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

Achasov, M.N. ; Aulchenko, V.M. ; Beloborodov, K.I. ; et al.
Phys.Rev.D 79 (2009) 112012, 2009.
Inspire Record 798415 DOI 10.17182/hepdata.50493

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.

2 data tables match query

The E+ E- --> MU+ MU- cross section obtained using the (GAMMA GAMMA) luminosity measurement.

The measured E+ E- --> E+ E- cross section in the electron angle 30 to 150 degrees.


Measurement of the e+e- -> K+K- process cross-section in the energy range s**(1/2) = 1.04 - 1.38 GeV with the SND detector in the experiment at VEPP-2M e+e- collider

Achasov, M.N. ; Beloborodov, K.I. ; Berdyugin, A.V. ; et al.
Phys.Rev.D 76 (2007) 072012, 2007.
Inspire Record 755881 DOI 10.17182/hepdata.51605

The cross section for 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 VEPP-2M $e^+e^-$ collider. The measured cross section is described by the Vector Meson Dominance model 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 %.

1 data table match query

The measured cross section and charged kaon form factor.


a(1)(1260) pi dominance in the process e+ e- ---> 4 pi at energies 1.05-GeV - 1.38-GeV

The CMD-2 collaboration Akhmetshin, R.R. ; Anashkin, E.V. ; Arpagaus, M. ; et al.
Phys.Lett.B 466 (1999) 392-402, 1999.
Inspire Record 483994 DOI 10.17182/hepdata.50145

First results of the study of the process e+e- \to 4\pi by 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 \pi^+\pi^- 2\pi^0 and e+e- \to 2\pi^+ 2\pi^- has been measured. Analysis of the differential distributions demonstrates the dominance of the a_1\pi and \omega\pi intermediate states. Upper limits for the contributions of other alternative mechanisms are also placed.

3 data tables match query

Energy dependence of the cross section for the 2PI+ 2PI- final state. Statistical errors only.

Energy dependence of the cross section for the PI+ PI- 2PI0 final state. Statistical errors only.

Energy dependence of the cross section for the OMEGA PI0 final state. Statistical errors only.


Study of the process e+ e- ---> eta gamma in center-of-mass energy range 600-MeV to 1380-MeV at CMD-2

The CMD-2 collaboration Akhmetshin, R.R. ; Anashkin, E.V. ; Aulchenko, V.M. ; et al.
Phys.Lett.B 509 (2001) 217-226, 2001.
Inspire Record 554522 DOI 10.17182/hepdata.27025

The cross section of the process e+ e- ---> eta gamma has been measured in the 600-1380 MeV c.m. energy range with the CMD-2 detector. The following branching ratios have been determined: B(rho ---> eta gamma) = (3.28 +- 0.37 +- 0.23) 10^{-4}, B(omega ---> eta gamma) = (5.10 +- 0.72 +- 0.34) 10^{-4}, B(phi --> eta gamma) = (1.287 +- 0.013 +- 0.063) 10^{-2}. Evidence for the rho'(1450) ---> eta gamma decay has been obtained for the first time.

1 data table match query

The measured Born cross section for the ETA GAMMA final state.


Form factor ...

Barkov, L.M. ; Blinov, G.A. ; Vasserman, I.B. ; et al.
1982.
Inspire Record 1501544 DOI 10.17182/hepdata.76464
1 data table match query

Axis error includes +- 7/7 contribution (/LUMINOCITY, RADIATIVE CORRECTIONS, NUCLEAR ABSORPTION AND DECAY IN FLIGHT).


Experimental study of the reaction e+ d- ---> K(S)K(L) in the energy range s**(1/2) = 1.04-GeV divided by 1.38-GeV

Achasov, M.N. ; Beloborodov, K.I. ; Berdyugin, A.V. ; et al.
J.Exp.Theor.Phys. 103 (2006) 720-727, 2006.
Inspire Record 720035 DOI 10.17182/hepdata.41792

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.

1 data table match query

The Born cross section for the process E+ E- --> KS KL.


Measurement of the pion form-factor in the range 1.04-GeV to 1.38-GeV with the CMD-2 detector

The CMD-2 collaboration Aul'chenko, V.M. ; Akhmetshin, R.R. ; Banzarov, V.Sh. ; et al.
JETP Lett. 82 (2005) 743-747, 2005.
Inspire Record 712216 DOI 10.17182/hepdata.41807

The cross section for the process $e^+e^-\to\pi^+\pi^-$ is measured in the c.m. energy range 1.04-1.38 GeV from 995 000 selected collinear events including 860000 $e^+e^-$ events, 82000 $\mu^+\mu^-$ events, and 33000 $\pi^+\pi^-$ events. The systematic and statistical errors of measuring the pion form factor are equal to 1.2-4.2 and 5-13%, respectively.

1 data table match query

Measured value of the pion form factor with statistical errors only.


Study of the process e+ e- ---> omega pi0 ---> pi0 pi0 gamma in c.m. energy range 920-MeV - 1380-MeV at CMD-2

The CMD-2 collaboration Akhmetshin, R.R. ; Aulchenko, V.M. ; Banzarov, V.Sh. ; et al.
Phys.Lett.B 562 (2003) 173-181, 2003.
Inspire Record 616446 DOI 10.17182/hepdata.41951

The cross section of the process e+ e- --> omega pi0 --> pi0 pi0 gamma has been measured in the c.m. energy range 920-1380 MeV with the CMD-2 detector. Its energy dependence is well described by the interference of the rho(770) and rho'(1450) mesons decaying to omega pi0. Upper limits for the cross sections of the direct processes e+ e- --> pi0 pi0 gamma, eta pi0 gamma have been set.

1 data table match query

Measurement of the Born cross section and the 'Bare' cross section of the process E+ E- --> OMEGA < PI0 GAMMA > PI0.


Study of the process e+ e- ---> K0(L) K0(S) in the CM energy range 1.05-GeV to 1.38-GeV with CMD-2

Akhmetshin, R.R. ; Aulchenko, V.M. ; Banzarov, V.Sh. ; et al.
Phys.Lett.B 551 (2003) 27-34, 2003.
Inspire Record 601222 DOI 10.17182/hepdata.41971

The process $e^+e^- \to K^0_L K^0_S$ has been studied with the CMD-2 detector using about 950 events detected in the center-of-mass energy range from 1.05 to 1.38 GeV. The cross section exceeds the expectation based on the contributions of the rho(770), omega(782) and phi(1020) mesons only.

1 data table match query

Measured cross section and 'bare' cross section for the process E+ E- --> KL KS.


Study of the process e+ e- ---> pi+ pi- pi+ pi- pi0 with CMD-2 detector

The CMD-2 collaboration Akhmetshin, R.R. ; Anashkin, E.V. ; Aulchenko, V.M. ; et al.
Phys.Lett.B 489 (2000) 125-130, 2000.
Inspire Record 532970 DOI 10.17182/hepdata.28019

The process e+e- to pi+ pi- pi+ pi- pi0 has been studied in the center of mass energy range 1280 -- 1380 MeV using 3.0 1/pb of data collected with the CMD-2 detector in Novosibirsk. Analysis shows that the cross section of the five pion production is dominated by the contributions of the eta pi+pi- and omega pi+pi- intermediate states.

3 data tables match query

Axis error includes +- 15/15 contribution.

Axis error includes +- 15/15 contribution.

Axis error includes +- 15/15 contribution.