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Nuclear Theory·nucl-th

Friday·April 3, 2020

10 papers—3 primary·7 cross-listed

All10Primary3Cross-lists7
  1. 04

    [Submitted on 1 Apr 2020] (cross-list from hep-ph)

    Radiative decay of in a hadronic molecule picture

    HongQiang Zhu🇨🇳 · Yin Huang🇨🇳

    The baryon with the quantum number is considered as a molecular state composed of a baryon and meson. The partial decay widths of the molecular state into and final states through hadronic loops are evaluated with the help of the effective Lagrangians. The partial widths for the and are evaluated to be about 1.50-1.02 KeV and 17.56-24.91 KeV, respectively, which may be accessible for the LHCb. Based on our results we argue that an experimental determination of the radiative decay width of is important for the understanding of its intrinsic properties.

    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2004.00728 [pdf]
    CPC(2020)·12 citations
  2. 05

    [Submitted on 2 Apr 2020] (cross-list from nucl-ex)

    A Study of the Properties of the QCD Phase Diagram in High-Energy Nuclear Collisions

    Xiaofeng Luo🇨🇳 · Shusu Shi🇨🇳 · Nu Xu🇨🇳 · Yifei Zhang🇨🇳

    With the aim of understanding the phase structure of nuclear matter created in high-energy nuclear collisions at finite baryon density, a beam energy scan program has been carried out at Relativistic Heavy Ion Collider (RHIC). In this mini-review, most recent experimental results on collectivity, criticality and heavy flavor productions will be discussed. The goal here is to establish the connection between current available data and future heavy-ion collision experiments in a high baryon density region.

    Comments:
    Invited review, 30 pages, 18 figures
    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2004.00789 [pdf]
    Particles(2020)·77 citations
  3. 06

    [Submitted on 2 Apr 2020] (cross-list from astro-ph.HE)

    Equation of state constraints from the threshold binary mass for prompt collapse of neutron star mergers

    Andreas Bauswein🇩🇪 · Sebastian Blacker🇩🇪 · Vimal Vijayan🇩🇪 · Nikolaos Stergioulas🇬🇷 · Katerina Chatziioannou🇺🇸 · James A. Clark🇺🇸 · Niels-Uwe F. Bastian🇵🇱 · David B. Blaschke🇵🇱 · Mateusz Cierniak🇵🇱 · Tobias Fischer🇵🇱

    Using hydrodynamical simulations for a large set of high-density matter equations of state (EoSs) we systematically determine the threshold mass M_thres for prompt black-hole formation in equal-mass and asymmetric neutron star (NS) mergers. We devise the so far most direct, general and accurate method to determine the unknown maximum mass of nonrotating NSs from merger observations revealing M_thres. Considering hybrid EoSs with hadron-quark phase transition, we identify a new, observable signature of quark matter in NS mergers. Furthermore, our findings have direct applications in gravitational wave searches, kilonova interpretations and multi-messenger constraints on NS properties.

    Comments:
    Accepted for publication in Phys. Rev. Lett.; 14 pages, 5 figures
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2004.00846 [pdf]
    PRL(2020)·144 citations
  4. 07

    [Submitted on 31 Mar 2020] (cross-list from astro-ph.HE)

    Crucial role of neutron diffusion in the crust of accreting neutron stars

    Andrey Chugunov · Nikolay Shchechilin

    Observed temperatures of transiently accreting neutron stars in the quiescent state are generally believed to be supported by deep crustal heating, associated with non-equilibrium exothermic reactions in the crust. Traditionally, these reactions are studied by considering nuclear evolution governed by compression of the accreted matter. Here we show that this approach has a basic weakness, that is that in some regions of the inner crust the conservative forces, applied for matter components (nuclei and neutrons), are not in mechanical equilibrium. In principle the force balance can be restored by dissipative forces, however the required diffusion fluxes are of the same order as total baryon flux at Eddington accretion. We argue that redistribution of neutrons in the inner crust should be involved in realistic model of accreted crust.

    Comments:
    Accepted for publication in MNRAS:Letters, 6 pages, 1 figure
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Theory (nucl-th)
    arXiv:
    2004.00997 [pdf]
    MNRAS(2020)·12 citations
  5. 08

    [Submitted on 1 Apr 2020] (cross-list from hep-ph)

    Quark model relations for b-baryon decay

    Jerrold Franklin🇺🇸

    Properties of b-baryon decay matrix elements (amplitudes) have been derived in a nonsymmetric quark model without any use of SU(6), SU(3), or SU(2) (isotopic spin) groups. Equalities between pairs of amplitudes are derived, and mixing is used to calculate the branching ratio for the transition .

    Comments:
    The derivation has been simplified
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
    arXiv:
    2004.01037 [pdf]
    J.Phys.G(2020)·3 citations
  6. 09

    [Submitted on 2 Apr 2020] (cross-list from nucl-ex)

    New estimator for symmetry plane correlations in anisotropic flow analyses

    Ante Bilandzic🇩🇪 · Marcel Lesch🇩🇪 · Seyed Farid Taghavi🇩🇪

    Correlations of symmetry planes are important observables used to quantify anisotropic flow phenomenon and constrain independently the properties of strongly interacting nuclear matter produced in the collisions of heavy ions at the highest energies. In this paper, we point out current problems of measuring correlations between symmetry planes and elaborate on why the available analysis techniques have a large systematic bias. To overcome this problem, we introduce a new approach to approximate multi-harmonic flow fluctuations via a two-dimensional Gaussian distribution. Employing this approximation, we introduce a new estimator, dubbed Gaussian Estimator (GE), to extract pure correlation between symmetry planes. We validate GE by using the realistic event-generator iEBE-VISHNU and demonstrate that it outperforms all existing estimators. Based on event-shape engineering, we propose an experimental procedure to improve GE accuracy even further.

    Comments:
    14 pages, 4 figures. v2: minor revision, v2 submitted to journal
    Subjects:
    Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2004.01066 [pdf]
    PRC(2020)·17 citations
  7. 10

    [Submitted on 2 Apr 2020] (cross-list from hep-ph)

    QCD Phase Diagram at NICA energies: horn effect and light clusters in THESEUS

    D. Blaschke🇷🇺 · A.V. Friesen🇷🇺 · Yu.B. Ivanov🇷🇺 · Yu.L. Kalinovsky🇷🇺 · M. Kozhevnikova🇷🇺 · S. Liebing🇷🇺 · A. Radzhabov🇷🇺 · G. Röpke🇷🇺

    We discuss recent progress in the development of the three-fluid hydrodynamics-based program THESEUS towards an event generator suitable for applications to heavy-ion collisions at the intermediate energies of the planned NICA and FAIR experiments. We follow the strategy that modifications of particle distributions at the freeze-out surface in the QCD phase diagram may be mapped directly to the observable ones within a sudden freeze-out scheme. We report first results of these investigations for the production of light clusters (deuterons and tritons) which can be compared to experimental data from the HADES and the NA49 experiment and for the interpretation of the "horn" effect observed in the collision energy dependence of the ratio. Medium effects on light cluster production in the QCD phase diagram are negligible at the highest NICA energies but shall play a dominant role at the lowest energies. A sharp "horn"-type signal in the ratio can be obtained when the onset of Bose condensation modelled by a pion chemical potential results in an enhancement of pions at low momenta (which is seen at LHC energies) and would occur already in the NICA energy range.

    Comments:
    5 pages, 3 figures, 3 references added, contribution to the Proceedings of "III NICA Days-2019 and IV MPD Collaboration Meeting", Warsaw, 21.-25.10.2019
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2004.01159 [pdf]
    Acta Phys.Polon.Supp.(2021)·4 citations

Affiliations

first authorsco-authorsvia INSPIRE