arXiv subjects

A. A. Baykov

Publications and source records attributed to A. A. Baykov.

4 recordsLinked to original sources

arXiv2020

Measurement of the $e^+e^- \to K^+ K^- π^0$ cross section with the SND detector

The process $e^+e^-\to K^+K^-π^0$ is studied with the SND detector at the VEPP-2000 $e^+e^-$ collider. Basing on data with an integrated luminosity of 26.4~pb$^{-1}$ we measure the $e^+e^-\to K^+K^-π^0$ cross section in the center-of-mass energy range from 1.28 up to 2 GeV. The measured mass spectrum of the $Kπ$ system indicates that the dominant mechanism of this reaction is the transition through the $K^{\ast}(892)K$ intermediate state. The cross section for the $ϕπ^0$ intermediate state is measured separately. The SND results are consistent with previous measurements in the BABAR experiment and have comparable accuracy. We study the effect of the interference between the $ϕπ^0$ and $K^\ast K$ amplitudes. It is found that the interference gives sizable contribution to the measured $e^+e^- \to ϕπ^0\to K^+K^-π^0$ cross section below 1.7 GeV.

hep-ex↗

arXiv2020

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

The cross section of the process $e^+ e^-\toπ^+π^-$ 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 $ρ$ meson parameters are obtained as $m_ρ= 775.3\pm 0.5\pm 0.6$ MeV, $Γ_ρ= 145.6\pm 0.6\pm 0.8$ MeV, $B_{ρ\to e^+ e^-}\times B_{ρ\toπ^+π^-} = (4.89\pm 0.02\pm 0.04)\times 10^{-5}$, and the parameters of the $e^+ e^-\toω\toπ^+π^-$ process, suppressed by $G$-parity, as $B_{ω\to e^+ e^-}\times B_{ω\toπ^+π^-}= (1.32\pm 0.06\pm 0.02)\times 10^{-6} $ and $ϕ_{ρω} = 110.7\pm 1.5\pm1.0$ degrees.

hep-ex↗

arXiv2020

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

The dynamics of the process $ e^+e^- \to π^+π^-π^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 $π^+π^-$ mass spectrum are analyzed in a model including the intermediate states $ρ(770)π$, $ρ(1450)π$, and $ωπ^0$. As a result, the energy dependences of the $ρ(770)π$ and $ρ(1450)π$ cross sections and the relative phases between the $ρ(770)π$ amplitude and the $ρ(1450)π$ and $ωπ^0$ amplitudes are obtained. The $ρ(1450)π$ cross section has a peak in the energy region of the $ω(1650)$ resonance (1.55-1.75 GeV). In this energy range the contributions of the $ρ(770)π$ and $ρ(1450)π$ states are of the same order of magnitude. No resonance structure near 1.65 GeV is observed in the $ρ(770)π$ cross section. We conclude that the intermediate state $ρ(1450)π$ gives a significant contribution to the decay of $ω(1650)\toπ^+π^-π^0$, whereas the $ρ(770)π$ mechanism dominates in the decay $ω(1420)\toπ^+π^-π^0$.

hep-ex↗

arXiv2020

Study of the process $e^+e^- \to ηπ^0γ$ in the energy range $\sqrt{s} = \mbox{1.05-2.00}$ GeV with the SND detector

The process $e^+e^-\toηπ^0γ$ is studied in the center-of-mass energy range 1.05-2.00 GeV using data with an integrated luminosity of 94.5 pb$^{-1}$ collected by the SND detector at the VEPP-2000 $e^+e^-$ collider. The $e^+e^-\toηπ^0γ$ cross section is measured for the first time. It is shown that the dominant mechanism of this reaction is the transition through the $ωη$ intermediate state. The measured cross section of the subprocess $e^+e^-\toωη\toηπ^0γ$ is consistent with previous measurements in the $e^+e^-\toπ^+π^-π^0η$ mode. It is found, with a significance of 5.6$σ$, that the process $e^+e^-\toηπ^0γ$ is not completely described by hadronic vector-pseudoscalar intermediate states. The cross section of this missing contribution, which can originate from radiation processes, e. g. $e^+e^-\to a_{0}(1450)γ$, is measured. It is found to be 15-20 pb in the wide energy range from 1.3 to 1.9 GeV.

hep-ex↗