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

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 $e^{+}{e}^{-}\to ({\hat{I}}_{ISR/FSR}^3)\hat{I}{¼}^{+}\hat{I}{¼}^{-}$, 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.