Abstract: | Using data samples of 89.5 fb-1, 711.0 fb-1, and 121.4 fb-1 collected with the Belle detector at the KEKB asymmetric-energy e+e- collider at center-of-mass energies 10.52, 10.58, and 10.867 GeV, respectively, we study the exclusive reactions e+e-???cJ (J=0, 1, 2) and e+e-???c. A significant ??c1 signal is observed for the first time at s=10.58 GeV with a significance of 5.1? including systematic uncertainties. No significant excesses for ??c0, ??c2, and ??c final states are found, and we set 90% credibility level upper limits on the Born cross sections (?B) at 10.52 GeV, 10.58 GeV, and 10.867 GeV. Together with cross sections measured by BESIII at lower center-of-mass energies, the energy dependency of ?B(e+e-???c1) is obtained. � 2018 authors. Published by the American Physical Society. |