Particle Transverse Momentum Distributions in p-p Collisions at √sNN=0.9 TeV

Abstract

The mid-rapidity transverse momentum spectra of hadrons (p, p , K + , K -, , φ, Λ, Λ , Ξ , Ξ , (Ξ + Ξ ), Ω, and Ω ) and the available rapidity distributions of the strange hadrons ( , (Λ + Λ ), (Ξ + Ξ ) produced in p-p collisions at LHC energy √s NN = 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 decayresonances have also been taken into account. We have also imposed the criteria of exact strangeness conservation in the system. *inamhep@gmail.com

Analysis of Midrapidity pT Distributions of Identified Charged Particles in Pb + Pb Collisions at snn = 5.02 TeV Using Tsallis Distribution with Embedded Transverse Flow

“…The critical temperature, T c ≈ 150-170 MeV, and corresponding critical energy density, ε c ≈ 1 GeV/fm 3 , for a phase transition from a nucleon to QGP matter have been obtained from lattice QCD (quantum chromodynamics) calculations [36,37]. The analogous QGP signatures with collective properties, similar to those in heavy-ion collisions, have also been observed in proton + proton collision events with high multiplicities [8][9][10]23,[38][39][40][41][42][43][44][45][46][47][48][49] in the LHC.…”

Multiplicity Dependencies of Midrapidity Transverse Momentum Distributions of Identified Charged Particles in Proton-Proton Collisions at (s)1/2 = 7 TeV at the LHC

“…The various features of QGP: the enhancement of strangeness [38], hardening of p t distributions [39,40], and other QGP characteristics [35][36][37][41][42][43][44][45][46][47][48][49][50]58], obtained in protonproton collisions at the LHC have been published. The onset of collective radial expansion in proton-proton collisions at (s) 1/2 = 900 and 7000 GeV at the LHC have been reported in [35].…”

“…Such analyses are needed not only because the results from proton-proton collisions are used as a baseline for the investigation of heavy-ion collisions, but also to study the collective properties of a system produced in proton-proton collisions at the largest energies achieved at modern collider experiments [15]. The observations [21,[35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50] of different QGP signals in high-multiplicity proton-proton collisions at the LHC, including strong similarity and resemblance of their collective properties to those of heavy ions, serve as a good motivation to further investigate the high-energy proton-proton collisions.…”