Current Schedule

Speaker = Prof. Elise Novitski of University of Washington

Host = Xing Wu wux@frib.msu.edu

When = 2025-02-19 Wednesday <color #ed1c24>15:30 (note the new time if needed!)</color>

Where = FRIB 1300 <color #ed1c24>(note the alternative location if needed!)</color>

Please feel free to sign up below, but note that some slots may need to be re-assigned to accommodate those with a specific need to meet the speaker. If this happens, the Admin or Speaker Host will reach out to you via email.

Title = A new approach to measuring neutrino mass

Abstract <blockquote> Of all the fundamental fermion masses, those of the neutrinos alone remain unmeasured. From their unknown origin to their effects on the evolution of the universe, neutrino masses are of interest across cosmology, nuclear physics, and particle physics. Neutrino oscillation experiments have set a non-zero lower limit on the mass scale, in contradiction to the original Standard Model prediction. To measure neutrino mass precisely and directly one must turn to beta decay and search for a telltale distortion in the spectrum. I will describe a new technique called Cyclotron Radiation Emission Spectroscopy (CRES), in which beta decay of tritium occurs in a magnetic field and each electron's ~1 fW of cyclotron radiation is directly detected. Electron energies are then determined via a relativistic relationship between energy and frequency. I will present the first CRES-based mass limits from the Project 8 experiment, which demonstrate the promise of this technique for surmounting the systematic and statistical barriers that currently limit the precision of direct neutrino mass measurements. I will also describe the next steps on the path to sensitivity to a mass of 40 meV/c^2, covering the entire inverted ordering of neutrino masses. </blockquote>

Relevant background with commentary from Speaker:

• Wilkinson and Huber are writeups in the online journal APS Physics Magazine iof the results of Phases I and II of Project 8, respectively. Together they are a quite-accessible introduction to the experiment.
• “Direct measurements of neutrino mass” by Formaggio et al. is a review paper covering this part of neutrino physics. It's long, but reading a subset–Secs. 1, 2.1, 2.5, 5.1, 5.2, and 9.2– would give a really nice overview of the most relevant material: Physics Reports, Volume 914, 3 June 2021, Pages 1-54
• The 2023 PRL is a neutrino mass result out of Project 8 that I'll discuss in my talk. It's probably too terse/dense: Phys. Rev. Lett. 131, 102502 – Published 6 September, 2023