Place: For zoom link, sign up at: https://groups.google.com/a/g-groups.wisc.edu/d/forum/theoryseminars/join
Speaker: Jeff Dror, UC Berkeley
Abstract: Light particles can imprint themselves on our detectors in spectacular and often subtle ways. In this talk, I will present two new probes of hidden sectors. In the first part, I consider the prospect of seeing a relativistic background of axions, a so-called "cosmic axion background" (CaB). This background can have a range of possible cosmic sources and I consider several possible mechanisms (with the most well known being thermal production). Furthermore, I will show that with dedicated searches, a CaB may be detectable with cavity experiments such as ADMX or DM-radio. In the second part, I revisit phenomenology of leptonic gauge bosons (such as Lmu-Ltau) showing that they couple to a non-conserved current.This property can be used to show that in the high energy limit, these gauge bosons are equivalent to majorons. This allows them to be discovered using several new probes including neutrino decays, meson decays, neutrinoless double beta decay searches, and neutrino annihilations in thermal systems. These bounds drastically shape the parameter space of these theories.