SEARCH FOR PARITY NONCONSERVING OPTICAL-ROTATION IN ATOMIC SAMARIUM

We have searched for parity nonconserving (PNC) optical rotation in fi ve optical transitions within the 4f(6)6s(2) ground configuration of a tomic samarium using laser polarimetry. It had been suggested that the se transitions might be favorable for studying electroweak effects bec ause the upper levels have close-lying levels of opposite parity which might give rise to strong mixing by the PNC Hamiltonian H-PNC. In ter ms of the usual parameter R[=Im(epsilon(PNC)/M)], we obtain (in units of 10(-8)) R-662 = 2.1(1.8) R-628 = -7(16), R-611 = -6(8), R-569 = -17 (30), and R-558 = -6(12), where the subscripts give the wavelengths of the transitions. The values of R are not significantly greater than t hose already reported for the heavy elements bismuth, lead, and thalli um, and we conclude that the samarium transitions do not offer the pro spect of a critical test of electroweak theory. Upper limits on the ma trix elements of H-PNC between the upper levels of the transitions and their close-lying opposite-parity neighbors are derived from the resu lts. [S1050-2947(98)06011-9].