Speaker: Robert Lasenby
Title: Electromagnetic searches for axion dark matter
Host: Da Liu
Room: 432
Abstract: Axions, and in particular the QCD axion, are a well-motivated dark matter candidate. They can generically couple to electromagnetic fields, and this coupling is the basis for many dark matter detection experiments, such as ADMX. In this seminar, I’ll talk about the theoretical limits on such experiments — how small a dark matter coupling could they detect, given the limits imposed by quantum mechanics? As well as giving some insights into what can and can’t help, these calculations motivate new approaches to axion dark matter detection, both at low masses (using microwave cavities) and high masses (using photonic materials).
Description:
Martin Luther King Day
User:
High-Energy Seminars
Time:
1:30pm - 2:30pm
Send Reminder:
Yes - 0 days 4 hour 0 minutes before start
Description:
Speaker:
Title:
Host:
Room: 432
Abstract:
User:
High-Energy Seminars
Time:
1:30pm - 2:30pm
Send Reminder:
Yes - 0 days 4 hour 0 minutes before start
Description:
Speaker: Hitoshi Murayama
Title: Two tales of baryogengesis
Host: Da Liu
Room: 432
Abstract:
How did we escape the complete annihilation? The origin of our atomic matter has been one of the major puzzles in modern cosmology, called the baryon asymmetry. There have been two major paradigms for the explanation: leptogenesis tied to the origin of neutrino mass at very high energy scales, and electroweak baryogenesis at the energy scale reachable by various experiments. Even though leptogenesis should have happened at energy scales well beyond the experimental reach, I point out that the gravitational waves from cosmic string network is a likely consequence detectable at future missions. On the other hand, the electroweak baryogenesis is too detectable and may be already excluded by the recent measurements of electric dipole moments of neutrons and atoms. I discuss a way to “hide” electroweak baryogenesis to the dark sector which also produces an asymmetric dark matter at the same time. It is still completely viable phenomenologically, yet predicts many experimental signatures for forthcoming experiments.