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Nuclear Theory·nucl-th

Monday·August 5, 2024

6 papers—3 primary·3 cross-listed

All6Primary3Cross-lists3
  1. 04

    Impact of dark energy on the structure of neutron stars: The vacuum case

    L. F. Araujo🇧🇷 · J. A. S. Lima🇧🇷 · G. Lugones🇧🇷

    The potential role of a cosmic vacuum dark component in the properties of neutron stars is investigated. It is assumed that the static, spherically symmetric distribution of matter within neutron stars is supported by two distinct components: ordinary matter and a vacuum fluid. For normal matter we use a set of state-of-the-art nuclear matter equations of state, each grounded in nuclear physics experiments. The vacuum energy component is inhomogeneously distributed within the star and obeys the standard equation of state (). This is characterized by an energy density fraction , which we model as either a constant or radius-dependent. Our findings reveal that the inclusion of vacuum energy significantly affects the mass-radius relationships in neutron stars, influencing both the maximum achievable masses and the qualitative form of these relationships. Some constraints from current multimessenger observational data limiting the amount of vacuum energy within neutron stars are also discussed.

    ↳ hep-phastro-ph.HEastro-ph.SRgr-qc+1PRD(2024)·6 citations
  2. 05

    Pole analysis for the - coupled-channel system

    Pan-Pan Shi🇪🇸 · F. Gil-Domínguez🇪🇸 · R. Molina🇪🇸 · Meng-Lin Du🇨🇳

    By solving the Lippmann-Schwinger equation, possible hadronic molecules in the - coupled-channel system are investigated with the one-meson exchange potentials, where both vector and pseudoscalar mesons are considered as exchange particles. We find an S-wave virtual state with mass MeV, and a resonance with and width MeV. In the invariant mass distribution, the virtual state appears as a cusp at the threshold, while the resonance potentially manifests as a dip. In particular, we take into account the three-body dynamics due to the on-shell pion exchange and the finite decay width for .

    ↳ hep-phhep-exnucl-thPLB(2025)·5 citations
  3. 06

    Hyperons during proto-neutron star deleptonization and the emission of dark flavoured particles

    Tobias Fischer🇵🇱 · Jorge Martin Camalich🇪🇸 · Hristijan Kochankovski🇪🇸 · Laura Tolos🇪🇸

    Complementary to high-energy experimental efforts, indirect astrophysical searches of particles beyond the standard model have long been pursued. The present article follows the latter approach and considers, for the first time, the self-consistent treatment of the energy losses from dark flavoured particles produced in the decay of hyperons during a core-collapse supernova (CCSN). To this end, general relativistic supernova simulations in spherical symmetry are performed, featuring six-species Boltzmann neutrino transport, and covering the long-term evolution of the nascent remnant proto-neutron star (PNS) deleptonization for several tens of seconds. A well-calibrated hyperon equation of state (EOS) is therefore implemented into the supernova simulations and tested against the corresponding nucleonic model. It is found that supernova observables, such as the neutrino signal, are robustly insensitive to the appearance of hyperons for the simulation times considered in the present study. The presence of hyperons enables an additional channel for the appearance of dark sector particles, which is considered at the level of the hyperon decay. Assuming massless particles that escape the PNS after being produced, these channels expedite the deleptonizing PNS and the cooling behaviour. This, in turn, shortens the neutrino emission timescale. The present study confirms the previously estimated upper limits on the corresponding branching ratios for low and high mass PNS, by effectively reducing the neutrino emission timescale by a factor of two. This is consistent with the classical argument deduced from the neutrino detection associated with SN1987A.

    ↳ astro-ph.HEhep-phnucl-thJCAP(2025)·13 citations

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first authorsco-authorsvia INSPIRE