13,662 research outputs found

    Detailed L3 measurements of Bose-Einstein correlations and a region of anti-correlations in hadronic Z^0 decays at LEP

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    L3 preliminary data of two-particle Bose-Einstein correlations are reported for hadronic Z^0 decays in e+e- annihilation at LEP. The invariant relative momentum Q is identified as the eigenvariable of the measured correlation function. Significant anti-correlations are observed in the Bose-Einstein correlation function in a broad region of 0.5 - 1.6 GeV with a minimum at Q close to 0.8 GeV. Absence of Bose-Einstein correlations is demonstrated in the region above Q >= 1.6 GeV. The effective source size is found to decrease with increasing value of the transverse mass of the pair, similarly to hadron-hadron and heavy ion reactions. These feautes and our data are described well by the non-thermal tau-model, which is based on strong space-time momentum-correlations.Comment: 5 pages, 1 figure, invited talk at the XXXIXth International Symposium on Multiparticle Dynamics, Gomel, Belarus, September 200

    Bose-Einstein or HBT correlations and the anomalous dimension of QCD

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    Bose-Einstein (or HBT) correlation functions are evaluated for the fractal structure of QCD jets. These correlation functions have a stretched exponential (or Levy-stable) form. The anomalous dimension of QCD determines the Levy index of stability, thus the running coupling constant of QCD becomes measurable with the help of two-particle Bose-Einstein correlation functions. These considerations are tested on NA22 and UA1 two-pion correlation data.Comment: 8 pages, 5 figures, presented by T. Csorgo at the XXXIV International Symposium on Multiparticle Dynamics, Sonoma County, California, USA, July 2004, to appear in Acta Physica Polonica

    Bose-Einstein or HBT correlation signature of a second order QCD phase transition

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    For particles emerging from a second order QCD phase transition, we show that a recently introduced shape parameter of the Bose-Einstein correlation function, the Levy index of stability equals to the correlation exponent - one of the critical exponents that characterize the behavior of the matter in the vicinity of the second order phase transition point. Hence the shape of the Bose-Einstein / HBT correlation functions, when measured as a function of bombarding energy and centrality in various heavy ion reactions, can be utilized to locate experimentally the second order phase transition and the critical end point of the first order phase transition line in QCD.Comment: 8 pages, talk given by T. Csorgo at the Workshop on Particle Correlations and Femtoscopy 2005, Kromeriz, Czech Republic, August 200

    Evidence of Odderon-exchange from scaling properties of elastic scattering at TeV energies

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    We study the scaling properties of the differential cross section of elastic proton-proton (pppp) and proton-antiproton (ppĖ‰p\bar p) collisions at high energies. We introduce a new scaling function, that scales -- within the experimental errors -- all the ISR data on elastic pppp scattering from s=23.5\sqrt{s} = 23.5 to 62.562.5 GeV to the same universal curve. We explore the scaling properties of the differential cross-sections of the elastic pppp and ppĖ‰p\bar p collisions in a limited TeV energy range. Rescaling the TOTEM pppp data from s=7\sqrt{s} = 7 TeV to 2.762.76 and 1.961.96 TeV, and comparing it to D0 ppĖ‰p\bar p data at 1.961.96 TeV, our results provide an evidence for a tt-channel Odderon exchange at TeV energies, with a significance of at least 6.26Ļƒ\sigma. We complete this work with a model-dependent evaluation of the domain of validity of the new scaling and its violations. We find that the H(x)H(x) scaling is valid, model dependently, within 200200 GeV ā‰¤sā‰¤ \leq \sqrt{s} \leq 8 8 TeV, with a āˆ’t-t range gradually narrowing with decreasing colliding energies.Comment: Accepted in EPJ C, with typos fixed, reorganized institutions updated, Appendix A, B, C, D, E added, 60 pages, 29 figures, 13 tables, Odderon significance: 6.26 sigma, conclusions unchange

    Pregled faune kosaca (Arachnida: Opiliones) Bosne i Hercegovine

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    A critical review of the literature on harvestmen from Bosnia and Herzegovina was performed, and data from major collections of harvestmen in Bosnia and Herzegovina have been listed to provide an overview of recent knowledge on the topic. Where needed, comments and/or corrections have been added to avoid further confusion. At the moment, 54 valid species and two subspecies have been identified of 59 nominal species in Bosnia and Herzegovina. Six nominal species must be confirmed with respect to taxonomical status and validity. Systematic taxonomical revisions are strongly required in the travuniid genera and in Paranemastoma. Six further species may be present in the country, and the discovery of new species cannot be excluded. According to present knowledge, the richness of the harvestman fauna of Bosnia and Herzegovina is comparable to that in the surrounding countries.U svrhu dobivanja trenutnog stanja poznavanja teme rada, donosi se kritički pregled literature o koscima Bosne i Hercegovine te podaci iz glavnih zbirki kosaca u Bosni i Hercegovini. Da bi se izbjegle eventualne daljnje greÅ”ke dodani su i komentari i/ili ispravci. U Bosni i Hercegovini sa sigurnoŔću su utvrđene 54 važeće vrste i jedna podvrsta od 59 nominalnih vrsta. Za Å”est nominalnih vrsta potrebne su taksonomske revizije, Å”to je pogotovo nužno u travuniidnim rodovima te u rodu Paranemastoma. Potencijalno tu živi joÅ” Å”est vrsta, a ne treba isključiti ni otkrivanje novih. Prema sadaÅ”njim spoznajama bogatstvo faune kosaca Bosne i Hercegovine može se usporediti s faunama kosaca susjednih zemalja

    Pregled faune kosaca (Arachnida: Opiliones) u Hrvatskoj

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    Critical review of the literature on harvestmen from Croatia was made, and data from major collections of harvestmen in Croatia are listed to provide an overview of recent knowledge on the topic. Where needed comments and/or corrections have been added to avoid further confusion. Altogether, 64 valid species and one subspecies have been firmly identified in Croatia. Two further species are undoubtedly present although not yet recorded, bringing the total number of opilionid species to 66 plus one subspecies. Potentially, up to 9ā€“11 further species inhabit the country, and the discovery of further new species cannot be excluded. Taxonomical revisions are required in some taxa. According to present knowledge, the harvestman fauna of Croatia is among the richest ones in the Balkans.Da bi se dobio pregled trenutnog poznavanja teme ovog rada, napravljen je kritički pregled literature o koscima u Hrvatskoj, te su navedeni podaci iz glavnih zbirki kosaca u Hrvatskoj. Da bi se izbjegle eventualne daljnje zbrke, dodani su i komentari i/ili ispravci. U Hrvatskoj je sa sigurnoŔću utvrđeno 64 važećih vrsta i jedna podvrsta. JoÅ” dvije vrste su sigurno prisutne u Hrvatskoj, iako nisu zabilježene, Å”to ukupno iznosi 66 vrsta i 1 podvrsta kosaca. Potencijalno tu živi joÅ” 9ā€“11 vrsta, a i ne treba isključiti ni otkrivanje novih. Kod nekih skupina potrebne su i taksonomske revizije. Prema sadaÅ”njim spoznajama fauna kosaca Hrvatske je među najbogatijima na balkanskom području

    Characterization and dewaterability of water treatment plant residues

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    nanA variety of water treatment residues were characterized in order to determine the influence of specific chemical constituents, process flow schemes and raw water quality on the performance of sludge dewatering processes. The use of conventional sludge characterization parameters for process selection and design was evaluated by comparing process yields to sludge characteristics. The extent of dewatering was determined for four sludge dewatering methods and the physical properties of chemical sludges at varying solids levels compared to process performance to determine which of the processes produces a 'handleable' sludge. In this study the draining and drying rates of chemical sludges applied to sand beds were related to several sludge characteristics. It was found that the time to drain was related to the sludge specific resistance, applied depth and solids concentration. Air drying occurred in two distinct phases. The initial or slow drying phase was governed by the sludge cake depth and drained solids concentration while the rapid drying rate was found to approximate the free surface water evaporation rate. Sludges with a coefficient of compressibility less than 0.7 were found to penetrate into the sand bed.Project # A-061-MO Agreement # 14-31-0001-3825 and 402
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