Bai, JZ (reprint author), INST HIGH ENERGY PHYS,BEIJING 100039,PEOPLES R CHINA.
A data-driven energy scan in the immediate vicinity of the tau pair production threshold has been performed using the Beijing Spectrometer at the Beijing Electron-Positron Collider. Approximately 5 pb(-1) of data, distributed over 12 scan points, have been collected. A previous mass value for the tau lepton, obtained using only the e mu final state, has been published. In this paper, the final BES result on the mass measurement is presented. The analysis is based on the combined data from the ee, e mu eh, mu mu, mu h, and hh final states, where h denotes a charged ir or K. A maximum likelihood fit to the tau pair production cross section data yields the value m(tau) = 1776.96(-0.21-0.17)(+0.18+0.25) MeV.