons.

  4. Spin Structure of the Nucleon - Status and Recent Results

    SciTech Connect

    Kuhn, Sebastian; Chen, Jian-Ping; Leader, Elliot

    2009-07-01

    After the initial discovery of the so-called "spin crisis in the parton model" in the 1980s, a large set of polarization data in deep inelastic lepton-nucleon scattering was collected at labs like SLAC, DESY and CERN. More recently, new high precision data at large $x$ and in the resonance region have come from experiments at Jefferson Lab. These data, in combination with the earlier ones, allow us to study in detail the polarized parton densities, the $Q^2$ dependence of various moments of spin structure functions, the duality between deep inelastic and resonance data, and the nucleon structure in the valence quark region. Together with complementary data from HERMES, RHIC and COMPASS, we can put new limits on the flavor decomposition and the gluon contribution to the nucleon spin. In this report, we provide an overview of our present knowledge of the nucleon spin structure and give an outlook on future experiments. We focus in particular on the spin structure functions $g_

  5. 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 PN*(E) of finding the bare state, N*, in the πN scattering states in infinite volume. We further demonstrate that the probability PVN*(E) of finding the same bare states in the eigenfunctions of the underlying Hamiltonian in finite volume approaches PN*(E) as the volume increases. Our findings suggestmore » that the comparison of PN*(E) and PVN*(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 PVN*(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

  6. Weak Deeply Virtual Compton Scattering

    SciTech Connect

    Ales Psaker; Wolodymyr Melnitchouk; Anatoly Radyushkin

    2007-03-01

    We extend the analysis of the deeply virtual Compton scattering process to the weak interaction sector in the generalized Bjorken limit. The virtual Compton scattering amplitudes for the weak neutral and charged currents are calculated at the leading twist within the framework of the nonlocal light-cone expansion via coordinate space QCD string operators. Using a simple model, we estimate cross sections for neutrino scattering off the nucleon, relevant for future high intensity neutrino beam facilities.

  7. Nucleon Optical Potential in Brueckner Theory

    SciTech Connect

    Haider, Wasi

    2008-10-13

    Recent results of g-matrix calculation of the nucleon optical potential are presented and their predictions are compared with experimental data for Sn-isotopes. Corrections to spin-orbit part of the potential are discussed. Extension of Bethe's method to calculate three nucleon interaction effects in the nucleon optical potential is presented.

  8. Leading chiral logarithms for the nucleon mass

    SciTech Connect

    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.

  9. 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.

  10. Magnetic polarizability of the nucleon

    SciTech Connect

    Ragusa, S.

    1996-01-01

    We derive an expression for the magnetic polarizability of the nucleon, as related to sums of products of its electromagnetic transition moments involving the electric and magnetic dipoles and mean-square radii, as well as the electric quadrupole moment. Two sum rules emerge from the calculation. {copyright} {ital 1995 The American Physical Society.}

  11. Soudan 2 nucleon decay experiment

    SciTech Connect

    Thron, J.L.

    1986-01-01

    The Soudan 2 nucleon decay experiment consists of a 1.1 Kton fine grained iron tracking calorimeter. It has a very isotropic detection structure which along with its flexible trigger will allow detection of multiparticle and neutrino proton decay modes. The detector has now entered its construction stage.

  12. Precision Search for Muon Antineutrino Disappearance Oscillations Using a Dual Baseline Technique

    SciTech Connect

    Cheng, Gary Li

    2013-01-01

    A search for short baseline muon antineutrino disappearance with the SciBooNE and MiniBooNE experiments at Fermi National Accelerator Laboratory in Batavia, Illinois is presented. Short baseline muon antineutrino disappearance measurements help constrain sterile neutrino models. The two detectors observe muon antineutrinos from the same beam, therefore the combined analysis of their data sets serves to partially constrain some of the flux and cross section uncertainties. A likelihood ratio method was used to set a 90% confidence level upper limit on muon antineutrino disappearance that dramatically improves upon prior sterile neutrino oscillation limits in the Δm2=0.1-100 eV2 region.

  13. Opportunities for applied measurements using the PROSPECT antineutrino detector: reactor physics and safeguards

    NASA Astrophysics Data System (ADS)

    Bowden, Nathaniel; Prospect Collaboration

    2015-10-01

    Disagreement of reactor antineutrino spectrum and flux measurements with updated predictions indicates that we have much to learn about the complicated processes underlying antineutrino production in reactors, as well as hinting at new physics. A number of new efforts seek to address these questions, including the PROSPECT experiment planned at the HFIR research reactor. In addition to greatly advancing our understanding of reactor antineutrino emissions, PROSPECT can support a rich applied physics program. The detection technology developed for PROSPECT will enable precision antineutrino spectrum measurements close to essentially any reactor type. Here we describe how such measurements provide opportunities to probe fissile isotope and fission daughter distributions, and their potential use for reactor physics and safeguards applications. LLNL-ABS-673983. Prepared by LLNL under Contract DE-AC52-07NA27344.

  14. Determination of the direction to a source of antineutrinos via inverse beta decay in Double Chooz

    NASA Astrophysics Data System (ADS)

    Nikitenko, Ya.

    2016-11-01

    To determine the direction to a source of neutrinos (and antineutrinos) is an important problem for the physics of supernovae and of the Earth. The direction to a source of antineutrinos can be estimated through the reaction of inverse beta decay. We show that the reactor neutrino experiment Double Chooz has unique capabilities to study antineutrino signal from point-like sources. Contemporary experimental data on antineutrino directionality is given. A rigorous mathematical approach for neutrino direction studies has been developed. Exact expressions for the precision of the simple mean estimator of neutrinos' direction for normal and exponential distributions for a finite sample and for the limiting case of many events have been obtained.

  15. Status of the JUNO reactor anti-neutrino experiment

    NASA Astrophysics Data System (ADS)

    Lu, Haoqi; JUNO Collaboration

    2017-06-01

    The Jiangmen Underground Neutrino Observatory (JUNO) is a reactor antineutrino experiment with the aim to determine the neutrino mass hierarchy. The detector will be filled with 20 kilotons of liquid scintillator and instrumented with 18000 20-inch PMTs to achieve an unprecedented energy resolution of 3%@1 MeV. A 35.4 m diameter acrylic sphere will be built as a liquid scintillator vessel.The detector will be constructed in a 700-m-deep-underground laboratory to reduce cosmogenic muon flux. An external veto cosisting of a water Cherenkov detector and a top tracker will be used for cosmogenic muon detection and background reduction. The mass hierarchy sensitivity is expected to reach 3-4σ after 6 years of data taking. Civil construction and detector R&D are underway. Data taking is expected to start in 2020.

  16. Three-nucleon problem: trinucleon bound states and trinucleon interactions

    SciTech Connect

    Friar, J.L.

    1985-01-01

    The assumptions underlying the formulation and solution of the Schroedinger equation for three nucleons in configuration space are reviewed, in conjunction with those qualitative aspects of the two-nucleon problem which are important. The geometrical features of the problem and the crucial role of the angular momentum barrier are developed. The boundary conditions for scattering are discussed qualitatively, and the Faddeev-Noyes equation is motivated. The method of splines and orthogonal collocation are shown to provide convenient techniques for generating numerical solutions. Properties of the many numerical solutions for the bound states and zero-energy scattering states are discussed. The evidence for three-body forces is reviewed, and the results of the recent calculations including such forces are discussed. The importance of electromagnetic interactions in the three-nucleon systems is motivated. Relativistic corrections and meson-exchange currents are discussed in the context of ''rules of scale'', and the pion-exchange currents of nonrelativistic order are derived. The experimental results for trinucleon electromagnetic interactions are reviewed, including recent tritium data. Conclusions are presented. 56 refs., 23 figs.

  17. Kaon-nucleus scattering

    NASA Technical Reports Server (NTRS)

    Hong, Byungsik; Buck, Warren W.; Maung, Khin M.

    1989-01-01

    Two kinds of number density distributions of the nucleus, harmonic well and Woods-Saxon models, are used with the t-matrix that is taken from the scattering experiments to find a simple optical potential. The parameterized two body inputs, which are kaon-nucleon total cross sections, elastic slope parameters, and the ratio of the real to imaginary part of the forward elastic scattering amplitude, are shown. The eikonal approximation was chosen as the solution method to estimate the total and absorptive cross sections for the kaon-nucleus scattering.

  18. Remote safeguards and monitoring of reactors with antineutrinos.

    SciTech Connect

    Kiff, Scott D.; Dazeley, Steven; Reyna, David; Cabrera-Palmer, Belkis; Bernstein, Adam; Keefer, Greg; Bowden, Nathaniel S.

    2010-09-01

    The current state-of-the-art in antineutrino detection is such that it is now possible to remotely monitor the operational status, power levels and fissile content of nuclear reactors in real-time. This non-invasive and incorruptible technique has been demonstrated at civilian power reactors in both Russia and the United States and has been of interest to the IAEA Novel Technologies Unit for several years. Expert's meetings were convened at IAEA headquarters in 2003 and again in 2008. The latter produced a report in which antineutrino detection was called a 'highly promising technology for safeguards applications' at nuclear reactors and several near-term goals and suggested developments were identified to facilitate wider applicability. Over the last few years, we have been working to achieve some of these goals and improvements. Specifically, we have already demonstrated the successful operation of non-toxic detectors and most recently, we are testing a transportable, above-ground detector system, which is fully contained within a standard 6 meter ISO container. If successful, such a system could allow easy deployment at any reactor facility around the world. As well, our previously demonstrated ability to remotely monitor the data and respond in real-time to reactor operational changes could allow the verification of operator declarations without the need for costly site-visits. As the global nuclear power industry expands around the world, the burden on maintaining operational histories and safeguarding inventories will increase greatly. Such a system for providing remote data to verify operator's declarations could greatly reduce the need for frequent site inspections while still providing a robust warning of anomalies requiring further investigation.

  19. Remote safeguards and monitoring of reactors with antineutrinos.

    SciTech Connect

    Reyna, David

    2010-10-01

    The current state-of-the-art in antineutrino detection is such that it is now possible to remotely monitor the operational status, power levels and fissile content of nuclear reactors in real-time. This non-invasive and incorruptible technique has been demonstrated at civilian power reactors in both Russia and the United States and has been of interest to the IAEA Novel Technologies Unit for several years. Expert's meetings were convened at IAEA headquarters in 2003 and again in 2008. The latter produced a report in which antineutrino detection was called a 'highly promising technology for safeguards applications' at nuclear reactors and several near-term goals and suggested developments were identified to facilitate wider applicability. Over the last few years, we have been working to achieve some of these goals and improvements. Specifically, we have already demonstrated the successful operation of non-toxic detectors and most recently, we are testing a transportable, above-ground detector system, which is fully contained within a standard 6 meter ISO container. If successful, such a system could allow easy deployment at any reactor facility around the world. As well, our previously demonstrated ability to remotely monitor the data and respond in real-time to reactor operational changes could allow the verification of operator declarations without the need for costly site-visits. As the global nuclear power industry expands around the world, the burden on maintaining operational histories and safeguarding inventories will increase greatly. Such a system for providing remote data to verify operator's declarations could greatly reduce the need for frequent site inspections while still providing a robust warning of anomalies requiring further investigation.

  20. 3D Animations for Exploring Nucleon Structure

    NASA Astrophysics Data System (ADS)

    Gorman, Waverly; Burkardt, Matthias

    2016-09-01

    Over the last few years many intuitive pictures have been developed for the interpretation of electron hadron scattering experiments, such as a mechanism for transverse single-spin asymmetries in semi-inclusive deep-inelastic scattering experiments. While Dr. Burkardt's pictures have been helpful for many researchers in the field, they are still difficult to visualize for broader audiences since they rely mostly on 2-dimensional static images. In order to make more accessible for a broader audience what can be learned from Jefferson Lab experiments, we have started to work on developing 3-dimensional animations for these processes. The goal is to enable the viewer to repeatedly look at the same microscopic mechanism for a specific reaction, with the viewpoint of the observer changing. This should help an audience that is not so familiar with these reactions to better understand what can be learned from various experiments at Jefferson Lab aimed at exploring the nucleon structure. Jefferson Lab Minority/Female Undergraduate Research Assistantship.

  1. Parity-violating electron scattering

    NASA Astrophysics Data System (ADS)

    Donnelly, T. W.

    Parity-violating responses, occurring as interferences between electromagnetic and weak neutral currents in studies of inclusive scattering of longitudinally polarized electrons, are discussed. Three specific aspects of such studies are highlighted: (1) The role played by isospin-mixing in elastic scattering from 0 +N = Z nuclei; (2) The possibility of having a clean probe of ground-state neutron distributions in nuclei; (3) The sensitivity found in particular experimentally accessible observables to sizes of various form factors of the nucleon itself, including dependences on GEn and on form factors which arise from s overlines configurations in the nucleon.

  2. Present status of sensitive detector of reactor's antineutrinos using scintillating detectors

    NASA Astrophysics Data System (ADS)

    Fajt, L.; Belov, V.; Burešová, H.; Egorov, V. G.; Fomina, M.; Kuznetsov, A.; Mamedov, F.; Ponomarev, D.; Přidal, P.; Rozova, I.; Špavorová, M.; Štekl, I.; Zhitnikov, I.

    2015-08-01

    In 2011, the reanalysis of the reactor antineutrinos spectra led to the formulation of the Reactor Antineutrino Anomaly (RAA) [1], which indicates the discrepancy between measured and expected antineutrino fluxes on short baselines. This discrepancy appears to favor the existence of the fourth "sterile" neutrino with |Δm2|>1 eV2. To confirm or reject this hypothesis a high sensitive antineutrino detector located close to the reactor is required. In addition to that such a detector could be used to online monitor the isotopic composition of the reactor core and to prevent illegal production and removal of239Pu, which is the essential part of nuclear weapons. Detector DANSSino [2] already proved that even a compact antineutrino detector (˜ 1 m3) based on polystyrene is capable of antineutrino detection in the close vicinity of a reactor core (˜ 10 m) with signal to background ratio about one. As a common activity between JINR Dubna and IEAP CTU a new prototype of detector (called S3) has been proposed and is under construction. The construction design, selected results of Monte Carlo simulations and results of benchmark tests are presented.

  3. Present status of sensitive detector of reactor’s antineutrinos using scintillating detectors

    SciTech Connect

    Fajt, L.; Mamedov, F.; Přidal, P.; Špavorová, M.; Štekl, I.; Belov, V.; Egorov, V. G.; Fomina, M.; Kuznetsov, A.; Ponomarev, D.; Rozova, I.; Zhitnikov, I.; Burešová, H.

    2015-08-17

    In 2011, the reanalysis of the reactor antineutrinos spectra led to the formulation of the Reactor Antineutrino Anomaly (RAA) [1], which indicates the discrepancy between measured and expected antineutrino fluxes on short baselines. This discrepancy appears to favor the existence of the fourth “sterile” neutrino with |Δm{sup 2}|>1 eV{sup 2}. To confirm or reject this hypothesis a high sensitive antineutrino detector located close to the reactor is required. In addition to that such a detector could be used to online monitor the isotopic composition of the reactor core and to prevent illegal production and removal of{sup 239}Pu, which is the essential part of nuclear weapons. Detector DANSSino [2] already proved that even a compact antineutrino detector (∼ 1 m{sup 3}) based on polystyrene is capable of antineutrino detection in the close vicinity of a reactor core (∼ 10 m) with signal to background ratio about one. As a common activity between JINR Dubna and IEAP CTU a new prototype of detector (called S{sup 3}) has been proposed and is under construction. The construction design, selected results of Monte Carlo simulations and results of benchmark tests are presented.

  4. Inclusive Inelastic Electron Scattering from Nuclei

    SciTech Connect

    Fomin, Nadia

    2007-10-26

    Inclusive electron scattering from nuclei at large x and Q{sup 2} is the result of a reaction mechanism that includes both quasi-elastic scattering from nucleons and deep inelastic scattering from the quark consitituents of the nucleons. Data in this regime can be used to study a wide variety of topics, including the extraction of nuclear momentum distributions, the infiuence of final state interactions and the approach to y-scaling, the strength of nucleon-nucleon correlations, and the approach to x-scaling, to name a few. Selected results from the recent experiment E02-019 at the Thomas Jefferson National Accelerator Facility will be shown and their relevance discussed.

  5. Chiral symmetry and the nucleon-nucleon interaction

    SciTech Connect

    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 the chiral EFT approach to the NN interaction.

  6. 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

  7. 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.

  8. Measurement of two- and three-nucleon short-range correlation probabilities in nuclei.

    PubMed

    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; De Sanctis, E; 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 C; 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'Relly, 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

    2006-03-03

    The ratios of inclusive electron scattering cross sections of 4He, 12C, and 56Fe to 3He have been measured at 1 < xB <. At Q2 > 1.4 GeV2, the ratios exhibit two separate plateaus, at 1.5 < xB < 2 and at xB > 2.25. 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.

  9. 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.

  10. Infinite-Cutoff Renormalization of the Chiral Nucleon-Nucleon Interaction up to N3LO

    NASA Astrophysics Data System (ADS)

    Zeoli, Ch.; Machleidt, R.; Entem, D. R.

    2013-12-01

    Naively, the "best" method of renormalization is the one where a momentum cutoff is taken to infinity while maintaining stable results due to a cutoff-dependent adjustment of counterterms. We have applied this renormalization method in the non-perturbative calculation of phase-shifts for nucleon-nucleon ( NN) scattering using chiral NN potentials up to next-to-next-to-next-to-leading order (N3LO). For lower partial waves, we find that there is either no convergence with increasing order or, if convergence occurs, the results do not always converge to the empirical values. For higher partial waves, we always observe convergence to the empirical phase shifts (except for the 3G5 state). Furthermore, no matter what the order is, one can use only one or no counterterm per partial wave, creating a rather erratic scheme of power counting that does not allow for a systematic order-by-order improvement of the predictions. The conclusion is that infinite-cutoff renormalization is inappropriate for chiral NN interactions, which should not come as a surprise, since the chiral effective field theory (chiral EFT), these interactions are based upon, is designed for momenta below the chiral-symmetry breaking scale of about 1 GeV. Therefore, this value for the hard scale should also be perceived as the appropriate upper limit for the momentum cutoff.

  11. Transverse force on transversely polarized quarks in longitudinally polarized nucleons

    NASA Astrophysics Data System (ADS)

    Abdallah, Manal; Burkardt, Matthias

    2016-11-01

    We study the semiclassical interpretation of the x3 and x4 moments of twist-3 parton distribution functions (PDFs). While no semiclassical interpretation for the higher moments of gT(x ) and e (x ) was found, the x3 moment of the chirally odd spin-dependent twist-3 PDF hL3(x ) can be related to the longitudinal gradient of the transverse force on transversely polarized quarks in longitudinally polarized nucleons in a deep-inelastic scattering experiment. We discuss how this result relates to the torque acting on a quark in the same experiment. This has further implications for comparisons between the Jaffe-Manohar and the Ji decompositions of the nucleon spin.

  12. Nucleon Compton Scaterring in the perturbative Limit

    NASA Astrophysics Data System (ADS)

    Thomson, Richard

    2004-11-01

    Results of perturbative calculation for nucleon Compton scattering are presented. The calculations consider both the case of the incoming photon being real and the case of the incoming photon being virtual. Hard scattering amplitudes are calculated using a software package developed at NC State Universityfootnote[1]A. Pang and C.-R. Ji, Computers in Physics Vol 9 (No. 6), Nov/Dec 1995 p589-593footnote[2]A. Pang and C.-R. Ji, J. Comp. Phys. 115, 267 (1994). The integrations required to calculate total cross section are made following the approach of Kronfeld and Nizicfootnote[3]A. Kronfeld and B. Nizic, Phys. Rev. D 44, 3445 (1991). Poles are split into a real principal part plus an imaginary delta function. The delta functions are evaluated explicitly by hand; principal part integrations are evaluated numerically, after making a variable transformation to render the integrand finite over the range of integration. For the real photon case, there are five previous calculations to consider, each of which produced a different result.^3footnote[4]E. Maina and G. Farrar, Phys. Lett. B 206, 120 (1988).footnote[5]G. Farrar and H. Zhang, Phys. Rev. D 41, 3348 (1990).footnote[6]M. Vanderhaeghen, P. Guichon, and J. Van de Wiele, presented at workshop on virtual Compton scattering, Clermont-Ferrand, France, 1996.footnote[7]T. Brooks and L. Dixon, Phys. Rev. D 62, 114021 (2000). There is an agreement with the results of Brooks and Dixon.^7 For the virtual photon case, the new result is compared with that of Farrar and Zhang.^5 Since there are differences, we discuss which result is more believable and why. For the deeply virtual case (DVCS), comparison is made with other non-pertubative methods using GPDs.

  13. Kaon Production Off the Nucleon

    SciTech Connect

    Alam, M. Rafi; Athar, M. Sajjad; Simo, I. Ruiz; Vacas, M. J. Vicente

    2011-10-06

    We have studied the weak kaon production off the nucleon induced by neutrinos at the low and intermediate energies. The studied mechanisms are the main source of kaon production for neutrino energies up to 1.2 to 1.5 GeV for the various channels and the cross sections are large enough to be amenable to be measured by experiments such as MINERvA and T2K.

  14. Gamma-Deuteron Compton Scattering in Effective Field Theory

    SciTech Connect

    Jiunn-Wei Chen; Harald W. Griesshammer; Martin J. Savage; Roxanne P. Springer

    1998-12-01

    The differential cross section for {gamma}-deuteron Compton scattering is computed to next-to-leading order (NLO) in an effective field theory that describes nucleon-nucleon interactions below the pion production threshold. Contributions at NLO include the nucleon isoscalar electric polarizability from its 1/m{sub {pi}} behavior in the chiral limit. The parameter free prediction of the {gamma}-deuteron differential cross section at NLO is in good agreement with data.

  15. Density dependence of microscopic nucleon optical potential in first order Brueckner theory

    NASA Astrophysics Data System (ADS)

    Saliem, S. M.; Haider, W.

    2002-06-01

    In the present work we apply the lowest order Brueckner theory of infinite nuclear matter to obtain nucleon-nucleus optical potential for p-40Ca elastic scattering at 200 MeV using Urbana V14 soft core internucleon potential. We have investigated the effect of target density on the calculated nucleon-nucleus optical potential. We find that the calculated optical potentials depend quite sensitively on the density distribution of the target nucleus. The important feature is that the real part of calculated central optical potential for all densities shows a wine-bottle-bottom type behaviour at this energy. We also discuss the effect of our new radial dependent effective mass correction. Finally, we compare the prediction of our calculated nucleon optical potential using V14 with the prediction using older hard core Hamada-Johnston internucleon potential for p-40Ca elastic scattering at 200 MeV.

  16. 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 g(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 ≲‑2000MeV and the above r0 values, Ψ1/2 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.

  17. What nucleon resonances teach us about nucleon structure

    NASA Astrophysics Data System (ADS)

    Burkert, Volker D.

    2014-03-01

    The excitation spectrum of atomic hydrogen contains the full information needed to describe its structure from its basic ingredients, protons and electrons, and the electromagnetic interaction between them. Similarly, the nucleon excitation spectrum contains information about the effective degrees of freedom and the forces between them. The difference between the two systems is that in the former case the electromagnetic interaction leads to a well-defined energy spectrum, while the latter has strongly interacting ingredients, hadrons, quarks and gluons, at its core leading to broad and overlapping energy levels that in most cases cannot be studied in isolation. Microscopic approaches such as modern constituent quark models and Lattice QCD, make predictions regarding masses and quantum numbers of the excited states and their internal structure according to radial, spin, and orbital transitions of the quark-gluon system. Pion induced transitions have revealed many states largely consistent with these predictions, but many of the predicted states have not been observed. The quest for a better understanding of the internal structure of nucleons has led to a worldwide effort to measure nucleon excitations using photon- and electron-induced processes and to determine their internal structure. At Jefferson Lab with the CLAS detector differential cross sections and polarization observables have been measured with unprecedented precision and some of these data have been analyzed with modern coupled channel approaches that led to evidence of a number of previously unobserved excited states. In this talk, I discuss the two main directions of current experimental research, the search for new states in meson photoproduction and the study of resonance transition form factors in electroproduction, which encode the internal structure and the nature of the excited states.

  18. On single nucleon wave functions in nuclei

    SciTech Connect

    Talmi, Igal

    2011-05-06

    The strong and singular interaction between nucleons, makes the nuclear many body theory very complicated. Still, nuclei exhibit simple and regular features which are simply described by the shell model. Wave functions of individual nucleons may be considered just as model wave functions which bear little resemblance to the real ones. There is, however, experimental evidence for the reality of single nucleon wave functions. There is a simple method of constructing such wave functions for valence nucleons. It is shown that this method can be improved by considering the polarization of the core by the valence nucleon. This gives rise to some rearrangement energy which affects the single valence nucleon energy within the nucleus.

  19. Elastic scattering of 400-MeV protons by Pb-208

    NASA Technical Reports Server (NTRS)

    Hutcheon, D. A.; Cameron, J. M.; Liljestrand, R. P.; Kitching, P.; Miller, C. A.; Mcdonald, W. J.; Sheppard, D. M.; Olsen, W. C.; Neilson, G. C.; Sherif, H. S.

    1981-01-01

    Cross-section and analyzing-power angular distributions for elastic scattering of 400-MeV protons by Pb-208 have been measured between 3 and 51 deg. Results have been compared to second-order Kerman-McManus-Thaler (1959) calculations of the optical potential. There is evidence that free nucleon-nucleon scattering amplitudes do not adequately describe nucleon propagation in nuclear matter at this energy.

  20. Determination of the Axial Nucleon Form Factor from the MiniBooNE Data

    SciTech Connect

    Butkevich, A. V.; Perevalov, D.

    2014-03-26

    Both neutrino and antineutrino charged-current quasi-elastic scattering on a carbon target are studied to investigate the nuclear effect on the determination of the axial form factor F_A(Q^2). A method for extraction of F_A(Q^2) from the flux-integrated $d\\sigma/dQ^2$ cross section of (anti)neutrino scattering on nuclei is presented. Data from the MiniBooNE experiment are analyzed in the relativistic distorted-wave impulse approximation, Fermi gas model, and in the Fermi gas model with enhancements in the transverse cross section. We found that the values of the axial form factor, extracted in the impulse approximation and predicted by the dipole approximation with the axial mass M_A~1.37 GeV are in good agreement. On the other hand, the Q^2-dependence of F_A extracted in the approach with the transverse enhancement is found to differ significantly from the dipole approximation.

  1. Pion content of the nucleon in polarized semi-inclusive DIS

    SciTech Connect

    Melnitchouk, W.; Thomas, A.W.

    1994-04-01

    An explicit pionic component of the nucleon may be identified by measuring polarized {Delta}{sup ++} fragments produced in deep-inelastic scattering (DIS) off polarized protons. The pion-exchange model predicts highly correlated polarizations of the {Delta}{sup ++} and target proton, in marked contrast with the competing diquark fragmentation process.

  2. Dynamical Model for Meson Production off Nucleon and Application to Neutrino-Nucleus Reactions

    SciTech Connect

    Satoshi Nakamura

    2011-11-01

    I explain the Sato-Lee (SL) model and its extension to the neutrino-induced pion production off the nucleon. Then I discuss applications of the SL model to incoherent and coherent pion productions in the neutrino-nucleus scattering. I mention a further extension of this approach with a dynamical coupled-channels model developed in Excited Baryon Analysis Center of JLab.

  3. Dynamical Model for Meson Production off Nucleon and Application to Neutrino-Nucleus Reactions

    SciTech Connect

    Nakamura, Satoshi X.

    2011-11-23

    I explain the Sato-Lee (SL) model and its extension to the neutrino-induced pion production off the nucleon. Then I discuss applications of the SL model to incoherent and coherent pion productions in the neutrino-nucleus scattering. I mention a further extension of this approach with a dynamical coupled-channels model developed in Excited Baryon Analysis Center of JLab.

  4. Dissecting nucleon transition electromagnetic form factors

    NASA Astrophysics Data System (ADS)

    Segovia, Jorge; Roberts, Craig D.

    2016-10-01

    In Poincaré-covariant continuum treatments of the three valence-quark bound-state problem, the force behind dynamical chiral symmetry breaking also generates nonpointlike interacting diquark correlations in the nucleon and its resonances. We detail the impact of these correlations on the electromagnetically induced nucleon-Δ and nucleon-Roper transitions, providing a flavor separation of the latter and associated predictions that can be tested at modern facilities.

  5. Gluon Contribution To The Nucleon Spin

    SciTech Connect

    Arash, Firooz; Shahveh, Abolfazl; Taghavi-Shahri, Fatemeh

    2011-07-15

    Gluon polarization in Nucleon is evaluated in the valon representation of hadrons. It is shown that although {delta}g/g is small at the currently measured kinematics, it does not imply that the gluon contribution to the nucleon spin is small. In fact the first moment of gluon polarization in the nucleon, {Delta}g(Q{sup 2}), is sizable. We also notice that the majority of {Delta}g is concentrated at around x = 0.08.

  6. Comment on S-matrix parameterizations in NN-scattering

    SciTech Connect

    Mulders, P. J.

    1981-08-01

    The parameterization of the S-matrix used for the elastic part of the NN-scattering matrix in, for example, the Virginia Polytechnic Institute ineractive nucleon-nucleon program SAID, is not general enough to parameterize any 2 by 2 submatrix of a unitary matrix.

  7. Monte Carlo approaches to the few-nucleon continuum

    SciTech Connect

    Schiavilla, R. |; Carlson, J.; Wiringa, R.B.

    1994-08-01

    Variational and Green`s Function Monte Carlo methods are reviewed as applied to the study of the few-nucleon continuum at low- and intermediate-energies. Results recently obtained for the radiative and weak capture reactions n + {sup 3}He {yields} {sup 4}He + {gamma} and p + {sup 3}He {yields} {sup 4}He + e{sup +} + {nu}{sub e}, the {sup 5}He P-wave resonances, and the inclusive and exclusive electron scattering reactions on {sup 3}H and the helium isotopes are summarized.

  8. 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.

  9. Gadolinium-loaded gel scintillators for neutron and antineutrino detection

    SciTech Connect

    Riddle, Catherine Lynn; Akers, Douglas William; Demmer, Ricky Lynn; Paviet, Patricia Denise; Drigert, Mark William

    2016-11-29

    A gadolinium (Gd) loaded scintillation gel (Gd-ScintGel) compound allows for neutron and gamma-ray detection. The unique gel scintillator encompasses some of the best features of both liquid and solid scintillators, yet without many of the disadvantages associated therewith. Preferably, the gel scintillator is a water soluble Gd-DTPA compound and water soluble fluorophores such as: CdSe/ZnS (or ZnS) quantum dot (Q-dot) nanoparticles, coumarin derivatives 7-hydroxy-4-methylcoumarin, 7-hydroxy-4-methylcoumarin-3-acetic acid, 7-hydroxycoumarin-3-carboxylic acid, and Alexa Fluor 350 as well as a carbostyril compound, carbostyril 124 in a stable water-based gel, such as methylcellulose or polyacrylamide polymers. The Gd-loaded ScintGel allows for a homogenious distribution of the Gd-DTPA and the fluorophores, and yields clean fluorescent emission peaks. A moderator, such as deuterium or a water-based clear polymer, can be incorporated in the Gd-ScintGel. The gel scintillators can be used in compact detectors, including neutron and antineutrino detectors.

  10. Discovering asymmetric dark matter with anti-neutrinos

    SciTech Connect

    Feldstein, Brian; Fitzpatrick, A. Liam E-mail: fitzpatr@physics.bu.edu

    2010-09-01

    We discuss possible signatures of Asymmetric Dark Matter (ADM) through dark matter decays to neutrinos. We specifically focus on scenarios in which the Standard Model (SM) baryon asymmetry is transferred to the dark sector (DS) through higher dimensional operators in chemical equilibrium. In such cases, the dark matter (DM) carries lepton and/or baryon number, and we point out that for a wide range of quantum number assignments, by far the strongest constraints on dark matter decays come from decays to neutrinos through the ''neutrino portal'' operator HL. Together with the facts that ADM favors lighter DM masses ∼ a few GeV and that the decays would lead only to anti-neutrinos and no neutrinos (or vice versa), the detection of such decays at neutrino telescopes would provide compelling evidence for ADM. We discuss current and future bounds on models where the DM decays to neutrinos through operators of dimension ≤ 6. For dimension 6 operators, the scale suppressing the decay is bounded to be ∼>10{sup 12}–10{sup 13} GeV.

  11. Investigating the spectral anomaly with different reactor antineutrino experiments

    NASA Astrophysics Data System (ADS)

    Buck, C.; Collin, A. P.; Haser, J.; Lindner, M.

    2017-02-01

    The spectral shape of reactor antineutrinos measured in recent experiments shows anomalies in comparison to neutrino reference spectra. New precision measurements of the reactor neutrino spectra as well as more complete input in nuclear data bases are needed to resolve the observed discrepancies between models and experimental results. This article proposes the combination of experiments at reactors which are highly enriched in 235U with commercial reactors with typically lower enrichment to gain new insights into the origin of the anomalous neutrino spectrum. The presented method clarifies, if the spectral anomaly is either solely or not at all related to the predicted 235U spectrum. Considering the current improvements of the energy scale uncertainty of present-day experiments, a significance of three sigma and above can be reached. As an example, we discuss the option of a direct comparison of the measured shape in the currently running Double Chooz near detector and the upcoming Stereo experiment. A quantitative feasibility study emphasizes that a precise understanding of the energy scale systematics is a crucial prerequisite in recent and next generation experiments investigating the spectral anomaly.

  12. A new scheme for short baseline electron antineutrino disappearance study

    NASA Astrophysics Data System (ADS)

    Shin, Jae Won; Cheoun, Myung-Ki; Kajino, Toshitaka; Hayakawa, Takehito

    2017-09-01

    A new scheme for the short baseline electron antineutrino ({\\bar{ν }}{{e}}) disappearance study is investigated. We propose to use an intense neutron emitter, 252Cf, which produces a 8Li isotope through the 7Li(n,γ)8Li reaction; 8Li is a {\\bar{ν }}{{e}} emitter via {β }- decay. Because this {\\bar{ν }}{{e}} source needs neither accelerator nor reactor facilities, the {\\bar{ν }}{{e}} can be placed on any neutrino detector as closely as possible. This short baseline circumstance with a suitable detector enables us to study the existence of possible sterile neutrinos, in particular, on 1 eV mass scale. Also, complementary comparison studies among different neutrino detectors can become feasible by using {\\bar{ν }}{{e}} from the 8Li source. As an example, applications to hemisphere and cylinder shape scintillator detectors are performed in detail with the expectation signal modification by the sterile neutrino. Sensitivities to mass and mixing angles of sterile neutrinos are also presented for comparison with those of other neutrino experiments.

  13. Two-current nucleon observables in Skyrme model

    NASA Astrophysics Data System (ADS)

    Chemtob, Marc

    1987-11-01

    Three independent two-current nucléon observables are studied within the two-flavor Skyrme model for the παω system. The effective lagrangian is that of the gauged chiral symmetry approach, consistent with the vector meson dominance, in the linear realization (for the vector mesons) of the global chiral symmetry. The first application deals with the nucleon electric polarizability and magnetic susceptibilty. Both seagull and dispersive contributions appear and we evaluate the latter in terms of the sums over intermediate states. The results are compared with existing quark model results as well as with empirical determinations. The second application concerns the zero-point quantum correction to the skyrmion mass. We apply a chiral perturbation theory approach to evaluate the pion loop contribution to the nucleon mass. The comparison with the conventional Skyrme model result reveals an important sensitivity to the stabilization mechanism. The third application is to lepton-nucleon deep inelastic scattering in the Bjorken scaling limit. The structure tensor is calculated in terms of the representation as a commutator product of two currents. Numerical results are presented for the scaling function F2( x). An essential use is made of the large Nc. (number of colors) approximation in all these applications. In the numerical computations we ignore the distortion effects, relative to the free plane wave limit, on the pionic fluctuations.

  14. A relativistic theory of few-nucleon systems

    SciTech Connect

    Alfred Stadler

    2010-12-01

    This talk provides an overview of recent results for two- and three-nucleon systems obtained within the framework of the covariant spectator theory (CST). The main features of two recently published models for the neutron–proton interaction, that fit the 2007 world data base containing several thousands of neutron-proton scattering data below 350 MeV with χ 2/N data ≈ 1, are presented. These one-boson-exchange models, called WJC-1 and WJC-2, have a considerably smaller number of adjustable parameters than are present in realistic nonrelativistic potentials. When applied to the three-nucleon bound state, the correct binding energy is obtained without additional three-body forces. First calculations of the electromagnetic form factors of helium-3 and the triton in complete impulse approximation also give very reasonable results. One can conclude that the CST yields a very efficient description of few-nucleon systems, in which the relativistic formulation of the dynamics is an essential element.

  15. New measurement of antineutrino oscillation with the full detector configuration at Daya Bay.

    PubMed

    An, F P; Balantekin, A B; Band, H R; Bishai, M; Blyth, S; Butorov, I; Cao, G F; Cao, J; Cen, W R; Chan, Y L; Chang, J F; Chang, L C; Chang, Y; Chen, H S; Chen, Q Y; Chen, S M; Chen, Y X; Chen, Y; Cheng, J H; Cheng, J; Cheng, Y P; Cherwinka, J J; Chu, M C; Cummings, J P; de Arcos, J; Deng, Z Y; Ding, X F; Ding, Y Y; Diwan, M V; Draeger, E; Dwyer, D A; Edwards, W R; Ely, S R; Gill, R; Gonchar, M; Gong, G H; Gong, H; Grassi, M; Gu, W Q; Guan, M Y; Guo, L; Guo, X H; Hackenburg, R W; Han, R; Hans, S; He, M; Heeger, K M; Heng, Y K; Higuera, A; Hor, Y K; Hsiung, Y B; Hu, B Z; Hu, L M; Hu, L J; Hu, T; Hu, W; Huang, E C; Huang, H X; Huang, X T; Huber, P; Hussain, G; Jaffe, D E; Jaffke, P; Jen, K L; Jetter, S; Ji, X P; Ji, X L; Jiao, J B; Johnson, R A; Kang, L; Kettell, S H; Kramer, M; Kwan, K K; Kwok, M W; Kwok, T; Langford, T J; Lau, K; Lebanowski, L; Lee, J; Lei, R T; Leitner, R; Leung, K Y; Leung, J K C; Lewis, C A; Li, D J; Li, F; Li, G S; Li, Q J; Li, S C; Li, W D; Li, X N; Li, X Q; Li, Y F; Li, Z B; Liang, H; Lin, C J; Lin, G L; Lin, P Y; Lin, S K; Ling, J J; Link, J M; Littenberg, L; Littlejohn, B R; Liu, D W; Liu, H; Liu, J L; Liu, J C; Liu, S S; Lu, C; Lu, H Q; Lu, J S; Luk, K B; Ma, Q M; Ma, X Y; Ma, X B; Ma, Y Q; Martinez Caicedo, D A; McDonald, K T; McKeown, R D; Meng, Y; Mitchell, I; Monari Kebwaro, J; Nakajima, Y; Napolitano, J; Naumov, D; Naumova, E; Ngai, H Y; Ning, Z; Ochoa-Ricoux, J P; Olshevski, A; Park, J; Patton, S; Pec, V; Peng, J C; Piilonen, L E; Pinsky, L; Pun, C S J; Qi, F Z; Qi, M; Qian, X; Raper, N; Ren, B; Ren, J; Rosero, R; Roskovec, B; Ruan, X C; Shao, B B; Steiner, H; Sun, G X; Sun, J L; Tang, W; Taychenachev, D; Themann, H; Tsang, K V; Tull, C E; Tung, Y C; Viaux, N; Viren, B; Vorobel, V; Wang, C H; Wang, M; Wang, N Y; Wang, R G; Wang, W; Wang, W W; Wang, X; Wang, Y F; Wang, Z; Wang, Z; Wang, Z M; Wei, H Y; Wen, L J; Whisnant, K; White, C G; Whitehead, L; Wise, T; Wong, H L H; Wong, S C F; Worcester, E; Wu, Q; Xia, D M; Xia, J K; Xia, X; Xing, Z Z; Xu, J Y; Xu, J L; Xu, J; Xu, Y; Xue, T; Yan, J; Yang, C G; Yang, L; Yang, M S; Yang, M T; Ye, M; Yeh, M; Yeh, Y S; Young, B L; Yu, G Y; Yu, Z Y; Zang, S L; Zhan, L; Zhang, C; Zhang, H H; Zhang, J W; Zhang, Q M; Zhang, Y M; Zhang, Y X; Zhang, Y M; Zhang, Z J; Zhang, Z Y; Zhang, Z P; Zhao, J; Zhao, Q W; Zhao, Y F; Zhao, Y B; Zheng, L; Zhong, W L; Zhou, L; Zhou, N; Zhuang, H L; Zou, J H

    2015-09-11

    We report a new measurement of electron antineutrino disappearance using the fully constructed Daya Bay Reactor Neutrino Experiment. The final two of eight antineutrino detectors were installed in the summer of 2012. Including the 404 days of data collected from October 2012 to November 2013 resulted in a total exposure of 6.9×10^{5} GW_{th}  ton days, a 3.6 times increase over our previous results. Improvements in energy calibration limited variations between detectors to 0.2%. Removal of six ^{241}Am-^{13}C radioactive calibration sources reduced the background by a factor of 2 for the detectors in the experimental hall furthest from the reactors. Direct prediction of the antineutrino signal in the far detectors based on the measurements in the near detectors explicitly minimized the dependence of the measurement on models of reactor antineutrino emission. The uncertainties in our estimates of sin^{2}2θ_{13} and |Δm_{ee}^{2}| were halved as a result of these improvements. An analysis of the relative antineutrino rates and energy spectra between detectors gave sin^{2}2θ_{13}=0.084±0.005 and |Δm_{ee}^{2}|=(2.42±0.11)×10^{-3}  eV^{2} in the three-neutrino framework.

  16. New measurement of antineutrino oscillation with the full detector configuration at Daya Bay

    DOE PAGES

    An, F. P.; Balantekin, A. B.; Band, H. R.; ...

    2015-09-11

    We report a new measurement of electron antineutrino disappearance using the fully constructed Daya Bay Reactor Neutrino Experiment. The final two of eight antineutrino detectors were installed in the summer of 2012. Including the 404 days of data collected from October 2012 to November 2013 resulted in a total exposure of 6.9×105 GWth ton days, a 3.6 times increase over our previous results. Improvements in energy calibration limited variations between detectors to 0.2%. Removal of six 241Am- 13C radioactive calibration sources reduced the background by a factor of 2 for the detectors in the experimental hall furthest from the reactors.more » Direct prediction of the antineutrino signal in the far detectors based on the measurements in the near detectors explicitly minimized the dependence of the measurement on models of reactor antineutrino emission. The uncertainties in our estimates of 2sin2θ13 and |Δm2ee| were halved as a result of these improvements. An analysis of the relative antineutrino rates and energy spectra between detectors gave 2sin2θ13=0.084±0.005 and |Δm2ee|=(2.42±0.11)×10–3 eV2 in the three-neutrino framework.« less

  17. New Measurement of Antineutrino Oscillation with the Full Detector Configuration at Daya Bay

    NASA Astrophysics Data System (ADS)

    An, F. P.; Balantekin, A. B.; Band, H. R.; Bishai, M.; Blyth, S.; Butorov, I.; Cao, G. F.; Cao, J.; Cen, W. R.; Chan, Y. L.; Chang, J. F.; Chang, L. C.; Chang, Y.; Chen, H. S.; Chen, Q. Y.; Chen, S. M.; Chen, Y. X.; Chen, Y.; Cheng, J. H.; Cheng, J.; Cheng, Y. P.; Cherwinka, J. J.; Chu, M. C.; Cummings, J. P.; de Arcos, J.; Deng, Z. Y.; Ding, X. F.; Ding, Y. Y.; Diwan, M. V.; Draeger, E.; Dwyer, D. A.; Edwards, W. R.; Ely, S. R.; Gill, R.; Gonchar, M.; Gong, G. H.; Gong, H.; Grassi, M.; Gu, W. Q.; Guan, M. Y.; Guo, L.; Guo, X. H.; Hackenburg, R. W.; Han, R.; Hans, S.; He, M.; Heeger, K. M.; Heng, Y. K.; Higuera, A.; Hor, Y. K.; Hsiung, Y. B.; Hu, B. Z.; Hu, L. M.; Hu, L. J.; Hu, T.; Hu, W.; Huang, E. C.; Huang, H. X.; Huang, X. T.; Huber, P.; Hussain, G.; Jaffe, D. E.; Jaffke, P.; Jen, K. L.; Jetter, S.; Ji, X. P.; Ji, X. L.; Jiao, J. B.; Johnson, R. A.; Kang, L.; Kettell, S. H.; Kramer, M.; Kwan, K. K.; Kwok, M. W.; Kwok, T.; Langford, T. J.; Lau, K.; Lebanowski, L.; Lee, J.; Lei, R. T.; Leitner, R.; Leung, K. Y.; Leung, J. K. C.; Lewis, C. A.; Li, D. J.; Li, F.; Li, G. S.; Li, Q. J.; Li, S. C.; Li, W. D.; Li, X. N.; Li, X. Q.; Li, Y. F.; Li, Z. B.; Liang, H.; Lin, C. J.; Lin, G. L.; Lin, P. Y.; Lin, S. K.; Ling, J. J.; Link, J. M.; Littenberg, L.; Littlejohn, B. R.; Liu, D. W.; Liu, H.; Liu, J. L.; Liu, J. C.; Liu, S. S.; Lu, C.; Lu, H. Q.; Lu, J. S.; Luk, K. B.; Ma, Q. M.; Ma, X. Y.; Ma, X. B.; Ma, Y. Q.; Martinez Caicedo, D. A.; McDonald, K. T.; McKeown, R. D.; Meng, Y.; Mitchell, I.; Monari Kebwaro, J.; Nakajima, Y.; Napolitano, J.; Naumov, D.; Naumova, E.; Ngai, H. Y.; Ning, Z.; Ochoa-Ricoux, J. P.; Olshevski, A.; Park, J.; Patton, S.; Pec, V.; Peng, J. C.; Piilonen, L. E.; Pinsky, L.; Pun, C. S. J.; Qi, F. Z.; Qi, M.; Qian, X.; Raper, N.; Ren, B.; Ren, J.; Rosero, R.; Roskovec, B.; Ruan, X. C.; Shao, B. B.; Steiner, H.; Sun, G. X.; Sun, J. L.; Tang, W.; Taychenachev, D.; Themann, H.; Tsang, K. V.; Tull, C. E.; Tung, Y. C.; Viaux, N.; Viren, B.; Vorobel, V.; Wang, C. H.; Wang, M.; Wang, N. Y.; Wang, R. G.; Wang, W.; Wang, W. W.; Wang, X.; Wang, Y. F.; Wang, Z.; Wang, Z.; Wang, Z. M.; Wei, H. Y.; Wen, L. J.; Whisnant, K.; White, C. G.; Whitehead, L.; Wise, T.; Wong, H. L. H.; Wong, S. C. F.; Worcester, E.; Wu, Q.; Xia, D. M.; Xia, J. K.; Xia, X.; Xing, Z. Z.; Xu, J. Y.; Xu, J. L.; Xu, J.; Xu, Y.; Xue, T.; Yan, J.; Yang, C. G.; Yang, L.; Yang, M. S.; Yang, M. T.; Ye, M.; Yeh, M.; Yeh, Y. S.; Young, B. L.; Yu, G. Y.; Yu, Z. Y.; Zang, S. L.; Zhan, L.; Zhang, C.; Zhang, H. H.; Zhang, J. W.; Zhang, Q. M.; Zhang, Y. M.; Zhang, Y. X.; Zhang, Y. M.; Zhang, Z. J.; Zhang, Z. Y.; Zhang, Z. P.; Zhao, J.; Zhao, Q. W.; Zhao, Y. F.; Zhao, Y. B.; Zheng, L.; Zhong, W. L.; Zhou, L.; Zhou, N.; Zhuang, H. L.; Zou, J. H.; Daya Bay Collaboration

    2015-09-01

    We report a new measurement of electron antineutrino disappearance using the fully constructed Daya Bay Reactor Neutrino Experiment. The final two of eight antineutrino detectors were installed in the summer of 2012. Including the 404 days of data collected from October 2012 to November 2013 resulted in a total exposure of 6.9 × 105 GWth ton days , a 3.6 times increase over our previous results. Improvements in energy calibration limited variations between detectors to 0.2%. Removal of six 241Am 241- 13C radioactive calibration sources reduced the background by a factor of 2 for the detectors in the experimental hall furthest from the reactors. Direct prediction of the antineutrino signal in the far detectors based on the measurements in the near detectors explicitly minimized the dependence of the measurement on models of reactor antineutrino emission. The uncertainties in our estimates of sin22 θ13 and |Δ mee 2| were halved as a result of these improvements. An analysis of the relative antineutrino rates and energy spectra between detectors gave sin22 θ13=0.084 ±0.005 and |Δ mee 2|=(2.42 ±0.11 )×10-3 eV2 in the three-neutrino framework.

  18. 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

  19. Overview of nucleon form factor experiments with 12 GeV at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Cisbani, Evaristo

    2014-06-01

    Since the R. Hofstadter pioneering experiments in the '50s, the measurements of the electromagnetic space-like nucleon form factors (FF's) have been a precious source of information for the understanding of the internal structure of the nucleons. In the last 15 years, the polarization transfer experiments at the Thomas Jefferson National Accelerator Facility (JLab) have undermined our view of the mechanism of the electron scattering and renewed critical interest in the FF measurements. In the coming years, JLab, with its upgraded 12 GeV polarized, high intensity, electron beam combined to new targets and readout equipments, will offer unprecedented opportunities to extend the current proton and neutron FF's measurements to higher momentum transfer Q2 and to improve statistical and uncertainties at lower Q2, where the nucleon size can be accurately investigated. The measurements at high Q2 will provide also new insights on the elusive quark orbital angular momenta, will contribute to constraint two of the nucleon Generalized Parton Distributions that are expected to describe more consistently the nucleon structure, and in general will test the validity of quite a few fundamental nucleon models in a region of transition between perturbative and non perturbative regimes. A selection of the relevant properties of the FF's, and the main results of JLab are shortly reviewed; the new proposed and approved experiments on FF's at JLab are presented addressing some key details, the expected experimental achievements and the new equipment designed for them.

  20. Structure and Spin of the Nucleon

    SciTech Connect

    Avakian, Harut A.

    2014-03-01

    Parton distribution functions, describing longitudinal momentum, helicity and transversity distributions of quarks and gluons, have been recently generalized to account also for transverse degrees of freedom. Two new sets of more general distributions, Transverse Momentum Distributions and Generalized Parton Distributions, were introduced to describe transverse momentum and space distributions of partons. Great progress has been made since then in measurements of different Single Spin Asymmetries (SSAs) in semi-inclusive and hard exclusive processes providing access to TMDs and GPDs, respectively. Facilities world-wide involved in studies of the 3D structure of nucleon include HERMES, COMPASS, BELLE, BaBar, Halls A, B, and C at JLab, and PHENIX and STAR at RHIC (BNL). TMD studies in the Drell-Yan process are also becoming an important part of the program of hadron scattering experiments. Studies of TMDs are also among the main driving forces of the JLab 12-GeV upgrade project, several of the forward upgrade proposals of STAR and PHENIX at RHIC, and future facilities, such as the Electron Ion Collider (EIC), FAIR in Germany, and NICA in Russia. In this contribution we present an overview of the latest developments in studies of parton distributions and discuss newly released results, ongoing activities, as well as some future measurements.