Gray Rybka

Assistant Professor
Department of Physics
University of Washington


I like to pick at the places where our understanding of physics is coming apart. I prefer to use ultra-sensitive low energy experiments to make precision measurements.

ADMX Search for Dark Matter Axions

Much of our universe appears to be made of matter that isn't accounted for in our standard model of particle physics. Axions are a good candidate to be this dark matter, but as of yet are unproven. I want to find them.

Project 8 Neutrino Mass

We know neutrinos must have a mass much lower than any other particle in our models, but we don't know what that mass is. I want to measure it.

Especially Important Publications

"Search for Invisible Axion Dark Matter with the Axion Dark Matter Experiment", N. Du et al., Phys. Rev. Lett. 120,151301 (2018). (arXiv)
The first experiment sensitive to the well-motivated DFSZ model of axion dark matter, marking the beginning of searches that have a good chance of discovery.
"Single-Electron Detection and Spectroscopy via Relativistic Cyclotron Radiation", D.M. Asner et al. (Project 8 Collaboration) Phys. Rev. Lett. 114, 162501 (2015). ( arXiv)
The first demonstration of "Cyclotron Radiation Emission Spectroscopy", using cyclotron frequency of emitted electrons to measure the energy of nuclear decays.

Especially Interesting Publications

"Search for dark matter axions with the Orpheus experiment", G. Rybka et al., Phys. Rev. D 91, 011701(R) (2015). (arXiv)
An early prototype of a multiwavelength resonator configuration to search for high frequency axion dark matter.
“Hidden Sector Photon Coupling of Resonant Cavities”, S. Parker, G. Rybka, M. Tobar Phys. Rev. D 87, 115008 (2013). (arXiv)
An scheme to use a pure frequency measurement to search for hidden sector photons.
“Search for Chameleon Scalar Fields with the Axion Dark Matter Experiment”, G. Rybka et al. Phys. Rev. Lett. 105, 051801 (2010). (arXiv)
A search for "chameleons", paricles which could be related to dark energy, using the axion dark matter experiment in an alternate configuration.