PHYSICAL REVIEW LETTERS 130, 091902 (2023)

ISSN: 0031-9007, SCIE

Observation of e + e − → ω χ b J ( 1 P ) and Search for X b → ω Υ ( 1 S ) at √ s near 10.75 GeV

I. Adachi et al. (Belle II Collaboration)

We study the processes eþe− → ωχbJð1PÞ (J ¼ 0, 1, or 2) using samples at center-of-mass energies ffiffi s p ¼ 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 ϒð4SÞ resonance. We report the first observation of ωχbJð1PÞ signals at ffiffi s p ¼ 10.745 GeV. By combining Belle II data with Belle results at ffiffi s p ¼ 10.867 GeV, we find energy dependencies of the Born cross sections for eþe− → ωχb1;b2ð1PÞ to be consistent with the shape of the ϒð10753Þ state. These data indicate that the internal structures of the ϒð10753Þ and ϒð10860Þ states may differ. Including data at ffiffi s p ¼ 10.653 GeV, we also search for the bottomonium equivalent of the Xð3872Þ state decaying into ωϒð1SÞ. No significant signal is observed for masses between 10.45 and 10.65 GeV=c2.

DOI: 10.1103/PhysRevLett.130.091902

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