Constraining Charming Penguins in Charmless B Decays

TL;DR

This paper constrains charming penguin contributions in charmless B decays using flavor symmetry and CP asymmetry data, finding small penguins and large color-suppressed amplitudes, impacting CP violation interpretations.

Contribution

It provides the first comprehensive global fit constraining charming penguins in B decays with updated data and flavor symmetry assumptions.

Findings

Small charming penguin contributions are consistent with data.

Large color-suppressed tree amplitude (C) relative to T remains favored.

Small charming penguins can still significantly affect CP asymmetries in KK decays.

Abstract

We discuss the correlations of charming penguin contributions to $B\to\pi\pi$, $\pi K$ and KK using approximate flavor SU(3) symmetry. Strong constraints are found from the direct CP asymmetries especially in $\pi K$ modes. We make a global fit to the latest data and find that only a small charming penguin is allowed, and the size of color-suppressed tree amplitude (C) relative to tree amplitudes (T) remains large $C/T\simeq0.6$, which disfavors the possibility of a large charming penguin as an explanation for the $\pi\pi$ puzzle. We show that a small charming penguin can still have sizable effect in the time-dependence CP asymmetries in KK mode.