194 research outputs found

    Energy calibration of the NaI(Tl) calorimeter of the SND detector using e+e−→e+e−e^+e^- \to e^+e^- events

    Full text link
    Calibration of the three layer NaI(Tl) spherical calorimeter of the SND detector using electron -- positron scattering events is described. Energy resolution of 55 % (FWHM/2.36) for 500 MeV photons was achieved.Comment: 12 pages, Latex, 8 figures (.EPS

    Energy calibration of the NaI(Tl) calorimeter of the SND detector using cosmic muons

    Get PDF
    The general purpose spherical nonmagnetic detector (SND) is now taking data at VEPP-2M e+e−e^+e^- collider in BINP (Novosibirsk) in the centre of mass energy range of 0.2Ă·1.40.2 \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 5.55.5 % (\sigma) for 500 MeV photons was achieved.Comment: 15 pages, Latex, 11 figures (.EPS

    Search for direct production of a2(1320) and f2(1270) mesons in e+e- annihilation

    Get PDF
    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.

    Squeezing based on nondegenerate frequency doubling internal to a realistic laser

    Get PDF
    We investigate theoretically the quantum fluctuations of the fundamental field in the output of a nondegenerate second harmonic generation process occuring inside a laser cavity. Due to the nondegenerate character of the nonlinear medium, a field orthogonal to the laser field is for some operating conditions indepedent of the fluctuations produced by the laser medium. We show that this fact may lead to perfect squeezing for a certain polarization mode of the fundamental field. The experimental feasibility of the system is also discussed.Comment: 6 pages, 5 figure

    Radiative decays of light vector mesons

    Get PDF
    The new data on ρ,ω,ϕ\rho,\omega,\phi radiative decays into π0Îł,ηγ,ηâ€ČÎł\pi^0\gamma,\eta\gamma,\eta'\gamma from SND experiment at VEPP-2M e+e−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 199

    New experimental data for the decays ϕ→Ό+Ό−\phi\to\mu^+\mu^- and ϕ→π+π−\phi\to\pi^+\pi^- from SND detector

    Full text link
    The processes e+e−→Ό+Ό−e^+e^-\to\mu^+\mu^- and e+e−→π+π−e^+e^-\to\pi^+\pi^- have been studied with SND detector at VEPP-2M e+e−e^+e^- collider in the vicinity of ϕ(1020)\phi(1020) resonance. The branching ratios B(ϕ→Ό+Ό−)=(3.30±0.45±0.32)×10−4B(\phi\to\mu^+\mu^-)=(3.30\pm 0.45\pm 0.32)\times 10^{-4} and B(ϕ→π+π−)=(0.71±0.11±0.09)×10−4B(\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 199

    The process e+e−→π+π−π0e^+e^-\to\pi^+\pi^-\pi^0 in the energy range 2E_0=1.04 - 1.38 GeV

    Get PDF
    In the experiment with the SND detector at VEPP-2M e^+e^- collider the process e+e−→π+π−π0e^+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 Mvis=1220±20M_{vis}=1220\pm 20 MeV and cross section in the maximum σ0≃4\sigma_0\simeq 4 nb. The peak can be interpreted as a ω\omega-like resonance ω(1200)\omega (1200).Comment: 10 pages LATEX and 5 figure

    Experimental Study of rho -> pi0 pi0 gamma and omega -> pi0 pi0 gamma Decays

    Full text link
    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.

    New Data from SND Detector in Novosibirsk

    Get PDF
    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 ϕ\phi, ω\omega and ρ\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 199

    Experimental study of the e+e- -> pi0 gamma process in the energy region sqrt(s)=0.60-0.97 GeV

    Get PDF
    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
    • 

    corecore