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CMD2 Collaboration

Publications and source records attributed to CMD2 Collaboration.

5 recordsLinked to original sources
arXiv2004

Study of the Processes e+ e- --> eta gamma, e+ e- --> pi0 gamma --> 3 gamma in the c.m. Energy Range 600--1380 MeV at CMD-2

The processes e+ e- --> eta gamma, e+ e- --> pi0 gamma --> 3 gamma have been studied in the c.m. energy range 600--1380 MeV with the CMD-2 detector. The following branching ratios have been determined: Br(rho --> eta gamma) = (3.21 +- 1.39 +- 0.20)x 10^{-4}; Br(omega --> eta gamma) = (4.44 + 2.29 -1.83 +- 0.28)x 10^{-4}; Br(phi --> eta gamma) = (1.373 +- 0.014 +- 0.085)x 10^{-2}; Br(rho --> pi0 gamma) = (6.21 +1.28 - 1.18 +- 0.39)x 10^{-4}; Br(omega --> pi0 gamma) = (9.06 +- 0.20 +- 0.57)x 10^{-2}; Br(phi --> pi0 gamma) = (1.258 +- 0.037 +- 0.077)x 10^{-3};

hep-ex↗
arXiv2003

Study of the Process e+ e- --> pi0 pi0 gamma in c.m. Energy Range 600--970 MeV at CMD-2

The cross section of the process e+ e- --> pi0 pi0 gamma has been measured in the c.m. energy range 600--970 MeV with the CMD-2 detector. The following branching ratios have been determined: B(rho --> pi0 pi0 gamma) =(5.2^{+1.5}_{-1.3} +- 0.6)x10^{-5} and B(omega --> pi0 pi0 gamma) =(6.4^{+2.4}_{-2.0} +- 0.8)x10^{-5}. Evidence for the rho --> f0(600) gamma decay has been obtained: B(rho --> f0(600) gamma) = (6.0^{+3.3}_{-2.7}\pm 0.9)x10^{-5}. From a search for the process e+ e- --> eta pi0 gamma the following upper limit has been obtained: B(omega --> eta pi0 gamma) < 3.3 10^{-5} at 90% CL.

hep-ex↗
arXiv1999

Observation of $K_S^0$ semileptonic decays with CMD-2 detector

The decay $K_S^0 \to πe ν$ has been observed by the CMD-2 detector at the e^+e^- collider VEPP-2M at Novosibirsk. Of 6 million produced $K_L^0K_S^0$ pairs, $75 \pm 13$ events of the $K_S^0 \to πe ν$ decay were selected. The corresponding branching ratio is $B(K_S^0 \to πe ν)=(7.2 \pm 1.4)\times10^{-4}$. This result is consistent with the evaluation of $B(K_S^0 \to πe ν)$ from the $K_L^0$ semileptonic rate and $K_S^0$ lifetime assuming $ΔS=ΔQ$ .

hep-ex↗
arXiv1999

a_1(1260) dominance in the process e+e- \to 4πat energies 1.05--1.38 GeV

First results of the study of the process e+e- \to 4πby the CMD-2 collaboration at VEPP-2M are presented for the energy range 1.05--1.38 GeV. Using an integrated luminosity of 5.8 pb^{-1}, energy dependence of the processes e+e- \to π^+π^- 2π^0 and e+e- \to 2π^+ 2π^- has been measured. Analysis of the differential distributions demonstrates the dominance of the a_1πand ωπintermediate states. Upper limits for the contributions of other alternative mechanisms are also placed.

hep-ex↗