ISSN - 00213640, EISSN - 10906487, JETP Letters, 2007, vol. 85, p. 347-352
Measurement of the τ lepton mass at the KEDR detector
A precise τ lepton mass measurement performed at the VEPP-4M collider with the KEDR detector is reported. The mass value is evaluated from the τ+τ- cross section behavior around the production threshold. The result based on 6.7 pb-1 of data is m τ = 1776.81 -0.23 +0.25 ± 0.15 MeV. Using 0.8 pb-1 of data collected at the ψ' peak, we have also determined that Γ ee B ττ(ψ') = 9.0 ± 2.6 eV. © Nauka/Interperiodica 2007.