1,501 research outputs found

    A ray mode parabolic equation for shallow water acoustics propagation problems

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    Ray mode parabolic equations which are suitable for shallow water acoustics propagation problems are derived by the multiple-scale method.Comment: 7 pp., 0 fi

    Optimal control over geomorphological systems

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    The method presented can be used for the planning of shore protection measures without seawalls or other cliff-protecting structures; it is particularly appropriate in cases where the system is eventually to control itself by adjustment to a dynamic equilibrium regim

    LHCb trigger streams optimization

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    The LHCb experiment stores around 101110^{11} collision events per year. A typical physics analysis deals with a final sample of up to 10710^7 events. Event preselection algorithms (lines) are used for data reduction. Since the data are stored in a format that requires sequential access, the lines are grouped into several output file streams, in order to increase the efficiency of user analysis jobs that read these data. The scheme efficiency heavily depends on the stream composition. By putting similar lines together and balancing the stream sizes it is possible to reduce the overhead. We present a method for finding an optimal stream composition. The method is applied to a part of the LHCb data (Turbo stream) on the stage where it is prepared for user physics analysis. This results in an expected improvement of 15% in the speed of user analysis jobs, and will be applied on data to be recorded in 2017.Comment: Submitted to CHEP-2016 proceeding

    Integrable relativistic systems given by Hamiltonians with momentum-spin-orbit coupling

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    In the paper we investigate the evolution of the relativistic particle (massive and massless) with spin defined by Hamiltonian containing the terms with momentum-spin-orbit coupling. We integrate the corresponding Hamiltonian equations in quadratures and express their solutions in terms of elliptic functions.Comment: 18 page

    Probing Low Energy Neutrino Backgrounds with Neutrino Capture on Beta Decaying Nuclei

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    We study the interaction of low energy neutrinos on nuclei that spontaneously undergo beta decay showing that the product of the cross section times neutrino velocity takes values as high as 10^{-42} cm^2 c for some specific nuclei that decay via allowed transitions. The absence of energy threshold and the value of the cross section single out these processes as a promising though very demanding approach for future experiments aimed at a direct detection of low energy neutrino backgrounds such as the cosmological relic neutrinos.Comment: Includes a discussion of local relic neutrino density effect on neutrino capture rate. Accepted for publication in JCA

    Scattering of neutrinos on a polarized electron target as a test for new physics beyond the Standard Model

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    In this paper, we analyze the scattering of the neutrino beam on the polarized electron target, and predict the effects of two theoretically possible scenarios beyond the Standard Model. In both scenarios, Dirac neutrinos are assumed to be massive. First, we consider how the existence of CP violation phase between the complex vector V and axial A couplings of the Left-handed neutrinos affects the azimuthal dependence of the differential cross section. The future superbeam and neutrino factory experiments will provide the unique opportunity for the leptonic CP violation studies, if the large magnetized sampling calorimeters with good event reconstruction capabilities are build. Next, we take into account a scenario with the participation of the exotic scalar S coupling of the Right-handed neutrinos in addition to the standard vector V and axial A couplings of the Left-handed neutrinos. The main goal is to show how the presence of the R-handed neutrinos, in the above process changes the spectrum of recoil electrons in relation to the expected Standard Model prediction, using the current limits on the non-standard couplings. The interference terms between the standard and exotic couplings in the differential cross section depend on the angle α\alpha between the transverse incoming neutrino polarization and the transverse electron polarization of the target, and do not vanish in the limit of massless neutrino. The detection of the dependence on this angle in the energy spectrum of recoil electrons would be a signature of the presence of the R-handed neutrinos in the neutrino-electron scattering. To make this test feasible, the polarized artificial neutrino source needs to be identified.Comment: 11 pages, 3 eps figures, revtex, submitted to publicatio
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