21 research outputs found

    Cross-Correlation Earthquake Precursors in the Hydrogeochemical and Geoacoustic Signals for the Kamchatka Peninsula

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    We propose a new type of earthquake precursor based on the analysis of correlation dynamics between geophysical signals of different nature. The precursor is found using a two-parameter cross-correlation function introduced within the framework of flicker-noise spectroscopy, a general statistical physics approach to the analysis of time series. We consider an example of cross-correlation analysis for water salinity time series, an integral characteristic of the chemical composition of groundwater, and geoacoustic emissions recorded at the G-1 borehole on the Kamchatka peninsula in the time frame from 2001 to 2003, which is characterized by a sequence of three groups of significant seismic events. We found that cross-correlation precursors took place 27, 31, and 35 days ahead of the strongest earthquakes for each group of seismic events, respectively. At the same time, precursory anomalies in the signals themselves were observed only in the geoacoustic emissions for one group of earthquakes.Comment: 21 pages, 5 figures, 1 table; to be published in "Acta Geophysica". arXiv admin note: substantial text overlap with arXiv:1101.147

    Non-Perturbative QCD Treatment of High-Energy Hadron-Hadron Scattering

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    Total cross-sections and logarithmic slopes of the elastic scattering cross-sections for different hadronic processes are calculated in the framework of the model of the stochastic vacuum. The relevant parameters of this model, a correlation length and the gluon condensate, are determined from scattering data, and found to be in very good agreement with values coming from completely different sources of information. A parameter-free relation is given between total cross-sections and slope parameters, which is shown to be remarkably valid up to the highest energies for which data exist.Comment: 60 pages, Heidelberg preprin

    Search for the exotic Ξ(1860)\Xi^{--}(1860) Resonance in 340GeV/c Σ\Sigma^--Nucleus Interactions

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    We report on a high statistics search for the Ξ(1860)\Xi^{--}(1860) resonance in Σ\Sigma^--nucleus collisions at 340GeV/c. No evidence for this resonance is found in our data sample which contains 676000 Ξ\Xi^- candidates above background. For the decay channel Ξ(1860)Ξπ\Xi^{--}(1860) \to \Xi^-\pi^- and the kinematic range 0.15<xF<<x_F<0.9 we find a 3σ\sigma upper limit for the production cross section of 3.1 and 3.5 μ\mub per nucleon for reactions with carbon and copper, respectively.Comment: 5 pages, 4 figures, modification of ref. 43 and 4

    Microscopic simulation of xenon-based optical TPCs in the presence of molecular additives

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    [EN] We introduce a simulation framework for the transport of high and low energy electrons in xenon-based optical time projection chambers (OTPCs). The simulation relies on elementary cross sections (electron-atom and electron-molecule) and incorporates, in order to compute the gas scintillation, the reaction/quenching rates (atom-atom and atom-molecule) of the first 41 excited states of xenon and the relevant associated excimers, together with their radiative cascade. The results compare positively with observations made in pure xenon and its mixtures with CO2 and CF4 in a range of pressures from 0.1 to 10 bar. This work sheds some light on the elementary processes responsible for the primary and secondary xenon-scintillation mechanisms in the presence of additives, that are of interest to the OTPC technology.DGD is supported by the Ramon y Cajal program (Spain) under contract number RYC-2015-18820. The authors want to acknowledge the RD51 collaboration for encouragement and support during the elaboration of this work, and in particular discussions with F. Resnati, A. Milov, V. Peskov, M. Suzuki and A. F. Borghesani. The NEXT Collaboration acknowledges support from the following agencies and institutions: the European Research Council (ERC) under the Advanced Grant 339787-NEXT; the Ministerio de Economia y Competitividad of Spain under grants FIS2014-53371-C04 and the Severo Ochoa Program SEV-2014-0398; the GVA of Spain under grant PROM-ETEO/2016/120; the Portuguese FCT and FEDER through the program COMPETE, project PTDC/FIS-NUC/2525/2014 and UID/FIS/04559/2013; the U.S. Department of Energy under contracts number DE-AC02-07CH11359 (Fermi National Accelerator Laboratory) and DE-FG02-13ER42020 (Texas A& and the University of Texas at Arlington.Azevedo, C.; Gonzalez-Diaz, D.; Biagi, SF.; Oliveira, CAB.; Henriques, CAO.; Escada, J.; Monrabal, F.... (2018). Microscopic simulation of xenon-based optical TPCs in the presence of molecular additives. Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment. 877:157-172. https://doi.org/10.1016/j.nima.2017.08.049S15717287

    A measurement of the branching ratio sigma+goes to rho gamma/ sigma+goes to rho pi0)

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    Bristol-Geneva-Heidelberg-Lausanne-Queen Mary College-RAL collaborationSIGLEAvailable from British Library Lending Division - LD:8053.4153(RAL--85-048) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

    A measurement of the branching ratio sigma+goes to rho gamma/ sigma+goes to rho pi0)

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    Bristol-Geneva-Heidelberg-Lausanne-Queen Mary College-RAL collaborationSIGLEAvailable from British Library Lending Division - LD:8053.4153(RAL--85-048) / BLDSC - British Library Document Supply CentreGBUnited Kingdo
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