PaperPanorama
FAQ

Nuclear Theory·nucl-th

Wednesday·September 12, 2018

12 papers—6 primary·6 cross-listed

All12Primary6Cross-lists6
  1. 01

    [Submitted on 11 Sept 2018]

    Microscopic description of structural evolution in Pd, Xe, Ba, Nd, Sm, Gd and Dy isotopes

    Tabassum Naz · G. H. Bhat · S. Jehangir · Shakeb Ahmad · J. A. Sheikh

    Aiming to understand the role of triaxiality and the evolution of the ground state nuclear shapes, we have carried out a microscopic study for a series of chains of Pd, Xe, Ba, Nd, Sm, Gd, and Dy isotopes. This is done within the self-consistent Relativistic-Hartree-Bogoliubov (RHB) formalism, and supported by the Triaxial Projected Shell Model (TPSM) approach. Pairing interaction separable in the momentum space with DD-ME2 force parameter is used to generate the potential energy surfaces(PESs) under the axial and triaxial symmetry. Shape evolution manifest themself in very clear manner in almost all the isotopic chains. Properties of the global mimima have been found to be in good agreement with the available experimental data. Relatively flat PESs, and -soft nature, have been suggested Pd, Xe and Ba as good candidates for E(5) symmetry, while Pd is not found suitable for E(5) symmetry. The PESs with a bump, and rigidity against triaxial variable() suggested Nd, Sm and Gd to be good candidates while Sm and Dy are poor candidates of X(5) critical-point symmetry. The findings of the present RHB calculations supported by TPSM are qualitatively in good agreement with the experimental and other theoretical calculations.

    Comments:
    accepted in Nucl. Phys. A
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1809.03686 [pdf]
    NPA(2018)·24 citations
  2. 02

    [Submitted on 11 Sept 2018]

    Strangeness production via resonances in heavy-ion collisions at SIS energies

    V. Steinberg🇩🇪 · J. Staudenmaier🇩🇪 · D. Oliinychenko🇩🇪 · F. Li🇩🇪 · Ö. Erkiner🇩🇪 · H. Elfner🇩🇪

    Production of strange hadrons in elementary and heavy-ion reactions is studied with the hadronic transport approach SMASH (Simulating Many Accelerated Strongly-interacting Hadrons). The poorly known branching ratios of the relevant hadronic resonances are constrained from the known elementary hadronic cross sections and from invariant mass spectra of dileptons. The constrained model is employed as a baseline to compare to heavy-ion-collision experiments at low energies () and to predict some of the upcoming pion-beam results by HADES, which are expected to be sensitive to the resonance properties. The employed vacuum-resonance approach proves to be viable for small systems at these energies, but for large systems additional in-medium effects might be required.

    Comments:
    20 pages, 34 figures, 4 tables
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1809.03828 [pdf]
    PRC(2019)·32 citations
  3. 03

    [Submitted on 11 Sept 2018]

    Correlated structure of nuclear symmetry energy from covariant nucleon self-energy

    Zhi Wei Liu🇨🇳 · Qian Zhao🇨🇳 · Bao Yuan Sun🇨🇳

    Based on the Hugenholtz-Van Hove theorem, the symmetry energy and its density slope parameter are decomposed in terms of the nucleon self-energies within the covariant density functional (CDF) theory. It is found that two structural connections between the different ingredients of and construct the fundamental correlation between and in the relativistic covariant framework, while the additional contribution from the isovector scalar channel of nucleon-nucleon interaction and those from the second-order symmetry self-energies lead to a deviation, especially the latter limits severely its correlation coefficient and confidence level. In addition, the relationship between the Landau mass and the Dirac mass is approximated to a reliable linear correlation, which is demonstrate to be sensitive to the momentum dependence of the nucleon self-energies.

    Comments:
    10 pages, 5 figures, corresponding to the talk given in NuSYM2018
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1809.03837 [pdf]
    4 citations
  4. 04

    [Submitted on 8 Sept 2018]

    Solution of the Specific Model of Five-Body Problem to Investigate the Effective Alpha-Nucleon Interaction in a Partial-wave Analysis

    E. Ahmadi Pouya · A. A. Rajabi

    In this paper, we have solved a simple specific model of the five-body problem in the framework of the Yakubovsky equations, restricted to the configurations of the alpha-nucleon types only, to investigate the effective interaction between an inert alpha-particle and a neutron. In general case, the Yakubovsky scheme for the solution of the five-body system leads to a set of four coupled equations related to four independent configurations, which can be restricted to two coupled ones, to describe the effective alpha-nucleon structure model, namely an inert four-body alpha-core and a nucleon. Hence, in such a model, the other configurations will not be taken into account. To calculate the binding energies of the five-body system in the model of alpha- nucleon structure, the two coupled equations are represented in the momentum space on the basis of the Jacobi momenta. After an explicit evaluation of the two coupled integral equations in a partial-wave analysis, the obtained equations are the starting point for a numerical calculation as an eigenvalue equation form, using typical iteration method. In the first step to the calculations, i.e. applying some spin-independent potential models, some obtained binding energy differences between the four-body as an alpha-particle and the five-body as an alpha-nucleon systems suggest that a simple effective interaction between an inert alpha-particle and a nucleon is attractive and of about 13 MeV. In addition, the represented binding energy results with respect to the regarded spin-independent potentials are in fair agreement with the obtained results from other methods.

    Comments:
    PACS. No: 21.45.+v, 21.30.Fe, 21.30.-x, 21.10.Dr http://www.actaphys.uj.edu.pl/findarticle?series=Reg&vol=48&page=1279. arXiv admin note: text overlap with arXiv:nucl-th/0605063, arXiv:1009.2319, arXiv:0704.2056 by other authors
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1809.03846 [pdf]
    Acta Phys.Polon.B(2017)·1 citation
  5. 05

    [Submitted on 11 Sept 2018]

    Production of Light Nuclei at Thermal Freezeout in Heavy-Ion Collisions

    Xinyuan Xu🇺🇸 · Ralf Rapp🇺🇸

    We revisit the problem of the production of light atomic nuclei in ultrarelativistic heavy-ion collisions. While their production systematics is well produced by hadro-chemical freezeout at temperatures near the QCD pseudo-critical temperature, their small binding energies of a few MeV per nucleon suggest that they cannot survive as bound states under these conditions. Here, we adopt the concept of effective chemical potentials in the hadronic evolution from chemical to thermal freezeout (at typically 100\,MeV), which, despite frequent elastic rescatterings in hadronic matter, conserves the effective numbers of particles which are stable under strong interactions, most notably pions, kaons and nucleons. It turns out that the large chemical potentials that build up for antibaryons result in thermal abundances of light nuclei and antinuclei, formed at thermal freezeout, which essentially agree with the ones evaluated at chemical freezeout. Together with their transverse-momentum spectra, which also indicate a kinetic freezeout near , this provides a natural explanation for their production systematics without postulating their survival at high temperatures.

    Comments:
    5 pages, 7 figures, v2: "Note added" corrected
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    1809.04024 [pdf]
    EPJA(2019)·34 citations
  6. 06

    [Submitted on 11 Sept 2018]

    Longitudinal Dynamics of High Baryon Density Matter in High Energy Heavy-Ion Collisions

    Ming Li🇺🇸 · Chun Shen🇺🇸

    In high energy heavy-ion collisions, the two colliding nuclei pass through each other leaving behind an almost baryon free central rapidity region. Most of the baryons are carried away by the nuclear remnants and are located in the so-called fragmentation regions. In previous papers \cite{Li:2016wzh,Li:2018ini}, it has been argued that very high baryon densities, more than ten times larger than the normal nuclear density, can be achieved in these fragmentation regions. In this paper, we assume the high baryon density matter is thermalized at the same time as the baryon-free quark-gluon plasma in the central rapidity region. We perform a 1+1D (temporal + longitudinal) hydrodynamic simulation covering both the fragmentation regions and the central rapidity region with the baryon diffusion equation included. Baryons are found to diffuse from the fragmentation regions to the central rapidity region driven by fugacity gradients. The baryon chemical potential at freezeout monotonically increases from the central rapidity region to the fragmentation regions, suggesting a rapidity scan in high energy heavy-ion collisions might be helpful in searching for the critical point of the QCD phase diagram.

    Comments:
    14 pages, 17 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1809.04034 [pdf]
    PRC(2018)·33 citations

Affiliations

first authorsco-authorsvia INSPIRE