Neutrino photoproduction on pseudo Nambu-Goldstone bosons

Abstract

Production of single neutrinos as well as neutrino-antineutrino pairs by photons interacting with pseudo Nambu-Goldstone bosons is studied within the Standard Model. The corresponding cross sections are found analytically. The energy loss due to neutrino emission in a thermal plasma of photons and pions is calculated. It is shown that the obtained neutrino emissivity may be significantly enhanced in hot and dense matter due to in-medium modification of the pion decay constant. Phenomenological consequences for ultrarelativistic heavy-ion collisions and astrophysics are discussed.

Comments: 20 pages, 7 figures. A discussion and calculations of neutrino emissivities in a hot and dense medium are inserted. Phenomenological consequences are considered. New figures and references added. Accepted for publication in Phys. Lett. B