Enhanced Muonization by Active-Sterile Neutrino Mixing in Protoneutron Stars

Anupam Ray, Yong-Zhong Qian.


We study \nu_\mu\nu_s and \bar\nu_\mu\bar\nu_s mixing in the protoneutron star (PNS) created in a core-collapse supernova (CCSN). We point out the importance of the feedback on the general composition of the PNS in addition to the obvious feedback on the \nu_\mu lepton number. We show that for our adopted mixing parameters \delta m^2\sim 10^2\,keV^2 and \sin^2 2\theta consistent with the current constraints, sterile neutrino production is dominated by the Mikheyev-Smirnov-Wolfenstein conversion of \bar\nu_\mu into \bar\nu_s and that the subsequent escape of \bar\nu_s increases the \nu_\mu lepton number, which in turn enhances muonization of the PNS primarily through \nu_\mu+n\to p+\mu^-. We find that this enhancement is amplified by diffusion of the \nu_e and \nu_\mu lepton numbers. While these results are qualitatively robust, their quantitative effects on the dynamics and active neutrino emission of CCSNe should be evaluated by including \nu_\mu\nu_s and \bar\nu_\mu\bar\nu_s mixing in the simulations.

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