Observation of e plus e- → ωχ_bJ(1P) and Search for X_b → ωγ(1S) at √s near 10.75 GeV

We study the processes e+e-→ωχbJ(1P) (J=0, 1, or 2) using samples at center-of-mass energies s=10.701, 10.745, and 10.805 GeV, corresponding to 1.6, 9.8, and 4.7 fb-1 of integrated luminosity, respectively. These data were collected with the Belle II detector during special operations of the SuperKEKB collider above the ϒ(4S) resonance. We report the first observation of ωχbJ(1P) signals at s=10.745 GeV. By combining Belle II data with Belle results at s=10.867 GeV, we find energy dependencies of the Born cross sections for e+e-→ωχb1,b2(1P) to be consistent with the shape of the ϒ(10753) state. These data indicate that the internal structures of the ϒ(10753) and ϒ(10860) states may differ. Including data at s=10.653 GeV, we also search for the bottomonium equivalent of the X(3872) state decaying into ωϒ(1S). No significant signal is observed for masses between 10.45 and 10.65 GeV/c2.