Implications for CP asymmetries of improved data on B→K0π0

The decay B0→K0π0, dominated by a b→s penguin amplitude, holds the potential for exhibiting new physics in this amplitude. In the pure QCD penguin limit one expects CKπ=0 and SKπ=sin2β for the coefficients of cos(Δmt) and sin(Δmt) in the time-dependent CP asymmetry. Small non-penguin contributions lead to corrections to these expressions which are calculated in terms of isospin-related B→Kπ rates and asymmetries, using information about strong phases from experiment. We study the prospects for incisive tests of the Standard Model through examination of these corrections. We update a prediction CKπ=0.15±0.04, pointing out the sensitivity of a prediction SKπ≈1 to the measured branching ratio for B0→K0π0 and to other observables.