A New Limit on Time-Reversal Violation in Beta Decay

Abstract

We report the results of an improved determination of the triple correlation $DP\cdot (p_e\times p_{\hat{I}}½)$ that can be used to limit possible time-reversal invariance in the beta decay of polarized neutrons and constrain extensions to the Standard Model. Our result is $D=(-0.96\pm 1.89(stat)\pm 1.01(sys))\times 10^{-4}$. The corresponding phase between g_A and g_V is $\ddot{I}{•}_{AV}=180.013^{\circ }\pm 0.028^{\circ }$ (68 % confidence level). This result represents the most sensitive measurement of D in beta decay.

4 pages, 4 figures Fixed typos, a Ref., and Fig. 1