384 research outputs found

    Measurement of J/Ïˆâ†’ÎłÎ·cJ/\psi\to\gamma\eta_{\rm c} decay rate and ηc\eta_{\rm c} parameters at KEDR

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    Using the inclusive photon spectrum based on a data sample collected at the J/ψJ/\psi peak with the KEDR detector at the VEPP-4M e+e−e^+e^- collider, we measured the rate of the radiative decay J/Ïˆâ†’ÎłÎ·cJ/\psi\to\gamma\eta_{\rm c} as well as ηc\eta_{\rm c} mass and width. Taking into account an asymmetric photon lineshape we obtained Γγηc0=2.98±0.18∣−0.33+0.15\Gamma^0_{\gamma\eta_{\rm c}}=2.98\pm0.18 \phantom{|}^{+0.15}_{-0.33} keV, Mηc=2983.5±1.4∣−3.6+1.6M_{\eta_{\rm c}} = 2983.5 \pm 1.4 \phantom{|}^{+1.6}_{-3.6} MeV/c2c^2, Γηc=27.2±3.1∣−2.6+5.4\Gamma_{\eta_{\rm c}} = 27.2 \pm 3.1 \phantom{|}^{+5.4}_{-2.6} MeV.Comment: 6 pages, 3 figure

    Measurement of J/psi to eta_c gamma at KEDR

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    We present a study of the inclusive photon spectra from 5.9 million J/psi decays collected with the KEDR detector at the VEPP-4M e+e- collider. We measure the branching fraction of radiative decay J/psi to eta_c gamma, eta_c width and mass. Our preliminary results are: M(eta_c) = 2979.4+-1.5+-1.9 MeV, G(eta_c) = 27.8+-5.1+-3.3 MeV, B(J/psi to eta_c gamma) = (2.34+-0.15+-0.40)%.Comment: To be published in Proceedings of the PhiPsi09, Oct. 13-16, 2009, Beijing, Chin

    Measurement of B(J/psi->eta_c gamma) at KEDR

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    We present a study of the inclusive photon spectrum from 6.3 million J/psi decays collected with the KEDR detector at the VEPP-4M e+e- collider. We measure the branching fraction of the radiative decay J/psi -> eta_c gamma, eta_c width and mass. Taking into account an asymmetric photon line shape we obtain: M(eta_c) = (2978.1 +- 1.4 +- 2.0) MeV/c^2, Gamma(eta_c) = (43.5 +- 5.4 +- 15.8) MeV, B(J/psi->eta_c gamma) = (2.59 +- 0.16 +- 0.31)%$.Comment: 6 pages, 1 figure. To be published in the proceedings of the 4th International Workshop on Charm Physics (Charm2010), October 21-24, 2010, IHEP, Beijin

    К ВЫБОРУ ИСбОЧНИКА бЕПЛОСНАБЖЕНИЯ МОБИЛЬНОГО СбРОИбЕЛЬНОГО СООРУЖЕНИЯ

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    The paper proposes a vortex heat generator with energy transformation of the highest  state  of matter motion  into  the  lowest  one  as  a  heat  supply  source  for a mobile object. Energy transformation coefficient indices close or equal to 1 have been obtained as a result of experiments on efficiency of the vortex heat generator. Such results can be explained with the help of the 2nd Bohr quantum postulate. Standard series of certified VTG heat generators has been proposed for heat supply of the mobile object (field hospital).В ĐșачДстĐČĐ” ĐžŃŃ‚ĐŸŃ‡ĐœĐžĐșĐ° Ń‚Đ”ĐżĐ»ĐŸŃĐœĐ°Đ±Đ¶Đ”ĐœĐžŃ ĐŒĐŸĐ±ĐžĐ»ŃŒĐœĐŸĐłĐŸÂ  ĐŸĐ±ŃŠĐ”Đșта ĐżŃ€Đ”ĐŽĐ»ĐŸĐ¶Đ”ĐœĐČОхрДĐČĐŸĐč Ń‚Đ”ĐżĐ»ĐŸĐłĐ”ĐœĐ”Ń€Đ°Ń‚ĐŸŃ€ с ĐżŃ€Đ”ĐŸĐ±Ń€Đ°Đ·ĐŸĐČĐ°ĐœĐžĐ”ĐŒ ŃĐœĐ”Ń€ĐłĐžĐž ĐČŃ‹ŃŃˆĐ”Đč Ń„ĐŸŃ€ĐŒŃ‹ ĐŽĐČĐžĐ¶Đ”ĐœĐžŃ ĐŒĐ°Ń‚Đ”Ń€ĐžĐž ĐČ ĐœĐžĐ·ŃˆŃƒŃŽ. В Ń…ĐŸĐŽĐ” ĐŸĐżŃ‹Ń‚ĐŸĐČ ĐżĐŸ ĐŸĐżŃ€Đ”ĐŽĐ”Đ»Đ”ĐœĐžŃŽ ŃŃ„Ń„Đ”ĐșтоĐČĐœĐŸŃŃ‚Đž ĐČОхрДĐČĐŸĐłĐŸ Ń‚Đ”ĐżĐ»ĐŸĐłĐ”ĐœĐ”Ń€Đ°Ń‚ĐŸŃ€Đ° былО ĐżĐŸĐ»ŃƒŃ‡Đ”ĐœŃ‹ Đ·ĐœĐ°Ń‡Đ”ĐœĐžŃ ĐșĐŸŃŃ„Ń„ĐžŃ†ĐžĐ”ĐœŃ‚Đ° ĐżŃ€Đ”ĐŸĐ±Ń€Đ°Đ·ĐŸĐČĐ°ĐœĐžŃ ŃĐœĐ”Ń€ĐłĐžĐž, блОзĐșОД Đž раĐČĐœŃ‹Đ” Đ”ĐŽĐžĐœĐžŃ†Đ”. йаĐșОД Ń€Đ”Đ·ŃƒĐ»ŃŒŃ‚Đ°Ń‚Ń‹ ĐŒĐŸĐłŃƒŃ‚ Đ±Ń‹Ń‚ŃŒ ĐŸĐ±ŃŠŃŃĐœĐ”ĐœŃ‹ с ĐżĐŸĐŒĐŸŃ‰ŃŒŃŽ ĐČŃ‚ĐŸŃ€ĐŸĐłĐŸ ĐșĐČĐ°ĐœŃ‚ĐŸĐČĐŸĐłĐŸ ĐżĐŸŃŃ‚ŃƒĐ»Đ°Ń‚Đ° Đ‘ĐŸŃ€Đ°.Â Đ”Đ»Ń Ń‚Đ”ĐżĐ»ĐŸŃĐœĐ°Đ±Đ¶Đ”ĐœĐžŃ ĐŒĐŸĐ±ĐžĐ»ŃŒĐœĐŸĐłĐŸ ĐŸĐ±ŃŠĐ”Đșта (ĐżĐŸĐ»Đ”ĐČĐŸĐłĐŸ ĐłĐŸŃĐżĐžŃ‚Đ°Đ»Ń) ĐżŃ€Đ”ĐŽĐ»ĐŸĐ¶Đ”Đœ Ń‚ĐžĐżĐŸŃ€ŃĐŽ ŃĐ”Ń€Ń‚ĐžŃ„ĐžŃ†ĐžŃ€ĐŸĐČĐ°ĐœĐœŃ‹Ń… Ń‚Đ”ĐżĐ»ĐŸĐłĐ”ĐœĐ”Ń€Đ°Ń‚ĐŸŃ€ĐŸĐČ ĐŒĐ°Ń€ĐșĐž ВбГ

    Measurement of Γee(J/ψ)\Gamma_{ee}(J/\psi) with KEDR detector

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    The product of the electronic width of the J/ψJ/\psi meson and the branching fractions of its decay to hadrons and electrons has been measured using the KEDR detector at the VEPP-4M e+e−e^+e^- collider. The obtained values are: Γee(J/ψ)=5.550±0.056±0.089 keV,\Gamma_{ee}(J/\psi) = 5.550 \pm 0.056 \pm 0.089 \, \text{keV}, Γee(J/ψ)⋅Bhadrons(J/ψ)=4.884±0.048±0.078 keV,\Gamma_{ee}(J/\psi) \cdot \mathcal{B}_\text{hadrons}(J/\psi) = 4.884 \pm 0.048 \pm 0.078 \, \text{keV}, Γee(J/ψ)⋅Bee(J/ψ)=0.3331±0.0066±0.0040 keV.\Gamma_{ee}(J/\psi) \cdot \mathcal{B}_{ee}(J/\psi) = 0.3331 \pm 0.0066 \pm 0.0040 \, \text{keV}. The uncertainties shown are statistical and systematic, respectively. Using the result presented and the world-average value of the electronic branching fraction, one obtains the total width of the J/ψJ/\psi meson: Γ=92.94±1.83 keV.\Gamma = 92.94 \pm 1.83 \, \text{keV}. These results are consistent with the previous experiments.Comment: 19 pages, 13 figure

    Measurement of the ratio of the leptonic widths Γee/ΓΌΌ\Gamma_{ee}/\Gamma_{\mu\mu} for the J/ψJ/\psi meson

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    The ratio of the electron and muon widths of the J/ψJ/\psi meson has been measured using direct J/ψJ/\psi decays in the KEDR experiment at the VEPP-4M electron-positron collider. The result $\Gamma_{ee}(J/\psi)/\Gamma_{\mu\mu}(J/\psi)=1.0022\pm0.0044\pm0.0048\ (0.65\%)isingoodagreementwiththeleptonuniversality.Theexperiencecollectedduringthisanalysiswillbeusedfora is in good agreement with the lepton universality. The experience collected during this analysis will be used for a J/\psi$ lepton width determination with up to 1% accuracy.Comment: 5 pages, 6 figures, 2 table

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

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    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal
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