PaperPanorama
FAQ

Nuclear Theory·nucl-th

Wednesday·December 4, 2019

7 papers—4 primary·3 cross-listed

All7Primary4Cross-lists3
  1. 01

    [Submitted on 3 Dec 2019]

    Alpha Decay to Doubly Magic Core in Quartetting Wave Function Approach

    Shuo Yang🇨🇳 · Chang Xu🇨🇳 · Gerd Roepke🇩🇪 · Peter Schuck🇫🇷 · Zhongzhou Ren🇨🇳 · Yasuro Funaki🇯🇵 · Hisashi Horiuchi🇯🇵 · Akihiro Tohsaki🇯🇵 · Taiichi Yamada🇯🇵 · Bo Zhou🇯🇵

    We present a microscopic calculation of -cluster formation in heavy nuclei Te (+Sn), Po (+Pb) and their neighbors Sn, Te, Pb and Po by using the quartetting wave function approach. Improving the local density approximation, the shell structure of the core nucleus is considered, and the center-of-mass (c.o.m.) effective potential for the quartet is obtained self-consistently from the shell model wavefunctions. The -cluster formation and decay probabilities are obtained by solving the bound-state of the c.o.m. motion of the quartet and the scattering state of the formed -cluster in the Gurvitz approach. Striking shell effects on the -cluster formation probabilities are analyzed for magic numbers 50, 82 and 126. The computed -decay half-lives of these special nuclei are compared with the newest experimental data.

    Comments:
    16 pages, 4 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1912.01151 [pdf]
    PRC(2020)·47 citations
  2. 02

    [Submitted on 3 Dec 2019]

    Wigner Function for Spin-1/2 Fermions in Electromagnetic Fields

    Xin-Li Sheng🇩🇪

    We study the Wigner function for massive spin-1/2 fermions in electromagnetic fields. Dirac form kinetic equation and Klein-Gordon form kinetic equation are obtained for the Wigner function, which are derived from the Dirac equation. The Wigner function and its kinetic equations are expanded in terms of the generators of Clifford algebra and a complicated system of partial differential equations is obtained. We prove that some component equations are automattically satisfied if the rest ones are fulfilled. In this thesis two methods are proposed for calculating the Wigner function, which are proved to be equivalent. The Wigner function is analytically calculated following the standard second-quantization procedure in the following cases: free fermions with or without spin imbalance, in constant magnetic field, in constant electric field, and in constant parallel electromagnetic field. Strong-field effects, such as the Landau levels and Schwinger pair-production are reproduced using the Wigner function approach. For an arbitrary space-time dependent field configuration, a semi-classical expansion with respect to the reduced Planck's constant is performed. We derive general expressions for the Wigner function components at linear order in , in which order the spin corrections start playing a role. A generalized Bargmann-Michel-Telegdi (BMT) equation and a generalized Boltzmann equation are obtained for the undetermined polarization density and net fermion number density, which can be used to construct spin-hydrodynamics in the future. We also make a comparison between analytical results and the ones from semi-classical expansion, which shows coincidence for weak electromagnetic fields and small spin imbalance.

    Comments:
    189 pages, 35 figures, Ph.D thesis
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Theory (hep-th)
    arXiv:
    1912.01169 [pdf]
    11 citations
  3. 03

    [Submitted on 1 Dec 2019]

    Photon spectra and anisotropic flow in heavy ion collisions at the top RHIC energy within the integrated hydrokinetic model with photon hadronization emission

    V. Yu. Naboka🇺🇦 · Yu. M. Sinyukov🇺🇦 · G. M. Zinovjev🇺🇦

    The integrated HydroKinetic Model (iHKM) is applied to analyse the results of direct photon spectra as well as elliptic and triangular flow measurements in 200A GeV Au+Au collisions at RHIC for different centrality bins. Experiments detect the strong centrality dependence of photon elliptic and triangular flow as increasing -coefficients towards peripheral collisions. The photon production in the model is accumulated from the different sources along with the process of relativistic heavy ion collision developing. Those include the primary hard photons from the parton collisions at the very early stage of the process, the photons generated at the pre-thermal phase of dense matter evolution, then thermal photons at partially equilibrated hydrodynamic quark-gluon stage, together with radiation displaying a confinement and, finally, from the hadron gas phase. Along the way a hadronic medium evolution is treated in two distinct, in a sense opposite, approaches: chemically equilibrium and chemically non-equilibrium, namely, chemically frozen expansion. We find the description of direct photon spectra, elliptic and triangular flow are significantly improved, similar to that found in iHKM for the LHC energies, if an additional portion of photon radiation associated with the confinement processes, the "hadronization photons", is included into consideration.

    Comments:
    28 pages, 11 figures. arXiv admin note: substantial text overlap with arXiv:1812.02763
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1912.01423 [pdf]
    NPA(2020)·7 citations
  4. 04

    [Submitted on 3 Dec 2019]

    Probing the equation of state of neutron star matter with gravitational waves from binary inspirals in light of GW170817: a brief review

    Andreas Guerra Chaves🇳🇱 · Tanja Hinderer🇳🇱

    Neutron stars are unique testbeds for exploring the physics of strongly interacting matter in extreme regimes of density, temperature, and isospin that are not accessible anywhere else in the universe. The nature of neutron star matter can now be probed with gravitational-waves (GWs) from binary driven by nonlinear gravity, where phenomena such as tidal effects lead to characteristic matter-dependent GW signatures. We focus here on the dominant tidal GW imprints that were most relevant for the event GW170817. We review the role of the tidal deformability parameter, its definition, computation, and relation to the equation of state. We briefly discuss the implications of GW170817, representing the first-ever constraints on tidal deformability from GW data. Finally, we outline opportunities and challenges for probing subatomic physics with GWs, as the measurements will become more precise and will probe a diversity of the binary neutron star population in the coming years.

    Comments:
    24 pages, 6 Figures. Topical Review for Journal of Physics G Special Issue "Hadrons & Gravitational Waves After GW170817"
    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
    arXiv:
    1912.01461 [pdf]
    J.Phys.G(2019)·68 citations

Affiliations

first authorsco-authorsvia INSPIRE