Thermodynamic and transport properties of matter formed in pp, p-Pb, Xe–Xe and Pb–Pb collisions at the Large Hadron Collider using color string percolation model

Abstract

To have a better understanding of the matter formed in ultra-relativistic collisions, using the color string percolation model, we have estimated initial energy density, mean free path, squared speed of sound, shear viscosity to entropy density ratio (η/s), bulk viscosity to entropy density ratio and bulk modulus for pp, p-Pb, Xe–Xe and Pb–Pb collisions at the Large Hadron Collider (LHC). These observables are studied as a function of final state charged particle multiplicity density normalized by nuclear overlap area and initial state percolation temperature. The results from this work are compared with the results from well known QCD models and with the transport properties of matter found in day-to-day life. These observables allow us to conclude an array of important findings about the matter formed in high-energy collisions at the LHC. For the high-multiplicity events, the estimated η/s are comparable with that is observed for heavy-ion collisions, which is an indication of a strongly coupled quark gluon plasma. This makes LHC high-multiplicity pp collision events as probable candidates for the search of quark-gluon plasma droplets.