A New Unified Approach to In-Medium Beta Decay

Weak processes like neutron decay and electron capture play a fundamental role in the transport properties of neutron stars and binary neutron star mergers. In dense nuclear matter, these processes are dominated by particles on the Fermi surface and are called direct and modified Urca processes. Traditionally, these processes are computed separately and semi-analytically, using various approximations. In this work we will present a new unified approach to modified and direct Urca. This new approach allows us to go beyond the Fermi surface approximation and to fundamentally improve the in-medium calculation of weak decays by including the nucleon width.