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

Abstract

A measurement of the number of J/$\psi$ events collected with the BESIII detector in 2009 and 2012 is performed using inclusive decays of the J/$\psi$. The number of J/$\psi$ events taken in 2009 is recalculated to be (223.7 ± 1.4) × 10$^6$, which is in good agreement with the previous measurement, but with significantly improved precision due to improvements in the BESIII software. The number of J/$\psi$ events taken in 2012 is determined to be (1086.9 ± 6.0) × 10$^6$. In total, the number of J/$\psi$ events collected with the BESIII detector is measured to be (1310.6 ± 7.0) × 106, where the uncertainty is dominated by systematic effects and the statistical uncertainty is negligible.