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Nuclear Theory·nucl-th

Wednesday·December 4, 2019

7 papers—4 primary·3 cross-listed

All7Primary4Cross-lists3
  1. 05

    [Submitted on 27 Nov 2019] (cross-list from hep-th)

    Effects of oscillating spacetime metric background on a complex scalar field and formation of topological vortices

    Shreyansh S. Dave🇮🇳 · Sanatan Digal🇮🇳

    We study the time evolution of a complex scalar field in the symmetry broken phase in the presence of oscillating spacetime metric background. In our (2+1)-dimensional simulations, we show that the spacetime oscillations can excite an initial field configuration, which ultimately leads to the formation of topological vortices in the system. At late times, field configuration achieves a disordered state. A detailed study of the momentum and frequency modes of the field reveals that these field excitations are driven by the phenomenon of parametric resonance. In extremely high frequency regime where frequency of spacetime oscillations is much larger than the field-mass, the formed vortices are not topological in nature. Interestingly in this regime, for a suitable choice of parameters of the simulation, we observe a persistent lattice structure of vortex-antivortex pairs. We discuss applications of our study to the dynamics of interior superfluidity of neutron stars during binary neutron star mergers, in generation of excitation in ultralight axion-like field near a strong gravitational wave source, etc.

    Comments:
    15 pages, 14 figures
    Subjects:
    High Energy Physics — Theory (hep-th); High Energy Astrophysical Phenomena (astro-ph.HE); Quantum Gases (cond-mat.quant-gas); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1911.13216 [pdf]
    PRD(2021)·5 citations
  2. 06

    [Submitted on 3 Dec 2019] (cross-list from astro-ph.HE)

    Crystallization of the inner crust of a neutron star and the influence of shell effects

    T. Carreau🇫🇷 · F. Gulminelli🇫🇷 · N. Chamel🇧🇪 · A. F. Fantina🇫🇷 · J. M. Pearson🇨🇦

    Context. In the cooling process of a non-accreting neutron star, the composition and properties of the crust are thought to be fixed at the finite temperature where nuclear reactions fall out of equilibrium. A lower estimation for this temperature is given by the crystallization temperature, which can be as high as K in the inner crust, potentially leading to sizeable differences with respect to the simplifying cold-catalyzed matter hypothesis. Aims. We extend the recent work by Fantina et al. (2019) on the outer crust, to the study of the crystallization of the inner crust and the associated composition in the one-component plasma approximation. Methods. The finite temperature variational equations for non-uniform matter in both the liquid and the solid phases are solved using a compressible liquid-drop approach with parameters optimized on four different microscopic models which cover the present uncertainties in nuclear modeling. Results. We consider separately the effect of the different nuclear ingredients with their associated uncertainties, namely the nuclear equation of state, the surface properties in the presence of a uniform gas of dripped neutrons, and the proton shell effects arising from the ion single-particle structure. Our results suggest that the highest source of model dependence comes from the smooth part of the nuclear functional. Conclusions. We show that shell effects play an important role at the lowest densities close to the outer crust, but the most important physical ingredient to be settled for a quantitative prediction of the inner crust properties is the surface tension at extreme isospin values.

    Comments:
    9 pages, 9 figures
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
    arXiv:
    1912.01265 [pdf]
    Astron.Astrophys.(2020)·52 citations
  3. 07

    [Submitted on 3 Dec 2019] (cross-list from hep-ph)

    Investigation of particle distributions in Xe-Xe collision at 5.44 TeV with Tsallis statistics

    Hai-Fu Zhao🇨🇳 · Bao-Chun Li🇨🇳 · Hong-Wei Dong🇨🇳

    The distribution characteristic of final-state particles is one of significant parts in high energy nuclear collisions. The transverse momentum distribution of charged particles carries essential evolution information about the collision system. Tsallis statistics is used to investigate the transverse momentum distribution of charged particles produced in Xe-Xe collisions at 5.44 TeV. On the basis, we reproduce the nuclear modification factor of the charged particles. The calculated results agree approximately with the experimental data measured by the ALICE Collaboration.

    Comments:
    9 pages, 2 figures, 1 table
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1912.01278 [pdf]
    Adv.High Energy Phys.(2020)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE