Search for Baryon-Number-Violating Processes in $B^{-}$ Decays to the $\bar{\hat{I}}{ž}_c^0\bar{\hat{I}}{›}_c^{-}$ Final State

Abstract

We report the results of the first search for $B^{-}$ decays to the $\bar{\hat{I}}{ž}_c^0\bar{\hat{I}}{›}_c^{-}$ final state using 711~$\mathrm{f}{\mathrm{b}}^{-1}$ of data collected at the $\hat{I}\yen (4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. The results are interpreted in terms of both direct baryon-number-violating $B^{-}$ decay and $\hat{I}{ž}_c^0-\bar{\hat{I}}{ž}_c^0$ oscillations which follow the Standard Model decay $B^{-}\to \hat{I}{ž}_c^0\bar{\hat{I}}{›}_c^{-}$. We observe no evidence for baryon number violation and set the 95\% confidence-level upper limits on the ratio of baryon-number-violating and Standard Model branching fractions $\mathcal{B}(B^{-}\to \bar{\hat{I}}{ž}_c^0\bar{\hat{I}}{›}_c^{-})/\mathcal{B}(B^{-}\to \hat{I}{ž}_c^0\bar{\hat{I}}{›}_c^{-})$ to be $<2.7\%$ and on the $\hat{I}{ž}_c^0-\bar{\hat{I}}{ž}_c^0$ oscillation angular frequency $\ddot{I}‰$ to be $<0.76{\mathrm{ps}}^{-1}$ (equivalent to $\ddot{I}{„}_{\mathrm{mix}}>1.3$~ps).

7 pages, 2 figures, submitted to Phys. Rev. Lett