On the Dalitz plot analysis of the B --> K eta gamma decays

Abstract

Recently B-factories have published new results on the $B \to K \eta \gamma$ decays being inspired by the theoretical suggestion to search for new physics in $B \to P_1 P_2 \gamma$ decays. Using heavy meson chiral perturbation theory we find mechanism which governs the amplitude in parts of the Dalitz plot where either $K$ or $\eta$ mesons are soft. The dominant contributions in these cases are coming from the nonresonant decay modes. We discuss also $B \to K \eta' \gamma$ Dalitz plot. Our partially integrated rates are in agreement with the experimental findings.