arXiv subjects
Publications and source records attributed to D. I. Ganyushin.
The $e^+e^-\toηγ\to 7γ$ process was studied in the energy range $2E=600÷1060$ MeV with an SND detector on a VEPP-2M $e^+e^-$ collider. The decay branching ratios $B(ϕ\toηγ)=(1.343\pm 0.012\pm 0.055)\cdot 10^{-2}$, $B(ω\toηγ)=(4.60\pm 0.72\pm 0.19)\cdot 10^{-4}$, and $B(ρ\toηγ)=(2.69\pm 0.32\pm 0.16)\cdot 10^{-4}$ were measured.
The $η\to π^0 γγ$ decay was investigated by the SND detector at VEPP-2M $e^+e^-$ collider in the reaction $e^+e^-\toϕ\to ηγ$. Here we present the results and some details of this study. We report an upper limit (90% c.l.) $Br(η\to π^0 γγ)<8.4\times 10^{-4}$ 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.
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.