876 research outputs found
Particle number fluctuations in high energy nucleus-nucleus collisions from microscopic transport approaches
Event-by-event multiplicity fluctuations in nucleus-nucleus collisions are studied within the HSD and UrQMD transport models. The scaled variances of negative, positive, and all charged hadrons in Pb+Pb at 158 AGeV are analyzed in comparison to the data from the NA49 Collaboration. We find a dominant role of the fluctuations in the nucleon participant number for the final hadron multiplicity fluctuations. This fact can be used to check di erent scenarios of nucleus-nucleus collisions by measuring the final multiplicity fluctuations as a function of collision centrality. The analysis reveals surprising e ects in the recent NA49 data which indicate a rather strong mixing of the projectile and target hadron production sources even in peripheral collisions. PACS numbers: 25.75.-q,25.75.Gz,24.60.-
Femtoscopy correlations of kaons in collisions at LHC within hydrokinetic model
We provide, within the hydrokinetic model, a detailed investigation of kaon
interferometry in collisions at LHC energy (
TeV). Predictions are presented for 1D interferometry radii of and
pairs as well as for 3D femtoscopy scales in out, side and
long directions. The results are compared with existing pion interferometry
radii. We also make predictions for full LHC energy.Comment: 12 pages, 6 figure
Electron-Hadron Correlations in pp Collisions at \sqrt{s} = 2.76 TeV with the ALICE experiment
In this work we are studying the relative beauty to charm production in pp
collisions at \sqrt{s} = 2.76 TeV, through correlations between electrons from
heavy-flavour decay and charged hadrons, with the ALICE detector at the LHC.
This study represents a baseline for the analysis in heavy-ion collisions where
heavy flavour production is a powerful tool to study the Quark Gluon Plasma
(QGP).Comment: Proceeding of the XII HADRON PHYSICS (2012, Bento Gon\c{c}alvez,
Brazil) conference. 3 Pages, 4 Figure
Using the Balance Function to study the charge correlations of hadrons
We present the recent Balance Function (BF) results obtained by the NA49
collaboration for the pseudo-rapidity dependence of non-identified charged
particle correlations for two SPS energies. Experimental results indicate a
clear centrality dependence only in the mid-rapidity region. The results of an
energy dependence study of the BF throughout the whole SPS energy range will
also be discussed. In addition, the correlation of identified hadrons is
studied and presented for the first time. The study of hadron correlation has
also been extended in order to cope with the high multiplicity environment that
is expected to be seen at LHC. We will present the latest results from
simulations concerning the extension of these studies to the ALICE experiment.Comment: To appear in the proccedings of the "Quark Confinement and Hadron
Spectrum VII" conferenc
Model independent analysis of nearly L\'evy correlations
A model-independent method for the analysis of the two-particle short-range
correlations is presented, that can be utilized to describe e.g. Bose-Einstein
(HBT), dynamical (ridge) or other correlation functions, that have a nearly
L\'evy or streched exponential shape. For the special case of L\'evy exponent
alpha = 1, the earlier Laguerre expansions are recovered, for the alpha = 2
special case, a new expansion method is obtained for nearly Gaussian
correlation functions. Multi-dimensional L\'evy expansions are also introduced
and their potential application to analyze rigde correlation data is discussed
Event-by-event multiplicity fluctuations in Pb-Pb collisions in ALICE
Fluctuations of various observables in heavy-ion collisions at
ultra-relativistic energies have been extensively studied as they provide
important signals regarding the formation of a Quark-Gluon Plasma (QGP).
Because of the large number of produced particles in each event, a detailed
study of event-by-event multiplicity fluctuations has been proposed as one of
the signatures of the phase transition. In addition, the understanding of
multiplicity fluctuations is essential for other event-by-event measurements.
In the present work, we have calculated the scaled variance () of the charged-particle multiplicity distributions
as a function of centrality in Pb-Pb collisions at LHC energies. Here,
and denote the mean and the width of the multiplicity distributions,
respectively. The trend of scaled variances as a function of centrality is
presented and discussed. Volume fluctuations play an important role while
measuring the multiplicity fluctuations, which are also discussed. The results
are expected to provide vital input to theoretical model calculations.Comment: Proceedings of "XI Workshop on Particle Correlations and Femtoscopy",
3-7 November 2015. 5 pages, 2 figure
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