D.A. Gorbachev

High-statistics measurement of the pion form factor in the ρ-meson energy range with the CMD-2 detector

We present a measurement of the pion form factor based on e+e- annihilation data from the CMD-2 detector in the energy range 0.6<sqrt(s)<1.0 GeV with a systematic uncertainty of 0.8%. A data sample is five times larger than that used in our previous measurement.

Measurement of the e + e - → π+π- cross section with the CMD-2 detector in the 370-520-MeV energy range

The cross section of the process e+e- ->pi+pi- has been measured at the CMD-2 detector in the 370-520 MeV center-of-mass (c.m.) energy range. A systematic uncertainty of the measurement is 0.7 %. Using all CMD-2 data on the pion form factor, the pion electromagnetic radius was calculated. The cross section of muon pair production was also determined.The results of the experiment on the measurement of the e+e− → π+π− cross section in a cm energy range of 370–520 MeV are presented. The systematic measurement error is equal to 0.7%. In the vector dominance model, the pion electromagnetic radius is calculated using all the CMD-2 data on the pion form factor. The cross section for the production of a muon pair is measured in the energy range of the experiment.

Measurement of the Pion Form Factor in the Range 1.04 1.38 GeV with the CMD-2 Detector

The cross section for the process e+e− → π+π− is measured in the c.m. energy range 1.04—1.38 GeV by analyzing 995 000 selected collinear events including 860000 e+e− events, 82000 μ+μ− events, and 33000 π+π− events. The systematic and statistical errors of measuring the pion form factor are equal to 1.2–4.2 and 5–13%, respectively.

Total cross section of the process e+e- → π+π-π+π- in the c.m. energy range 980-1380 MeV

Abstract The e + e − → π + π − π + π − cross section has been measured using 5.8 pb −1 of integrated luminosity collected with the CMD-2 detector at the VEPP-2M collider. Analysis of the data with a refined efficiency determination and use of both three- and four-track events allowed doubling of a data sample and reduction of systematic errors to 5–7%.

Study of the process e+e−→ηγ in c.m. energy range 600–1380 MeV at CMD-2

The cross section of the process e+ e- --> pi0 pi0 gamma has been measured in the c.m. energy range 600--970 MeV with the CMD-2 detector. The following branching ratios have been determined: B(rho --> pi0 pi0 gamma) =(5.2^{+1.5}_{-1.3} +- 0.6)x10^{-5} and B(omega --> pi0 pi0 gamma) =(6.4^{+2.4}_{-2.0} +- 0.8)x10^{-5}. Evidence for the rho --> f0(600) gamma decay has been obtained: B(rho --> f0(600) gamma) = (6.0^{+3.3}_{-2.7}\pm 0.9)x10^{-5}. From a search for the process e+ e- --> eta pi0 gamma the following upper limit has been obtained: B(omega --> eta pi0 gamma) < 3.3 10^{-5} at 90% CL.

The CMD-2 cryogenic magnetic detector

The CMD-2 cryogenic magnetic detector used in a set of experiments on the VEPP-2M electron-positron collider at energies as great as 1.4 GeV is described. The design of the detector subsystems and the algorithms for reconstructing tracks in the drift chamber and the CsI and BGO calorimeters are presented. The spatial and energy resolutions of the detector systems have been determined from analysis of experimental data. The design of the superconducting solenoid and the layout of its powering by means of a superconducting transformer are shown. The trigger system of the detector and the conditions for recording “charged” and “neutral” events on a magnetic tape are described. The procedure used to monitor the parameters of the detector systems during the experiment is presented.

Nonforward color octet BFKL kernel

The kernel of the nonforward BFKL equation is obtained in the case of the antisymmetric color octet state of the two Reggeized gluons in the t-channel. The explicit form of the kernel is presented.

Study of the ρ and ω meson decays into a pseudoscalar meson and e+e- pair with the CMD-2 detector

Using 3.3 pb

Measurement of the cross section for the process e+e− → K L 0 K S 0 in the energy range 2E=1.05–1.38 GeV with the CMD-2 detector at VEPP-2M

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THE PERFORMANCE OF THE DRIFT CHAMBER FOR THE CMD-2 DETECTOR

of data collected with the CMD-2 detector in the 720 -- 840 MeV c.m. energy range, the branching fraction of the conversion decay