High Energy Physics Seminar - Ting Cheng (FNAL) "Ultralight Dark Matter Imprints on Astrophysical Neutrinos" 

Astrophysical neutrinos traveling through a dark matter background have the advantage of long baselines and negligible Standard Model noise. Neutrino mass models give them a reason to couple to that dark matter. In this talk, I will show two ways to use this advantage. The first is vector dark matter, which induces periodic nonadiabatic transitions between neutrino and antineutrino states. We show that these transitions can probe local U(1)_{B-L} dark matter beyond the reach of current precision experiments. The second is the majoron, an axion-like particle motivated by neutrino mass that arises from a broken global U(1)_L symmetry. This dark matter splits the energies of neutrino and antineutrino states. The splitting opens phase space for neutrinos to spontaneously emit majorons, which leaves rich astrophysical signatures.