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Nuclear Theory·nucl-th

Thursday·January 7, 2021

7 papers—2 primary·5 cross-listed

All7Primary2Cross-lists5
  1. 01

    [Submitted on 6 Jan 2021]

    The Gluon Exchange Model for diffractive and inelastic collisions

    Marek Jeżabek🇵🇱 · Andrzej Rybicki🇵🇱

    We propose a new model for a homogeneous description of hadron-hadron and hadron-nucleus collisions, the Gluon Exchange Model, fundamentally based on color octet (gluon) exchange. In proton-proton collisions we provide an exact description of the final state proton and neutron spectrum including the proton diffractive peak. In proton-nucleus reactions we find that the projectile proton diquark cannot survive in more than about half of multiple proton-nucleon processes and consequently must be very frequently disintegrated, leading to long transfers of baryon number over rapidity space.

    Comments:
    10 pages, 4 figures
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2101.01999 [pdf]
    PLB(2021)·5 citations
  2. 02

    [Submitted on 6 Jan 2021]

    Efficiency corrections for factorial moments and cumulants of overlapping sets of particles

    Volodymyr Vovchenko🇺🇸 · Volker Koch🇺🇸

    In this note we discuss subtleties associated with the efficiency corrections for measurements of off-diagonal cumulants and factorial moments for a situation when one deals with overlapping sets of particles, such as correlations between numbers of protons and positively charged particles. In particular, we discuss the situation commonly encountered in heavy-ion experiments, where first all charges are reconstructed and then protons are selected from these charges by an additional particle identification procedure. We present the efficiency correction formulas for the case when the detection efficiencies follow a binomial distribution.

    Comments:
    13 pages, 1 figure, to appear in Nucl. Phys. A
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    2101.02182 [pdf]
    NPA(2021)·5 citations
  3. 03

    [Submitted on 5 Jan 2021] (cross-list from astro-ph.HE)

    GW170817 and GW190814: tension on the maximum mass

    Antonios Nathanail🇩🇪 · Elias R. Most🇺🇸 · Luciano Rezzolla🇩🇪

    The detection of the binary events GW170817 and GW190814 has provided invaluable constraints on the maximum mass of nonrotating configurations of neutron stars, . However, the large differences in the neutron-star masses measured in GW170817 and GW190814 has also lead to a significant tension between the predictions for such maximum masses, with GW170817 suggesting that , and GW190814 requiring if the secondary was a (non- or slowly rotating) neutron star at merger. Using a genetic algorithm, we sample the multidimensional space of parameters spanned by gravitational-wave and astronomical observations associated with GW170817. Consistent with previous estimates, we find that all of the physical quantities are in agreement with the observations if the maximum mass is in the range within a confidence level. By contrast, maximum masses with , not only require efficiencies in the gravitational-wave emission that are well above the numerical-relativity estimates, but they also lead to a significant under-production of the ejected mass. Hence, the tension can be released by assuming that the secondary in GW190814 was a black hole at merger, although it could have been a rotating neutron star before.

    Comments:
    added references and minor changes; version accepted by ApJL
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
    arXiv:
    2101.01735 [pdf]
    ApJL(2021)·125 citations
  4. 04

    [Submitted on 5 Jan 2021] (cross-list from hep-ph)

    Cone size dependence of jet suppression in heavy-ion collisions

    Yacine Mehtar-Tani🇺🇸 · Daniel Pablos🇳🇴 · Konrad Tywoniuk🇳🇴

    The strong suppression of high- jets in heavy ion collisions is a result of elastic and inelastic energy loss suffered by the jet multi-prong collection of color charges that are resolved by medium interactions. Hence, quenching effects depend on the fluctuations of the jet substructure that are probed by the cone size dependence of the spectrum. In this letter, we present the first complete, analytic calculation of the inclusive -dependent jet spectrum in PbPb collisions at LHC energies, including resummation of energy loss effects from hard, vacuum-like emissions occurring in the medium and modeling of soft energy flow and recovery at the jet cone. Both the geometry of the collision and the local medium properties, such as the temperature and fluid velocity, are given by a hydrodynamic evolution of the medium, leaving only the coupling constant in the medium as a free parameter. The calculation yields a good description of the centrality and dependence of jet suppression for together with a mild cone size dependence, which is in agreement with recent experimental results. Gauging the theoretical uncertainties, we find that the largest sensitivity resides in the leading logarithmic approximation of the phase space of resolved splittings, which can be improved systematically, while non-perturbative modeling of the soft-gluon sector is of relatively minor importance up to large cone sizes.

    Comments:
    10 pages, 3 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2101.01742 [pdf]
    PRL(2021)·85 citations
  5. 05

    [Submitted on 5 Jan 2021] (cross-list from astro-ph.HE)

    Time dependent signatures of core-collapse supernova neutrinos at HALO

    B. Ekinci🇹🇷 · Y. Pehlivan🇹🇷 · Amol V. Patwardhan🇺🇸

    We calculate the response of a lead-based detector, such as the Helium and Lead Observatory (HALO) or its planned upgrade HALO-1kt to a galactic core-collapse supernova. We pay particular attention to the time dependence of the reaction rates. All reaction rates decrease as the neutrino luminosity exponentially drops during the cooling period but the ratio of one-neutron (1n) to two-neutron (2n) event rates in HALO is independent of this overall decrease. Nevertheless, we find that this ratio still changes with time due to the changing character of neutrino flavor transformations with the evolving conditions in the supernova. In the case of inverted hierarchy, this is caused by the fact that the spectral splits become less and less sharp with the decreasing luminosity. In the case of normal hierarchy, it is caused by the passage of the shock wave through the Mikheyev-Smirnov-Wolfenstein resonance region. However, in both cases, we find that the change in the ratio of 1n to 2n event rates is limited to a few percent.

    Comments:
    12 pages with 7 figures
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2101.01797 [pdf]
    PRD(2021)·2 citations
  6. 06

    [Submitted on 6 Jan 2021] (cross-list from hep-ph)

    Chiral Soliton Models and Nucleon Structure Functions

    Herbert Weigel🇿🇦 · Ishmael Takyi🇬🇭

    We outline and review the computations of polarized and unpolarized nucleon structure functions within the bosonized Nambu-Jona-Lasinio chiral soliton model. We focus on a consistent regularization prescription for the Dirac sea contribution and present numerical results from that formulation. We also reflect on previous calculations on quark distributions in chiral quark soliton models and attempt to put them into perspective.

    Comments:
    40 pages, review to appear in special issue 'Advances in Chiral Quark Models' of Symmetry (MDPI)
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2101.02114 [pdf]
    Symmetry(2021)·3 citations
  7. 07

    [Submitted on 6 Jan 2021] (cross-list from hep-ph)

    QCD pressure: renormalization group optimized perturbation theory confronts lattice

    Jean-Loïc Kneur🇫🇷 · Marcus Benghi Pinto🇧🇷 · Tulio E. Restrepo🇧🇷

    The quark contribution to the QCD pressure, , is evaluated up to next-to-leading order (NLO) within the renormalization group optimized perturbation theory (RGOPT) resummation approach. To evaluate the complete QCD pressure we simply add the perturbative NLO contribution from massless gluons to the resummed . Despite of this unsophisticated approximation our results for at the central scale show a remarkable agreement with ab initio lattice predictions for . We also show that by being imbued with RG properties, the RGOPT produces a drastic reduction of the embarrassing remnant scale dependence that plagues both standard thermal perturbative QCD and hard thermal loop perturbation theory (HTLpt) applications.

    Comments:
    6 pages and 3 figures. Further clarifications. To appear in Phys. Rev. D
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    2101.02124 [pdf]
    PRD(2021)·13 citations

Affiliations

first authorsco-authorsvia INSPIRE