Search for the decay $B^0\to K^{\ast 0}\ddot{I}{„}^{+}\ddot{I}{„}^{-}$ at the Belle experiment

Abstract

This letter presents a search for the rare flavor-changing neutral current process $B^0\to K^{\ast 0}\ddot{I}{„}^{+}\ddot{I}{„}^{-}$ using data taken with the Belle detector at the KEKB asymmetric energy $e^{+}{e}^{-}$ collider. The analysis is based on the entire $\hat{I}\yen (4S)$ resonance data sample of 711 $\mathrm{f}{\mathrm{b}}^{-1}$, corresponding to $772\times 10^{6}B\bar{B}$ pairs. In our search we fully reconstruct the companion $B$ meson produced in the process $e^{+}{e}^{-}\to \hat{I}\yen (4S)\to B\bar{B}$ from its hadronic decay modes, and look for the decay $B^0\to K^{\ast 0}\ddot{I}{„}^{+}\ddot{I}{„}^{-}$ in the rest of the event. No evidence for a signal is found. We report an upper limit on the branching fraction $\mathcal{B}(B^0\to K^{\ast 0}\ddot{I}{„}^{+}\ddot{I}{„}^{-})<3.1\times 10^{-3}$ at 90\% confidence level. This is the first direct limit on $\mathcal{B}(B^0\to K^{\ast 0}\ddot{I}{„}^{+}\ddot{I}{„}^{-})$.

8 pages, 3 figures, accepted by PRD as a Letter