High precision particle mass measurements using the KEDR detector at the VEPP-4M collider
K.Yu. Todysheva,c aBudker Institute of Nuclear Physics, Siberian Branch of the Russian Academy of Sciences, prosp. akad. Lavrenteva 11, Novosibirsk, 630090, Russian Federation bNovosibirsk State Technical University, pr. K. Marksa 20, Novosibirsk, 630092, Russian Federation cNovosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090, Russian Federation
High precision experiments on the measurement of particle masses are reviewed that have been performed with the KEDR detector at the VEPP-4M accelerator. In these experiments, the resonant depolarization method developed in the G.I. Budker Institute of Nuclear Physics, Siberian Branch of the RAS, in 1975 for measuring the beam energy has been further developed to the point of providing an unprecedented precision of 5× 10−7. Using this method and also measuring energy from Compton backscattering allowed a series of experiments to be carried out which provided the world’s most accurate values for the masses of J/ψ, ψ(2S), ψ(3770), and D± mesons and the τ lepton.