Parity violation in atomic ytterbium: Experimental sensitivity and systematics

We present a detailed description of the observation of parity violation in the (S0-D1)-S-1-D-3 408-nm forbidden transition of ytterbium, a brief report of which appeared earlier. Linearly polarized 408-nm light interacts with Yb atoms in crossed E and B fields. The probability of the 408-nm transition contains a parity-violating term, proportional to (is an element of center dot B)[(E x is an element of) center dot B], arising from interference between the parity-violating amplitude and the Stark amplitude due to the E field (is an element of is the electric field of the light). The transition probability is detected by measuring the population of the P-3(0) state, to which 65% of the atoms excited to the D-3(1) state spontaneously decay. The population of the P-3(0) state is determined by resonantly exciting the atoms with 649-nm light to the 6s7s S-3(1) state and collecting the fluorescence resulting from its decay. Systematic corrections due to E-field and B-field imperfections are determined in auxiliary experiments. The statistical uncertainty is dominated by parasitic frequency excursions of the 408-nm excitation light due to the imperfect stabilization of the optical reference with respect to the atomic resonance. The present uncertainties are 9% statistical and 8% systematic. Methods of improving the accuracy for future experiments are discussed.