Search for the B ?y (4260)K, y (4260) ?j /??+?- decays

Abstract

We report the results of a search for the B?Y(4260)K, Y(4260)?J/??+?- decays. This study is based on a data sample corresponding to an integrated luminosity of 711 fb-1, collected at the (4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We investigate the J/??+?- invariant mass distribution in the range 4.0 to 4.6 GeV/c2 using both B+?J/??+?-K+ and B0?J/??+?-KS0 decays. We find excesses of events above the background levels, with significances of 2.1 and 0.9 standard deviations for charged and neutral B?Y(4260)K decays, respectively, taking into account the systematic uncertainties. These correspond to upper limits on the product of branching fractions, B(B+?Y(4260)K+)�B(Y(4260)?J/??+?-)<1.4�10-5 and B(B0?Y(4260)K0)�B(Y(4260)?J/??+?-)<1.7�10-5 at the 90% confidence level. � 2019 authors.