Speaker
SABITA DAS
(NISER, Bhubaneswar, India)
Description
Particle multiplicities measured at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) facilities can be used to understand the chemical freeze-out dynamics. At chemical freeze-out (CFO), inelastic collisions cease and the freeze-out parameters can be determined using measured particle multiplicities within the framework of a statistical model.The statistical model has proven to be quite successful in describing the particle production from elementary $p-p$ and $e^{+}e^{-}$ collisions up to heavy-ion collisions [1,2]. It helps to do a systematic study of the centrality and energy dependence of freeze-out parameters in heavy-ion collisions from lower SPS to higher LHC energies [3]. The new data at LHC along with the RHIC data can be used to do such a systematic study in proton-proton collisions.
Here, we will present the particle production in proton-proton collisions within a statistical model at RHIC center-of-mass energy $\sqrt{s}$ = 200 GeV and at LHC center-of-mass energy $\sqrt{s}$ = 900 GeV and 7 TeV. In this model, particle production is described by a set of thermal parameters like the temperature, the volume and the set of chemical potentials corresponding to different conserved quantities such as baryon number, strangeness and charge. Two different freeze-out schemes have been used for this study. One is single freeze-out (1CFO) [4] where all hadrons freeze-out together. Other one is double freeze-out (2CFO) [5] where strange and non-strange hadrons freeze-out separately giving two different sets of parameters. We will discuss the energy dependence of different chemical freeze-out parameters in 1CFO. The freeze-out parameters are also extracted in 2CFO and compared with 1CFO. The non-strange temperature is found to be lower than that of strange temperature in 2CFO for all energies studied here which can be interpreted as the early freeze-out of strange hadrons. The freeze-out parameters from 1CFO found to lie intermediate to the corresponding strange and non-strange values of 2CFO.
**References**
1. J. Cleymans et al. Phys. Rev. C 79, 014901 (2009).
2. J. Cleymans and K. Redlich, Phys. Rev. C 60, 054908 (1999).
3. S. Chatterjee et al., Adv. in High Eng. Phys., Vol. 2015, Review Article ID: 349013.
4. S. Wheaton and J. Cleymans, Comput. Phys. Commun. 180, 84 (2009).
5. S. Chatterjee, R. Godbole, and S. Gupta, Phys. Lett. B 727, 554(2013).
Author
SABITA DAS
(NISER, Bhubaneswar, India)
Co-authors
Bedangadas Mohanty
(NISER, Bhubaneshwar, India)
DEBADEEPTI MISHRA
(NISER, Bhubaneshwar, India)
Sandeep Chatterjee
(Variable Energy Cyclotron Centre)
