In this work we consider various URCA processes relevant for neutrino emissions in the core region of neutron stars. The parameters which enter these processes, such as effective masses, proton pairing gaps, proton fractions, and electron and muon chemical potentials, are calculated in a self-consistent Brueckner-Hartree-Fock approach for $\beta$-stable nuclear matter. Modern meson-exchange potential models are employed. We find that the emissivities from modified URCA processes are reduced due to the presence of superconducting protons at densities below $0.4{\mathrm{fm}}^{-3\mathrm{}}$.

• Received 24 October 1995

DOI:https://doi.org/10.1103/PhysRevLett.76.1994