A
bstract
The cross section of the process
e
+
e
−
→ ηπ
+
π
−
is measured using the data collected with the CMD-3 detector at the VEPP-2000 collider in the center-of-mass energy range from 1
.
1 to 2
....
0 GeV. The decay mode
η → γγ
is used for
η
meson reconstruction in the data sample corresponding to an integrated luminosity of 78
.
3 pb
−
1
. The energy dependence of the
e
+
e
−
→ ηπ
+
π
−
cross section is fitted within the framework of vector meson dominance in order to extract the Γ(
ρ
(1450)
→ e
+
e
−
)
B
(
ρ
(1450)
→ ηπ
+
π
−
) and the Γ(
ρ
(1700)
→ e
+
e
−
)
B
(
ρ
(1700)
→ ηπ
+
π
−
) products. Based on conservation of vector current, the analyzed data are used to test the relationship between the
e
+
e
−
→ ηπ
+
π
−
cross section and the spectral function in
τ
−
→ ηπ
−
π
0
ντ
decay. The
e
+
e
−
→ ηπ
+
π
−
cross section obtained with the CMD-3 detector is in good agreement with the previous measurements.
We present a measurement of the pion form factor based on e+e− annihilation data from the CMD-2 detector in the energy range 0.6<s<1.0 GeV with a systematic uncertainty of 0.8%. A data sample is five ...times larger than that used in our previous measurement.
The results of the experiment on the measurement of the e+e− → π+π− cross section in a cm energy range of 370–520 MeV are presented. The systematic measurement error is equal to 0.7%. In the vector ...dominance model, the pion electromagnetic radius is calculated using all the CMD-2 data on the pion form factor. The cross section for the production of a muon pair is measured in the energy range of the experiment.
Experimental input from $e^+e^-$ machines to hadronic contribution to muon (g-2) M. N. Achasov, R. R. Akhmetshin, A. N. Amirkhanov, A. V. Anisenkov, V. M. Aulchenko, V. Sh. Banzarov, A. Yu. Barnyakov, N. S. Bashtovoy, K. I. Beloborodov, A. V. Berdyugin, D. E. Berkaev, A. G. Bogdanchikov, A. E. Bondar, A. A. Botov, A. V. Bragin, T. V. Dimova, V. P. Druzhinin, S. I. Eidelman, D. A. Epifanov, L. B. Epshteyn, A. L. Erofeev, G. V. Fedotovich, S. E. Gayazov, V. B. Golubev, A. A. Grebenuk, S. S. Gribanov, D. N. Grigoriev, F. V. Ignatov, V. L. Ivanov, L. V. Kardapoltsev, S. V. Karpov, V. F. Kazanin, A. G. Kharlamov, A. N. Kirpotin, I. A. Koop, A. A. Korol, A. A. Korobov, S. V. Koshuba, A. N. Kozyrev, E. A. Kozyrev, D. P. Kovrizhin, P. P. Krokovny, A. S. Kupich, A. E. Kuzmenko, A. S. Kuzmin, R. A. Litvinov, I. B. Logashenko, P. A. Lukin, K. A. Martin, N. A. Melnikova, K. Yu. Mikhailov, A. E. Obrazovsky, V. S. Okhapkin, A. V. Otboev, E. V. Pakhtusova, Yu. N. Pestov, A. S. Popov, K. V. Pugachev, G. P. Razuvaev, A. A. Ruban, N. M. Ryskulov, A. E. Ryzhenenkov, A. I. Senchenko, S. I. Serednyakov, Yu. M. Shatunov, P. Yu. Shatunov, V. E. Shebalin, D. N. Shemyakin, D. A. Shtol, B. A. Shwartz, D. B. Shwartz, A. L. Sibidanov, Z. K. Silagadze, E. P. Solodov, I. K. Surin, A. A. Talyshev, V. M. Titov, S. S. Tolmachev, A. I. Vorobiov, I. M. Zemlyansky, Yu. V. Yudin
SciPost physics proceedings,
02/2019
1
Journal Article
Recenzirano
Odprti dostop
Precise study of the hadrons production in $e^+e^-$ annihilation at low energies provides important information about interactions of light quarks and spectroscopy of their bound states. These ...studies are especially important for theoretical calculations of the muon $(g-2)$ via the Standard Model because of the present difference between theoretical and experimental values exceeds three standard deviations. In this report we will discuss current status and recent results obtained by the CMD-3 experiment and will give a brief look to status of the BaBar and Belle II experiments.
Recent results from the CMD-3 detector Lukin, P.A.; Akhmetshin, R.R.; Amirkhanov, A.N. ...
Nuclear and particle physics proceedings,
January-March 2020, 2020-01-00, Letnik:
309-311
Journal Article
Recenzirano
This paper reports a current status of the measurements of the hadronic cross sections in the c.m. energy range from 0.32 to 2.0 GeV with the CMD-3 detector at the VEPP-2000 electron-positron ...collider. The overall size of the data, acquired by the CMD-3 in the runs of 2010–2013 and 2017–2018 years, is about 160 pb−1. The results of data analysis for various exclusive modes of e+e−→hadrons are described.
The process e+e−→ϕ→K+K− has been studied with the CMD-2 detector using about 542 000 events detected in the center-of-mass energy range from 1.01 to 1.034 GeV. The systematic error of the cross ...section is estimated to be 2.2%. The ϕ(1020) meson parameters in the ϕ→K+K− decay channel have been measured: σ0(ϕ→K+K−)=2016±8±44 nb, mϕ=1019.441±0.008±0.080 MeV/c2, Γϕ=4.24±0.02±0.03 MeV, Be+e−BK+K−=(14.27±0.05±0.31)×10−5.
This paper reports measurements of the hadronic cross sections with the CMD-3 detector at the VEPP-2000 electron-positron collider. The overall size of the data sample analyzed is about 60 pb-1, ...collected by the CMD- 3 running since December 2010 up to June 2013 in the c.m. energy range from 0.32 to 2.0 GeV. The preliminary results of data analysis for various modes of e+e−→hadrons are discussed.
The ϕ(1020) meson leptonic width has been determined from the combined analysis of 4 major decay modes of the resonance (ϕ→K+K−,KL0KS0,π+π−π0,ηγ) studied with the CMD-2 detector at the VEPP-2M e+e− ...collider. The following value has been obtained: Γ(ϕ→e+e−)=1.235±0.006±0.022 keV. The ϕ(1020) meson parameters in four main decay channels have been also recalculated: B(ϕ→K+K−)=0.493±0.003±0.007, B(ϕ→KLKS)=0.336±0.002±0.006, B(ϕ→π+π−π0)=0.155±0.002±0.005, B(ϕ→ηγ)=0.0138±0.0002±0.0002.
The cross section of the process
e
+
e
−
→
K
S
K
L
π
0
has been studied with the CMD-3 detector at the VEPP-2000 electron-positron collider in the center-of-mass energy range from 1.1 to 2 GeV. ...Preliminary results on the total cross section of the process are presented.
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