Searching for Tensor Currents in the Weak Interaction Using $^{8}$Li $\beta$ Decay
ORAL
Abstract
The Standard Model’s description of the weak interaction follows a pure vector-axial-vector structure. Any observation of scalar or tensor contributions would indicate new physics. We will present preliminary analysis of a calibrated, high-statistics, $^{8}$Li beta decay data set taken with the Beta decay Paul Trap (BPT) at Argonne National Lab that has been used to precisely measure the tensor current-sensitive $\beta-\nu$ correlation coefficient (a$_{\beta\nu}$). This data set contains over ten times more statistics with reduced systematic effects compared to our collaboration’s previous experiment, which constrained a$_{\beta\nu}$ to ~1 percent of its predicted value and improved on the previous best limit set by $^{6}$He in 1963. Upon completion of the analysis, we are poised to further constrain the value of a$_{\beta\nu}$ to approximately 0.1 percent relative uncertainty.
*We acknowledge NSERC, Canada, App. No. 216974, the U.S. DOE Contract No. DE-AC02-06CH11357 [ANL] and DE-AC52-07NA27344 [LLNL], NSF grant no. 1144082 and the ANL ATLAS facility
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