Search

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 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 <1/\alpha> = 134.1\pm 0.5 \pm 1.2 and this is in agreement with theoretical expectation., Comment: 29 pages, 23 figures

In the experiment with the SND detector at the VEPP-2M $e^+e^-$ collider measuring the $e^+e^-\to \eta\gamma$ cross section in the energy range $0.6<\sqrt{s}<1.38 \mathrm{GeV}$ the reanalysis of data is performed. The goal is to improve the accuracy of the previous results by analysing ambiguities in the approximation of energy dependence of the $e^+e^-\to \eta\gamma$ cross section, which were not taken into account in our previous study. We report new results on the approximation of the $e^+e^-\to \eta\gamma$ cross section based on Vector Dominance Model under new model parameter assumptions., Comment: 3 pages, 4 tables

The cross section of the process $e^+e^- \to K^+K^-$ was measured in the energy range $\sqrt{s}$ = 1.04--1.38 GeV in the SND experiment at the VEPP-2M $e^+e^-$ collider. The measured cross section is described by the model of vector meson dominance with contributions from the light vector mesons $\rho$, $\omega$, $\phi$ and their lowest excitations. The mean statistical accuracy of the measurement is 4.4 %, and the systematic uncertainty is 5.2 %., Comment: 20 pages, 11 figures

We present a measurement of the $e^+e^-\to K_SK_L$ cross section in the energy range $\sqrt{s}=1.04 \div 1.38$ GeV. For the energy $\sqrt{s}\geq 1.2$ GeV the cross section exceeds vector meson dominance model predictions with only $\rho(770)$, $\omega(783)$, and $\phi(1020)$ mesons taken into account. Measured cross section agrees well with previous measurements., Comment: 15 pages, 5 figures

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 tables

The corrected cross section of the e^+e^-\to\pi^+\pi^- process measured in the SND experiment at the VEPP-2M e^+e^- collider is presented. The update is necessary due to a flaw in the e^+e^-\to\pi^+\pi^- and e^+e^-\to\mu^+\mu^- Monte Carlo events generators used previously in data analysis., Comment: 10 pages,7 figures

The update of the e^+e^-\to\pi^+\pi^- process cross section, measured in the energy region \sqrt{s}<1 GeV with SND detector at VEPP-2M collider is presented., Comment: Talk given at Int. Workshop e+e- Collisions from phi to psi, February 27 - March 2, 2006

New results of the e+e- -> pi+pi-, K+K-, K_SK_L, pi0/gamma, eta0/gamma processes cross section measurements are presented. The results are based on the 30 pb^-1 data, accumulated by SND detector at VEPP-2M e+e- collider in the energy range sqrt(s)=0.4-1.4 GeV during 1995-2000 years. The comparison with existing experimental data shows that the measurement accuracy is close to or better than the world average. For the e+e- -> pi+pi- process the accuracy is about 0.01. This is important for calculation of hadronic contribution into the muon anomalous magnetic moment., Comment: 4 pages, 7 figures, contribution to the proceedings of International Europhysics Conference on High Energy physics, 2005, Lisbon, Portugal

The cross section of the process e^+e^-\to \pi^+\pi^- was measured in the SND experiment at the VEPP-2M collider in the energy region 400<\sqrt[]{s}<1000 MeV. This measurement was based on about 12.4 \times 10^6 selected collinear events, which include 7.4\times 10^6 e^+e^-\to e^+e^-, 4.5\times 10^6 e^+e^-\to\pi^+\pi^- and 0.5\times 10^6 e^+e^-\to\mu^+\mu^- selected events. The systematic uncertainty of the cross section determination is 1.3 %. The \rho-meson parameters were determined: m_\rho=774.9\pm 0.4\pm 0.5 MeV, \Gamma_\rho=146.5\pm 0.8\pm 1.5 MeV, \sigma(\rho\to\pi^+\pi^-)=1220\pm 7\pm 16 nb as well as the parameters of the G-parity suppressed decay \omega\to\pi^+\pi^-: \sigma(\omega\to\pi^+\pi^-)=29.9\pm 1.4\pm 1.0 nb and \phi_{\rho\omega} = 113.5\pm 1.3\pm 1.7 degree., Comment: 30 pages REVTEX and 31 figures

The process e^+e^-\to\pi^0\gamma in the energy range \sqrt{s}=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 \rho^0, \omega ,\phi \to \pi^0\gamma radiative decays are presented., Comment: 6 pages, 1 figure, Talk given at the X International Conference on Hadron Spectroskopy, Aschaffenburg, Germany, August 31 - September 6, 2003 Replacement: e-print authors list corrected, contents not modified

The review of the SND results of the $e^+e^-\to\pi^+\pi^-\pi^0$ process study in the energy range $\sqrt[]{s}=0.42$ -- 1.38 GeV at VEPP-2M collider, based on about $2\times 10^6$ selected events, is presented. The total cross section, parameters of the $\rho$, $\omega$, $\phi$ resonances, and $\omega^\prime$, $\omega^{\prime\prime}$ states were obtained. It was found that $\rho\pi$ and $\omega\pi^0$ intermediate states describe the reaction dynamics. The experimental data cannot be described by a sum of only $\omega$, $\phi$, $\omega^\prime$ and $\omega^{\prime\prime}$ resonances contributions. This can be interpreted as a manifestation of the $\rho\to 3\pi$ decay, suppressed by $G$-parity, with relative probability $B(\rho\to 3\pi) = (1.01\pm^{0.54}_{0.36}\pm 0.034) \times 10^{-4}$., Comment: 6 pages and 2 figures. Talk given at the X International Conference on Hadron Spectroskopy, Aschaffenburg, Germany, August 31 - September 6, 2003

The cross section of the process $e^+e^-\to \pi^+\pi^-\pi^0$ was measured in the Spherical Neutral Detector (SND) experiment at the VEPP-2M collider in the energy region $\sqrt[]{s}$ below 980 MeV. This measurement was based on about $1.2 \times 10^6$ selected events. The obtained cross section was analyzed together with the SND and DM2 data in the energy region $\sqrt[]{s}$ up to 2 GeV. The $\omega$-meson parameters: $m_\omega=782.79\pm 0.08\pm 0.09$ MeV, $\Gamma_\omega=8.68\pm 0.04\pm 0.15$ MeV and $\sigma(\omega\to 3\pi)=1615\pm 9\pm 57$ nb were obtained. It was found that the experimental data cannot be described by a sum of only $\omega$, $\phi$, $\omega^\prime$ and $\omega^{\prime\prime}$ resonances contributions. This can be interpreted as a manifestation of $\rho\to 3\pi$ decay, suppressed by $G$-parity, with relative probability $B(\rho\to 3\pi) = (1.01\pm^{0.54}_{0.36}\pm 0.034) \times 10^{-4}$., Comment: 41 pages REVTEX and 34 figures

Results of the study of the e+e-->pi0 gamma process with SND detector at VEPP-2M collider in the c.m.s. energy range sqrt(s)=0.60-0.97 GeV are presented. Using 36513 selected events corresponding to a total integrated luminosity of 3.4 pb^-1 the e+e-->pi0 gamma cross section was measured. The energy dependence of the cross section was analyzed in the framework of the vector meson dominance model. The data are well described by a sum of phi,omega,rho0->pi0 gamma decay contributions with measured decay probabilities: Br(omega->pi0 gamma)=(9.34+-0.15+-0.31)% and Br(rho0->pi0 gamma)=(5.15+-1.16+-0.73)*10^-4 . The rho-omega relative interference phase is phi(rho,omega}=(-10.2+-6.5+-2.5) degree.

The e+e- -> pi0 pi0 gamma process was studied in the SND experiment at VEPP-2M e+e- collider in the energy region 0.60-0.97 GeV. From the analysis of the energy dependence of measured cross section the branching ratios B(omega -> pi0 pi0 gamma)= (6.6 +1.4-0.8(stat) +-0.6(syst))x10^-5 and B(rho -> pi0 pi0 gamma)=(4.1 +1.0-0.9(stat) +-0.3(syst))x10^-5 were obtained., Comment: 16 pages, 7 figures, submitted to Phys. Lett. B

The $e^+e^-\to\eta\gamma\to 7\gamma$ process was studied in the energy range $2E=600\div 1060$ MeV with an SND detector on a VEPP-2M $e^+e^-$ collider. The decay branching ratios $B(\phi\to\eta\gamma)=(1.343\pm 0.012\pm 0.055)\cdot 10^{-2}$, $B(\omega\to\eta\gamma)=(4.60\pm 0.72\pm 0.19)\cdot 10^{-4}$, and $B(\rho\to\eta\gamma)=(2.69\pm 0.32\pm 0.16)\cdot 10^{-4}$ were measured., Comment: 5 pages, 4 figures

The cross section of the process $e^+e^-\to \pi^+\pi^-\pi^0$ was measured in the Spherical Neutral Detector experiment at the VEPP-2M collider in the energy region $\sqrt[]{s} = 980 \div 1380$ MeV. The measured cross section, together with the $e^+e^-\to \pi^+\pi^-\pi^0$ and $\omega\pi^+\pi^-$ cross sections obtained in other experiments, was analyzed in the framework of the generalized vector meson dominance model. It was found that the experimental data can be described by a sum of $\omega$, $\phi$ mesons and two $\omega^\prime$ and $\omega^{\prime\prime}$ resonances contributions, with masses $m_{\omega^\prime}\sim 1490$,$m_{\omega^{\prime\prime}}\sim 1790$ MeV and widths $\Gamma_{\omega^\prime}\sim 1210$, $\Gamma_{\omega^{\prime\prime}}\sim 560$ MeV. The analysis of the $\pi^+\pi^-$ invariant mass spectra in the energy region $\sqrt[]{s}$ from 1100 to 1380 MeV has shown that for their descriptionone should take into account the $e^+e^-\to\omega\pi^0\to\pi^+\pi^-\pi^0$ mechanism also. The phase between the amplitudes corresponding to the $e^+e^-\to\omega\pi$ and $e^+e^-\to\rho\pi$ intermediate states was measured for the first time. The value of the phase is close to zero and depends on energy., Comment: 29 pages REVTEX and 17 figures, accepted for publication in Physical Review D

The review of experimental results obtained with SND detector at VEPP-2M $e^+e^-$ collider in the energy region $\sqrt[]{s}=0.36$ -- 1.38 GeV is given. The presented results include the following items: studies of the light vector mesons radiative decays, OZI-rule and G-parity suppressed $\phi$-meson rare decays, $\phi$-meson parameters measurements, studies of $e^+e^-\to\pi^+\pi^-\pi^0$ process dynamics, $\eta$ and $K_S$ mesons rare decays, $\eta$ and $\phi$ mesons conversion decays, and study of the $e^+e^-$ annihilation into hadrons., Comment: 12 pages and 6 figures. Talk given at the IX International Conference on Hadron Spectroskopy, Protvino, Russia, August 25 - September 1, 2001

The invariant mass spectra of the $\pi^+\pi^-$ and $\pi^\pm\pi^0$ pairs in the process $e^+e^- \to \pi^+\pi^-\pi^0$ were studied in the SND experiment at the VEPP-2M collider in the energy region $\sqrt[]{s} \simeq 1020$ MeV. These studies were based on about $0.5 \times 10^6$ experimental events. The spectra were analyzed in the framework of the vector meson dominance model. It was found that the experimental data can be described with $e^+e^- \to \rho\pi \to \pi^+\pi^-\pi^0$ transition only. Upper limit on the branching ratio of the $\phi(1020)\to\pi^+\pi^-\pi^0$ decay through intermediate states different from $\rho\pi$ was obtained at the 90 % confidence level: $B(\phi\to\pi^+\pi^-\pi^0)<6 \cdot 10^{-4}$. The $\rho$-meson mass and width which follow from the spectra analysis are $m_\rho=775.0\pm 1.3$ MeV, $\Gamma_\rho=150.4 \pm 3.0$ MeV. Neutral and charged $\rho$-mesons mass difference was found to equal $m_{\rho^\pm}-m_{\rho^0}=-1.3\pm2.3$ MeV. In the $\pi^+\pi^-$ mass spectrum the $\rho-\omega$ interference was seen at two standard deviations level., Comment: 22 pages REVTEX and 19 figures

The program of upgrade of the Spherical Neutral Detector for future experiments at a new VEPP-2000 $e^+e^-$ collider is presented. Modernization includes upgrades of electromagnetic calorimeter, tracking system, detector electronics, data acquisition system, and offline software. It is also planned to equip the detector with two new subsystems: particle identification system based on aerogel Cherenkov counters and external electron tagging system for $\gamma\gamma$ physics., Comment: Invited talk at "e+e- Physics at Intermediate Energies Workshop", SLAC, Stanford, California, April 30 - May 2, 2001, (T10) 6 pages, 9 figures

The process e+e-->mu+mu- has been studied by SND detector at VEPP-2M e+e- collider in the phi(1020)-resonance energy region. The measured effective phi meson leptonic branching ratio: B(phi->l+l-)=sqrt{B(phi->e+e-)*B(phi->mu+mu-)}=(2.89+-0.10+-0.06)*10^{-4} agrees well with the PDG value B(phi->e+e-)=(2.91+-0.07)*10^{-4} confirming mu-e universality. Without additional assumption of mu-e universality the branching ratio B(phi->mu+mu-)=(2.87+-0.20+-0.14)*10^{-4} was obtained., Comment: RevTeX, 5 pages, 3 figures. To be published in Phys. Rev. Lett

The $\eta \to \pi^0 \gamma \gamma$ decay was investigated by the SND detector at VEPP-2M $e^+e^-$ collider in the reaction $e^+e^-\to\phi\to \eta\gamma$. Here we present the results and some details of this study. We report an upper limit (90% c.l.) $Br(\eta \to \pi^0 \gamma \gamma)<8.4\times 10^{-4}$ as our final result. Our upper limit does not contradict the earlier measurement by GAMS spectrometer. To facilitate future studies a rather detailed review of the problem is also given., Comment: 24 pages, 6 figures, LaTex. To be published in Nucl. Phys. B

The current status of experiments with SND detector at VEPP-2M $e^+e^-$ collider in the energy range $2E_0=0.4-1.4$ GeV is given. The new results of analysis of $\phi$ decay into $\pi^0\pi^0\gamma$, $\eta\pi^0\gamma$ are based on the full SND statistics corresponding 20 million of $\phi$ decay. New measurement of $\omega\to\pi^0\pi^0\gamma$ decay and a first observation of $\rho\to\pi^0\pi^0\gamma$ are presented. The accuracy of many other rare decays of light vector mesons was improved. In the energy range $2E_0=1.0\div1.4$ GeV the cross sections of the processes $e^+e^-\to\omega\pi^0$ and $e^+e^-\to\pi^+\pi^-\pi^0$ were measured. The results of the fitting of data are discussed., Comment: 13 pages, Talk given at the XXIII International Workshop on the Fundamental Problems of High Energy Physics and Field Theory, Protvino, Russia, June 21-23,2000

A search for direct production of C-even resonances a2(1320) and f2(1270) in e+e- annihilation was performed with SND detector at VEPP-2M e+e- collider. The upper limits of electronic widths of these mesons were obtained at 90% confidence level: Gamma(a2(1320) \to e+e-) < 0.56 eV, Gamma(f2(1270) \to e+e-) < 0.11 eV., Comment: 6 pages, 5 figures, 1 table. Submitted to Phys. Lett. B

The cross sections of the processes $e^+e^- \to K^+K^-$, $e^+e^- \to K_SK_L$ and $e^+e^- \to \pi^+\pi^-\pi^0$ were measured in the SND experiment at the VEPP-2M collider in the energy region near the $\phi(1020)$ meson. These measurements were based on about $10^6$ $K^+K^-$, $0.5 \times 10^6$ $K_SK_L$ and $0.4 \times 10^6$ $\pi^+\pi^-\pi^0$ selected events. Themeasured cross sections have been analyzed in the framework of the vector meson dominance model and the main parameters of the $\phi$-resonance were obtained, such as its mass, width, the production cross section and branching ratios of the main decay modes. The measured value of the $\phi$ meson total width, $\Gamma_{\phi} = 4.21 \pm 0.04$ is lower than the present world average of $4.458 \pm 0.032$ MeV. Contributions in addition to the conventional vector meson dominance model were found in the $e^+e^- \to \pi^+\pi^-\pi^0$ reaction cross section., Comment: 26 pages REVTEX and 15 figures, accepted for publication in Physical Review D

The cross section of the $e^+e^-\to\omega\pi^0\to\pi^0\pi^0\gamma$ reaction was measured by the SND detector at VEPP-2M $e^+e^-$ collider in the energy range from threshold up to 1.4 GeV. Results of the cross section fitting by the sum of $\rho$, $\rho^{\prime}$ and $\rho^{\prime\prime}$ contributions are presented., Comment: 8 pages, 3 figures, 2 tables. Submitted to Phys. Lett. B

In the SND experiment at VEPP-2M $e^+e^-$ collider the $\phi(1020)\to\pi^0\pi^0\gamma$ decay was studied and its branching ratio was measured: $B(\phi\to\pi^0\pi^0\gamma)=(1.221\pm 0.098\pm0.061)\cdot10^{-4}$. It was shown, that $f_0(980)\gamma$ intermediate state dominates in this decay and the $f_0(980)$-meson parameters were obtained., Comment: 15 pages, 5 figure, 4 table, Submitted to Phys. Lett. B

The process e+e- ->pi+pi- has been studied with the SND detector at VEPP-2M e+e- collider in the vicinity of phi(1020) resonance. From the analysis of the energy dependence of measured cross section the branching ratio B(phi->pi+pi-)=(7.1+-1.1+-0.9)*10^{-5} and the phase psi_pi=-(34+-4+-3)degrees of interference with the non-resonant pi+pi- production amplitude were obtained., Comment: 6 pages, 5 figures, to be published in Physics Letters B

The processes $e^+e^-\to\mu^+\mu^-$ and $e^+e^-\to\pi^+\pi^-$ have been studied with SND detector at VEPP-2M $e^+e^-$ collider in the vicinity of $\phi(1020)$ resonance. The branching ratios $B(\phi\to\mu^+\mu^-)=(3.30\pm 0.45\pm 0.32)\times 10^{-4}$ and $B(\phi\to\pi^+\pi^-)=(0.71\pm 0.11\pm 0.09)\times 10^{-4}$ were obtained., Comment: 5 pages, 4 figures, talk given at 8th International Conference on Hadron Spectroscopy (HADRON 99), Beijing, China, 24-28 Aug 1999

The new data on $\rho,\omega,\phi$ radiative decays into $\pi^0\gamma,\eta\gamma,\eta'\gamma$ from SND experiment at VEPP-2M $e^+e^-$ collider are presented., Comment: 5 pages, 2 figures, talk given at 8th International Conference on Hadron Spectroscopy (HADRON 99), Beijing, China, 24-28 Aug 1999

The current status of experiments with SND detector at VEPP-2M e^+e^- collider in the energy range 2E_0=400-1400 MeV and recent results of data analysis for $\phi$, $\omega$ and $\rho$ decays and e^+e^- annihilation into hadrons are presented., Comment: 7 pages, 8 figures, Latex2e, uses espcrc1.sty. Talk given at 8th International Conference on Hadron Spectroscopy (HADRON 99), Beijing, China, 24-28 Aug 1999

In the experiment with the SND detector at VEPP-2M e^+e^- collider the process $e^+e^-\to\pi^+\pi^-\pi^0$ was studied in the energy range 2E_0 from 1.04 to 1.38 GeV. A broad peak was observed with the visible mass $M_{vis}=1220\pm 20$ MeV and cross section in the maximum $\sigma_0\simeq 4$ nb. The peak can be interpreted as a $\omega$-like resonance $\omega (1200)$., Comment: 10 pages LATEX and 5 figures

The Spherical Neutral Detector (SND) operates at VEPP-2M collider in Novosibirsk studying e^+e^- annihilation in the energy range up to 1.4 GeV. Detector consists of a fine granulated spherical scintillation calorimeter with 1632 NaI(Tl) crystals, two cylindrical drift chambers with 10 layers of sense wires, and a muon system made of streamer tubes and plastic scintillation counters. The detector design, performance, data acquisition and processing are described., Comment: 30 pages LATEX and 24 figures

Results of the SND experiment at the VEPP-2M e+ e- collider on the QED processes e+ e- --> e+ e- gamma and e+ e- --> e+ e- gamma gamma with production at large angles are presented. Energy and angular distributions of the final particles were studied. No deviations from QED with an accuracy of 3.8% for the first process and 10.3% for the second were found., Comment: 6 pages, 7 figures, 6 tables; to be published in EPJ-C; one figure replaced

SND (Spherical Neutral Detector) is a general purpose nonmagnetic detector, successfully operating at Novosibirsk VEPP-2M collider during last four years in the center of mass energy range from 400 MeV up to 1400 MeV. Its crucial part is a 3-layer, fine grained, spherical NaI(Tl) electromagnetic calorimeter consisted of 1632 individual counters. Here we present a detailed description of the calorimeter and its performance, including such topics as calorimeter design, electronics, calibration, energy and spatial resolutions, particle identification. The calorimeter performance is illustrated by examples from the current studies of different physical processes., Comment: 23 pages, 20 figures, LaTeX. Contribution to Lisbon CALOR99 conference. To be published in the proceedings

The $e^+e^- \to \omega \pi^0 \to \pi^0 \pi^0 \gamma$ process was investigated in the SND experiment at the VEPP-2M collider. A narrow energy interval near the $\phi$-meson was scanned. The observed cross-section reveals, at the level of three standard deviation, the interference effect caused by $\phi \to \pi^0\pi^0\gamma$ decay. The cross-section parameters, as well as the real and imaginary parts of the $\phi$-meson related amplitude, were measured., Comment: 34 pages, 7 figures, LaTeX, uses FEYNMAN package. Erroneously reported C_{12} coefficient corrected (an error discovered in hep-ph/0603241). in the published version Nucl. Phys. B569(2000), 158 this coefficient is reported incorrectly

The search for CP-violating K_S\to3\pi^0 decay was performed with SND detector at VEPP-2M e^+e^- collider. The total amount of data corresponding to 7 million produced K_S mesons was analyzed. No candidate events were found, giving an upper limit of the decay branching ratio: Br(K_S\to3\pi^0) < 1.4\cdot10^{-5} at 90% confidence level., Comment: 6 pages, 4 figures, to be published in Physics Letters B

The process e^+e^- ->mu^+mu^- has been studied with SND detector at VEPP-2M e^+e^- collider in the vicinity of phi(1020) resonance. The product of branching ratios of phi meson into leptons \sqrt{B(phi->mu^+mu^-) B(phi-> e^+e^-)}=(3.14+-0.22+-0.14)x10^{-4} was measured from the interference in the cross section of the process e^+e^- ->mu^+mu^-. The branching ratio B(phi->mu^+mu^-)=(3.30+-0.45+-0.32)x10^{-4} was obtained., Comment: 6 pages, 5 figures, to be published in Physics Letters B

The reaction e^+e^- ---> OMEGA+PI0 ---> PI+PI- 2PI0 has been studied with SND detector at VEPP-2M e^+e^- collider in the vicinity of the PHI(1020) meson resonance. The observed interference pattern in the energy dependence of the cross section is consistent with existence of the decay PHI ---> OMEGA+PI0 with a branching ratio of B(PHI ---> OMEGA+PI0)=(4.8+1.9-1.7+-0.8)x10^{-5}. The real and imaginary parts of the decay amplitude were measured. The PHI ---> OMEGA+PI0 decay was observed for the first time., Comment: 6 pages, 5 figures, Will be published in Phys.Lett.B

Short overview of experiments with SND detector at VEPP-2M e^+e^- collider in the energy range 2E = 400 - 1400 MeV and preliminary results of data analysis are presented., Comment: 68 pages, 63 figures

Signal of the rare radiative decay PHI--->ETA+PI0+GAMMA was observed in the SND experiment at VEPP-2M electron-positron collider.The result is based on the analysis of data, corresponding to a total integrated luminosity of 4 pb^{-1}, or 8x10^6 PHI mesons produced. The measured branching ratio of PHI--->ETA+PI0+GAMMA decay is equal to (0.83+-0.23)x10^{-4}.

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 Lett

In the SND experiment at the VEPP-2M electron-positron collider the PHI(1020)--->PI0+PI0+GAMMA decay was studied. The branching ratio B(PHI--->PI0+PI0+GAMMA)=(1.14+-0.10+-0.12)x10^{-4} was measured. It was shown, that the F0(980)GAMMA mechanism dominates in this decay and the 4-quark model of F0(980) describes our data most consistently., Comment: 6 pages, 6 figures, 1 table, Will be published in Phys.Lett.B

Calibration of the three layer NaI(Tl) spherical calorimeter of the SND detector using electron -- positron scattering events is described. Energy resolution of $5 % (FWHM/2.36)$ for 500 MeV photons was achieved., Comment: 12 pages, Latex, 8 figures (.EPS)

The general purpose spherical nonmagnetic detector (SND) is now taking data at VEPP-2M $e^+e^-$ collider in BINP (Novosibirsk) in the centre of mass energy range of $0.2 \div 1.4$ GeV. The energy calibration of the NaI(Tl) calorimeter of the SND detector with cosmic muons is described. Using this method, the energy resolution of $5.5 % (\sigma)$ for 500 MeV photons was achieved., Comment: 15 pages, Latex, 11 figures (.EPS)

Results from the Spherical Nonmagnetic Detector (SND) on $\Delta (1232)$ isobar electroproduction in the collisions of beam electrons (positrons) and residual gas nuclei in the VEPP-2M $e^+e^-$ collider are presented. On the basis of the obtained data the expected counting rate of this process in future high luminosity $e^+e^-$ colliders (~$\phi$-, $c$-$\tau$- and $b$-factories) was estimated., Comment: 7 pages LATEX and 3 figures

Upper bound 6*10^{-4} with 90% confidence is reported for the eta -> pi^0 pi^0 decay from the SND experiment at the VEPP-2M collider., Comment: 6 pages, LaTex, 1 figure. To appear in Phys. Lett. B

Preliminary results on the study of e+e- --> phi(1020) --> pi0 pi0 gamma, eta pi0 gamma processes from SND experiment at VEPP-2M collider in Novosibirsk are presented. Branching ratios of rare radiative phi --> pi0 pi0 gamma and phi --> pi0 eta gamma decays are measured: B(phi --> pi0 pi0 gamma ) = (1.1 +- 0.2) * 10^-4 (invariant mass (pi0 pi0) < 800 MeV), B(phi --> eta pi0 gamma ) = (1.3 +- 0.5) * 10^-4., Comment: Talk at the HADRON97 conference, BNL, Aug 24-30 1997; LaTeX, 4 pages, 4 eps figures

The paper describes experiments with the SND detector at VEPP-2M collider, carried out during the period from October 1995 until June 1997. The total integrated luminosity of 6.4 pb^{-1} was collected in the energy range 2E=0.4-1.4 GeV (MHAD97 experiment), corresponding to 4*10^5 mu^+ mu^- pairs produced. Preliminary results of the 1996 phi-meson experiment (FI96) are presented. The total number of phi-mesons produced is 4*10^6. New data on rare decays of phi and eta (550) mesons, in particular B(phi -> eta gamma) = (1.30+-0.06+-0.07)%, B(phi -> pi^0 pi^0 gamma) = (1.1+-0.2)*10^{-4}, (M_{pi^0 pi^0} > 800 MeV), B(phi -> f^0 gamma) = (4.7+-1.0)*10^{-4}, B(phi -> eta pi^0 gamma) = (1.3+-0.5)*10^{-4}, B(phi -> eta' gamma) < 1.7*10^{-4}, B(phi -> 2 pi^0 ) < 6*10^{-4} were obtained., Comment: 49 pages, LaTeX, 31 eps-figures