Project 8: precisely probing neutrino mass with Cyclotron Radiation Emission Spectroscopy*

Neutrino mass is one of the most crucial physics puzzles of our time, with its absolute scale unknown, its source unexplained within the Standard Model, and its magnitude an influence on the evolution of structure in the universe. Tensions are becoming apparent in the standard $\Lambda$CDM cosmology, highlighting the importance of experimental, model-independent, laboratory-based approaches to measuring neutrino mass. The most precise direct neutrino mass measurements are done by tritium $\beta^-$ spectroscopy, since neutrino mass induces a small distortion of the 18.6-keV endpoint region of the spectrum of electrons produced in this decay. Cyclotron Radiation Emission Spectroscopy (CRES) is an emerging frequency-based technique that has the potential to surpass the precision of existing methods. The Project 8 Collaboration has set the first CRES-based neutrino-mass limit, demonstrating high resolution and extremely low background. I will discuss the CRES technique, Project 8's results, and its prospects for pushing beyond current neutrino mass sensitivity limits.