The Kolmogorov-Smirnov test and its use for the identification of fireball fragmentation

Physical Review C (Impact Factor: 3.73). 02/2009; 80:024904. DOI: 10.1103/PhysRevC.80.024904
Source: arXiv


We propose an application of the Kolmogorov-Smirnov test for rapidity distributions of individual events in ultrarelativistic heavy ion collisions. The test is particularly suitable to recognise non-statistical differences between the events. Thus when applied to a narrow centrality class it could indicate differences between events which would not be expected if all events evolve according to the same scenario. In particular, as an example we assume here a possible fragmentation of the fireball into smaller pieces at the quark/hadron phase transition. Quantitative studies are performed with a Monte Carlo model capable of simulating such a distribution of hadrons. We conclude that the Kolmogorov-Smirnov test is a very powerful tool for the identification of the fragmentation process. Comment: 9 pages, 10 figures

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Available from: Mikulas Gintner
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    ABSTRACT: We propose to use the Kolmogorov-Smirnov test to uncover non-statistical differences between events created in heavy ion collisions within the same centrality class. The advantage of the method over other approaches which are currently in use, is that it is sensitive to any difference between the events and is not restricted to simple moments of the distribution of hadrons. The particular application examined here is the identification of the fireball decay due to spinodal fragmentation and/or sudden rise of the bulk viscosity. Comment: 4 pages, 2 figures - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennessee v2 one typo corrected and references updated
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