Dalitz plot analysis of theB→Kηγdecays

Abstract

Recently $B$ factories have published new results on the $B\ensuremath{\rightarrow}K\ensuremath{\eta}\ensuremath{\gamma}$ decays being inspired by the theoretical suggestion to search for new physics in $B\ensuremath{\rightarrow}{P}_{1}{P}_{2}\ensuremath{\gamma}$ decays. Using heavy-meson chiral perturbation theory, we find a mechanism which governs the amplitude in parts of the Dalitz plot where either $K$ or $\ensuremath{\eta}$ mesons are soft. The dominant contributions in these cases are coming from the nonresonant decay modes. We discuss also the $B\ensuremath{\rightarrow}K{\ensuremath{\eta}}^{\ensuremath{'}}\ensuremath{\gamma}$ Dalitz plot. Our partially integrated rates are in agreement with the experimental findings.