摘要Aiming at using sphericity as a tool to study the isotropy-equilibrium property of a multi-particle system, in particular the hadronic final state IFS produced in instanton-induced DIS events, we discuss in detail the dependence of sphericity on multiplicity and the multiplicity distribution, as well as on the isotropy degree of the system. A rotational symmetric model with a fluctuating isotropy-degree is constructed, which can fit the mean and width of sphericity of the Monte Carlo IFS-results simultaneously. The IFS from the Monte Carlo simulation is found to be not ideally isotropic but has a probability of 4.7% to be isotropic within error of 5%. The results provide us a description of how far the IFS departs from equilibrium. The method developed is applicable to any Monte Carlo generated multi-particle system, for which the isotropy-equilibrium property is significant.
Abstract：Aiming at using sphericity as a tool to study the isotropy-equilibrium property of a multi-particle system, in particular the hadronic final state IFS produced in instanton-induced DIS events, we discuss in detail the dependence of sphericity on multiplicity and the multiplicity distribution, as well as on the isotropy degree of the system. A rotational symmetric model with a fluctuating isotropy-degree is constructed, which can fit the mean and width of sphericity of the Monte Carlo IFS-results simultaneously. The IFS from the Monte Carlo simulation is found to be not ideally isotropic but has a probability of 4.7% to be isotropic within error of 5%. The results provide us a description of how far the IFS departs from equilibrium. The method developed is applicable to any Monte Carlo generated multi-particle system, for which the isotropy-equilibrium property is significant.
LIU Zhi-Qing;LI Run-Ze;XU Ming-Mei;LIU Lian-Shou. A Measure for Isotropy-Equilibrium Degree of a Multi-Particle System[J]. 中国物理快报, 2008, 25(2): 447-450.
LIU Zhi-Qing, LI Run-Ze, XU Ming-Mei, LIU Lian-Shou. A Measure for Isotropy-Equilibrium Degree of a Multi-Particle System. Chin. Phys. Lett., 2008, 25(2): 447-450.
[1]Braun-Munzinger P et al 2004 Quark Gluon Plasma 3 edsHwa R C and Wang X N (Singapore: World Scientific) p 491 [2] Ringwald A and Schrempp F 1995 Proceedings Quarks'94 eds Grigoriev D et al (Singapore: World Scientific)hep-ph/9411217 Moch S, Ringwald A and Schrempp F 1997 Proceedings DISand QCD (DIS97) eds Repond J et al (Woodbury: AIP) hep-ph/9706400 [3] Strobele H et al 1983 Phys. Rev. C 271349 [4] Sjostrand T 1994 Comput. Phys. Commun. 82 74 [5] Belavin A et al 1975 Phys. Lett. B 59 85 [6] Hooft G 1976 Phys. Rev. Lett. 37 8 Hooft G 1976 Phys. Rev. D 14 3432 Hooft G Erratum in 1978 Phys.Rev. D 18 2199 Hooft G 1986 Phys. Rep. 142 357 [7] Bjorken J D and Brodsky S J 1970 Phys. Rev. D 1 1416 [8] Xu M M and Liu L S hep-ph/0610244 [9] Csorg\H{o T et al 2005 Proceedings of QuarkMatter (Amsterdam: Elsevier) and references therein [10] STAR white paper nucl-ex/0501009 v2 Adler et al (STAR Collab.) 2002 Phys. Rev. Lett. 89 132301 [11] Bravina L 2006 J. Phys. G 32 S213, and talkgiven at ICHEP'06 in Moscow [12] Belkacem M 1998 Phys. Rev. C 58 1727 [13] Sorge H 1995 Phys. Rev. C 52 3291 [14] Bass S A et al 1998 Prog. Part. Nucl. Phys. 41 225 [15] Lin Z W et al 2005 Phys. Rev. C 72 064901 Zhang B et al 2000 Phys. Rev. C 61 067901
2008, Vol. 25 
