Overview of St. Benedict & Recent Developments

Precision measurements of beta decay offer a unique insight into studies of fundamental symmetries in the standard model. In particular, the ft-values of superallowed beta decays can be used to probe the up/down quark coupling strength, Vud, as a means of testing the unitarity of the CKM quark-mixing matrix. Recent revisions of the radiative corrections applied to this calculation have shifted the value of Vud, such that there is now a 3σ tension with unitarity when using data from 0+ to 0+ transitions. Given this, there is now a focus on extracting this matrix element using different ensembles of decays. Currently, the Superallowed Transition Beta-Neutrino Decay Ion Coincidence Trap (St. Benedict) is under construction at the University of Notre Dame Nuclear Science Laboratory, with the goal of measuring the beta-neutrino correlation parameter for superallowed mixed beta-decay transitions between mirror nuclei. Over the past year, the offline commissioning of the gas catcher, differential pumping system, and the cooler-buncher was complete. During the summer of 2025, radioactive beam from TwinSol was detected & stopped in the gas catcher. Details about each component of St. Benedict, results from previous experimental runs, along with plans for future measurements, will be presented. This work is supported by the National Science Foundation under grant numbers PHY-1725711, 2310059, as well as the University of Notre Dame.