Observation of $e^{+}{e}^{-}\to \hat{I}\cdot h_c$ at center-of-mass energies from 4.085 to 4.600 GeV

Abstract

We observe for the first time the process $e^{+}{e}^{-}\to \hat{I}\cdot h_c$ with data collected by the BESIII experiment. Significant signals are observed at the center-of-mass energy $\sqrt{s}=4.226$ GeV, and the Born cross section is measured to be $(9.5_{-2.0}^{+2.2}\pm 2.7)$ pb. Evidence for $\hat{I}\cdot h_c$ is observed at $\sqrt{s}=4.358$ GeV with a Born cross section of $(10.0_{-2.7}^{+3.1}\pm 2.6)$ pb, and upper limits on the production cross section at other center-of-mass energies between 4.085 and 4.600 GeV are determined.