Search for Bs0 →η′Xs s ¯ at Belle using a semi-inclusive method SEARCH for Bs0 →η′Xs s ¯ ... DUBEY et al.

Abstract

We report the first search for the penguin-dominated process Bs0→η′Xss¯ using a semi-inclusive method. A 121.4 fb-1 integrated luminosity ϒ(5S) data set collected by the Belle experiment, at the KEKB asymmetric-energy e+e- collider, is used. We observe no statistically significant signal and, including all uncertainties, we set a 90% confidence level upper limit on the partial branching fraction at 1.4×10-3 for M(Xss¯)≤2.4 GeV/c2.