Role of system size in freeze-out conditions extracted from transverse momentum spectra of hadrons

作     者：Ajay Kumar Dash Ranbir Singh Sandeep Chatterjee Chitrasen Jena Bedangadas Mohanty 

作者机构：School of Physical Sciences National Institute of Science Education and Research HBNI Jatni 752050 India AGH University of Science and Technology Faculty of Physics and Applied Computer Science al. Mickiewicza 30 30-059 Krakow Poland and Department of Physical Sciences Indian Institute of Science Education and Research Berhampur Transit Campus Government ITI Berhampur 760010 Odisha India Indian Institute of Science Education and Research Tirupati 517507 India 

出 版 物：《Physical Review C》 (物理学评论C辑：核物理学)

年 卷 期：2018年第98卷第6期

页      面：064902-064902页

核心收录：

学科分类：07[理学] 070202[理学-粒子物理与原子核物理] 0702[理学-物理学] 

基　　金：Ministry of Science and Higher Education Narodowe Centrum Nauki, NCN, (2015/17/B/ST2/00101) Narodowe Centrum Nauki, NCN Akademia Górniczo-Hutnicza im. Stanislawa Staszica, AGH Department of Science and Technology, Government of West Bengal, DST 

主　　题：Hydrodynamic models Particle & resonance production Relativistic heavy-ion collisions Thermal & statistical models 

摘      要：The data on hadron transverse momentum spectra in different centrality classes of p + Pb collisions at sNN=5.02 TeV have been analyzed to extract the freeze-out hypersurface within a simultaneous chemical and kinetic freeze-out scenario. The freeze-out hypersurface has been extracted for three freeze-out schemes that differ in the way strangeness is treated: (i) unified freeze-out for all hadrons at complete thermal equilibrium (1FO), (ii) unified freeze-out for all hadrons with an additional parameter γS which accounts for possible out-of-equilibrium production of strangeness (1FO+γS), and (iii) separate freeze-out for hadrons with and without strangeness content (2FO). Unlike in heavy-ion collisions where 2FO performs best in describing the mean hadron yields as well as the transverse momentum spectra, with p + Pb we find that 1FO+γS with one fewer parameter than 2FO performs better. This confirms expectations based on previous analysis of system size dependence in the freeze-out scheme with mean hadron yields: while heavy-ion collisions that are dominated by constituent interactions prefer 2FO, smaller collision systems like proton + nucleus and proton + proton collisions with lesser constituent interaction prefer a unified freeze-out scheme with varying degrees of strangeness equilibration.