The cross section of the process e + e − → π + π − 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 an integrated luminosity of about 88 pb − 1 , of which 62 pb − 1 represent a complete dataset collected by CMD-3 at center-of-mass energies below 1 GeV. In the dominant region near the ρ resonance a systematic uncertainty of 0.7% was achieved. The implications of the presented results for the evaluation of the hadronic contribution to the anomalous magnetic moment of the muon are discussed. Published by the American Physical Society 2024
Overview of the CMD-3 recent results Ryzhenenkov, A E; Akhmetshin, R R; Amirkhanov, A N ...
Journal of physics. Conference series,
04/2020, Letnik:
1526, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The CMD-3 detector started data taking at the electron-positron collider VEPP-2000 in December 2010 with a goal to collect about 1 fb−1. The collected data sample corresponds to an integrated ...luminosity of 200 pb−1 in the center-of-mass energy range from 0.32 up to 2 GeV. This paper reports recent results on the hadronic cross sections measurements with the CMD-3 detector.
The process e+e−→K+K− has been studied using 1.7×106 events from a data sample corresponding to an integrated luminosity of 5.7 pb−1 collected with the CMD-3 detector in the center-of-mass energy ...range 1010–1060 MeV. The cross section is measured with about 2% systematic uncertainty and is used to calculate the contribution to the anomalous magnetic moment of the muon aμK+K−=(19.33±0.40)×10−10, and to obtain the ϕ(1020) meson parameters. We consider the relationship between the e+e−→K+K− and e+e−→KS0KL0 cross sections and compare it to the theoretical prediction.
The cross section of the process e + e − → π + π − 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 ρ -resonance region, a systematic uncertainty of 0.7% has been reached. At energies around ϕ -resonance the π + π − production cross section was measured for the first time with high beam energy resolution. The forward-backward charge asymmetry in the π + π − 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. Published by the American Physical Society 2024
The process e+e−→K+K−π+π− has been studied in the center-of-mass energy range from 1500 to 2000 MeV using a data sample of 23 pb−1 collected with the CMD-3 detector at the VEPP-2000 e+e− collider. ...Using about 24 000 selected events, the e+e−→K+K−π+π− cross section has been measured with a systematic uncertainty decreasing from 11.7% at 1500–1600 MeV to 6.1% above 1800 MeV. A preliminary study of K+K−π+π− production dynamics has been performed.
Calorimetry of the CMD-3 detector Akhmetshin, R R; Anisenkov, A V; Aulchenko, V M ...
Journal of physics. Conference series,
11/2017, Letnik:
928, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The CMD-3 detector has been collecting data since 2010 at the e+e− collider VEPP-2000 in the Budker Institute of Nuclear Physics. VEPP-2000 uses the novel round beam technique and provides high ...luminosity in a wide c.m.energy range from 0.32 to 2 GeV. The physics goal of the CMD-3 experiment is a study of the e+e− annihilation into hadrons. CMD-3 is a general-purpose detector, which provides high efficiency for both charged and neutral particles. The electromagnetic calorimeter consists of the barrel calorimeter based on liquid xenon and CsI crystals, and the endcap calorimeter based on BGO crystals. The main parameters of the calorimeters are presented.
The electromagnetic calorimeter for the Belle-II detector is briefly described. The algorithm of reconstruction of amplitude and time of calorimeter signals is described. The status of preparation of ...the electromagnetic calorimeter for the data-taking is presented.
The cross section of the process
e
+
e
−
→ π
+
π
−
π
+
π
−
has been measured using an integrated luminosity of 17 pb
−1
collected with the CMD-3 detector in the center-of-mass energy range 650-1000 ...MeV. High-precision measurements of various hadronic cross sections are of great interest in relation with the problem of the muon anomalous magnetic moment g-2. This measurement can be also used to test the relation between the cross section of
e
+
e
−
→ π
+
π
−
π
+
π
−
and the spectral function for the τ
−
→ π
−
π
0
π
0
π
0
decay predicted by the conservation of vector current (CVC).
A search for the process
e
+
e
−
→
D
*0
(2007) has been performed with the CMD-3 detector at the VEPP-2000
e
+
e
−
-collider. Two main decay modes of the
D
*0
(2007) decay,
D
0
π
0
and
D
0
γ, ...followed by
D
0
→
K
+
π
−
π
+
π
−
are used in this analysis. With an integrated luminosity of 3.7 pb
−1
collected at the center-of-mass energy E
c.m.
=2006.62 MeV our preliminary upper limit is B
D*
0
→
e
+
e
−
<1.6× 10
−6
at 90%C.L.
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