The pure annihilation type decays $B^0\rightarrow D_{s}^{-}K_{2}^{*+}$ and $B_{s}\rightarrow \bar{D}a_{2}$ in perturbative QCD approach

TL;DR

This paper predicts the branching ratios of specific pure annihilation B meson decays using perturbative QCD, providing results that are experimentally accessible and offering relations to test theoretical accuracy and new physics.

Contribution

It introduces precise perturbative QCD calculations for pure annihilation B decays and proposes relations among decay channels to reduce uncertainties.

Findings

Predicted branching ratios are within measurable range.

No direct CP asymmetries due to lack of penguin contributions.

Derived relations among decay channels to aid experimental tests.

Abstract

We calculate the branching ratios of pure annihilation type decays $B^0\rightarrow D_{s}^{-}K_{2}^{*+}$ and $B_s\rightarrow \bar{D}a_{2}$ using the perturbative QCD approach based on $k_T$ factorization. The branching ratios are predicted to be $(60.6_{-16.5\,-10.4\,-2.1}^{+17.3\,+4.3\,+3.2}) \times 10^{-6}$ for $B^0\rightarrow D_{s}^{-}K_{2}^{*+}$, $(1.1_{-0.4\,-0.2\,-0.1}^{+0.4\,+0.1\,+0.1})\times 10^{-6}$ for $B_s\rightarrow \bar{D}a_{2}^{0}$ and $(2.3_{-0.8\,-0.4\,-0.1}^{+0.8\,+0.2\,+0.1})\times 10^{-6}$ for $B_{s}\rightarrow D^{-}a_{2}^{+}$. They are large enough to be measured in the ongoing experiment. Due to the shortage of contributions from penguin operators, there are no direct CP asymmetries for these decays in the standard model. We also derive simple relations among these decay channels to reduce theoretical uncertainties for the experiments to test the accuracy of theory and search of new physics signal.