PaperPanorama
FAQ

Nuclear Theory·nucl-th

Thursday·December 1, 2016

13 papers—8 primary·5 cross-listed

All13Primary8Cross-lists5
  1. 09

    [Submitted on 30 Nov 2016] (cross-list from hep-ph)

    More about the light baryon spectrum

    Gernot Eichmann🇩🇪

    We discuss the light baryon spectrum obtained from a recent quark-diquark calculation, implementing non-pointlike diquarks that are self-consistently calculated from their Bethe-Salpeter equations. We examine the orbital angular momentum content in the baryons' rest frame and highlight the fact that baryons carry all possible values of L compatible with their spin, without the restriction P=(-1)^L which is only valid nonrelativistically. We furthermore investigate the meaning of complex conjugate eigenvalues of Bethe-Salpeter equations, their possible connection with 'anomalous' states, and we propose a method to eliminate them from the spectrum.

    Comments:
    9 pages, 4 figures. Presented at Light Cone 2016, September 5-8 2015, IST, Universidade de Lisboa, Lisbon, Portugal
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1611.10118 [pdf]
    Few Body Syst.(2017)·23 citations
  2. 10

    [Submitted on 30 Nov 2016] (cross-list from hep-ph)

    Event patterns extracted from top quark-related spectra in proton-proton collisions at 8 TeV

    Ya-Hui Chen🇨🇳 · Fu-Hu Liu🇨🇳 · Roy A. Lacey🇺🇸

    We analyze the transverse momentum () and rapidity () spectra of top quark pairs, hadronic top quarks, and top quarks produced in proton-proton () collisions at center-of-mass energy TeV. For spectra, we use the superposition of the inverse power-law suggested by the QCD (quantum chromodynamics) calculus and the Erlang distribution resulting from a multisource thermal model. For spectra, we use the two-component Gaussian function resulting from the revised Landau hydrodynamic model. The modelling results are in agreement with the experimental data measured at the detector level, in the fiducial phase-space, and in the full phase-space by the ATLAS Collaboration at the Large Hadron Collider (LHC). Based on the parameter values extracted from and spectra, the event patterns in three-dimensional velocity (--), momentum (--), and rapidity (--) spaces are obtained, and the probability distributions of these components are also obtained.

    Comments:
    18 pages, 9 figures. Chinese Physics C, accepted
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1611.10150 [pdf]
    CPC(2018)·2 citations
  3. 11

    [Submitted on 30 Nov 2016] (cross-list from astro-ph.HE)

    Nuclear pasta and supernova neutrinos at late times

    C. J. Horowitz🇺🇸 · D. K. Berry🇺🇸 · M. E. Caplan🇺🇸 · T. Fischer🇵🇱 · Zidu Lin🇺🇸 · W. G. Newton🇺🇸 · E. O'Connor🇺🇸 · L. F. Roberts🇺🇸

    Nuclear pasta, with nucleons arranged into tubes, sheets, or other complex shapes, is expected in core collapse supernovae (SNe) at just below nuclear density. We calculate the additional opacity from neutrino-pasta coherent scattering using molecular dynamics simulations. We approximately include this opacity in simulations of SNe. We find that pasta slows neutrino diffusion and greatly increases the neutrino signal at late times of 10 or more seconds after stellar core collapse. This signal, for a galactic SN, should be clearly visible in large detectors such as Super-Kamiokande.

    Comments:
    6 pages, 4 figures
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1611.10226 [pdf]
    32 citations
  4. 12

    [Submitted on 30 Nov 2016] (cross-list from hep-ph)

    J/psi+Z production at the LHC

    Jean-Philippe Lansberg🇫🇷 · Hua-Sheng Shao🇨🇭

    We briefly review recent results which we have obtained in the study of J/psi+Z production at the LHC. Considering our NLO computation in the Colour Evaporation Model (CEM) as an upper theory limit for the single-parton-scattering contributions, we claim that the existing data set from ATLAS points at a dominant double-parton-scattering contribution with an effective cross section smaller than that for jet-related observables. As a side product of our analysis, we have computed, for the first time, the one-loop QCD corrections to the J/psi P_T-differential cross section in the CEM.

    Comments:
    6 pages, 6 figures, LaTeX uses webofc.cls and woc.bst (provided). Proceedings of the XIIth Quark Confinement and the Hadron Spectrum Conference, 28 August - 4 September 2016, Thessaloniki, Greece
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1611.10306 [pdf]
    EPJ Web Conf.(2017)·1 citation
  5. 13

    [Submitted on 30 Nov 2016] (cross-list from hep-ph)

    Kinematics of Current Region Fragmentation in Semi-Inclusive Deeply Inelastic Scattering

    M. Boglione🇮🇹 · J. Collins🇺🇸 · L. Gamberg🇺🇸 · J. O. Gonzalez-Hernandez🇺🇸 · T. C. Rogers🇺🇸 · N. Sato🇺🇸

    Different kinematical regimes of semi-inclusive deeply inelastic scattering (SIDIS) processes correspond to different underlying partonic pictures, and it is important to understand the transition between them. This is particularly the case when there is sensitivity to intrinsic transverse momentum, in which case kinematical details can become especially important. We address the question of how to identify the current fragmentation region --- the kinematical regime where a factorization picture with fragmentation functions is appropriate. We distinguish this from soft and target fragmentation regimes. Our criteria are based on the kinematic regions used in derivations of factorization theorems. We argue that, when hard scales are of order a few GeVs, there is likely significant overlap between different rapidity regions that are normally understood to be distinct. We thus comment on the need to take this into account with more unified descriptions of SIDIS, which should span all rapidities for the produced hadron. Finally, we propose general criteria for estimating the proximity to the current region at large Q.

    Comments:
    9 Pages, 5 figures; minor clarifications and corrections, version appearing in Physics Letters B
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1611.10329 [pdf]
    PLB(2017)·57 citations

Affiliations

first authorsco-authorsvia INSPIRE