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arXiv · 1608.00643

Contrasting Freezeouts in Large Versus Small Systems

Sandeep Chatterjee·Ajay Kumar Dash·Bedangadas Mohanty
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Abstract

We study the data on mean hadron yields and contrast the chemical freezeout conditions in p+p, p+Pb and Pb+Pb at the Large Hadron Collider (LHC) 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 freezeout scheme could be an indication of the additional interaction in Pb+Pb over p+Pb and p+p.

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Sandeep Chatterjee, Ajay Kumar Dash, Bedangadas Mohanty. 2017-09-06. Contrasting Freezeouts in Large Versus Small Systems. https://doi.org/10.1088/1361-6471%2Faa8857

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