Physics @ Berkeley
Events in Physics
Title: Ultra-sensitive Searches For Dark-matter Axions    (Colloquia)
Start Date: 02/13/2012
Time: 4:15 pm
Location: 1 LeConte Hall
Speaker: Leslie Rosenberg
Affiliation: Professor of Physics, University of Washington
Contact Person: Sarah Wittmer   (510) 642-3034

The axion is an interesting hypothetical particle. It arose from a solution to the “Strong CP Problem” in the Standard Model of particle physics, and it happens to be an ideal dark matter candidate. Hence, axions would be a very compelling addition to the particle zoo. However, The axion is exceedingly hard to detect. A dark-matter axion does indeed decay, but with a lifetime of perhaps 1050 years. This colloquium will describe this interesting particle and an experiment that aims to detect its incredibly feeble decay by an apparatus consisting of a strong static magnetic field threading a high Q microwave resonator.
Nearby relic axions inside the resonator convert into a sub-yoctoWatt microwave signal, which in turn is amplified and detected by the world's lowest-noise quantum-noise-limited SQUID amplifier-receiver. This experiment has improved over the years and now has the sensitivity to detect such axions or reject the dark-matter axion hypothesis at high confidence.