Determination of the number of $J/\psi$ events with inclusive $J/\psi$ decays

TL;DR

This paper accurately measures the total number of $J/\psi$ events collected by BESIII in 2009 and 2012 using inclusive decay analysis, achieving high precision and consolidating previous data.

Contribution

It provides a precise recalculation of $J/\psi$ events in 2009 and a comprehensive total count for 2012, improving the accuracy of previous measurements.

Findings

Total $J/\psi$ events: $(1310.6\pm 7.0) imes 10^6$

2009 $J/\psi$ events: $(223.7\pm 1.4) imes 10^6$

2012 $J/\psi$ events: $(1086.9\pm 6.0) imes 10^6$

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 $(223.7\pm1.4)\times 10^6$, 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 $(1086.9\pm 6.0)\times 10^6$. In total, the number of $J/\psi$ events collected with the BESIII detector is measured to be $(1310.6\pm 7.0)\times 10^6$, where the uncertainty is dominated by systematic effects and the statistical uncertainty is negligible.