Search for $B^0$ decays to invisible final states at Belle

Abstract

We report a search for $B^0$ decays into invisible final states using a data sample of $657\times 10^6$ $B\bar{B}$ pairs collected at the $\hat{I}\yen (4S)$ resonance with the Belle detector at the KEKB $e^{+}{e}^{-}$ collider. The signal is identified by fully reconstructing a hadronic decay of the accompanying $B$ meson and requiring no other particles in the event. No significant signal is observed, and we obtain an upper limit of $1.3\times 10^{-4}$ at the 90% confidence level for the branching fraction of invisible $B^0$ decay.

6 pages, 5 figures (9 figure files)