Experiments with the KEDR Detector at the Collider VEPP-4M e +e - in the Energy Range √s=1.84-3.88 GeV

The review presents the experiments performed with the KEDR detector at the e(+) e(-) collider VEPP-4M in the energy range of root s= 1.84-3.88 GeV. The cross section of e(+) e(-) annihilation to hadrons was measured at 22 points of this range and the search for narrow resonances was conducted below 3.1 GeV. The masses of j/psi and psi(2s) mesons were measured with a record accuracy better than 3 x 10(-6); their partial and total widths were determined. Measurements of the tau lepton mass and masses of charged and neutral mesons were performed with high precision. The measurements of the psi(3770) parameters are discussed, and attention is drawn to some inconsistency of the procedure employed by the Particle Data Group for determining its parameters.

Automated summary

This article presents the experiments conducted with the KEDR detector at the e(+) e(-) collider VEPP-4M in the energy range of root s= 1.84-3.88 GeV. The cross section of e(+) e(-) annihilation to hadrons was measured at 22 points in this range, and narrow resonances were searched for below 3.1 GeV. The masses and widths of j/psi and psi(2s) mesons were measured with exceptional accuracy, and precision measurements were also performed for tau lepton and meson masses. The article also discusses the parameters of psi(3770) and highlights inconsistencies in the procedure used by the Particle Data Group for determining these parameters.