# ${mathcal A} { m CP}$ Puzzle: Possible Evidence for Large Strong Phase in $B o Kπ$ Color-Suppressed Tree Amplitude - High Energy Physics - Phenomenology

${mathcal A} { m CP}$ Puzzle: Possible Evidence for Large Strong Phase in $B o Kπ$ Color-Suppressed Tree Amplitude - High Energy Physics - Phenomenology - Download this document for free, or read online. Document in PDF available to download.

Abstract: In QCD FactorizationQCDF, the suppression of the color-suppressed treeamplitude relative to the color-allowed one in $B\to K\pi$ decay implies adirect CP asymmetry in $B^{-}\to K^{-}\pi^{0}$ to be of the same sign andcomparable in magnitude to that in ${\bar B}^{0}\to K^{+}\pi^{-}$, incontradiction with experiment. This is the $A { m CP}$ $B\to K\pi$ puzzle. Oneof the current proposal to solve this puzzle is the existence of a largecolor-suppressed amplitude with large strong phase which implies also a largenegative ${\bar B}^{0}\to {\bar K}^{0}\pi^{0}$ CP asymmetry. In this paper, byan essentially model-independent calculation, we show clearly that the largenegative direct CP asymmetry in ${\bar B}^{0}\to {\bar K}^{0}\pi^{0}$ implies alarge $C-T$, the ratio of the color-suppressed to the color-allowed treeamplitude and a large negative strong phase for $C$. By adding to the QCDFamplitude an additional color-suppressed term to generate a large $C-T$ and alarge strong phase for $C$ and an additional penguin-like contribution, weobtain branching ratios for all $B\to K\pi$ modes and CP asymmetry for ${\barB}^{0}\to K^{+}\pi^{-}$ and $B^{-}\to K^{-}\pi^{0}$ in agreement withexperiment, and a large and negative CP asymmetry in ${\bar B}^{0}\to {\barK}^{0}\pi^{0}$ which could be checked with more precise measurements.

Author: ** T. N. Pham**

Source: https://arxiv.org/