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تسجيل مستخدم جديدThe statistical model in Pb-Pb collisions at the LHC
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We briefly review the predictions of the thermal model for hadron production in comparison to latest data from RHIC and extrapolate the calculations to LHC energy. Our main emphasis is to confront the model predictions with the recently released data from ALICE at the LHC. This comparison reveals an apparent anomaly for protons and anti-protons which we discuss briefly. We also demonstrate that our statistical hadronization predictions for J/$psi$ production agree very well with the most recent LHC data, lending support to the picture in which there is complete charmonium melting in the quark-gluon plasma (QGP) followed by statistical generation of J/$psi$ mesons at the phase boundary.
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The systematics of Statistical Model parameters extracted from heavy-ion collisions at lower energies are exploited to extrapolate in the LHC regime. Predictions of various particle ratios are presented and particle production in central Pb-Pb collis
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We study charm production in Pb+Pb collisions at $sqrt{s_{rm NN}}=$2.76 TeV in the Parton-Hadron-String-Dynamics transport approach and the charm dynamics in the partonic and hadronic medium. The charm quarks are produced through initial binary nucle
on-nucleon collisions by using the PYTHIA event generator taking into account the (anti-)shadowing incorporated in the EPS09 package. The produced charm quarks interact with off-shell massive partons in the quark-gluon plasma and are hadronized into $D$ mesons through coalescence or fragmentation close to the critical energy density, and then interact with hadrons in the final hadronic stage with scattering cross sections calculated in an effective Lagrangian approach with heavy-quark spin symmetry. The PHSD results show a reasonable $R_{rm AA}$ and elliptic flow of $D$ mesons in comparison to the experimental data for Pb+Pb collisions at $sqrt{s_{NN}}$ = 2.76 TeV from the ALICE Collaboration. We also study the effect of temperature-dependent off-shell charm quarks in relativistic heavy-ion collisions. We find that the scattering cross sections are only moderately affected by off-shell charm degrees of freedom. However, the position of the peak of $R_{rm AA}$ for $D$ mesons depends on the strength of the scalar partonic forces which also have an impact on the $D$ meson elliptic flow. The comparison with experimental data on the $R_{rm AA}$ suggests that the repulsive force is weaker for off-shell charm quarks as compared to that for light quarks. Furthermore, the effects from radiative charm energy loss appear to be low compared to the collisional energy loss up to transverse momenta of $sim$ 15 GeV/c.
Predictions for particle production at LHC are discussed in the context of the statistical model. Moreover, the capability of particle ratios to determine the freeze-out point experimentally is studied, and the best suited ratios are specified. Final
ly, canonical suppression in p-p collisions at LHC energies is discussed in a cluster framework. Measurements with p-p collisions will allow us to estimate the strangeness correlation volume and to study its evolution over a large range of incident energies.
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