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\ndetector in 2009 and 2012 is performed using inclusive decays of the $J/\\psi$ .\nThe number of $J/\\psi$ events taken in 2009 is recalculated to be\n$(223.7\\pm1.4)\\times 10^6$, which is in good agreement with the previous\nmeasurement, but with significantly improved precision due to improvements in\nthe BESIII software. The number of $J/\\psi$ events taken in 2012 is determined\nto be $(1086.9\\pm 6.0)\\times 10^6$. In total, the number of $J/\\psi$ events\ncollected with the BESIII detector is measured to be $(1310.6\\pm 7.0)\\times\n10^6$, where the uncertainty is dominated by systematic effects and the\nstatistical uncertainty is negligible.\n