Sumita Ghosh (MIT) - Two Microwave Axion Experiments with HAYSTAC

Wednesday 14 Aug 2024, 12:30 → 13:30 America/Los_Angeles

48/2-224 - Madrone (SLAC)

The axion has in recent years become a very compelling dark matter candidate, as it simultaneously solves the strong CP problem in QCD. The traditional axion experiment, referred to as a ‘haloscope,’ consists of a strong magnetic field, a microwave cavity to resonantly enhance the photons produced by the axion, and a low-noise amplifier to enhance the inherently tiny axion signal. This talk will cover significant advancements in axion detection using the Haloscope At Yale Sensitive To Axion CDM (HAYSTAC), a tunable microwave cavity experiment that searches for dark matter axions of masses above 20 μeV. HAYSTAC has been used as an R&D testbed for axion searches, such as its use of a quantum squeezed-state receiver to reduce noise below the standard quantum limit.
The two efforts discussed here are the RAY (Rydberg atoms for Axions at Yale) extension and the CaB (Cosmic Axion Background) search. RAY aims to eliminate quantum noise through single photon counting using Potassium-39 Rydberg atoms, thereby increasing sensitivity to axion masses above 50 μeV. Initial work using electromagnetically induced transparency shows promise. It has the potential to measure masses in the range of 150-200 μeV at KSVZ sensitivity in 5 years using a standard tunable cavity, or 50-200 μeV at KSVZ sensitivity in 5 years using a resonator with volume independent of frequency.
The latter effort involves the development of a CaB analysis of current HAYSTAC data. I will describe a python-based Nested Sampling Bayesian analysis to search for CaB as a product of dark matter decay. This analysis is in preparation for a design proposal for a new experiment specifically optimized at searching for a potential CaB signal.

Zoom link: https://stanford.zoom.us/j/98973156241?pwd=cEU5RFdlVXoyc0JTeTlDMkozKzQ5UT09

video2835719605.mp4