paper

Search for ( = 0, 1, 2) near GeV at Belle II

arXiv:2508.16036 · doi:10.1103/2rv3-s3w7

Abstract

We search for the ( = 0, 1, 2) processes at center-of-mass energies = 10.653, 10.701, 10.746, and 10.804 GeV. These data were collected with the Belle II detector at the SuperKEKB collider and correspond to 3.5, 1.6, 9.8, and 4.7 fb of integrated luminosity, respectively. We set upper limits at the 90\% confidence level on the Born cross sections for at each center-of-mass energy near 10.746 GeV. The upper limits at 90\% confidence level on the Born cross sections for are significantly smaller than the corresponding measured values for and at = 10.746 GeV.

Belle II Preprint 2025-022, KEK Preprint 2025-21