Precision determination of weak charge ofCs133from atomic parity violation

Abstract

We discuss results of the most accurate to-date test of the low-energy electroweak sector of the standard model of elementary particles. Combining previous measurements with our highprecision calculations we extracted the weak charge of the 133 Cs nucleus, QW = −73.16 (29)exp (20) (3), and confirms energy-dependence (or running) of the electroweak interaction and places constraints on a variety of new physics scenarios beyond the standard model. In particular, we increase the lower limit on the masses of extra Z-bosons predicted by models of grand unification and string theories. This paper provides additional details to the Letter. We discuss large-scale calculations in the framework of the coupled-cluster method, including full treatment of single, double, and valence triple excitations. To determine the accuracy of the calculations we computed energies, electric-dipole amplitudes, and hyperfine-structure constants. An extensive comparison with high-accuracy experimental data was carried out.

Lifetime measurement of the cesium6P3/2level using ultrafast pump-probe laser pulses

“…Our 6P 3/2 D 6S 1/2 result does not agree within the measurement uncertainty to either of the theoretical values, differing by 0.18% from ref. [5] and by 0.25% from ref. [6].…”

“…[27,28]; (G) ref. [5]; (H ) ref. [6] an all-orders ab initio calculation utilizing the correlation potential method.…”

“…By comparing such calculations to precision lifetime measurements a direct test of the accuracy of the underlying theory is obtained. Calculations are most accurate for alkali atoms because of their simple atomic structure, with uncertainties approaching 0.1% in the case of cesium [5,6]. We describe in detail our measurement of the Cs 6P 3/2 excited state lifetime which achieves an experimental uncertainty of 0.15%, compared to 0.23% for the best previous direct measurement [7].…”

“…Only recently has a comparison approaching the 0.1% level in heavy alkali atoms become possible due to advances in relativistic manybody perturbation theory such as the all-order method [5,6,22]. Previous direct high-precision measurements of the Cs 6P 3/2 lifetime employed position-correlated photon counting in a fast Cs beam with a reported value of 30.57(7) ns [7] and time-correlated single-photon counting in a thermal Cs beam resulting in a value of 30.41 (10) ns [23].…”

Coupled-cluster calculations of properties of the boron atom as a monovalent system

“…While the experiments are carried out at low energies, the derived constraints are both unique and complementary to those obtained from direct searches for new physics with high-energy particle colliders. For example, the latest APV results [4,5] set new mass bounds on exotic new-physics particles, Z ′ bosons, which are ubiquitous in competing extensions of the standard model. These APV bounds improve upon the earlier results of the Tevatron collider and cut out the lower-energy part of the discovery reach of the Large Hadron Collider.…”