Searches for New Currents in Nuclear Beta Decays

Dr. Alejandro Garcia
Department of Physics
University of Washington

This talk will be addressed at undergraduate students.  The helicities of the particles produced in nuclear beta decays, in particular the electron and neutrino, lead to peculiar correlations between the particles themselves and with the change in nuclear angular momentum. We will describe how these are described by the standard model of particle physics by Vector and Axial-Vector currents. We will also describe the historical confusion that led in the 1950's to assuming that weak currents were not V-A but Scalar and Tensor instead.  Although the latter are not in the standard model any longer, models that go beyond it, trying to naturally explain apparent capricious coincidences, predict some contribution from them. We will describe presnt efforts to use lasers to trap 6He atoms to perform the most sensitive searches for Tensor currents.