Benjamin Brubaker

Benjamin Brubaker's picture
Graduate Student Year 5 (Lamoreaux)
SPL 2 / WL-W 328
203-436-3948, 203-432-8324

I work for professor Steve Lamoreaux on the Haloscope At Yale Sensitive to Axion CDM (HAYSTAC), an experiment which aims to detect dark matter axions with mass of order 20 micro-eV.

Before coming to Yale, I worked for a year on the Fermilab Holometer experiment for PIs Stephan Meyer and Aaron Chou. As an undergraduate at UChicago I worked for two years on the K0TO experiment for professor Yau Wah.

I'm generally interested in small-scale, low-energy probes of fundamental physics, and developing techniques and technology to facilitate such experiments.

BA, University of Chicago, 2011
Field of Study: 
Axion Dark Matter Detection
Thesis Advisor: 
Steve Lamoreaux
Dissertation Title: 
First Results from the HAYSTAC axion search
Dissertation Abstract: 
The axion is a well-motivated cold dark matter (CDM) candidate first postulated to explain the absence of CP violation in the strong interactions. CDM axions may be detected via their resonant conversion into photons in a “haloscope” detector: a tunable high-Q microwave cavity maintained at cryogenic temperature, immersed a strong magnetic field, and coupled to a low-noise receiver. This dissertation reports on the design, commissioning, and first operation of the Haloscope at Yale Sensitive to Axion CDM (HAYSTAC), a new detector designed to search for CDM axions with masses above 20 µeV. I also describe the analysis procedure used to derive limits on axion CDM from the first HAYSTAC data run, which excluded axion models with two-photon coupling g_{aγγ} > 2×10^{-14} GeV^{-1}, a factor of 2.3 above the benchmark KSVZ model, over the mass range 23.55 < m_a < 24.0 µeV. This result represents two important achievements. First, it demonstrates cosmologically relevant sensitivity an order of magnitude higher in mass than any existing direct limits. Second, by incorporating a dilution refrigerator and Josephson parametric amplifier, HAYSTAC has demonstrated total noise approaching the standard quantum limit for the first time in an axion search.
Degree Date: 
December, 2017