7,672 research outputs found

    Experimental investigations on liquid-metal MHD generators

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    Liquid metal magnetohydrodynamic generator hydraulic losses and duct flo

    Omega_{ccc} production via fragmentation at LHC

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    In the framework of the leading order of perturbative QCD and the nonrelativistic quark-diquark model of baryons we have obtained fragmentation function for c-quark to split into Omega_{ccc} baryon. It is shown that at LHC one can expect 3.5 10^3 events with Omega_{ccc} at p_t>5 GeV/c and -1<y<1 per year.Comment: LaTex, 5 pages and 2 figures. Talk presented at XIV Workshop on High Energy Physics and Quantum Field Theory, Moscow, May 27 - June 4, 199

    Prompt ηc\eta_c meson production at the LHC in the NRQCD with kTk_T-factorization

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    In the framework of the kTk_T-factorization, the prompt production of ηc\eta_c mesons at the LHC conditions is studied. Our consideration is based on the off-shell amplitudes for hard partonic subprocesses and on the nonrelativistic QCD (NRQCD) formalism for the formation of bound states. We try two latest parametrizations for noncollinear, or transverse momentum dependent (TMD) gluon densities derived from the Catani-Ciafaloni-Fiorani-Marchesini (CCFM) equation. We use the values of the nonperturbative matrix elements obtained from a combined fit of the ηc\eta_c and J/ψJ/\psi differential cross sections. Finally, we show an universal set of parameters that provides a reasonable simultaneous description for all of the available data on the prompt J/ψJ/\psi and ηc\eta_c production at the LHC.Comment: 5 pages, 2 figures, 3 table

    Prompt charmonia production and polarization at LHC in the NRQCD with kTk_T-factorization. Part III: J/ψJ/\psi meson

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    In the framework of kTk_T-factorization approach, the production and polarization of prompt J/ψJ/\psi mesons at the LHC energies is studied. Our consideration is based on the non-relativistic QCD formalism for bound states and off-shell amplitudes for hard partonic subprocesses. Both the direct production mechanism and feed-down contributions from χc\chi_c and ψ(2S)\psi(2S) decays are taken into account. The transverse momentum dependent (or unintegrated) gluon densities in a proton were derived from Ciafaloni-Catani-Fiorani-Marchesini evolution equation or, alternatively, were chosen in accordance with Kimber-Martin-Ryskin prescription. The non-perturbative color-octet matrix elements were first deduced from the fits to the latest CMS data on J/ψJ/\psi transverse momentum distributions and then applied to describe the ATLAS and LHCb data on J/ψJ/\psi production and polarization at s=7\sqrt s = 7, 88 and 1313 TeV. We perform an estimation of polarization parameters λθ\lambda_\theta, λϕ\lambda_\phi and λθϕ\lambda_{\theta \phi} which determine J/ψJ/\psi spin density matrix and demonstrate that treating the soft gluon emission as a series of explicit color-electric dipole transitions within NRQCD leads to unpolarized J/ψJ/\psi production at high transverse momenta, that is in qualitative agreement with the LHC data.Comment: 23 pages, 14 figures. arXiv admin note: substantial text overlap with arXiv:1508.0548

    First estimates of the BcB_c wave function from the data on the BcB_c production cross section

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    In the framework of perturbative QCD and nonrelativistic bound state formalism, we calculate the production of BcB_c and BcB_c^* mesons at the conditions of the CDF and LHCb experiments. We derive first estimations for the BcB_c wave function from a comparison with the available data.Comment: 3 pages, 1 figur
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