Dense matter in compact stars cools efficiently by neutrino emission via the direct Urca processes n→p+e+ν̄e and p+e→n+νe. Below the pairing phase transition temperature Tc these processes are suppressed - at asymptotically low temperatures exponentially. We compute the emissivity of the Urca process at one loop for temperatures T≤Tc, in the case where the baryons are paired in the1S0partial wave. The Urca process is suppressed linearly, rather than exponentially, within the temperature range 0.1≤T/Tc≤1. The charge-current Cooper pair-breaking process contributes up to 50% of the total Urca emissivity in this temperature range. © 2004 Elsevier B.V. All rights reserved.
Sedrakian, A. (2005). Direct Urca neutrino radiation from superfluid baryonic matter. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 607(1–2), 27–34. https://doi.org/10.1016/j.physletb.2004.12.026