标题： μ子和中子星核心中的中微子发射率 显示英文标题

标题： Muons and emissivities of neutrinos in neutron star cores

摘要： 在本工作中，我们考虑了μ子在各种URCA过程中的作用，这些过程与中子星核心区域的中微子辐射相关。 计算是针对$\beta$稳定的核物质进行的，包括有μ子和没有μ子的情况。 我们发现，在密度为$\rho = 0.15$fm$^{-3}$时会出现μ子，略微围绕核物质的饱和密度$\rho_0 =0.16$fm$^{-3}$。 直接URCA过程对于核子在密度低于$\rho = 0.5$fm$^{-3}$时被禁止，然而带有μ子的修改URCA过程（$(n+N\rightarrow p+N +\mu +\overline{\nu}_{\mu}, p+N+\mu \rightarrow n+N+\nu_{\mu}$），其中$N$是一个核子，导致中微子发射率与$(n+N\rightarrow p+N +e +\overline{\nu}_e, p+N+e \rightarrow n+N+\nu_e$相当。这为进一步解释中子星快速冷却提供了可能。然而超导质子在密度低于$0.4$fm$^{-3}$时会减少这些发射率。 显示英文摘要

摘要： 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 $(n+N\rightarrow p+N +\mu +\overline{\nu}_{\mu}, p+N+\mu \rightarrow n+N+\nu_{\mu}$), where $N$ is a nucleon, result in neutrino emissivities comparable to those from $(n+N\rightarrow p+N +e +\overline{\nu}_e, p+N+e \rightarrow n+N+\nu_e$). 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$^{-3}$.