Measuring β- ν angular correlation with laser trapped 6He

Exotic current contributions to the weak interaction can be constrained through measuring the beta-neutrino angular correlation parameter a_βν in nuclear beta decay - providing opportunities to find evidence for physics beyond the Standard Model. Our goal is to measure a_βν with a precision of 0.1% for the beta decay of ⁶He (t1_/2 = 807 ms) which is particularly sensitive to the exotic tensor currents. For this purpose, we have built a double magneto-optical trap (MOT) system to provide a cold and point-like source of ⁶He. Of the 1x10^{10 6}He atoms/s produced via the ⁷Li(d,3He)⁶He nuclear reaction, roughly 1000 atoms/s are captured in the first MOT and periodically transferred to the second, low background MOT that is surrounded by a detector system. Coincidence detection of the beta particle and the recoiling ion offers kinematic reconstruction of a_βν in combination with high statistic numerical simulations of the detector setup. The performance of the trap setup, preliminary coincidence data, and studies of systematic uncertainties will be presented. This work is supported by DOE, Office of Nuclear Physics, under contract nos. DE-AC02-06CH11357 and DE-FG02-97ER41020.