Determination of the number of J/ψ events with J/ψ → inclusive decays

Abstract

The number of J/psi events collected with the BESIII detector at the BEPC II from June 12 to July 28, 2009 is determined to be (225.3 +/- 2.8) x 10(6) using J/psi -> inclusive events, where the uncertainty is the systematic error and the statistical one is negligible.