报告时间：2025年11月18日下午14:30 (14:30, Nov.18, 2025)

报告地点：物质科研楼A309会议室 Room A309 Material Science Building)

报告人： Gavilan Martin Daniel，Helmholtz institute in Mainz，Germany

报告题目/Title:Searching for axion backgrounds with K-Rb-He comagnetometers

摘要/Abstract:

Self-compensated comagnetometers, employing overlapping samples of spin-polarized alkali and noble gases (for example Rb-K-3He) are promising sensors for exotic beyond-the-standard-model fields and dark matter searches. I will show a calibration method for such system to arbitrary spin interactions that takes into account the frequency response of the system. One of the exotic signals that could be detected is the axion background generated through Black Hole Superradiance. If an axion in a certain mass range exists, the rotational energy of a Black Hole would be transferred to the axion field via the superradiant process. A bound state around the Black Hole would be exponentially populated. Depending on the self-interactions, the number density of the bound states can stabilize, emitting axions in the process. We study the collective axion signal from the black hole population in the Milky way and characterize its stochasticity and properties, paving the way to a new way of searching axions independent of the dark matter density or composition.

报告人简介/Curriculum Vitae:

Dr. Gavilan is currently doing his third year of PhD at the Dmitry Budker group in Mainz, Germany. His interests are both theoretical and experimental; he is interested in atomic physics experiments to look for new physics. This includes magnetometry and, in particular K-He comagnetometers, as well as modeling the expected exotic physics signals. Before coming to Mainz, he studied in Madrid and Barcelona, where he specialized in high energy particle physics.