Contrasting freezeouts in large versus small systems. (6th September 2017)

• Record Type: Journal Article
• Authors: Chatterjee, Sandeep; Dash, Ajay Kumar; Mohanty, Bedangadas
• Is Part Of: Journal of physics. Volume 44:Number 10(2017:Oct.)
• Publication Date: 2017-09-06
• Subjects: chemical freezeout -- thermal model -- particle production; Nuclear physics -- Periodicals; Particles (Nuclear physics) -- Periodicals; Physique nucléaire -- Périodiques; Particules (Physique nucléaire) -- Périodiques; Kernfysica; Elementaire deeltjes; 539.7
• DOI: 10.1088/1361-6471/aa8857
• Languages: English
• ISSNs: 0954-3899

Abstract

Abstract: We study the data on mean hadron yields and contrast the chemical freezeout (CFO) conditions in p+p, p+Pb and Pb+Pb at the Large Hadron Collider energies. We study several schemes for freezeout that mainly differ in the way strangeness is treated: i. Strangeness freezes out along with the non-strange hadrons in complete equilibrium (1CFO), ii. Strangeness freezes out along with non-strange hadrons with an additional parameter γ S accounting for non-equilibrium production of strangeness (1CFO+ γ S ), and iii. Strangeness freezes out earlier than non-strange hadrons and in thermal equilibrium (2CFO). A comparison of the chisquares of the fits indicate a dependence of the freezeout scheme on the system size. The minimum bias p+p and different centralities of p+Pb and peripheral Pb+Pb data prefer 1CFO + γ S with γ S approaching unity as we go from p+p to central p+Pb and peripheral Pb+Pb. On the other hand, the mid-central to central Pb+Pb data prefer 2CFO over 1CFO+ γ S . Such system size dependence of the freezeout scheme could be an indication of the additional interaction in Pb+Pb over p+Pb and p+p.