A self-consistent treatment of the parity non-conserving interaction in atoms

• Main Author: Plummer, Edmund
• Published: University of Oxford 1984
• Subjects: 539.7; Atomic physics & molecular physics
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236148

The Weinberg-Salam model of the weak interaction predicts that any wavefunction contains a small admixture of functions of the opposite parity. As a result, radiative transitions which would have pure magnetic dipole (M1) character in the absence of weak parity mixing interactions acquire a small component of electric dipole (E1) character, implying that atoms will show weak optical activity in proportion to the ratio of the matrix elements R = E1/M1. This work describes a generalization of the MCDF procedure to include the weak interaction. This allows us to treat correlation, exchange, orthogonality and shielding in a consistent and rigorous manner. A pilot calculation on bismuth using a model potential highlighted numerical problems associated with the use of a uniform nuclear density distribution. Therefore we have used a Fermi distribution in the main calculations to avoid these difficulties. We give results for bismuth, thallium, lead and cesium; correlation (for the first three of these) and shielding (for all of these atoms) have been included by means of configuration interaction. We give the ratio R in both Coulomb (velocity) and Babushkin (length) gauges, and for bismuth, thallium and cesium a reasonable level of gauge invariance in the unshielded calculations was obtained, in contrast to other calculations.