Active-to-sterile neutrino dipole portal and the XENON1T excess

In this paper, we find that a magnetic transition dipole moment between tau and sterile neutrinos can account for the XENON1T excess events. Unlike ordinary neutrino moment, introduction of new mass scale allows astrophysical bounds to be suppressed. Interestingly, best-fit regions are compatible with SN1987A imply either boron-8 as source flux. We in $\ensuremath{\sim}(500--800)\text{ }\mathrm{keV}$ range capable evading constraints while being able successfully explain event rate. also set on portal based Xenon 1T data. The best fit parameter space may have significant effects big bang nucleosynthesis (BBN). show region which low reheating temperature Universe allow BBN alleviated.