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A. K. Chaudhuri

Publications and source records attributed to A. K. Chaudhuri.

95 records · Page 6Linked to original sources
arXiv1998

Chemical equilibration in viscous quark-gluon plasma and electromagnetic signals

We investigate the chemical equilibration of the parton distributions in collisions of two heavy nuclei, assuming the partonic fluid to be ideal as well as viscous. The initial conditions are taken from HIJING calculations for Au+Au collisions at RHIC and LHC energies. It was seen that when the viscous drag is taken into account in the fluid flow, the life time of the plasma is increased by nearly a factor of 2. The temperature as well as fugacities evolve slowly than their ideal counterpart. The photon and lepton pair production was also investigated. There is a two fold increase in the photon and lepton pair numbers with viscosity on. The increase in the large $p_T$ photons and the large invariant mass lepton pairs are due to slower rate of temperature evolution.

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arXiv1997

Frozen motion model and dilepton production from 200A GeV S+W collisions at CERN SPS

We have analysed the invariant mass distribution of dileptons in S+W collisions at 200A GeV as measured by the HELIOS-3 collaboration at CERN SPS. Three scenarios were considered where the collision lead to formation of (i) the quark-gluon plasma, (ii) the ideal hot hadron gas and (iii) the viscous hot hadron gas. The space-time evolution was governed by the minimal extension of the Bjorken hydrodynamics. All the three scenarios indicate excess dileptons in the experiment.

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arXiv1997

Superstring dominated early universe and epoch dependent gauge coupling

We have explored the possibility that the universe at very early stage was dominated by (macroscopic) heterotic strings. We have found that the dimensionless parameter $Gμ$ for the heterotic strings varies from $10^{-2}$ to $10^{-4}$ as the universe evolve from the matter dominance to radiation dominance. This led to the interesting consequence of epoch dependent gauge coupling constant. The gauge coupling constant at early times was found to be much stronger than the present strong interaction.

hep-th↗
arXiv1997

Effect of viscosity on one dimensional hydrodynamic flow and direct photons from 200 AGeV S+Au collisions at CERN SPS

We have analysed the direct photon data obtained by the WA80 collaboration in 200 A GeV S+Au collision at CERN SPS, in a one dimensional hydrodynamical model. Two scenario was considered: (i) formation of quark-gluon plasma and (ii) formation of hot hadronic gas. For both the scenario, ideal as well as extremely viscous fluid was considered. It was found that direct photon yield from QGP is not affected much whether the fluid is treated as ideal or extremely viscous. The yield however differ substantially if hadron gas is produced. Both the scenario do not give satisfactory description of the data.

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