Search for the process e + e − → η Achasov, M. N.; Barnyakov, A. Yu; Beloborodov, K. I. ...
Physical review. D,
09/2018, Volume:
98, Issue:
5
Journal Article
Peer reviewed
Open access
A search for the rare decay η→e+e− is performed using the inverse process e+e−→η in the decay mode η→π0π0π0. We analyze data with an integrated luminosity of 654 nb−1 accumulated at the VEPP-2000 ...e+e− collider with the SND detector at the center-of-mass energy E=mηc2≈548 MeV, and set the upper limit B(η→e+e−)<7×10−7 at the 90% confidence level.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
Since 2010 the CMD-3 detector has been collecting data at the e+e− collider VEPP-2000 in the Budker Institute of Nuclear Physics. One of the main goals of experiments with CMD-3 detector is the ...precise measurement of the cross sections of the e+e− annihilation into hadrons. For a large number of processes the main source of systematic uncertainty in cross sections determination due to accuracy of polar angles determination of the tracks. Z-chamber is used for the reconstruction of the track longitudinal coordinate which is with low systematic uncertainty. The measurement of longitudinal coordinates is performed by the collecting of the charge which is induced on the strip cathodes of the Z-chamber. The algorithms of the reconstruction of cathodes clusters and calibration procedure are presented.
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.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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
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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.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the framework of the large hadron collider (LHC) upgrade project, new materials are proposed for the vacuum. Amorphous carbon deposited onto the vacuum-chamber wall is examined as a coating with a ...low secondary electron emission rate for superconducting systems designed to upgrade the LHC, i.e., to increase the luminosity of the machine (HL-LHC). Since protons will generate synchrotron radiation with a critical energy of ~10 eV and a flux of 10
16
photon m
–1
s
–1
, it is important to study the effect of photons on a surface covered with amorphous carbon at room and cryogenic temperatures. The construction and parameters of the setup on the new synchrotron beamline of the VEPP-2000 booster are described. The first results of measuring the photodesorption coefficient are also presented.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
18.
Status and perspectives of the VEPP-2000 Shatunov, P. Yu; Berkaev, D. E.; Zharinov, Yu. M. ...
Physics of particles and nuclei letters,
12/2016, Volume:
13, Issue:
7
Journal Article
Peer reviewed
The electron-positron collider VEPP-2000 operates at BINP from 2010 year. The application of round colliding beams concept along with the accurate orbit and lattice correction yielded the high peak ...luminosity of 1.2 × 10
31
cm
−2
s
−1
at 500MeV. The peak luminosity limited only by beam-beam effects, while average luminosity–by present lack of positrons in whole energy range of 160–1000 MeV. To perform high luminosity at high energies the top-up injection is needed. At present new electron and positron injection complex at BINP is commissioned and ready to feed VEPP-2000 collider with intensive beams with energy of 450MeV.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
19.
Recent results from CMD-3 Ignatov, F. V.; Akhmetshin, R. R.; Amirkhanov, A. N. ...
EPJ Web of Conferences,
2019, Volume:
212
Journal Article, Conference Proceeding
Peer reviewed
Open access
Regular data taking with the CMD-3 at the electron-positron collider VEPP-2000 is under way since 2010. The collected data sample corresponds to about 200 inverse picobarns of integrated luminosity ...per detector in the energy range from 0.32 up to 2 GeV, with a goal to collect about 1
fb
−1
during next five years. Some of the recent results from the CMD-3 detector are discussed.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
A brief review of the recent results on the hadronic cross section measurements with the CMD-3 detector at the
e
+
e
−
collider VEPP-2000 is given. Focus is made on the processes with charged kaons ...in multihadron events, which have a strong impact on strange meson spectroscopy and form factors that are important ingredients in the Dalitz plot analysis. Experimental data relevant to the topic are presented from the broad energy range covered by VEPP-2000 and compared to earlier measurements by the different collaborations. The analysis is based on the integrated luminosity of about 100 pb
−1
collected in 2011, 2012 and 2017.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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