A search for μ-e conversion in muonic gold Bertl, W.; Engfer, R.; Hermes, E.A. ...
The European physical journal. C, Particles and fields,
8/2006, Volume:
47, Issue:
2
Journal Article
Peer reviewed
Open access
We report on a search for μ-e conversion in muonic gold performed with the SINDRUM II spectrometer at PSI. The measurement resulted in Γ(μ-Au→e-Aug.s.)/Γcapture(μ-Au)<7×10-13 (90% C.L.).
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DOBA, FZAB, GEOZS, IJS, IMTLJ, IZUM, KILJ, KISLJ, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A recent result of the cross section measurement of the process e + e − → K S K π at e + e − collider VEPP-2000 is presented using a data sample of the ∼150 pb−1 integrated luminosity collected with ...the CMD-3 detector. The processes with charged kaons in multi hadron events attract special interest, because they impact strongly on studies of light quark hadronization, isospin symmetry, and strange meson spectroscopy. Experimental results of e + e − → K S K π cross section are presented in a broad energy range covered by the VEPP-2000 and compared to earlier measurements. A study of the production dynamics confirms the dominance of neutral KK * ( 892 ) intermediate state.
The time-of-flight (TOF) system now is installed at the CMD-3 detector of the VEPP-2000 electron-positron collider at the Budker Institute of Nuclear Physics. It is based on the strips of organic ...scintillator with shifter fibers readout and silicon photomultiplier (SiPM) photodetectors. The new electronics for TOF system is designed at the Budker Institute of Nuclear Physics. The main feature of the new electronics is usage a ripple-free technology for providing a bias voltage for SiPM photodetectors. Also this design has very low power consumption. It allows the individual controlled bias voltage generator to be integrated to front-end electronics, near the photodetectors. In this paper the structure of the TOF electronic hardware is described.
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.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The paper describes a method of the charged particle identification, developed for the CMD-3 detector, installed at the VEPP-2000 e+e− collider. The method is based on application of boosted decision ...trees classifiers, trained for the optimal separation of electrons, muons, pions and kaons in the momentum range from 100 to 1200MeV/c. The input variables for the classifiers are linear combinations of the energy depositions of charged particles in 12 layers of the liquid xenon calorimeter of the CMD-3. The event samples for training of the classifiers are taken from the simulation. Various issues of the calorimeter strip channels response simulation and their calibration are considered. Application of the method is illustrated by the examples of separation of the e+e−(γ) and π+π−(γ) final states and of selection of the K+K− final state at high energies.
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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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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
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.
A large amount of data collected with the CMD-3 detector above the threshold of the
nn
̅pair allows to measure the cross section of the process
e
+
e
−
→
nn
̅and the neutron form factor with good ...accuracy. This task is complicated by a large number of background events and necessity of finding ways to suppress them. A technique of identification for
e
+
e
−
→
nn
̅events is described.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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