Breit correction to the parity-nonconservation amplitude in cesium

Abstract

Including the Breit interaction leads to a 0.6% reduction in the magnitude of the 6s-7s paritynonconservation ͑PNC͒ amplitude in 133 Cs, confirming a result recently obtained by A. Derevianko ͓Phys. Rev. Lett. 85, 1618 ͑2000͔͒. A revised value of the theoretical PNC amplitude for 133 Cs is given; the corresponding value of the weak charge shows no noticeable deviation from the standard model.

Breit interaction and parity nonconservation in many-electron atoms

“…Interpretation of this result using earlier atomic calculations [3,4] lead to apparent disagreement with the standard model [5]. This disagreement had been resolved when Breit [6,7,8] and radiative [9,10,11] corrections were included into analysis.…”

“…In other words, Hartree-Fock potential in the left-hand side of equations (6,7,8) is the sum of Coulomb and Breit terms. Correction to the potential δV in the right-hand side of equations (6,7,8,9) is also the sum of Coulomb and Breit terms:…”

“…Equations (6,7,8) are first solved self-consistently for states in the core. Then corrections to valence states are calculated in the field of frozen core.…”

“…We have developed such approach in our previous work [7] and applied it to the analysis of the PNC in cesium. Breit and Coulomb interaction were equally treated on the self-consistent field level (Hartree-Fock and random-phase approximation calculations).…”

Parity nonconservation in thallium

“…The simplest and best understood such atom is cesium, where theory has the accuracy of 1% [3,4] (see also more recent calculations [5,6,7]). That, together with the best experimental result for Cs [8] allowed one to obtain the most accurate result for the weak charge of the cesium nucleus [6,7]: Q W ( 133 Cs) = −72.5 (3) expt (7) theor ,…”