Tests of FARICH prototype with precise photon position detection Barnyakov, A.Yu; Barnyakov, M.Yu; Basok, I.Yu ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2014, Letnik:
766
Journal Article
Recenzirano
In June 2012 a FARICH prototype from Philips Digital Photon Counting (PDPC) based on a photon camera with dimensions of 200200 mm has been tested at CERN. Remarkable particle separation has been ...achieved with a 4-layer aerogel sample: the pi /K separation at a 6 GeV/c momentum is 3.5 sigma , the mu / pi mu / pi separation is 5.3 sigma at 1 GeV/c. The analysis of the data has shown that the main contribution to the accuracy of the ring radius measurement comes from aerogel. The development of focusing aerogels is proceeding in two main directions: tuning of production technology of multilayer blocks and development of a new production method with continuous density (refractive index) gradient along the block depth. The beam test was carried out in December 2012-January 2013 at the electron beam test facility at the VEPP-4 M e super(+)e super(-) collider. The goal of this test was to measure different single layer and focusing aerogel samples, both multilayer and gradient. Aerogel samples were tested with a PDPC FARICH prototype. A part of DPC SPADs in each pixel was disabled to form an active area of 11 mm super(2). The collected data proved that gradient aerogel samples focus Cherenkov light.
The ratio of the electron and muon widths of the J/ psi J/ psi meson has been measured using direct J/ psi J/ psi decays in the KEDR experiment at the VEPP-4M electron-positron collider. The result ...Gamma e+e-(J/ psi )/ Gamma mu + mu -(J/ psi )=1.0022 plus or minus 0.0044 plus or minus 0.0048(0.65%) is in good agreement with the lepton universality. The experience collected during this analysis will be used for J/ psi J/ psi lepton width determination with up to 1% accuracy.
Focusing Aerogel RICH for particle identification and momentum measurement Barnyakov, A.Yu; Barnyakov, M.Yu; Basok, I.Yu ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2011, Letnik:
639, Številka:
1
Journal Article
Recenzirano
The work is devoted to the development of the Focusing Aerogel RICH (FARICH). The option of the forward RICH for the SuperB project in Italy is presented. It features an aerogel-NaF radiator and MCP ...photodetectors. Monte Carlo simulation predicts the
π
/ K separation at the level better than
3
σ
from 0.2 to 7
GeV/
c, the
μ
/
π
separation—from 0.13 to 1.3
GeV/
c, and the kaon momentum measurement with an accuracy of about 1% at 1
GeV/
c. FARICH for the Super Charm-Tau Factory project in Novosibirsk is proposed. Monte Carlo simulation predicts
μ
/
π
separation at the level better than
3
σ
for a momentum from 0.3 to 1.7
GeV/
c. A prototype will be tested on the new electron test beam facility at VEPP-4M collider.
Measurement of parameters Anashin, V V; Aulchenko, V M; Baldin, E M ...
Physics letters. B,
05/2012, Letnik:
711, Številka:
3-4
Journal Article
Recenzirano
We report the final results of a study of the psi ( 3770 ) meson using a data sample collected with the KEDR detector at the VEPP-4M electron-positron collider. The data analysis takes into account ...interference between the resonant and nonresonant D D macr production, where the latter is related to the nonresonant part of the energy-dependent form factor F D . The vector dominance approach and several empirical parameterizations have been tried for the nonresonant F D N R ( s ) . Our results for the mass and total width of psi ( 3770 ) are M = 3779.2 - 1.7 + 1.8 - 0.7 + 0.5 - 0.3 + 0.3 MeV , Gamma = 24.9 - 4.0 + 4.6 - 0.6 + 0.5 - 0.9 + 0.2 MeV , where the first, second and third uncertainties are statistical, systematic and model, respectively. For the electron partial width two possible solutions have been found: ( 1 ) Gamma e e = 154 - 58 + 79 - 9 + 17 - 25 + 13 eV , ( 2 ) Gamma e e = 414 - 80 + 72 - 26 + 24 - 10 + 90 eV . Our statistics are insufficient to prefer one solution to another. The Solution (2) mitigates the problem of non- D D macr decays but is disfavored by potential models. It is shown that taking into account the resonance-continuum interference in the near-threshold region affects resonance parameters, thus the results presented cannot be directly compared with the corresponding PDG values obtained ignoring this effect.
A high-precision determination of the main parameters of the psi ( 2 S ) resonance has been performed with the KEDR detector at the VEPP-4M e + e - collider in three scans of the psi ( 2 S ) - psi ( ...3770 ) energy range. Fitting the energy dependence of the multihadron cross section in the vicinity of the psi ( 2 S ) we obtained the mass value M = 3686.114 plus or minus 0.007 plus or minus 0.011 - 0.012 + 0.002 MeV and the product of the electron partial width by the branching fraction into hadrons Gamma e e B h = 2.233 plus or minus 0.015 plus or minus 0.037 plus or minus 0.020 keV . The first and second uncertainties are statistical and systematic, respectively. The third uncertainty quoted is an estimate of the model dependence of the result due to assumptions on the interference effects in the cross section of the single-photon e + e - annihilation to hadrons explicitly considered in this work. Implicitly, the same assumptions were employed to obtain the charmonium leptonic width and the absolute branching fractions in many experiments. Using the result presented and the world average values of the electron and hadron branching fractions, one obtains the electron partial width and the total width of the psi ( 2 S ) : Gamma e e = 2.282 plus or minus 0.015 plus or minus 0.038 plus or minus 0.021 keV , Gamma = 296 plus or minus 2 plus or minus 8 plus or minus 3 keV . These results are consistent with and more than two times more precise than any of the previous experiments.
We report results of a search for narrow resonances in e super(+e) super(-) annihilation at center-of-mass energies between 1.85 and 3.1 GeV performed with the KEDR detector at the VEPP-4M e ...super(+e) super(-) collider. The upper limit on the leptonic width of a narrow resonance inline image has been obtained (at 90% C.L.).
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