Search for P and T violations in the hyperfine structure of thallium fluoride

A molecular-beam experiment using TlF is described. The experiment searched for a P- and T-violating interaction of the form HPT=dTl, where d is a coupling constant, T is a unit vector parallel to the thallium nuclear spin, and TlF is a unit vector parallel to the internuclear axis. The experiment yields the null result dh=812 mHz. Interpreting the interaction in terms of an electric dipole moment on the proton, Dp, or in terms of a possible weak neutral-current tensor interaction with a coupling constant CT, this result corresponds to Dp=(1.32.0)×10-21 e cm and CT=(69)×10-6GF, where the errors incorporate unexplained systematic effects as well as statistical errors.