Measurements of the center-of-mass energies of $e^{+}e^{-}$ collisions at BESIII

TL;DR

This paper reports precise measurements of the center-of-mass energies at BESIII during 2016-2019, crucial for studying charmonium states, confirming energy stability with 0.6 MeV accuracy.

Contribution

It provides high-precision center-of-mass energy measurements for BESIII data samples, enhancing the accuracy of charmonium studies.

Findings

Center-of-mass energies measured with 0.6 MeV precision.

Energy stability confirmed throughout most data-taking periods.

Data samples suitable for excited charmonium state analysis.

Abstract

During the 2016-17 and 2018-19 running periods, the BESIII experiment collected 7.5~fb$^{-1}$ of $e^+e^-$ collision data at center-of-mass energies ranging from 4.13 to 4.44 GeV. These data samples are primarily used for the study of excited charmonium and charmoniumlike states. By analyzing the di-muon process $e^{+}e^{-} \to (\gamma_{\rm ISR/FSR}) \mu^{+}\mu^{-}$, we measure the center-of-mass energies of the data samples with a precision of 0.6 MeV. Through a run-by-run study, we find that the center-of-mass energies were stable throughout most of the data-taking period.