NUCLEI, PARTICLES, FIELDS, GRAVITATION, AND ASTROPHYSICS Experiments on the Physics of Charged Particle Beams at the VEPP4M Electron-Positron Collider

The VEPP�4M accelerator facility with a univer sal KEDR detector is designed to conduct exper� iments with colliding electron-positron beams. Highe nergy physics, nuclear physics, and studies using syn� chrotron radiation are the main directions of research with this facility. In addition, experiments on poorly explored issues in the physics of beams in the electron-positron storage ring and methodological studies to prepare an experiment aimed at testing corollaries of the CPT theorem for an electron and a positron are reg� ularly conducted at the VEPP�4 facility. A number of wo rks performed in recent years are described: studies to increase the accuracy of comparing the electron and positron spin precession frequencies by the resonant depolarization method; measurements of the count rate of Touschek electrons as a function of the beam energy in a wide range; comparison of the methods for measuring the beam energy spread; a study of the elec� tron beam dynamics when a nonlinear betatron resonance is crossed.