Speaker
Description
Precision measurements of $\beta-$decay spectra can provide exquisitely sensitive tests of various predictions and underlying symmetry assumptions of the Standard Model (SM) of Particle Physics. Possible symmetry violations can alter the shape of $\beta$-decay spectra in characteristic ways. Beyond SM physics e.g. causes the finite masses of neutrinos that alter the $\beta-$decay spectrum of tritium in a predictable but still undetectable way. In a first step to design an experiment with a sensitivity of $40\,\mathrm{meV/c^2}$ to the neutrino mass scale the Project 8 collaboration has recently demonstrated a novel, frequency-based electron spectroscopy technique. Cyclotron Radiation Emission Spectroscopy (CRES) determines the electron's kinetic energy from the feeble cyclotron radiation emitted by an electron spiralling in a magnetic trap. I will present the basics of CRES and results obtained with mono-energetic conversion electrons from $^{83\mathrm{m}}\mathrm{Kr}$ as well as preliminary results from measurements using molecular tritium. I will discuss the prospect of CRES in the context of precision $\beta-$decay experiments of the next generation, in particular with a focus on the neutron decay spectrum.
This work has been supported by the Cluster of Excellence "PRISMA+" (EXC 2118/1) funded by the German Research Foundation (DFG) within the German Excellence Strategy (Project ID 39083149), the US DOe and NSF and by internal investments at all collaborating institutions.
