Parity and Time Reversal Violations in Tlf.

This thesis describes an experimental search for a violation of parity and time reversal symmetries using a Thallium Fluoride (TlF) molecular beam. The violation appears as a shift in the frequency of a hyperfine transition in the ground electronic, ground vibrational, first rotational (J = 1) state of the molecule. The frequency shift occurs under a reversal of the relative direction of laboratory electric and magnetic fields. Two interpretations are given for the origin of such an effect. One involves an electric dipole moment on the proton, and the other, a parity and time reversal violating tensor coupling for weak neutral currents. The final results set a new upper limit on the proton electric dipole moment, d(,p), given by. d(,p) = (1.3 (+OR-) 2.0) x 10('-21) e-cm. Alternatively, the null result of the experiment can be used to set a limit on the tensor weak neutral current coupling, C(,T), which in terms of the Fermi coupling constant G(,F) becomes,. (VBAR)C(,T)(VBAR) < 1.4 x 10('-5) (90% confidence). These results were limited by partially understood systematic effects which gave rise to false frequency shifts on the order of 20 mHz (transition frequency (TURNEQ) 120 kHz, linewidth (TURNEQ) 45 Hz) compared to the statistical precision of (TURN) 1 mHz. Despite the difficulties experienced with systematic effects in this experiment, it was felt that the TlF molecular beam technique could potentially lead to a precision on the order of 0.1 mHz. Suggestions for obtaining this 200 fold improvement are given in the thesis.