Plasma induced neutrino spin-flip in a supernova and new bounds on the neutrino magnetic moment
Abstract
The neutrino chirality-flip process under the conditions of the supernova core is investigated in detail with the plasma polarization effects in the photon propagator taken into account in a more complete form than in earlier publications. It is shown in part that the contribution of the proton fraction of plasma is essential. New upper bounds on the neutrino magnetic moment are obtained: munu < (0.5 - 1.1) 10-12 muB from the limit on the supernova core luminosity for nuR emission, and munu < (0.4 - 0.6) 10-12 muB from the limit on the averaged time of the left-handed neutrino washing out. The best upper bound on the neutrino magnetic moment from SN1987A is improved by the factor of 3 to 7.
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