NLO contributions to $B \to K K^*$ Decays in the pQCD approach

TL;DR

This paper calculates next-to-leading-order contributions to specific B meson decays using the perturbative QCD approach, providing predictions for branching ratios and CP asymmetries that align with experimental data and other theoretical models.

Contribution

It presents the first detailed NLO calculations of $B o K K^*$ decays within the pQCD framework, including vertex corrections, quark loops, and magnetic penguins.

Findings

Predicted branching ratios agree with experimental limits.

Calculated direct CP asymmetries for key decay modes.

NLO pQCD results are consistent with QCD factorization predictions.

Abstract

We calculate the important next-to-leading-order (NLO) contributions to the $B \to K K^*$ decays from the vertex corrections, the quark loops, and the magnetic penguins in the perturbative QCD (pQCD) factorization approach. The pQCD predictions for the CP-averaged branching ratios are $Br(B^+ \to K^+ \bar{K}^{*0}) \approx 3.2\times 10^{-7}$, $Br(B^+ \to \bar{K}^0 {K}^{*+}) \approx 2.1\times 10^{-7}$, $Br(B^0/\ov{B}^0 \to K^0\bar{K}^{*0}+\bar{K}^0 K^{*0}) \approx 8.5\times 10^{-7}$, $Br(B^0/\ov{B}^0 \to K^+K^{*-} + K^-K^{*+}) \approx 1.3\times 10^{-7}$, which agree well with both the experimental upper limits and the predictions based on the QCD factorization approach. Furthermore, the CP-violating asymmetries of the considered decay modes are also evaluated. The NLO pQCD predictions for $\acp(B^+ \to K^+\bar{K}^{*0})$ and $\acp(B^+ \to K^{*+}\bar{K}^{0})$ are $\acp^{dir}(K^+\bar{K}^{*0})\approx -6.9 %$ and $\acp^{dir}(K^{*+}\bar{K}^0)\approx 6.5 %$.