The intensities, widths, and shifts of the centres of the emission lines of a laser plasma generated on the surfaces of solid targets were determined experimentally as a function of the ambient gas ...pressure. The Stark broadening and the Stark shift of the emission lines were used to estimate the electron temperature and the electron density at various gas pressures. (interaction of laser radiation with matter)
A new experiment is suggested in order to investigate the positron yield at the exit of crystal tungsten targets of different thicknesses submitted to 10 GeV electron beam at one of the SPS CERN ...transfer lines. The Set-up consists of the beam control counters, targets mounted on the goniometer, positron detector and photon detector. The positron detector is based mainly on a drift chamber inserted between the poles of the magnet. It allows to reconstruct the track of the charged particles, to define the vertex coordinates and initial angle of the particles at the exit of the target, to measure the total and transverse momenta. A Monte Carlo simulation corresponding to the theoretical description of chanelling radiation and also numerical calculation were provided for the estimations of the expected distributions and detector response. The optimization of the Set-up is considered, as well as the status of the project in general.
The process e+e- - > 0 in the energy range = 0.60 - 1.06 GeV was studied at VEPP-2M collider with SND detector using ~ 14 pb-1 of integrated luminosity. Data were analyzed in the framework of the ...vector meson dominance model. Preliminary results on obtained cross-section and parameters of 0, , - > 0 radiative decays are presented.
The review of the SND results of the e+e- - > +-0 process study in the energy range = 0.42 - 1.38 GeV at VEPP-2M collider, based on about 2 X 106 selected events, is presented. The total cross ...section, parameters of the , , , resonances, and , states were obtained. It was found that and 0 intermediate states describe the reaction dynamics. The experimental data cannot be described by a sum of only , , and resonances contributions. This can be interpreted as a manifestation of the - > 3 decay, suppressed by G-parity, with relative probability B( - > 3) = (1.01 +/-0.360.54{expression}+/-0.034) X 10-4.
The search for lepton-flavor-violation process e^+e^-\to e\mu in the energy region \sqrt{s}=984 - 1060 MeV with SND detector at VEPP-2M e^+e^- collider is reported. The model independent 90% CL upper ...limits on the e^+e^-\to e\mu cross section, \sigma_{e\mu} < 11 pb, as well as on the corresponding \phi\to e\mu branching fraction, B(\phi\to e\mu) < 2 \times 10^{-6}, for the final particles polar angles 55^\circ<\theta<125^\circ, were obtained.
The process
e
+
e
−→
π
+
π
− has been studied with the SND detector at VEPP-2M
e
+
e
− collider in the vicinity of
φ(1020) resonance. From the analysis of the energy dependence of measured cross ...section the branching ratio
B(
φ→
π
+
π
−)=(7.1±1.1±0.9)·10
−5 and the phase
ψ
π
=−(34±4±3)° of interference with the non-resonant
π
+
π
− production amplitude were obtained.
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