arXiv subjects

Riyaz Ahmed Bhat

Publications and source records attributed to Riyaz Ahmed Bhat.

6 recordsLinked to original sources

arXiv2015

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

The mid-rapidity transverse momentum spectra of hadrons (p, p-bar, K+, K-, K0-short, phi, Λ, Λ-bar, Ξ,Ξ-bar, (Ξ + Ξ-bar), Ω, and Ω-bar) and the available rapidity distributions of the strange hadrons K0-short, (Λ + Λ-bar), (Ξ + Ξ-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.

hep-ph↗

arXiv2015

Evidence of Collective Flow in p-p Collision at LHC

The transverse momentum distributions of hadrons produced in p-p collisions at LHC energies of Root(sNN) = 0.9 TeV, 2.76 TeV and Root(sNN) = 7.0 TeV have been studied using a unified statistical thermal freeze-out model. A good agreement is seen between the theoretical calculations and experimental data. The extracted thermal freeze-out parameters 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. The transverse momentum distributions of protons and Kaons produced in p-p collisions at Root(sNN) = 200 GeV have also been reproduced successfully. The model incorporates a longitudinal as well as transverse hydrodynamic flow. The contributions from heavier decay resonances have also been taken into account.

hep-ph↗

arXiv2014

Study of Centrality Dependence of Transverse Momentum Spectra of Hadrons and the Freeze-out Parameters at root(sNN) of 62.4 GeV, 130 GeV and 200 GeV

We attempt to describe the rapidity distribution of P, P-bar, K+ and K- for the most central Au+Au collisions at root(sNN) of 62.4 GeV,130 GeV and 200 GeV. The transverse momentum spectra of strange as well as non-strange hadrons e.g. P, P-bar, K+, K-, Lambda, Lambda-bar, Cascade,Cascade-bar and (Omega + Omega-bar) are studied for the whole centrality classes at all the three RHIC energies. The experimental data of the transverse momentum spectra and the rapidity distributions are well reproduced. This is done by using a statistical thermal freeze-out model which incorporates the rapidity (collision) axis as well as transverse direction boosts developed within an expanding hot and dense hadronic fluid (fireball) till the final freeze-out. We determine the thermo-chemical freeze-out conditions particularly in terms of temperature, baryon chemical potential and collective flow effect parameters for different particle species. The parameters indicate occurrence of freeze-out of the singly and doubly strange hyperon species at somewhat earlier times during the evolution of the fireball. Dependence of the freeze-out parameters on the degree of centrality is also described and it is found that the kinetic temperature increases and collective flow effect decreases with decreasing centrality at all energies studied. The nuclear transparency effect is also studied and it is clear from our model that the nuclear matter becomes more transparent at the highest RHIC energy compared to lower RHIC energies. The contribution of heavier hadronic resonance decay is taken into account.

hep-ph↗

arXiv2014

Study of Centrality Dependence of Kinetic Freeze-out Conditions in Pb + Pb Collisions at Root(sNN)= 2.76 TeV

The transverse momentum spectra of identified particles at midrapidity in Pb + Pb collisions at Root(sNN) = 2.76 TeV have been studied as a function of collision centrality by using a unified statistical thermal freeze-out model. The calculated results are found to be in good agreement with the experimental data measured by the ALICE experiment at LHC. The model calculations provide the thermal freeze-out conditions in terms of the temperature and collective flow parameters for different particle species. We observe a rise in the thermal freeze-out temperature but a mild decrease in the collective flow velocity parameter from central to peripheral collisions. The model used incorporates the simultaneous effect of the longitudinal as well as transverse hydrodynamic flows. The baryon chemical potential is assumed to be zero (μB ~ 0), a situation expected in the heavy ion collisions at LHC energies due to a high degree of nuclear transparency.

hep-ph↗

arXiv2014

A Study of Transverse Momentum Distributions of Hadrons at LHC

The transverse momentum distributions of various hadrons produced in most central Pb+Pb collisions at LHC energy Root(s_NN) = 2.76 TeV have been studied using our earlier proposed unified statistical thermal freeze-out model. The calculated results are found to be in good agreement with the experimental data measured by the ALICE experiment. The model calculation fits provide the thermal freeze-out conditions in terms of the temperature and collective flow effect parameters for different particle species. Interestingly the model parameter fits reveal a strong collective flow in the system which appears to be a consequence of the increasing particle density at LHC. The model used incorporates a longitudinal as well as transverse hydrodynamic flow. The chemical potential has been assumed to be nearly equal to zero for the bulk of the matter owing to a high degree of nuclear transparency effect at such energies. The contributions from heavier decay resonances are also taken into account in our calculations.

hep-ph↗

arXiv2014

Systematic of Particle Thermal Freeze-out in a Hadronic Fireball at RHIC

We attempt to describe the rapidity and transverse momentum spectra of strange as well as non-strange hadrons e.g. cascade,cascadebar, lambda , lambdabar, proton, protonbar,(omega+omegabar, Kaon, anti-Kaon and their ratios in the ultra-relativistic collisions of gold nuclei at (Root sNN)=200 GeV. This is done by using a statistical thermal freeze-out model which incorporates the rapidity (collision) axis as well as transverse direction boosts developed within an expanding hot and dense hadronic fluid (fireball) till the final freeze-out. We determine the thermo-chemical freeze-out conditions particularly in terms of the temperature, baryon chemical potential and collective flow effect parameters for different particle species. The parameters indicate occurrence of freeze-out of the singly and doubly strange hyperon species at somewhat earlier times during the evolution of the fireball. The experimental data of the transverse momentum and rapidity distribution are well reproduced. The contribution of heavier hadronic resonance decay is taken into account.

hep-ph↗