Signal of New Physics and Test of Isospin-SU(3) Relations and CP Violation in Charmless B Decays

Abstract

A model-independent analytical analysis for charmless B decays is presented. It is demonstrated that the CP-averaging branching ratio difference $\Delta R=R_c-R_n$ in $B\to \pi K$ decays with $R_c=2Br({\pi }^0{K}^{-})/Br({\pi }^{-}{\bar{K}}^0)$ and $R_n=Br({\pi }^{+}{K}^{-})/2Br({\pi }^0{\bar{K}}^0)$ defines a sensitive quantity for probing new physics as $\Delta R$ is dominated by the second order of electroweak penguin contributions. A large discrepancy between experimental data and standard model (SM) prediction $\Delta R^{exp}/\Delta R^{SM}>9.0\pm 5.0$ strongly indicates a signal of new physics in the electroweak penguin sector. Within the SM, the current $\pi K$ data favor a very large color-suppressed tree amplitude $|C^{\prime }/T^{\prime }|\sim 2$, large CP violations ($A_{CP}({\pi }^0{\bar{K}}^0)\sim 0.69$ and $A_{CP}({\pi }^0{\bar{K}}^{-})\sim 0.56$), which is connected to $\Delta R$ and be solved simultaneously with extra electroweak penguin contributions. More accurate measurements on the ratio difference $\Delta R$ and CP violation in $B\to \pi \pi ,\pi K$ decays may provide a window for probing new physics and testing the isospin and SU(3) symmetries.

Comments: 15 pages, no figures, RevTex