New astrophysical limit on neutrino millicharge

Abstract

An impact of a nonzero neutrino millicharge in astrophysics is tested. It is shown that in astrophysical environments electromagnetic interactions of the neutrino millicharge with strong electromagnetic fields as well as weak interactions of the neutrinos with dense background matter can produce new phenomena accessible for astrophysical observations. On this basis a new limit on the neutrino millicharge $q_0<1.3\times10^{-19}e_0$ is obtained. This limit is among the strongest astrophysical constraint on the neutrino millicharge. Some other possible applications of the obtained results to astrophysics are discussed in details.