[Triumf-seminars] Next week's seminar

[TRIUMF Seminars]

Dear TRIUMF Seminars Subscriber,

Next week's TRIUMF seminar, entitled "Recent Results on the Limit of Weak Tensor Currents from 8Li Beta-decay," will be delivered by Matthew Sternberg of the University of Chicago and Argonne National Lab at the usual time and place. The seminar abstract is appended below. Mr. Sternberg will be here from Wednesday afternoon through Friday morning. If you would like to meet with him individually or in a group, please send an email to davids at triumf.ca with your preferred time(s).

Thanks,

Barry

Precise measurements of the beta-neutrino angular correlation coefficient, ‘a’, provide information on the presence of possible exotic couplings in the weak interaction. In the beta-decay of 8Li to 8Be* and subsequent breakup into two alpha particles, the large Q value and the beta-alpha-neutrino correlation provide enhanced sensitivity to any potential tensor coupling. An initial measurement using the Beta-decay Paul Trap (BPT) at Argonne National Laboratory detected 2•10^4 beta-alpha-alpha coincidences, resulting in an upper limit of 1.5% on any tensor contribution. The BPT has since been upgraded with improved double-sided silicon strip detectors--including finer segmentation, thinner dead layers, and thicker active silicon--along with new plastic scintillators to kinematically over-determine the decay. Recent measurements using the improved system detected more than 2•10^5 beta-alpha-alphas and it is anticipated that this data will provide the first improved limits on weak tensor currents in over 50 years. I will discuss the current state of the analysis as well as future plans at the BPT.