Session KP01 - Poster Session III.
POSTER session, Tuesday afternoon, March 23
Exhibit Hall, GWCC
We present a new experimental proposal to search for time reversal-violating (T-odd, but P-even) forces in atomic thallium. Important modifications to the method originally proposed(M.G. Kozlov and S.G. Porsev, Phys. Lett. 142A, 233 (1989)) should lead to substantially increased sensitivity to possible `TOPE' effects. In our new scheme, a linearly polarized 1283 nm laser, tuned near the 6P_1/2(F=0)\rightarrow 6P_3/2(F^\prime=1) transition, is injected in both directions into a high-finesse ring cavity. A thallium atomic beam passes through the ring cavity, intersecting the laser beams at right angles. In the presence of a static electric field, \vecE, a `TOPE' signature is revealed by a cavity phase shift proportional to (\hatk_laser\cdot\vecE). We would search for a differential phase shift of the counterpropagating laser beam components correlated to electric field reversal. The cavity finesse both amplifies any TOPE effect and increases the precision with which it can be detected, while the differencing technique reduces sensitivity to common-mode laser frequency or mechanical fluctuations. An analysis of statistical phase shift resolution and consideration of potential systematic errors leads to predicted experimental limits on an atomic TOPE matrix element at the 10^4 Hz level or below. Preliminary results of new thallium calculations(S.G. Porsev, private communication), and a comparative discussion of direct vs. indirect (atomic EDM-based) limits on TOPE forces will be presented, as will further experimental details.