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Nuclear Theory·nucl-th

Friday·January 10, 2020

11 papers—6 primary·5 cross-listed

All11Primary6Cross-lists5
  1. 01

    [Submitted on 8 Jan 2020]

    Partonic transport model application to heavy flavor

    Weiyao Ke🇺🇸

    Heavy-flavor particles are excellent probes of the properties of the hot and dense nuclear medium created in the relativistic heavy-ion collisions. Heavy-flavor transport coefficients in the quark-gluon plasma (QGP) stage of the collisions are particularly interesting, as they contain important information on the strong interaction at finite temperatures. Studying the heavy-flavor evolution in a dynamically evolving medium requires a comprehensive multi-stage modeling approach of both the medium and the probes, with an accurate implementation of the physical ingredients to be tested. For this purpose, I have developed a new partonic transport model (Linear-Boltzmann-plus-Diffusion-Transport-Model) LIDO and applied it to heavy quark propagation inside a QGP. The model has an improved implementation of parton in-medium bremsstrahlung and a flexible treatment of the probe-medium interactions, combining both large angle scatterings and diffusion processes. The model is then coupled to a high-energy event-generator, a hydrodynamic medium evolution and a hadronic transport model. Finally, applying a Bayesian analysis, I extract the heavy quark transport coefficients from a model-to-data comparison. The results, with uncertainty quantification, are found to be consistent with earlier extraction of the light-quark transport coefficients at high momentum and with first-principle calculations of the heavy flavor diffusion constant at low momentum.

    Comments:
    Ph.D. dissertation; 203 pages, 61 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2001.02766 [pdf]
    4 citations
  2. 02

    [Submitted on 9 Jan 2020]

    An {\it ab-initio} Gamow shell model approach with a core

    B. S. Hu · Q. Wu · J. G. Li · Y. Z. Ma · Z. H. Sun · N. Michel · F. R. Xu

    Gamow shell model (GSM) is usually performed within the Woods-Saxon (WS) basis in which the WS parameters need to be determined by fitting experimental single-particle energies including their resonance widths. In the multi-shell case, such a fit is difficult due to the lack of experimental data of cross-shell single-particle energies and widths. In this paper, we develop an {\it ab-initio} GSM by introducing the Gamow Hartree-Fock (GHF) basis that is obtained using the same interaction as the one used in the construction of the shell-model Hamiltonian. GSM makes use of the complex-momentum Berggren representation, then including resonance and continuum components. Hence, GSM gives a good description of weakly bound and unbound nuclei. Starting from chiral effective field theory and employing many-body perturbation theory (MBPT) (called nondegenerate -box folded-diagram renormalization) in the GHF basis, a multi-shell Hamiltonian ({\it sd-pf} shells in this work) can be constructed. The single-particle energies and their resonance widths can also been obtained using MBPT. We investigated O and F isotopes, for which multi-shell calculations are necessary. Calculations show that continuum effects and the inclusion of the {\it pf} shell are important elements to understand the structure of nuclei close to and beyond driplines.

    Comments:
    Accept by Physics Letters B
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2001.02832 [pdf]
    PLB(2020)·40 citations
  3. 03

    [Submitted on 9 Jan 2020]

    Dynamics of the linear-chain alpha cluster in microscopic time-dependent relativistic density functional theory

    Z. X. Ren · P. W. Zhao · J. Meng

    The time-dependent covariant density functional theory in 3D lattice space has been developed and applied to investigate the microscopic dynamics of the linear-chain cluster states for carbon isotopes in the reactions HeBe and HeBe without any symmetry assumptions. By examining the density distribution and its time evolutions, the structure and dynamics of the linear-chain states are analyzed, and the quasiperiodic oscillations of the clusters are revealed. For HeBe, the linear-chain states evolve to a triangular configuration and then to a more compact shape. In contrast, for HeBe, the lifetime of the linear-chain states is much more prolonged due to the dynamical isospin effects by the valence neutrons which slow down the longitudinal oscillations of the clusters and persist the linear-chain states. The dependence of the linear chain survival time and dynamical isospin effects on impact parameters have been illustrated as well.

    Comments:
    14 pages, 5 figures
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2001.02834 [pdf]
    PLB(2020)·35 citations
  4. 04

    [Submitted on 9 Jan 2020]

    Temperature effects on the neutron matter equation of state obtained from chiral effective field theory

    F. Sammarruca🇺🇸 · R. Machleidt🇺🇸 · R. Millerson🇺🇸

    Temperature effects on the neutron matter equation of state are investigated in the framework of chiral effective field theory. Latest, state-of-the-art chiral two-nucleon forces are applied from third to fifth order in the chiral expansion together with chiral three-nucleon forces, allowing for a determination of the truncation error of the theoretical predictions. The thermodynamic quantities considered include the chemical potential, the internal energy, the entropy, and the free energy. In general, good order-by-order convergence of all predictions is observed. As to be expected, temperature effects are largest at low density. The temperature dependence of the chiral three-nucleon force turns out to be weak.

    Comments:
    9 pages, 9 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2001.02845 [pdf]
    Mod.Phys.Lett.A(2020)·7 citations
  5. 05

    [Submitted on 9 Jan 2020]

    Theoretical Analysis of Double Differential Cross Section of Proton, Deuteron and Triton for Li Reaction at 14 MeV

    Jiaqi Hu · Xiaojun Sun · Jingshang Zhang · Sheng Wang · Sheng Wang · Yinlu Han

    Based on the statistical theory of light nucleus reactions (STLN), the description of the complicated emission processes of proton and light composite charged particles are further improved through considering the effects of Coulomb barriers both in incident and different outgoing reaction channels. And the analysis of the reaction channels including the sequential and simultaneous emission processes for Li reaction is performed in detail. So the partial spectra of all of outgoing particles are also obtained for different reaction processes. The calculated double differential cross sections of total outgoing proton, deuteron and triton at MeV agree well with the available experimental data for different outgoing angles. The ENDF-6 formatted data, which includes all of the reaction cross sections, elastic angular distributions, double differential cross sections of nucleon and light composite charged particles for Li reaction, are also obtained by PUNF code.

    Comments:
    34 pages, 16 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2001.02891 [pdf]
    PRC(2020)·6 citations
  6. 06

    [Submitted on 9 Jan 2020]

    Breakdown of the tensor component in the Skyrme energy density functional

    J. M. Dong · X. L. Shang

    The tensor force, as an important component of strong nuclear force, generates a variety of intriguing effects ranging from few-body systems to neutron stars. It is responsible for the nucleon-nucleon correlation beyond mean-field approximation, and is accordingly proved to play no role in the standard Skyrme energy density functionals in the present work. Therefore, the Skyrme's original tensor interaction that is extensively-employed presently is invalid. As an alternative strategy, we introduced a central interaction, i.e., the term, to improve the description of experimental single-particle structure, and to address its effect, we established two Skyrme interactions IMP1 and IMP2 complemented by the calibrated charge-violating interactions. The central interaction turns out to substantially improve the description of shell evolution in Sn isotopes and isotones.

    Comments:
    6 pages, 1 figure, Phys. Rev. C 101, 014305 (2020)
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2001.02937 [pdf]
    PRC(2020)·10 citations

Affiliations

first authorsco-authorsvia INSPIRE