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Nuclear Theory·nucl-th

Wednesday·October 12, 2022

7 papers—2 primary·5 cross-listed

All7Primary2Cross-lists5
  1. 01

    [Submitted on 11 Oct 2022]

    Is Relativistic Hydrodynamics always Symmetric-Hyperbolic in the Linear Regime?

    Lorenzo Gavassino

    Close to equilibrium, the kinetic coefficients of a thermodynamic system must satisfy a set of symmetry conditions, which follow from the Onsager-Casimir principle. Here, we show that, if a system of hydrodynamic equations is analysed from the perspective of the Onsager-Casimir principle, then it is possible to impose very strong symmetry conditions also on the principal part of such equations (the part with highest derivatives). In particular, we find that, in the absence of macroscopic magnetic fields and spins, relativistic hydrodynamics should always be symmetric-hyperbolic, when linearised about equilibrium. We use these results to prove that Carter's multifluid theory and the Israel-Stewart theory in the pressure frame are both symmetric-hyperbolic in the linear regime. Connections with the GENERIC formalism are also explored.

    Comments:
    17 pages; No figures; Published on PRD, see https://journals.aps.org/prd/abstract/10.1103/PhysRevD.107.065013
    Subjects:
    Nuclear Theory (nucl-th); General Relativity and Quantum Cosmology (gr-qc)
    arXiv:
    2210.05067 [pdf]
    PRD(2023)·23 citations
  2. 02

    [Submitted on 11 Oct 2022]

    Density profiles near nuclear surface of Ti: An indication of clustering

    W. Horiuchi🇯🇵 · N. Itagaki🇯🇵

    We investigate the degree of (He nucleus) clustering in the ground-state density profiles of Ti and Ti. Two types of density distributions, shell- and cluster-model configurations, are generated fully microscopically with the antisymmetrized quasi-cluster model, which can describe both the j-j coupling shell and -cluster configurations in a single scheme. Despite both the models reproducing measured charge radius data, we found that the clustering significantly diffuses the density profiles near the nuclear surface compared to the ideal j-j coupling shell model configuration. The effect is most significant for Ti, while it is less for Ti due to the occupation of the orbits in the Ca core. This difference can be detected by measuring proton-nucleus elastic scattering or the total reaction cross section on a carbon target at intermediate energies.

    Comments:
    9 pages, 7 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2210.05172 [pdf]
    PRC(2022)·12 citations

Affiliations

first authorsco-authorsvia INSPIRE