1,289 research outputs found

    Stable Bose-Einstein correlations

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    The shape of Bose-Einstein (or HBT) correlation functions is determined for the case when particles are emitted from a stable source, obtained after convolutions of large number of elementary random processes. The two-particle correlation function is shown to have a {\it stretched exponential} shape, characterized by the L\'evy index of stability 0<α2 0 < \alpha \le 2 and the scale parameter RR. The normal, Gaussian shape corresponds to a particular case, when α=2\alpha = 2 is selected. The asymmetry parameter of the stable source, β\beta is shown to be proportional to the angle, measured by the normalized three-particle cumulant correlations.Comment: 7 pages, no figures, invited talk of T. Csorgo at the 2nd Warsaw Meeting on Particle Correlations and Resonances in HIC, see http://hirg.if.pw.edu.pl/en/meeting/oct2003/talks/csorgo/Csorgo.pp

    Parallelized Particle and Gaussian Sum Particle Filters for Large Scale Freeway Traffic Systems

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    Large scale traffic systems require techniques able to: 1) deal with high amounts of data and heterogenous data coming from different types of sensors, 2) provide robustness in the presence of sparse sensor data, 3) incorporate different models that can deal with various traffic regimes, 4) cope with multimodal conditional probability density functions for the states. Often centralized architectures face challenges due to high communication demands. This paper develops new estimation techniques able to cope with these problems of large traffic network systems. These are Parallelized Particle Filters (PPFs) and a Parallelized Gaussian Sum Particle Filter (PGSPF) that are suitable for on-line traffic management. We show how complex probability density functions of the high dimensional trafc state can be decomposed into functions with simpler forms and the whole estimation problem solved in an efcient way. The proposed approach is general, with limited interactions which reduces the computational time and provides high estimation accuracy. The efciency of the PPFs and PGSPFs is evaluated in terms of accuracy, complexity and communication demands and compared with the case where all processing is centralized

    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

    Hyperthermia versus oncothermia: Cellular effects in complementary cancer therapy

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    Hyperthermia means overheating of the living object completely or partly. Hyperthermia, the procedure of raising the temperature of a part of or the whole body above normal for a defined period of time, is applied alone or as an adjunctive with various established cancer treatment modalities such as radiotherapy and chemotherapy. However, hyperthermia is not generally accepted as conventional therapy. The problem is its controversial performance. The controversy is originated from the complications of the deep heating and the focusing of the heat effect. The idea of oncothermia solves the selective deep action on nearly cellular resolution. We would like to demonstrate the force and perspectives of oncothermia, as a highly specialized hyperthermia in clinical oncology. Our aim is to prove the ability of oncothermia to be a candidate to become a widely accepted modality of the standard cancer care. We would like to show the proofs and the challenges of the hyperthermia and oncothermia applications to provide the presently available data and summarize the knowledge in the topic. Like many early stage therapies, oncothermia lacks adequate treatment experience and long-range, comprehensive statistics that can help us optimize its use for all indications. © 2013 Gabriella Hegyi et al

    Analytic Solution of the Pion-Laser Model

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    Brooding over bosons, wave packets and Bose - Einstein correlations, we find that a generalization of the pion-laser model for the case of overlapping wave-packets is analytically solvable with complete n-particle symmetrization. The effective radius parameter of the two-particle correlation function is reduced for low values and enlargened for high values of the mean momentum in the rare gas limiting case, as compared to the case when multi-particle symmetrization effects are neglected. These results explicitly depend on the multiplicity, providing a theoretical basis for event-by-event analysis of high energy heavy ion reactions.Comment: LaTeX, ReVTeX 3.1, 7 pages, uses 1 eps figure and epsfig.sty (shortened version
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