Chiral effective field theory calculations of neutrino processes in dense matter

Abstract

We calculate neutrino processes involving two nucleons at subnuclear densities using chiral effective field theory. Shorter-range noncentral forces reduce the neutrino rates significantly compared with the one-pion exchange approximation currently used in supernova simulations. For densities rho < 10^{14} g cm^{-3}, we find that neutrino rates are well constrained by nuclear interactions and nucleon-nucleon scattering data. As an application, we calculate the mean-square energy transfer in scattering of a neutrino from nucleons and find that collision processes and spin-dependent mean-field effects dominate over the energy transfer due to nucleon recoil.

Comments: 5 pages, 3 figures; NORDITA-2008-57; minor changes and additions, added results for the energy transfer in neutrino scattering, to appear as Rapid. Comm. in Phys. Rev. C