147 research outputs found
Particle production at energies available at the CERN Large Hadron Collider within evolutionary model
The particle yields and particle number ratios in Pb+Pb collisions at the LHC
energy TeV are described within the integrated
hydrokinetic model (iHKM) at the two different equations of state (EoS) for the
quark-gluon matter and the two corresponding hadronization temperatures,
MeV and MeV. The role of particle interactions at the final
afterburner stage of the collision in the particle production is investigated
by means of comparison of the results of full iHKM simulations with those where
the annihilation and other inelastic processes (except for resonance decays)
are switched off after hadronization/particlization, similarly as in the
thermal models. An analysis supports the picture of continuous chemical
freeze-out in the sense that the corrections to the sudden chemical freeze-out
results, which arise because of the inelastic reactions at the subsequent
evolution times, are noticeable and improve the description of particle and
number ratios. An important observation is that although the particle number
ratios with switched-off inelastic reactions are quite different at different
particlization temperatures which are adopted for different equations of state
to reproduce experimental data, the complete iHKM calculations bring very close
results in both cases.Comment: 12 pages, 4 figure
Photon spectra and anisotropic flow in heavy ion collisions at the top RHIC energy within the integrated hydrokinetic model with photon hadronization emission
The integrated HydroKinetic Model (iHKM) is applied to analyse the results of
direct photon spectra as well as elliptic and triangular flow measurements in
200A GeV Au+Au collisions at RHIC for different centrality bins. Experiments
detect the strong centrality dependence of photon elliptic and triangular flow
as increasing -coefficients towards peripheral collisions. The photon
production in the model is accumulated from the different sources along with
the process of relativistic heavy ion collision developing. Those include the
primary hard photons from the parton collisions at the very early stage of the
process, the photons generated at the pre-thermal phase of dense matter
evolution, then thermal photons at partially equilibrated hydrodynamic
quark-gluon stage, together with radiation displaying a confinement and,
finally, from the hadron gas phase. Along the way a hadronic medium evolution
is treated in two distinct, in a sense opposite, approaches: chemically
equilibrium and chemically non-equilibrium, namely, chemically frozen
expansion. We find the description of direct photon spectra, elliptic and
triangular flow are significantly improved, similar to that found in iHKM for
the LHC energies, if an additional portion of photon radiation associated with
the confinement processes, the "hadronization photons", is included into
consideration.Comment: 28 pages, 11 figures. arXiv admin note: substantial text overlap with
arXiv:1812.0276
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