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Nuclear Theory·nucl-th

Thursday·January 12, 2023

10 papers—5 primary·5 cross-listed

All10Primary5Cross-lists5
  1. 01

    [Submitted on 11 Jan 2023]

    Collective flows of protons and deuterons in Au + Au collisions at = 1.23 GeV by the IQMD model

    Ling-Meng Fang🇨🇳 · Yu-Gang Ma🇨🇳 · Song Zhang🇨🇳

    Collective flows of protons and deuterons for Au + Au collisions at beam energy = 1.23 GeV were simulated by an Isospin dependent Quantum Molecular Dynamics (IQMD) model. Two coalescence models, namely naive coalescence and dynamical coalescence models, for the formation of deuterons are compared. After reasonable match of rapidity spectra of protons and deuterons to the High Acceptance DiElectron Spectrometer (HADES) data is reached, we apply an event-plane method to calculate the first four-order collective flow coefficients as well as the ratios of and , and observe the number of constituent nucleon scaling among protons and deuterons. In addition, the dependence of and as well as the ratio / on the centrality is obtained. Lastly, we further investigate the Pearson coefficients between the first four harmonic flows for protons and deuterons as a function of rapidity and centrality.

    Comments:
    9 pages, 8 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2301.04279 [pdf]
    PRC(2023)·10 citations
  2. 02

    [Submitted on 11 Jan 2023]

    Chiral uncertainties in ab initio nucleon-nucleus elastic scattering

    R.B. Baker · M. Burrows · Ch. Elster · K.D. Launey · P. Maris · G. Popa · S.P. Weppner

    The effective interaction between a nucleon and a nucleus is one of the most important ingredients for reaction theories. Theoretical formulations were introduced early by Feshbach and Watson, and efforts of deriving and computing those `optical potentials' in a microscopic fashion have a long tradition. However, only recently the leading order term in the Watson multiple scattering approach could be calculated fully {\it ab initio}, meaning that the same nucleon-nucleon (NN) interaction enters both the structure as well as the reaction pieces on equal footing. This allows the uncertainties from the underlying chiral effective NN interaction to be systematically explored in nucleon-nucleus elastic scattering observables. In this contribution the main ingredients for arriving at the {\it ab initio} leading order of the effective nucleon-nucleus interaction in the Watson approach will be reviewed. Concentrating on one specific chiral NN interaction from the LENPIC collaboration and light nuclei with a 0 ground state, the leading order nucleon-nucleus interaction is calculated using up to the third chiral order (N2LO) in the nucleon-nucleon potential, and elastic scattering observables are extracted. Then pointwise as well as correlated uncertainty quantification is used for the estimation of the chiral truncation error. Elastic scattering observables for He, C, and O for between 65 and 200 MeV projectile energy will be analyzed.

    Comments:
    14 pages, 11 figures, to appear in Frontiers in Physics
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2301.04293 [pdf]
    7 citations
  3. 03

    [Submitted on 11 Jan 2023]

    Elastic scatering cross-sections obtained on the basis of the potential of the modified Thomas-Fermi method and taking the core into account

    V.A. Nesterov · O.I. Davydovska · V.Yu. Denisov

    Nucleon density distributions and nucleus-nucleus interaction potentials for the reactions O+Ca, O+Fe and O+Zr have been calculated in the framework of the modified Thomas-Fermi method and considering all terms up to the second order in in the quasi-classical expansion of the kinetic energy. Skyrme forces dependent on the nucleon density are used as the nucleon-nucleon interaction. A parametrization of the nucleus-nucleus interaction potential, which well describes the potential value calculated within the modified Thomas-Fermi approach with density-dependent Skyrme forces, is found. On the basis of the obtained potentials, the cross-sections of elastic scattering are calculated in a good agreement with experimental data.

    Comments:
    8 pages, 5 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2301.04358 [pdf]
    ISSN 2071-0186. Ukr. J. Phys. 2022. Vol. …·1 citation
  4. 04

    [Submitted on 11 Jan 2023]

    Systematic study of the effect of individual rotational energy levels on the fusion cross-section of \texorpdfstring{}--based reactions of range

    Nishu Jain🇮🇳 · M. Bhuyan🇲🇾 · Raj Kumar🇮🇳

    The present work aims to investigate the effect of individual rotational energy levels on the fusion cross-sections for O-based reaction systems, namely, O + W, O + {Hf}, O + {Yb}, O + {Er}, O + Sm, O + Nd at energies below the fusion barrier. Using the CCFULL code, the effect of low-lying rotational energy levels on the fusion cross-section for O induced reactions has been investigated at energies below and around the Coulomb barrier. The calculations are performed by assuming the fixed value of diffuseness parameter fm in the Woods-Saxon nuclear potential and the other two parameters are optimised by fitting the experimental data at the above barrier. Here we have determined the and as a function of , where experimental cross-sections are available. From our calculations, it is observed that the hexadecapole deformation () with different magnitudes has a significant influence on the fusion cross sections. For the case of the value of , beyond , the rotational levels cease to contribute significantly and also there is a significant difference between the contribution of sequential channels. On the other hand, in the case of -ve , up to levels contribute significantly. Furthermore, we have established an algebraic systematic of fitting, which one can use to determine the parameters , of Woods-Saxon nuclear potential within the range of lie in between .

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2301.04363 [pdf]
    Phys.Scripta(2023)·6 citations
  5. 05

    [Submitted on 11 Jan 2023]

    Pre-Equilibrium Evolution of Conserved Charges with ICCING Initial Conditions

    Patrick Carzon🇺🇸 · Mauricio Martinez🇺🇸 · Jacquelyn Noronha-Hostler🇺🇸 · Philip Plaschke🇩🇪 · Soeren Schlichting🇩🇪 · Matthew Sievert🇺🇸

    Heavy-ion collisions can be well described through relativistic viscous hydrodynamics, but questions still remain when hydrodynamics is applicable because the initial state may begin very far-from-equilibrium. Thus, a pre-equilibrium evolution phase is used to bridge the gap between the initial state and hydrodynamics. KMPST is one such pre-equilibrium model that propagates the energy-momentum tensor by decomposing it into the background and fluctuations around that background, whose evolution is captured by Green's functions. We extend this formalism to include conserved charges and calculate the corresponding non-equilibrium Green's functions in the relaxation time approximation. The ICCING algorithm initializes conserved charges in the initial state by sampling splitting probabilities and is, thus, perfectly positioned to implement Green's functions for charge propagation. We show that this method alters the initial state charge geometries and is applicable in central to mid-central collisions.

    Comments:
    66 pages, 18 figures
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    2301.04572 [pdf]
    PRC(2023)·18 citations

Affiliations

first authorsco-authorsvia INSPIRE