Muons and emissivities of neutrinos in neutron star cores

Abstract

In this work we consider the role of muons in various URCA processes relevant for neutrino emissions in the core region of neutron stars. The calculations are done for $\beta$--stable nuclear matter with and without muons. We find muons to appear at densities $\rho =0.15$ fm${}^{-3}$, slightly around the saturation density for nuclear matter ${\rho }_0=0.16$ fm${}^{-3}$. The direct URCA processes for nucleons are forbidden for densities below $\rho =0.5$ fm${}^{-3}$, however the modified URCA processes with muons $(n+N\to p+N+\mu +{\overline{\nu }}_{\mu },p+N+\mu \to n+N+{\nu }_{\mu }$), where $N$ is a nucleon, result in neutrino emissivities comparable to those from $(n+N\to p+N+e+{\overline{\nu }}_e,p+N+e\to n+N+{\nu }_e$). This opens up for further possibilities to explain the rapid cooling of neutrons stars. Superconducting protons reduce however these emissivities at densities below $0.4$ fm${}^{-3}$.

arXiv comment14 pages, Revtex style, 3 uuencoded figs included

References in corpus (5)

• From Kaon-Nuclear Interactions to Kaon Condensation
• Asymmetric nuclear matter and neutron star properties
• Observational constraints on the neutron star mass distribution
• Geminga: A Cooling Superfluid Neutron Star
• Neutrino Pair Bremsstrahlung in Neutron Star Crusts: a Reappraisal

Cited by in corpus (8)

• Triplet pairing in beta-stable neutron star matter
• Superfluidity in beta-stable neutron star matter
• Correlations and spectral functions in asymmetric nuclear matter
• Triplet Pairing in Neutron Matter
• Neutron Stars and Massive Quark Matter
• Superfluidity of ${\Sigma }^{-}$ hyperons in $\beta$-stable neutron star matter
• Dense Matter in Neutron Stars with eXTP
• Three-body force effect on neutrino emissivities of neutron stars within the framework of the Brueckner-Hartree-Fock approach