Topical Seminar: Constraints from the duration of supernova neutrino burst on resonant light gauge boson production by neutrinos

by Yasaman Farzan (Institute for Research in Fundamental Sciences (IPM))

Monday 25 Sep 2023, 12:00 → 13:00 Europe/Madrid

1001-Primera-1-1-1 - Paterna. Seminario (Universe)

We discuss the resonant production of low-mass vector mediators from neutrino antineutrino interactions in the core of proto-neutron stars, and determine how they may affect the neutrino energy distribution and their diffusion time in the first seconds after the supernova explosion. Taking into account the radial dependence of the density, energy, and temperature inside the proto-neutron star, we determine the neutrino-antineutrino interaction rate in the star interior in two well-motivated new physics scenarios that feature a low-mass vector mediator, namely $U(1)_{B−L}$  and $U(1)_{ L_\mu −L_\tau}$ . First, we determine the values of the coupling above which the neutrino self-interaction dominates over the standard neutrino nucleon scattering. We argue that, although in this regime a redistribution of the neutrino energies might take place, this only affects a small part of the neutrino population and cannot be constrained with the SN 1987A data. Thus, contrary to previous claims, the region of the parameter space where this model explains the discrepancy in the muon anomalous magnetic moment is not ruled out. We then focus on small gauge couplings, for which the decay length of the new gauge boson is comparable to (or larger than) the size of protoneutron star. We show that in this regime, the duration of the neutrino burst can be significantly reduced, and values of the coupling as small as O($10^{−9}$ ) can be probed, ruling out new areas of the parameter space. These results are relevant for any other model that features new MeV-scale mediators that couple to the neutrino sector.