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


Experiments at VEPP-2M with SND detector

The SND collaboration Achasov, M.N. ; Aulchenko, V.M. ; Baru, S.E. ; et al.
BINP-98-65, 1998.
Inspire Record 476386 DOI 10.17182/hepdata.50374

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.

4 data tables match query

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Measurement of the $K_L$ nuclear interaction length in the NaI(Tl) calorimeter

Achasov, M.N. ; Beloborodov, K.I. ; Berdyugin, A.V. ; et al.
JINST 10 (2015) P09006, 2015.
Inspire Record 1392011 DOI 10.17182/hepdata.69471

In the study of the reaction $e^+e^-\to K_{S}K_{L}$ at the VEPP-2M $e^+e^-$ collider with the SND detector the nuclear interaction length of $K_{L}$ meson in NaI(Tl) has been measured. Its value is found to be 30--50 cm in the $K_{L}$ momentum range 0.11--0.48 GeV/$c$. The results are compared with the values used in the simulation programs GEANT4 and UNIMOD.

1 data table match query

The energy interval ($\sqrt{s}$), integrated luminosity ($IL$), number of selected events ($N$), number of background events ($N_{\rm bkg}$), number of events with five or more photons ($N_{5\gamma}$, $N_{5\gamma,{\rm bkg}}$), and the measured $K_L$ nuclear interaction length in NaI(Tl) ($\lambda_{\rm int}$).


Measurement of the $e^+e^- \to \eta\pi^+\pi^-$ cross section in the center-of-mass energy range 1.22--2.00 GeV with the SND detector at the VEPP-2000 collider

The SND collaboration Aulchenko, V.M. ; Achasov, M.N. ; Barnyakov, A.Yu. ; et al.
Phys.Rev.D 91 (2015) 052013, 2015.
Inspire Record 1332929 DOI 10.17182/hepdata.73176

In the experiment with the SND detector at the VEPP-2000 $e^+e^-$ collider the cross section for the process $e^+e^-\to\eta\pi^+\pi^-$ has been measured in the center-of-mass energy range from 1.22 to 2.00 GeV. Obtained results are in agreement with previous measurements and have better accuracy. The energy dependence of the $e^+e^-\to\eta\pi^+\pi^-$ cross section has been fitted with the vector-meson dominance model. From this fit the product of the branching fractions $B(\rho(1450)\to\eta\pi^+\pi^-)B(\rho(1450)\to e^+e^-)$ has been extracted and compared with the same products for $\rho(1450)\to\omega\pi^0$ and $\rho(1450)\to\pi^+\pi^-$ decays. The obtained cross section data have been also used to test the conservation of vector current hypothesis.

1 data table match query

The c.m. energy ($\sqrt{s}$), integrated luminosity ($L$), detection efficiency ($\varepsilon$), number of selected signal events ($N$), radiative-correction factor ($1 + \delta$), measured $e^+e^- \to \eta \pi^+\pi^-$ Born cross section ($\sigma_B$). For the number of events and cross section the statistical error is quoted. The systematic uncertainty on the cross section is 8.3% at $\sqrt{s}<1.45$ GeV, 5.0% at $1.45<\sqrt{s}<1.60$ GeV, and 7.8% at $\sqrt{s}>1.60$ GeV.


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.


Precise pion electroproduction in the p (e, e-prime pi+) n reaction at W = 1125-MeV

Blomqvist, K.I. ; Boeglin, W.U. ; Böhm, R. ; et al.
Z.Phys.A 353 (1996) 415-421, 1996.
Inspire Record 428951 DOI 10.17182/hepdata.16502

The reactione+p →> e+π++n at c.m. energyW=1125MeV and momentum transfer Q2=0.117GeV2/c2 has been measured. The transverse and longitudinal structure functions have been separated by varying the polarization of the virtual photon (Rosenbluth plot) with a 3 to 4% error. In addition the longitudinal-transverse interference term has been determined measuring the right-left asymmetry with an accuracy of 3%. The experimental data are compared to model calculations, and the sensitivity of the results to the axial and pion formfactors is discussed.

2 data tables match query

Angle PHI(P=4) is the angle between the scattering plane (defined by 1 and 3 particles) and the reaction plane (defined by 4 and 5 particles).

Angle PHI(P=4) is the angle between the scattering plane (defined by 1 and 3 particles) and the reaction plane (defined by 4 and 5 particles).


Study of dynamics of the process $e^+e^-\to \pi^+\pi^-\pi^0$ in the energy range 1.15--2.00 GeV

The SND collaboration Achasov, M.N. ; Barnyakov, A.Yu. ; Baykov, A.A. ; et al.
Eur.Phys.J.C 80 (2020) 993, 2020.
Inspire Record 1809286 DOI 10.17182/hepdata.151394

The dynamics of the process $ e^+e^- \to \pi^+\pi^-\pi^0 $ is studied in the energy region from 1.15 to 2.00 GeV using data accumulated with the SND detector at the VEPP-2000 $e^+e^-$ collider. The Dalitz plot distribution and $\pi^+\pi^-$ mass spectrum are analyzed in a model including the intermediate states $\rho(770)\pi$, $\rho(1450)\pi$, and $\omega\pi^0$. As a result, the energy dependences of the $\rho(770)\pi$ and $\rho(1450)\pi$ cross sections and the relative phases between the $\rho(770)\pi$ amplitude and the $\rho(1450)\pi $ and $\omega\pi^0$ amplitudes are obtained. The $\rho(1450)\pi$ cross section has a peak in the energy region of the $\omega(1650)$ resonance (1.55-1.75 GeV). In this energy range the contributions of the $\rho(770)\pi$ and $\rho(1450)\pi$ states are of the same order of magnitude. No resonance structure near 1.65 GeV is observed in the $\rho(770)\pi$ cross section. We conclude that the intermediate state $\rho(1450)\pi$ gives a significant contribution to the decay of $\omega (1650)\to\pi^+\pi^-\pi^0$, whereas the $\rho(770)\pi$ mechanism dominates in the decay $\omega(1420)\to\pi^+\pi^-\pi^0$.

3 data tables match query

The Born cross section of the process e+e- -> pi+pi-pi0, scan 2012.

The Born cross section of the process e+e- -> pi+pi-pi0, scan 2011.

The cross section of intermediate states rho pi0, rho' pi0, omega pi0 in the process e+e- -> pi+pi-pi0 extracted by the Dalitz plot analysis.


Study of e+e- --> omega pi0 --> pi0 pi0 gamma in the energy range 1.05--2.00 GeV with SND

Achasov, M.N. ; Aulchenko, V.M. ; Barnyakov, A.Yu. ; et al.
Phys.Rev.D 88 (2013) 054013, 2013.
Inspire Record 1224801 DOI 10.17182/hepdata.62287

The cross section for the process e+e- --> omega pi0 --> pi0 pi0 gamma has been measured in the energy range 1.05--2.00 GeV. The experiment has been performed at the e+e- collider VEPP-2000 with the SND detector. The measured e+e- --> omega pi0 cross section above 1.4 GeV is the most accurate to date. Below 1.4 GeV our data are in good agreement with the previous SND and CMD-2 measurements. Data on the e+e- --> omega pi0 cross section are well described by the VMD model with two excited rho-like states. From the measured cross section we have extracted the gamma^* --> omega pi0 transition form factor. It has been found that the VDM model cannot describe simultaneously our data and data obtained from the omega --> pi0 mu+ mu- decay. We have also tested CVC hypothesis comparing our results on the e+e- --> omega pi0 cross section with data on the tau- --> omega pi- nu_{tau} decay.

1 data table match query

The c.m. energy(E) and measured Born cross section(SIG). For the cross section, the first error is statistical, the second is systematic.


Study of the e$^{+}$ e$^{–}$ → π$^{+}$π$^{–}$π$^{0}$ process in the energy range 1.05–2.00 GeV

Aul'chenko, V.M. ; Achasov, M.N. ; Barnyakov, A.Yu. ; et al.
J.Exp.Theor.Phys. 121 (2015) 27-34, 2015.
Inspire Record 1389908 DOI 10.17182/hepdata.151395

The cross section for the e$^{+}$ e$^{–}$ → π$^{+}$π$^{–}$π$^{0}$ process in the energy range 1.05–2.00 GeV has been measured using the data collected in the experiment with the Spherical Neutral Detector (SND) at the VEPP-2000 e$^{+}$ e$^{–}$ collider. The obtained results on the cross section are in good agreement with previous measurements by the SND at the VEPP-2M collider and BABAR, but have a better accuracy.

1 data table match query

The Born cross section of the process e+e- -> pi+pi-pi0.


Study of the e+ e- --> eta gamma process with SND detector at the VEPP-2M e+ e- collider.

Achasov, M.N. ; Aulchenko, V.M. ; Beloborodov, K.I. ; et al.
Phys.Rev.D 74 (2006) 014016, 2006.
Inspire Record 717778 DOI 10.17182/hepdata.41804

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.

1 data table match query

Cross section from the ETA --> 3PI0 decay mode.