B Beta Decay to Set Tensor Current Limits and Determine the Neutrino Energy Spectrum*

Studies of the beta decay of ⁸B provide unique sensitivity to physics beyond the Standard Model and are vital for the interpretation of solar neutrino data. A high-statistics experiment was performed at Argonne National Laboratory using the Beta-decay Paul Trap (BPT) surrounded by four double-sided silicon strip detectors to measure α and β energies from ⁸B → ⁸Be(2α) + β + ν . Through precise measurements of the kinematics of the decay products, limits on the exotic tensor current contribution to the weak interaction can be determined. At the same time, the decay product kinematics can be leveraged to reconstruct the undistorted ⁸B neutrino energy spectrum, a necessary ingredient for precision measurements of neutrino oscillations. Preliminary results for both the tensor current limit and the neutrino spectrum will be presented.