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Nuclear Theory·nucl-th

Friday·February 1, 2019

12 papers—7 primary·5 cross-listed

All12Primary7Cross-lists5
  1. 01

    Symmetries and order in cluster nuclei

    Roelof Bijker🇲🇽

    It is shown that the rotational band structure of the cluster states in 12C and 16O can be understood in terms of the underlying discrete symmetry that characterizes the geometrical configuration of the alpha-particles, i.e. an equilateral triangle for 12C, and a regular tetrahedron for 16O. The structure of rotational bands provides a fingerprint of the underlying geometrical configuration of alpha-particles. Finally, some first results are presented for odd-cluster nuclei.

    nucl-thnucl-exAIP Conf.Proc.(2019)·4 citations
  2. 02

    Ground-state properties of doubly magic nuclei from the unitary-model-operator approach with the chiral two- and three-nucleon forces

    T. Miyagi · T. Abe · M. Kohno · P. Navratil · R. Okamoto · T. Otsuka · N. Shimizu · S. R. Stroberg

    The ground-state energies and radii for He, O, and Ca are calculated with the unitary-model-operator approach (UMOA). In the present study, we employ the similarity renormalization group (SRG) evolved nucleon-nucleon () and three-nucleon () interactions based on the chiral effective field theory. This is the first UMOA calculation with both and interactions. The calculated ground-state energies and radii are consistent with the recent {\it ab initio} results with the same interaction. We evaluate the expectation values with two- and three-body SRG evolved radius operators, in addition to those with the bare radius operator. With the aid of the higher-body evolution of radius operator, it is seen that the calculated radii tend to be SRG resolution-scale independent. We find that the SRG evolution gives minor modifications for the radius operator.

    nucl-thPRC(2019)·12 citations
  3. 03

    Dynamically Integrated Transport Approach for High-Energy Nuclear Collisions at High Baryon Density

    Koichi Murase🇯🇵 · Yukinao Akamatsu🇯🇵 · Masayuki Asakawa🇯🇵 · Tetsufumi Hirano🇯🇵 · Masakiyo Kitazawa🇯🇵 · Kenji Morita🇵🇱 · Yasushi Nara🇯🇵 · Chiho Nonaka🇯🇵 · Akira Ohnishi🇯🇵

    To explore the structure of the QCD phase diagram in high baryon density domain, several high-energy nuclear collision experiments in a wide range of beam energies are currently performed or planned using many accelerator facilities. In these experiments search for a first-order phase transition and the QCD critical point is one of the most important topics. To find the signature of the phase transition, experimental data should be compared to appropriate dynamical models which quantitatively describe the process of the collisions. In this study we develop a new dynamical model on the basis of the non-equilibrium hadronic transport model JAM and 3+1D hydrodynamics. We show that the new model reproduce well the experimental beam-energy dependence of hadron yields and particle ratio by the partial thermalization of the system in our core-corona approach.

    nucl-thhep-phnucl-exJPS Conf.Proc.(2019)·2 citations
  4. 04

    Probing QCD critical fluctuations from intermittency analysis in relativistic heavy-ion collisions

    Jin Wu🇨🇳 · Yufu Lin🇨🇳 · Yuanfang Wu🇨🇳 · Zhiming Li🇨🇳

    It is shown that intermittency, a self-similar correlation with respect to the size of the phase space volume, is sensitive to critical density fluctuations of baryon numbers in a system belonging to the three-dimensional (3D) Ising universality class. The relation between intermittency index and relative baryon density fluctuation is obtained. We thus suggest that measuring the intermittency in relativistic heavy-ion collisions could be used as a good probe of density fluctuations associated with the QCD critical phenomena. From recent preliminary results on neutron density fluctuations in central Au + Au collisions at = 7.7, 11.5, 19.6, 27, 39, 62.4 and 200 GeV at RHIC/STAR, the collision energy dependence of intermittency index is extracted and shows a non-monotonic behavior with a peak at around 20 - 27 GeV, indicating that the strength of intermittency becomes the largest in this energy region. The transport UrQMD model without implementing critical physics cannot describe the observed behavior.

    nucl-thhep-exhep-phnucl-exPLB(2020)·31 citations
  5. 05

    Variational calculation of nuclear matter in finite particle number approach using unitary correlation operator and high-momentum pair methods

    Takayuki Myo · Hiroki Takemoto · Mengjiao Lyu · Niu Wan · Chang Xu · Hiroshi Toki · Hisashi Horiuchi · Taiichi Yamada · Kiyomi Ikeda

    We propose a new variational method for describing nuclear matter from nucleon-nucleon interaction. We use the unitary correlation operator method (UCOM) for central correlation to treat the short-range repulsion and further include the two-particle two-hole (2p2h) excitations of nucleon pair involving a large relative momentum, which is called 'high-momentum pair'(HM). We describe nuclear matter in finite size with finite particle number on periodic boundary condition and increase the 2p2h configurations until we get the convergence of the total energy per particle. We demonstrate the validity of this 'UCOM+HM' framework by applying it to the symmetric nuclear and neutron matters with the Argonne V4 potential having short-range repulsion. The nuclear equations of state obtained in UCOM+HM are fairly consistent to those of other calculations such as Brueckner-Hartree-Fock and auxiliary field diffusion Monte Carlo in the overall density region.

    nucl-thPRC(2019)·9 citations
  6. 06

    Equation of state of dense matter in the multimessenger era

    Ying Zhou🇨🇳 · Lie-Wen Chen🇨🇳 · Zhen Zhang🇨🇳

    While the equation of state (EOS) of symmetric nuclear matter (SNM) at suprasaturation densities has been relatively well constrained from heavy-ion collisions, the EOS of high-density neutron-rich matter is still largely uncertain due to the poorly known high-density behavior of the symmetry energy. Using the constraints on the EOS of SNM at suprasaturation densities from heavy-ion collisions together with the data of finite nuclei and the existence of neutron stars from electromagnetic (EM) observations, we show that the high-density symmetry energy cannot be too soft, which leads to lower bounds on dimensionless tidal deformability of and radius of km for neutron star. Furthermore, we find that the recent constraint of from the gravitational wave signal GW170817 detected from the binary neutron star merger by the LIGO and Virgo Collaborations rules out too stiff high-density symmetry energy, leading to an upper limit of km. All these terrestrial nuclear experiments and astrophysical observations based on strong, EM and gravitational measurements together put stringent constraints on the high-density symmetry energy and the EOS of SNM, pure neutron matter and neutron star matter.

    nucl-thastro-ph.HEastro-ph.SRhep-ph+1PRD(2019)·64 citations
  7. 07

    Parton Distribution Functions from a Light Front Hamiltonian and QCD Evolution for Light Mesons

    Jiangshan Lan🇨🇳 · Chandan Mondal🇨🇳 · Shaoyang Jia🇺🇸 · Xingbo Zhao🇨🇳 · James P. Vary🇺🇸

    We obtain the pion and the kaon parton distribution functions from the eigenstates of a light front effective Hamiltonian in the constituent quark-antiquark representation suitable for low-momentum scale applications. By taking these scales as the only free parameters, the valence quark distribution functions of the pion, after QCD evolution, are consistent with the data from the FNAL-E615 experiment. The ratio of the up quark distribution of the kaon to that of the pion also agrees with the CERN-NA3 experiment. Supplemented by known parton distribution functions for the nucleons, we further obtain the cross section consistent with experimental data for the Drell-Yan process.

    nucl-thhep-phPRL(2019)·132 citations

Affiliations

first authorsco-authorsvia INSPIRE