Particle multiplicity distributions in p-p Collisions at root(sNN) = 0.9 TeV

Abstract: The mid-rapidity transverse momentum spectra of hadrons (p, p-bar, K+, K-, K0-short, phi, {\Lambda}, {\Lambda}-bar, {\Xi},{\Xi}-bar, ({\Xi} + {\Xi}-bar), {\Omega}, and {\Omega}-bar) and the available rapidity distributions of the strange hadrons K0-short, ({\Lambda} + {\Lambda}-bar), ({\Xi} + {\Xi}-bar) produced in p-p collisions at LHC energy root(sNN) = 0.9 TeV have been studied using a Unified Statistical Thermal Freeze-out Model (USTFM). The calculated results are found to be in good agreement with the experimental data. The theoretical fits of the transverse momentum spectra using the model calculations provide the thermal freeze-out conditions in terms of the temperature and collective flow parameters for different hadronic species. The study reveal the presence of significant collective flow and a well defined temperature in the system thus indicating the formation of a thermally equilibrated hydrodynamic system in p-p collisions at LHC. Moreover, the fits to the available experimental rapidity distributions data of strange hadrons show the effect of almost complete transparency in p-p collisions at LHC. The model incorporates longitudinal as well as a transverse hydrodynamic flow. The contributions from heavier decay resonances have also been taken into account. We have also imposed the criteria of exact strangeness conservation in the system.