Observation of e+e- ??+?-?0?b1,2 (1P) and search for e+e- ???b1,2 (1P) at s =10.96 - 11.05 GeV

Abstract

We report searches for the processes e+e-??+?-?0?bJ and e+e-???bJ (J=1, 2) based on data samples collected by the Belle experiment at the KEKB collider. We report the first observation of the process e+e-?(?+?-?0)non-??b1 and first evidence for e+e-???bJ in the vicinity of the ?(11020) resonance, with center-of-mass energies from 10.96 to 11.05 GeV. The significances for (?+?-?0)non-??b1 and ??bJ are greater than 5.3? and 4.0?, respectively. We also investigate the energy dependence of the e+e-??+?-?0?bJ cross section, but we cannot determine whether the contributions are from the ?(10860) and ?(11020) resonances or nonresonant continuum processes. The signals for e+e-???bJ are not significant, and the upper limits of the Born cross sections at the 90% confidence level are 0.7 and 1.0 pb for e+e-???b1 and ??b2, respectively, for center-of-mass energies from 10.96 to 11.05 GeV. � 2018 authors. Published by the American Physical Society.