Upper limit onTnonconserving tensor couplings in nuclear beta decay

Abstract

Upper limits are derived for the first time on charged, tensor coupling constants that violate time reversal invariance (T). Various previous measurements of beta polarization from nuclear decays are analyzed. The best limit is Im($C_T$ $C_A^{\mathcal{’}\mathrm{*}}$+$C_T^{\mathcal{’}}$ $C_A^{\mathrm{*}}$) =-0.063±0.052, a factor of 5 more precise than the present limit on analogously-defined, scalar T-violating terms. Finally, the relation of tensor couplings to searches for scalar couplings is discussed. No T violations are inferred.