Study of the e+e−→ηγe^+e^-\to\eta\gamma process with SND detector at the VEPP-2M e+e−e^+e^- collider

In experiment with the SND detector at VEPP-2M $e^+e^-$ collider the $e^+e^-\to\eta\gamma$ cross section was measured in the energy range $E$=0.60--1.38 GeV with the integrated luminosity of 27.8 pb$^{-1}$. The measured cross section is well described by the vector meson dominance model with contributions from the $\rho(770)$, $\omega(783)$, $\phi(1020)$, $\rho^{\prime}(1465)$ resonances and agrees with results of previous measurements. The decay probabilities \BR(\phi\to\eta\gamma), \BR(\omega\to\eta\gamma) and \BR(\rho\to\eta\gamma) were measured with the accuracies better than or comparable to the world averages.Comment: 13 pages, 6 figures, 5 table

Measurement of hadron cross sections with the SND detector

New results on exclusive hadron production in $e^+e^-$ annihilation obtained in experiments with the SND detector at the VEPP-2M and VEPP-2000 $e^+e^-$ colliders are presented.Comment: 4 pages, 4 figures, presented at the 14th International Workshop on Meson Production, Properties and Interaction (MESON 2016), Cracow, Poland, 2nd - 7th June 201

Study of the process e+e-\to \mu+\mu- in the energy region \sqrt{s}=980, 1040 -- 1380 MeV

The cross section of the process e+e-\to\mu+\mu- was measured in the SND experiment at the VEPP-2M e+e- collider in the energy region \sqrt{s}=980, 1040 -- 1380 MeV. The event numbers of the process e+e-\to\mu+\mu- were normalized to the integrated luminosity measured using e+e-\to e+e- and e+e-\to\gamma\gamma processes. The ratio of the measured cross section to the theoretically predicted value is 1.006\pm 0.007 \pm 0.016 and 1.005 \pm 0.007 \pm 0.018 in the first and second case respectively. Using results of the measurements, the electromagnetic running coupling constant \alpha in the energy region \sqrt{s}=1040 -- 1380 MeV was obtained = 134.1\pm 0.5 \pm 1.2 and this is in agreement with theoretical expectation.Comment: 29 pages, 23 figure

Experimental study of the decay PHI(1020)--->ETA+GAMMA in multi-photon final state

In the SND experiment at VEPP-2M e^+e^- collider the phi(1020) ---> eta+gamma ---> 3pi^0+gamma decay was studied. The branching ratio B(phi--->eta+gamma) = (1.246 +- 0.025 +- 0.057)% was measured.Comment: 4 pages, 1 figure, 1 table, Submitted to JETP Let