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My primary research interest is in the physics of the neutrino, a fundamental particle that is generated in particle decays and nuclear reactions and that, in the Standard Model of particle physics, interacts only via the weak force. At Earth's distance from the Sun, about 65 billion solar neutrinos pass through every square centimeter every second, and the vast majority of them pass right through the planet. Neutrinos interact with matter so rarely that they were originally assumed to be massless, but in the last two decades several clever experiments showed that neutrinos do have a small but nonzero mass. Furthermore, despite its small magnitude, the mass of the neutrino has made an imprint on a cosmic scale: vast numbers of neutrinos were created in the early universe, and their collective mass affected the way that early structures formed. Neutrinos provided the first evidence of physics beyond the Standard Model in the electroweak sector, and they provide a bridge between very small scales and very large ones.

To better understand the properties of the neutrino, I use the kinematics of tritium beta decay to study the absolute neutrino-mass scale with the KATRIN experiment based in Karlsruhe, Germany, and I study low-energy neutrino interactions with matter with the COHERENT experiment based at Oak Ridge National Laboratory in Tennessee. Through detailed measurements and careful analysis, both COHERENT and KATRIN test the edges of the Standard Model while providing input to astrophysics and cosmology. I am an Analysis Co-Coordinator for both experiments and also serve as KATRIN's US spokesperson. I am also one of two PIs on the TRIMS experiment to better understand the molecular physics of gaseous tritium sources.