Pushing noble liquids to new limits: dark matter detection in xenon and superfluid helium

Pushing noble liquids to new limits: dark matter detection in xenon and superfluid helium
Scott Hertel, UC Berkeley
Date and time: Tue, Mar 01, 2016 - 2:30pm
Location: LGRT 419B
Category: ACFI Seminar
Abstract:
We live immersed in a bath of particles beyond the standard model. I will describe several technological efforts to detect interactions between these ghostly particles and standard atomic nuclei, efforts that may in time reveal the more fundamental 'standard' model we know is waiting. Liquefied noble elements are increasingly the standard target material for this effort. I will give an overview of two xenon-based efforts, the ongoing LUX experiment and its successor LZ, emphasizing our recently-improved world-leading sensitivity and our efforts to better calibrate such detectors by mixing radioactive isotopes into the liquid xenon itself. Light-mass dark matter hypotheses are difficult to probe in liquid xenon, which motivates detector development using the lightest noble: helium. Its superfluid phase supports unique low-energy excitations, and its mK-scale temperature supports the use of ultra-sensitive calorimetry. I will discuss a recent demonstration of this approach, along with a general outlook for the field as a whole.