General ILL seminar
organised by College 3
Tuesday September 16, 2025 at 13h30
Seminar room 110-111, ILL 50, 1st floor
Zoom link: https://ill.zoom.us/j/98964195699?pwd=vPhNT17CAeoDUr7QX4PjfyPnWsHuMU.1
Password: SeminarC3
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“The neutrino electron correlation coefficient in neutron beta decay”
Stefan Baessler
University of Virginia and Oak Ridge National Lab
One of the current problems of the Standard Model of Elementary Particle Physics is the about three sigma failure of the first-row unitarity test of the Cabbibo-Kobayashi-Maskawa matrix. A long-standing goal of the study of free neutron beta decay is to better determine its upper left element ("Vud"). That is possible with measurements of the neutron lifetime and a correlation coefficient (the beta asymmetry "A" or the neutrino-electron correlation coefficient "a"). In this talk, I will present a recent measurement of the neutrino electron correlation coefficient with aSPECT, and I will present commissioning and physics data from a next generation experiment, Nab. The Nab collaboration is working on an improvement in the accuracy of neutrino electron correlation coefficient that - if achieved - is large enough to base the determination of Vud competitively on neutron data alone.
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Hanno Filter (College 3 Secretary)