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Nuclear Theory·nucl-th

Monday·May 31, 2021

6 papers—4 primary·2 cross-listed

All6Primary4Cross-lists2
  1. 05

    [Submitted on 28 May 2021] (cross-list from hep-ph)

    Detecting Chiral Magnetic Effect via Deep Learning

    Yuan-Sheng Zhao🇨🇳 · Lingxiao Wang🇩🇪 · Kai Zhou🇩🇪 · Xu-Guang Huang🇨🇳

    The search of chiral magnetic effect (CME) in heavy-ion collisions has attracted long-term attentions. Multiple observables have been proposed but all suffer from obstacles due to large background contaminations. In this Letter, we construct an observable-independent CME-meter based on a deep convolutional neural network. After trained over data set generated by a multiphase transport model, the CME-meter shows high accuracy in recognizing the CME-featured charge separation from the final-state pion spectra. It also exhibits remarkable robustness to diverse conditions including different collision energies, centralities, and elliptic flow backgrounds. In a transfer learning manner, the CME-meter is validated in isobaric collision systems, showing good transferability among different colliding systems. Based on variational approaches, we utilize the DeepDream method to derive the most responsive CME-spectra that demonstrates the physical contents the machine learns.

    Comments:
    7 pages, 10 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2105.13761 [pdf]
    PRC(2022)·25 citations
  2. 06

    [Submitted on 28 May 2021] (cross-list from astro-ph.HE)

    Effects of Nuclear Equation of State on Type-I X-ray Bursts: Interpretation of the X-ray Bursts from GS 1826-24

    A. Dohi · N. Nishimura · M. Hashimoto · Y. Matsuo · T. Noda · S. Nagataki

    Type I X-ray bursts are thermonuclear explosions on the neutron star (NS) surface caused by mass accretion from a companion star. Observations of X-ray bursts provide valuable information on X-ray binary systems, e.g., binary parameters, the chemical composition of accreted matter, and the nuclear equation of state (EOS) of NSs. There have been several theoretical studies to constrain the physics of X-ray bursters. However, they have mainly focused on the burning layers above the solid crust of the NS, which brings up issues of the treatment of NS gravitation and internal energy. In this study, focusing on the microphysics inside NSs, we calculate a series of X-ray bursts using a general-relativistic stellar-evolution code with several NS EOSs. We compare the X-ray-burst models with the burst parameters of a clocked burster associated with GS 1826-24. We find a monotonic correlation between the NS radius and the light-curve profile. A larger radius shows a higher recurrence time and a large peak luminosity. In contrast, the dependence of light curves on the NS mass becomes more complicated, where the neutrino cooling suppresses the efficiency of nuclear ignition. We also constrain the EOS and mass of GS 1826-24, i.e., stiffer EOSs, corresponding to larger NS radii, are not preferred due to too-high peak luminosity. The EOS and the cooling and heating of NSs are important to discuss the theoretical and observational properties of X-ray bursts.

    Comments:
    19 pages, 16 figures, 3 tables, updated to match published version (ApJ)
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Theory (nucl-th)
    arXiv:
    2105.13958 [pdf]
    ApJ(2021)·19 citations

Affiliations

first authorsco-authorsvia INSPIRE