Parity-nonconserving transitions in Cs and Tl: A semiempirical treatment of core-polarization effects

The parity-nonconserving (PNC) electric dipole matrix elements ($A_{\mathrm{el}\left(\mathrm{PNC}\right)\mathrm{})}$ for Cs (6$s_{1/2}$→7$s_{1/2}$) and Tl (6$p_{1/2}$→7$p_{1/2}$) are calculated. In each case the active valence electron is assumed to move in the potential of a Hartree-Fock core augmented by a semiempirical core-polarization potential. Also included are the modifications to the core potential created by PNC effects within the core. The results we obtain are in good agreement with other calculations and measurements.