Search for $B^0 \to K^{*0} \overline{K}{}^{*0}$, $B^0 \to K^{*0} K^{*0}$ and $B^0 \to K^+\pi^- K^{\mp}\pi^{\pm}$ Decays

TL;DR

This study searches for specific rare B meson decay modes involving kaons and pions, setting upper limits on their branching fractions based on data from the Belle experiment, contributing to understanding charmless B decays.

Contribution

It provides the first upper limits on the branching fractions of $B^0 o K^{*0} ar{K}^{*0}$ and $B^0 o K^{*0} K^{*0}$ decays, using a large data sample from Belle.

Findings

Upper limit of $0.81 imes 10^{-6}$ for $B^0 o K^{*0} ar{K}^{*0}$

Upper limit of $0.20 imes 10^{-6}$ for $B^0 o K^{*0} K^{*0}$

Measured branching fractions for other charmless decay modes.

Abstract

We report a search for the decays $B^0\to K^{*0} \overline{K}{}^{*0}$ and $B^0\to K^{*0} K^{*0}$. We also measure other charmless decay modes with $K^+\pi^-K^-\pi^+$ and $K^{+}\pi^{-}K^{+}\pi^{-}$ final states. The results are obtained from a data sample containing $657 \times 10^6$ $B \overline B$ pairs collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. We set upper limits on the branching fractions for $B^0\to K^{*0} \kstarbar$ and $B^0\to K^{*0} K^{*0}$ of $0.81 \times 10^{-6}$ and $0.20\times 10^{-6}$, respectively, at the 90% confidence level.