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Nuclear Theory·nucl-th

Friday·August 2, 2019

11 papers—7 primary·4 cross-listed

All11Primary7Cross-lists4
  1. 01

    [Submitted on 1 Aug 2019]

    Ab Initio Structure of p-Shell Nuclei with Chiral Effective Field Theory and Daejeon16 Interactions

    Pieter Maris🇺🇸 · Ik Jae Shin🇰🇷 · James P. Vary🇺🇸

    We present No-Core Full Configuration results for the ground state energies of all particle-stable p-shell nuclei, as well as the excitation energies of more than 40 narrow states, excluding isobaric analog states. We used the chiral LENPIC nucleon-nucleon plus three-nucleon interaction at N2LO with semi-local coordinate space regulators, and also the phenomenological Daejeon16 nucleon-nucleon potential. With simple exponential extrapolations of the total energies of each state, binding energies and spectra are found to be in good agreement with experiment. Both interactions produce a trend towards some overbinding of nuclei at the upper end of the p-shell.

    Comments:
    15 pages, 3 figures, Proceedings of the International Conference `Nuclear Theory in the Supercomputing Era - 2018' (NTSE-2018), Daejeon, South Korea, October 29 - November 2, 2018, eds. A. M. Shirokov and A. I. Mazur. Pacific National University, Khabarovsk, Russia, 2019, p. 77
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1908.00155 [pdf]
    8 citations
  2. 02

    [Submitted on 1 Aug 2019]

    Centrality Dependence of Multiplicity Fluctuations in Ion-Ion Collisions from the Beam Energy Scan at FAIR

    Anuj Chandra🇮🇳 · Bushra Ali🇮🇳 · Shakeel Ahmad🇮🇳

    Multiplicity distributions and event-by-event multiplicity fluctuations in AuAu collisions at energies in future heavy-ion experiment at the Facility for Anti-proton and Ion Research (FAIR) are investigated. Events corresponding to FAIR energies are simulated in the frame work of Ultra Relativistic Quantum Molecular Dynamics (URQMD) model. It is observed that the mean and the width of multiplicity distributions monotonically increase with beam energy. The trend of variations of dispersion with mean number of participating nucleons for the centrality-bin width of 5\% are in accord with the Central Limit Theorem. The multiplicity distributions in various centrality bins as well as for full event samples are observed to obey Koba, Nielsen and Olesen (KNO) scaling. The trends of variations of scaled variance with beam energy are also found to support the KNO scaling predictions for larger collision centrality. The findings also reveal that the statistical fluctuations in 5\% centrality-bin width appear to be under control.

    Comments:
    18 pages, 9 figures, 6 tables. Accepted for publication in Advances in High Energy Physics
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    1908.00233 [pdf]
    Adv.High Energy Phys.(2019)·3 citations
  3. 03

    [Submitted on 1 Aug 2019]

    How accurately we know the standard Cf(sf) neutron multiplicity?

    R. Capote · D. Neudecker

    Small uncertainties obtained for the Neutron Standards have been associated with possible missing correlations in the input data, with an incomplete uncertainty budget of the employed experimental database or with unrecognized uncertainty sources common to many measurements. While further detailed studies may improve the first two issues, the issue of potential unrecognized uncertainties and correlations between different experiments has long been neglected. We address this gap with a test-case study ons the evaluation of the total neutron multiplicity of the Cf(sf) source, which is included in the evaluation of the Thermal Neutron Constants within the Neutron Standards.

    Comments:
    Presented at the American Nuclear Society winter meeting, ANTPC November 2018, Orlando, FL, USA
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex); Data Analysis, Statistics and Probability (physics.data-an)
    arXiv:
    1908.00272 [pdf]
    1 citation
  4. 04

    [Submitted on 22 Jul 2019]

    Perturbation Scheme for the Effective Nuclear Force

    Kun Ratha Kean · Takashi Nishikawa · Yoritaka Iwata

    Based on a systematic Hartree-Fock+BCS calculation, new perturbation scheme is proposed to modify the existing Skyrme-type effective nuclear force. Much attention is paid to have a better description of fission property of heavy nuclei. In terms of incorporating the nuclear medium effects on the fission barrier height more correctly, two typical Skyrme parameter sets (SkM* and SLy4) are modified. In conclusion, according to the comparison to experiments, the calculated fission barrier heights are improved by almost 90.

    Comments:
    To be published in JPS Conference Proceedings (NN2018)
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    1908.00400 [pdf]
    JPS Conf.Proc.(2020)·2 citations
  5. 05

    [Submitted on 1 Aug 2019]

    PHSD -- a microscopic transport approach for strongly interacting systems

    E.L. Bratkovskaya🇩🇪 · W. Cassing🇩🇪 · P. Moreau🇩🇪 · L. Oliva🇩🇪 · O.E. Soloveva🇩🇪 · T. Song🇩🇪

    We present the basic ideas of the Parton-Hadron-String Dynamics (PHSD) transport approach which is a microscopic covariant dynamical model for strongly interacting systems formulated on the basis of Kadanoff-Baym equations for Green's functions in phase-space representation (in 1st order gradient expansion beyond the quasi-particle approximation). The approach consistently describes the full evolution of a relativistic heavy-ion collision from the initial hard scatterings and string formation through the dynamical deconfinement phase transition to the strongly-interacting quark-gluon plasma (sQGP) as well as hadronization and the subsequent interactions in the expanding hadronic phase. The PHSD approach has been applied to p+p, p+A and A+A collisions from lower SIS to LHC energies and been successful in describing a large number of experimental data including single-particle spectra, collective flow and electromagnetic probes. Some highlights of recent PHSD results will be presented.

    Comments:
    17 pages, 6 figures, to be published in the Proceedings of the Indo-French Seminar on "Multi-fragmentation, collective flow and subthreshold partice production in heavy ion reactions", February 4-6 2019, Punjab University, Chandigarh, India
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    1908.00451 [pdf]
    14 citations
  6. 06

    [Submitted on 1 Aug 2019]

    IAEA Photonuclear Data Library 2019

    T. Kawano · Y. S. Cho · P. Dimitriou · D. Filipescu · N. Iwamoto · V. Plujko · X. Tao · H. Utsunomiya · V. Varlamov · R. Xu · R. Capote · I. Gheorghe and 15 other authors

    Photo-induced reaction cross section data are of importance for a variety of current or emerging applications, such as radiation shielding design and radiation transport analyses, calculations of absorbed dose in the human body during radiotherapy, physics and technology of fission reactors (influence of photo-reactions on neutron balance) and fusion reactors (plasma diagnostics and shielding), activation analyses, safeguards and inspection technologies, nuclear waste transmutation, medical isotope production and astrophysical applications. Since the release of the IAEA Photonuclear Data Library in 1999 however, new experimental data as well as new methods to assess the reliability of experimental cross sections have become available. Theoretical models and input parameters used to evaluate photo-induced reactions have improved significantly over the years. In addition, new measurements of partial photoneutron cross sections using mono-energetic photon beams and advanced neutron detection systems have been performed allowing for the validation of the evaluations and assessments of the experimental data. Furthermore, technological advances have led to the construction of new and more powerful gamma-beam facilities, therefore new data needs are emerging. We report our coordinated efforts to address these data needs and present the results of the new evaluations of more than 200 nuclides included in the new updated IAEA Photonuclear Data Library, where the photon energy goes up to 200 MeV. We discuss the new assessment method and make recommendations to the user community in cases where the experimental data are discrepant and the assessments disagree. In addition, in the absence of experimental data, we present model predictions for photo-induced reaction cross section on nuclides of potential interest to medical radioisotope production.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1908.00471 [pdf]
    Nucl.Data Sheets(2020)·120 citations
  7. 07

    [Submitted on 1 Aug 2019]

    Anomalous quartic term in the expansion of the symmetry energy

    N. Zabari · S. Kubis · W. Wójcik

    The quartic term in the framework of relativistic mean field theory with inclusion of scalar meson interactions is investigated. It is shown that the quartic term in the asymmetric expansion of nuclear matter energy may reach very large values. This makes the even power expansion of asymmetry questionable and suggests possible non-analytic contributions to the energy of matter.

    Comments:
    5 pages, 3 figures, accepted to Phys.Rev. C
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1908.00476 [pdf]
    PRC(2019)·11 citations

Affiliations

first authorsco-authorsvia INSPIRE