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Nuclear Theory·nucl-th

Friday·July 2, 2021

11 papers—5 primary·6 cross-listed

All11Primary5Cross-lists6
  1. 01

    [Submitted on 1 Jul 2021]

    Hyperon Dynamics in Heavy-ion Collisions near threshold energy

    Ding-Chang Zhang🇨🇳 · Hui-Gan Cheng🇨🇳 · Zhao-Qing Feng🇨🇳

    Within the framework of quantum molecular dynamics transport model, the isospin and in-medium effects on the hyperon production in the reaction of Au + Au are investigated thoroughly. A repulsive hyperon-nucleon potential from the chiral effective field theory is implemented into the model, which is related to the hyperon momentum and baryon density. The correction on threshold energy of the elementary hyperon cross section is taken into account. It is found that the yields are suppressed in the domain of midrapidity and kinetic energy spectra with the potential. The hyperons are emitted in the reaction plane because of the strangeness exchange reaction and reabsorption process in nuclear medium. The ratio depends on the stiffness of nuclear symmetry energy, in particular in the high-energy region (above 500 MeV).

    Comments:
    5 pages, 4 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2107.00277 [pdf]
    Chin.Phys.Lett.(2021)·16 citations
  2. 02

    [Submitted on 1 Jul 2021]

    Nuclear Structure at the Crossroads

    R.J. Furnstahl🇺🇸 · H.-W. Hammer🇩🇪 · A. Schwenk🇩🇪

    Steven Weinberg's seminal papers from 1990-92 initiated the use of effective field theories (EFTs) for nuclei. We summarize progress, priorities, and open questions for nuclear EFT developments based on the 2019 INT program "Nuclear Structure at the Crossroads."

    Comments:
    15 pages, Contribution to Special Issue: Celebrating 30 years of Steven Weinberg's papers on Nuclear Forces from Chiral Lagrangians; published version
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    2107.00413 [pdf]
    Few Body Syst.(2021)·16 citations
  3. 03

    [Submitted on 1 Jul 2021]

    Eccentricities, fluctuations and A-dependence of elliptic and triangular flows in heavy-ion collisions

    G.Kh. Eyyubova🇷🇺 · V.L. Korotkikh🇷🇺 · A.M. Snigirev🇷🇺 · E.E. Zabrodin🇷🇺

    A simple geometrical model with event-by-event fluctuations is suggested to study elliptical and triangular eccentricities in the initial state of relativistic heavy-ion collisions. This model describes rather well the ALICE and ATLAS data for Pb+Pb collisions at center-of-mass energy ~TeV per nucleon pair, assuming that the second, , and third, , harmonics of the anisotropic flow are simply linearly proportional to the eccentricities and , respectively. We show that the eccentricity has a pure fluctuation origin and is substantially dependent on the size of the overlap area only, while the eccentricity is mainly related to the average collision geometry. Elliptic flow, therefore, is weakly dependent on the event-by-event fluctuations everywhere except of the very central collisions 0--2%, whereas triangular flow is mostly determined by the fluctuations. The scaling dependence of the magnitude of the flow harmonics on atomic number, , is predicted for this centrality interval.

    Comments:
    Further development and extension of ideas discussed in arXiv:2007.04850. Accepted for publication in J. of Physics G: Nucl. and Part. Physics
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    2107.00521 [pdf]
    J.Phys.G(2021)·9 citations
  4. 04

    [Submitted on 29 Jun 2021]

    Diffusion as a possible mechanism controlling the production of superheavy nuclei in cold fusion reactions

    T. Cap · M. Kowal · K. Siwek-Wilczyńska

    The fusion probability for the production of superheavy nuclei in cold fusion reactions was investigated and compared with recent experimental results for Ca, Ti, and Cr incident on a Pb target. Calculations were performed within the fusion-by-diffusion model (FbD) using new nuclear data tables by Jachimowicz et al. It is shown that the experimental data could be well explained within the framework of the FbD model. The saturation of the fusion probability at bombarding energies above the interaction barrier is reproduced. It emerges naturally from the physical effect of the suppression of contributions of higher partial waves in fusion reactions and is related to the critical angular momentum. The role of the difference in values of the rotational energies in the fusion saddle point and contact (sticking) configuration of the projectile-target system is discussed.

    Comments:
    submitted to PLB
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2107.00579 [pdf]
    PRC(2022)·9 citations
  5. 05

    [Submitted on 1 Jul 2021]

    Constraining the hadronic spectrum and repulsive interactions in a hadron resonance gas via fluctuations of conserved charges

    Jamie M. Karthein🇺🇸 · Volker Koch🇺🇸 · Claudia Ratti🇺🇸 · Volodymyr Vovchenko🇺🇸

    We simultaneously incorporate two common extensions of the hadron resonance gas model, namely the addition of extra, unconfirmed resonances to the particle list and the excluded volume repulsive interactions. We emphasize the complementary nature of these two extensions and identify combinations of conserved charge susceptibilities that allow to constrain them separately. In particular, ratios of second-order susceptibilities like and are sensitive only to the baryon spectrum, while fourth-to-second order ratios like , , or are mainly determined by repulsive interactions. Analysis of the available lattice results suggests the presence of both the extra states in the baryon-strangeness sector and the repulsive baryonic interaction, with indications that hyperons have a smaller repulsive core than non-strange baryons. The modified hadron resonance gas model presented here significantly improves the description of lattice QCD susceptibilities at chemical freeze-out and can be used for the analysis of event-by-event fluctuations in heavy-ion collisions.

    Comments:
    10 pages, 5 figures, version published in Phys. Rev. D
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2107.00588 [pdf]
    PRD(2021)·28 citations

Affiliations

first authorsco-authorsvia INSPIRE