Measurement of the $e^+e^- \to\pi^+\pi^- $ process cross section with the SND detector at the VEPP-2000 collider in the energy region $0.525<\sqrt{s}<0.883$ GeV

The SND collaboration Achasov, M.N. ; Baykov, A.A. ; Barnyakov, A.Yu. ; et al.
JHEP 01 (2021) 113, 2021.
Inspire Record 1789269 DOI 10.17182/hepdata.114983

The cross section of the process $e^+ e^-\to\pi^+\pi^-$ has been measured in the Spherical Neutral Detector (SND) experiment at the VEPP-2000 $e^+e^-$ collider VEPP-2000 in the energy region $525 <\sqrt[]{s} <883$ MeV. The measurement is based on data with an integrated luminosity of about 4.6 pb$^{-1}$. The systematic uncertainty of the cross section determination is 0.8 % at $\sqrt{s}>0.600$ GeV. The $\rho$ meson parameters are obtained as $m_\rho = 775.3\pm 0.5\pm 0.6$ MeV, $\Gamma_\rho = 145.6\pm 0.6\pm 0.8$ MeV, $B_{\rho\to e^+ e^-}\times B_{\rho\to\pi^+\pi^-} = (4.89\pm 0.02\pm 0.04)\times 10^{-5}$, and the parameters of the $e^+ e^-\to\omega\to\pi^+\pi^-$ process, suppressed by $G$-parity, as $B_{\omega\to e^+ e^-}\times B_{\omega\to\pi^+\pi^-}= (1.32\pm 0.06\pm 0.02)\times 10^{-6} $ and $\phi_{\rho\omega} = 110.7\pm 1.5\pm1.0$ degrees.

3 data tables

The Born cross section of the process e+e- -> pi+pi- taking into account the radiative corrections due to the initial and final state radiation.

Measured value of the pion form factor

The bare e+e- -> pi+pi- undressed cross without vacuum polarization, but with the final state radiative correction.


THE PHI ---> PI+ PI- DECAY. (IN RUSSIAN)

Golubev, V.B. ; Druzhinin, V.P. ; Ivanchenko, V.N. ; et al.
Yad.Fiz. 44 (1986) 633-636, 1986.
Inspire Record 239292 DOI 10.17182/hepdata.47188

None

1 data table

Summary of experiments with the neutral detector at the e+ e- storage ring VEPP-2M

Dolinsky, S.I. ; Druzhinin, V.P. ; Dubrovin, M.S. ; et al.
Phys.Rept. 202 (1991) 99-170, 1991.
Inspire Record 321108 DOI 10.17182/hepdata.19310

The complete results of the experiments carried out with the Neutral Detector at the e + e − storage ring VEPP-2M in the energy range 2 E =0.5–1.4 GeV are reviewed. The data sample corresponds to a total integrated luminosity of 19 pb −1 .

17 data tables

ND results from Dolinsky et al., PL B174 (1986) 453.. Statistical errors only are shown. There is an additional systematic errorof 8%.

New ND data.. Statistical errors only are shown. There is an additional systematic errorof 8%.

Averaged ND data.. Statistical errors only are shown. There is an additional systematic errorof 8%.

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