Neutrino Pair Emission by a Stellar Plasma

Abstract

Various current models and generalizations of a universal weak Fermi interaction predict a first-order weak coupling between electrons and $\ensuremath{\nu}\ensuremath{-}\overline{\ensuremath{\nu}}$ pairs. The radiation of such pairs by a hot, partially degenerate relativistic plasma is calculated for temperatures and densities that appear to be relevant for stellar evolution. Neutrino-pair emission by collective electron modes, especially transverse plasma excitations, is found to be the main mechanism for neutrino radiation by a dense stellar plasma when electron-positron production is small either because the temperature is too low ($T\ensuremath{\lesssim}{10}^{8}$ \ifmmode^\circ\else\textdegree\fi{}K) or degeneracy supresses it. The neutrino luminosity of a star can greatly exceed its photon luminosity for a central core temperature greater than ${10}^{8}$ \ifmmode^\circ\else\textdegree\fi{}K.