https://doi.org/10.1140/epja/i2019-12669-6
Regular Article - Theoretical Physics
Radial flow and differential freeze-out in proton-proton collisions at 
TeV at the LHC
1
Discipline of Physics, School of Basic Sciences, Indian Institute of Technology Indore, 453552, Indore, India
2
UCT-CERN Research Centre and Department of Physics, University of Cape Town, 7701, Rondebosch, South Africa
* e-mail: Raghunath.Sahoo@cern.ch
Received:
8
August
2018
Accepted:
4
December
2018
Published online:
18
January
2019
We analyse the transverse momentum (
)-spectra as a function of charged-particle multiplicity at midrapidity (
) for various identified particles, such as 
, 
, 
, 
, 
, 
, and 
in proton-proton collisions at 
TeV using Boltzmann-Gibbs Blast Wave (BGBW) model and thermodynamically consistent Tsallis distribution function. We obtain the multiplicity-dependent kinetic freeze-out temperature (
) and radial flow (
) of various particles after fitting the p
T-distribution with BGBW model. Here, exhibits mild dependence on multiplicity class while 
shows almost independent behaviour. The information regarding Tsallis temperature and the non-extensivity parameter (q are drawn by fitting the 
-spectra with Tsallis distribution function. The extracted parameters of these particles are studied as a function of charged particle multiplicity density (
). In addition to this, we also study these parameters as a function of particle mass to observe any possible mass ordering. All the identified hadrons show a mass ordering in temperature, non-extensive parameter and also a strong dependence on multiplicity classes, except the lighter particles. It is observed that as the particle multiplicity increases, the q-parameter approaches to Boltzmann-Gibbs value, hence a conclusion can be drawn that system tends to thermal equilibrium. The observations are consistent with a differential freeze-out scenario of the produced particles.
© SIF, Springer-Verlag GmbH Germany, part of Springer Nature, 2019
