Eur. Phys. J. A (2016) 52: 196
https://doi.org/10.1140/epja/i2016-16196-8

Regular Article - Experimental Physics

Event-by-Event pseudorapidity fluctuation analysis: An outlook to multiplicity and phase space dependence

¹ Nuclear and Particle Physics Research Centre, Department of Physics, Jadavpur University, 700 032, Kolkata, India
² Department of Physics, New Alipore College, L Block, 700053, New Alipore, Kolkata, India

Received: 21 January 2016
Revised: 16 June 2016
Accepted: 24 June 2016
Published online: 21 July 2016

Abstract

A detailed study of Event-by-Event pseudorapidity fluctuation of the pions produced in ¹⁶O -AgBr interactions at 60A GeV and ³²S -AgBr interactions at 200A GeV has been carried out in terms of , a variable defined as a measure of fluctuation. Non-zero values indicate the presence of strong correlation among the pions for both interactions. Multiplicity and rapidity dependence of the Event-by-Event pseudorapidity fluctuation has been investigated. A decrease of with average multiplicity and increase of the same variable with pseudorapidity width are observed. Decrease of with average multiplicity is concluded as the particle emission by several independent sources occurs for higher-multiplicity events. The increase in values with pseudorapidity width, taken around central rapidity, might hint towards the presence of long-range correlation and its dominance over short range one. We have compared our experimental results with Monte Carlo simulation generated assuming independent particle emission. Comparison shows that the source of correlation and fluctuation is the dynamics of the pion production process. We have also compared our results with events generated by FRITIOF code. Such events also show the presence of fluctuation and correlation; however they fail to replicate the experimental findings.