  We have calculated the 6s-7s parity nonconserving E1 transition amplitude
(E_{PNC}) in cesium. This calculation has been performed with higher numerical
accuracy than our 1989 calculation [V.A. Dzuba, V.V. Flambaum, and O.P.
Sushkov, Phys. Lett. A {\bf 141}, 147]. Also the Breit interaction has been
included and the radiative corrections estimated. Our final result is
E_{PNC}=0.902 (1 +/- 0.7%)iea_{B}(Q_{W}/N). This represents an improvement in
the accuracy of the calculation from the 1% error claimed in 1989. This result
corresponds to a nuclear weak charge for Cs, Q_{W}=-72.39 (1 +/- 0.4% (exp) +/-
0.7% (theory)). We conclude that there is no significant deviation from the
Standard Model value -73.09(3).

High Energy Physics - Phenomenology;Atomic Physics