New bounds on the neutrino magnetic moment from the plasma induced neutrino chirality flip in a supernova

TL;DR

This paper refines the bounds on the neutrino magnetic moment by analyzing plasma effects in supernova cores, leading to significantly improved upper limits based on supernova observations.

Contribution

It provides more accurate bounds on the neutrino magnetic moment by incorporating plasma polarization effects and proton contributions in supernova models.

Findings

Upper bounds on mu_nu are (0.5 - 1.1) x 10^{-12} mu_B from supernova luminosity limits.

Upper bounds on mu_nu are (0.4 - 0.6) x 10^{-12} mu_B from neutrino spin-flip time limits.

The new bounds improve previous limits from SN1987A by a factor of 3 to 7.

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 consistent way 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: mu_nu < (0.5 - 1.1) 10^{-12} mu_B from the limit on the supernova core luminosity for nu_R emission, and mu_nu < (0.4 - 0.6) 10^{-12} mu_B from the limit on the averaged time of the neutrino spin-flip. The best upper bound on the neutrino magnetic moment from SN1987A is improved by the factor of 3 to 7.