Cooling of Neutron Stars Revisited: Application of Low Energy Theorems

Abstract

Cooling of neutrons stars proceeds mainly via neutrino emission; As an example we study the modified neutrino bremsstrahlung process $nn\to nn\nu \bar{\nu }.$ The radiated energy is small compared to other scales in the system. Hence one can use low-energy theorems to compute the neutrino emissivity in terms of the non-radiative process, ie the on-shell $T$ matrix. We find that the use of the $T-$matrix as compared to previous estimates based upon one pion exchange leads a substantial reduction of the predicted emissivity.

Comments: 6 pages, 2 figures. To appear in the Proceedings of "Bologna 2000: Structure of the Nucleus at the Dawn of the Century",May 29 - June 3, 2000, Bologna,Italy