Observation of e+e−→ηhc at center-of-mass energies from 4.085 to 4.600 GeV

Abstract

We observe for the first time the process e+e-→ηhc with data collected by the BESIII experiment. Significant signals are observed at the center-of-mass energy s=4.226 GeV, and the Born cross section is measured to be (9.5-2.0+2.2±2.7) pb. Evidence for ηhc is observed at s=4.358 GeV with a Born cross section of (10.0-2.7+3.1±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.