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.
Barrel calorimeter of the CMD-3 detector Anisenkov, A.V.; Aulchenko, V.M.; Barkov, L.M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2013, Volume:
732
Journal Article
Peer reviewed
Since 2010 the CMD-3 detector has been collecting data at the e+e− collider VEPP-2000 at Budker Institute of Nuclear Physics. CMD-3 is a general purpose detector designed to study e+e− annihilation ...into hadrons in the wide energy range s=0.3–2GeV. The CMD-3 barrel electromagnetic calorimeter consists of two subsystems: closest to the beam pipe is the Liquid Xenon calorimeter and the outer one is based on CsI scintillation crystals. The design of the calorimeter and its current performance are presented.
The process e+e−→K+K−η has been studied in the center-of-mass energy range from 1.59 to 2.007 GeV using the data sample of 59.5 pb−1, collected with the CMD-3 detector at the VEPP-2000 e+e− collider ...in 2011, 2012 and 2017. The K+K−η final state is found to be dominated by the contribution of the ϕ(1020)η intermediate state. The cross section of the process e+e−→ϕ(1020)η has been measured with a systematic uncertainty of 5.1% on the base of 3009 ± 67 selected events. The obtained cross section has been used to calculate the contribution to the anomalous magnetic moment of the muon: aμϕη(E<1.8GeV)=(0.321±0.015stat±0.016syst)×10−10, aμϕη(E<2.0GeV)=(0.440±0.015stat±0.022syst)×10−10. From the cross section approximation the ϕ(1680) meson parameters have been determined with better statistical precision, than in previous studies.
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.
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
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
Calorimetry of the CMD-3 detector Akhmetshin, R R; Anisenkov, A V; Aulchenko, V M ...
Journal of physics. Conference series,
11/2017, Volume:
928, Issue:
1
Journal Article
Peer reviewed
Open access
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.
A cross section of the process e+e−→π+π−π+π− has been measured using 6798±93 signal events from a data sample corresponding to an integrated luminosity of 9.8 pb−1 collected with the CMD-3 detector ...in the center-of-mass energy range 920–1060 MeV. The measured cross section exhibits a pattern of interference of the ϕ(1020)→π+π−π+π− decay with a non-resonant process e+e−→π+π−π+π−, from which we obtain the branching fraction of the doubly suppressed decays (by G-parity and OZI rule): B(ϕ→π+π−π+π−)=(6.5±2.7±1.6)×10−6.
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.
Calorimetry of the CMD-3 detector Shebalin, V.E.; Akhmetshin, R.R.; Anisenkov, A.V. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2016, Volume:
824
Journal Article
Peer reviewed
CMD-3 is a general purpose detector designed to study e+e− annihilation into hadrons. It is mounted at VEPP-2000 collider which operates in the wide energy range, Ec.m.s=0.32−2GeV. The calorimetry at ...the detector is based on three subsystems: closest to the beam pipe barrel Liquid Xenon calorimeter, outer barrel calorimeter based on CsI scintillation crystals and the endcap calorimeter made of BGO scintillation crystals. We describe the structure of the calorimeters, their electronics and the energy calibration procedures.
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