Speaker: Christina Gao
Title: Reconciling Neutrino Mass Bounds with Strongly Self-Interacting Dark Radiation
Room: 3024
Host: Markus Luty
Abstract: Cosmological measurements have dramatically improved, with recent constraints on neutrino masses (Σmν < 0.0642 eV from Planck + DESI-II BAO) approaching the lower bounds required by neutrino oscillation experiments. While not yet in tension for normal hierarchy, the viable parameter space is rapidly shrinking. Simultaneously, cosmological data shows preference for strongly self-interacting neutrinos—a property severely constrained by laboratory experiments. We present a mechanism exploiting cosmology's inability to distinguish between neutrinos and similarly-behaving dark radiation, potentially addressing this narrowing gap and other cosmological puzzles.
User:
High-Energy Seminars
Time:
1:30pm - 3:00pm
Send Reminder:
Yes - 0 days 6 hour 0 minutes before start
Description:
Speaker: Asher Berlin
Title: Cavendish Tests of Millicharged Particles
Room: 3024, with Zoom link https://ucdavis.zoom.us/j/186024391
Host: Hsin-Chia Cheng
Abstract: The simplest cosmologies motivate the consideration of dark matter subcomponents that interact significantly with normal matter. Moreover, such strongly-coupled relics may have evaded detection to date if upon encountering the Earth they rapidly thermalize down to terrestrial temperatures, well below the thresholds of most existing dark matter detectors. This motivates the consideration of alternative detection techniques sensitive to a terrestrial population of slowly-moving dark matter particles. In this talk, I will focus on such a population of millicharged particles, and show how reinterpretations of Cavendish tests of Coulomb's Law, first performed in the late 18th century, provide some of the strongest bounds on this largely unexplored parameter space.
Cinco de Mayo