Improved measurement of Born cross sections for χbJ ω and χbJ (π π−π0)non−ω (J = 0, 1, 2) at Belle and Belle II

Abstract

We study the processes χbJ ω and χbJ (π+π−π0)non−ω (J = 0, 1, 2) at center-of-mass energies from 10.73 to 11.02 GeV using a 142.5 fb−1 data sample collected with the Belle detector at the KEKB asymmetric-energy e+e− collider; and at GeV using a 19.8 fb−1 sample collected with Belle II at SuperKEKB. We find that the Υ(10753) state decays into χbJ ω but not into χbJ (π+π−π0)non−ω, while the Υ(10860) state, in contrast, decays into χbJ (π+π−π0)non−ω but not into χbJ ω. The mass and width of the Υ(10753) state are measured to be (10756.1 ± 3.4(stat.) ± 2.7(syst.)) MeV/c2 and (32.2 ± 11.3(stat.) ± 14.9(syst.)) MeV. The products of the partial width to e+e− and branching fractions for Υ(10753) → χ..