Phys. Rev. D 109, 112002 (2024) The cross section of the process $e^+e^-\to\pi^+\pi^-$ has been measured in
the center of mass energy range from 0.32 to 1.2 GeV with the CMD-3 detector at
the ...electron-positron collider VEPP-2000. The measurement is based on a full
dataset collected below 1 GeV during three data taking seasons, corresponding
to an integrated luminosity of about 62 pb$^{-1}$. In the dominant
$\rho$-resonance region, a systematic uncertainty of 0.7% has been reached. At
energies around $\phi$-resonance the $\pi^+\pi^-$ production cross section was
measured for the first time with high beam energy resolution. The
forward-backward charge asymmetry in the $\pi^+\pi^-$ production has also been
measured. It shows a strong deviation from the theoretical prediction based on
the conventional scalar quantum electrodynamics framework, and it is in good
agreement with the generalized vector-meson-dominance and dispersive-based
predictions. The impact of the presented results on the evaluation of the
hadronic contribution to the anomalous magnetic moment of muon is discussed.
Preliminary results of the SND experiment at the VEPP-2000 e+e− collider are presented. Data corresponding to about 40 pb−1 of integrated luminosity were collected in the e+e− c.m. energy range from ...1.05 to 2.00 GeV. The cross sections for e+e− → ωπ0, π+π−4π0, ${\rm{p\bar p}}$, ${\rm{n\bar n}}$ have been measured.
The ϕ → π
+
π
−
γγ and ϕ → π
+
π
−
η decays are sought in the experimental data obtained with the CMD-2 detector in the region of the ϕ-meson resonance. Upper limits ℛ(ϕ → ππγγ)< 1.2 × 10
−4
and ℛ(ϕ ...→ ππη) < 6.1 × 10
−5
(both at a C.L. of 90%) are determined for the branching ratios of these decays.
Study of Φ → π+π-π0 with CMD-2 detector AKHMETSHIN, R. R; AULCHENKO, V. M; FEDOTOVICH, G. V ...
Physics letters. B,
2006, Letnik:
642, Številka:
3
Journal Article
We present a measurement of the e{sup +}e{sup -} {sup {yields}} K{sub S}K{sub L} cross section in the energy range {radical}s = 1.04-1.38 GeV. For an energy of {radical}s {>=} 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. The measured cross section agrees well with previous measurements.
Search for the η ′ → e + e − decay with the SND detector Achasov, M. N.; Aulchenko, V. M.; Barnyakov, A. Yu ...
Physical review. D, Particles, fields, gravitation, and cosmology,
05/2015, Letnik:
91, Številka:
9
Journal Article
The cross section of the process \(e^+e^-\to\pi^+\pi^-\) has been measured in the center of mass energy range from 0.32 to 1.2 GeV with the CMD-3 detector at the electron-positron collider VEPP-2000. ...The measurement is based on a full dataset collected below 1 GeV during three data taking seasons, corresponding to an integrated luminosity of about 62 pb\(^{-1}\). In the dominant \(\rho\)-resonance region, a systematic uncertainty of 0.7% has been reached. At energies around \(\phi\)-resonance the \(\pi^+\pi^-\) production cross section was measured for the first time with high beam energy resolution. The forward-backward charge asymmetry in the \(\pi^+\pi^-\) production has also been measured. It shows a strong deviation from the theoretical prediction based on the conventional scalar quantum electrodynamics framework, and it is in good agreement with the generalized vector-meson-dominance and dispersive-based predictions. The impact of the presented results on the evaluation of the hadronic contribution to the anomalous magnetic moment of muon is discussed.
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