EXPERIMENTS WITH THE MD-1 DETECTOR AT THE E(-) COLLIDER VEPP-4 IN THEENERGY REGION OF UPSILON-MESONS()E()

This paper reviews physical results obtained at the e(+)e(-) collider VEPP-4 with the MD-1 detector. The results of experiments on the gamma meson physics and study of the hadron production in continuum in the energy region 7.2-10.3 GeV as well as the results of study of the two photon reactions are presented. Among results obtained in the upsilon physics: the precise measurement of the gamma(1S), gamma(2S), gamma(3S ) masses and the precise determination of the gamma(1S) and gamma(2S) electronic widths. In the experiments on study of the hadron productio n in continuum the precise measurement of the R was carried out. The p eculiarity of the detector is the magnetic field transverse to the orb it plane which provided the possibility to study two photon reactions with tagging one or both scattered electrons even at zero emission ang le. Among results on the gamma gamma reactions is the measurement of t he two photon total hadronic cross section performed in the double-tag mode. In the QED experiments a new QED effect - the impact parameter cut-off in single bremsstrahlung was discovered.