Speaker
Description
Results from RHIC for Au-Au and from LHC for Pb-Pb collisions are compiled in terms of $R_{AA}$, $R_{CP}$ and ratio of the $p_T$ spectra, normalized with the corresponding $dN_{ch}/d\eta$, for each centrality to the most peripheral one ($R^N_{CP}$). The studies are focused on the $p_T$ range in the region of maximum suppression evidenced in the experiment. The $R_{CP}$ for 4 GeV/c < $p_T$ < 6 GeV/c as a function of $\sqrt{s_{NN}}$ evidences a suppression enhancement from $\sqrt{s_{NN}}$ = 39 GeV up to 200 GeV after which a saturation sets in up to the highest energy of $\sqrt{s_{NN}}$ =5.02 TeV. For collision energies from 200 GeV (Au-Au) up to 5.02 TeV (Pb-Pb), within the error bars, a good scaling of $R_{AA}$ as a function of <$N_{part}$> is evidenced. This scaling improves for $R_{AA}$, when only the core contribution is considered. $R^N_{CP}$ evidences the same saturation starting from 200 GeV collision energy and a very good scaling as a function of <$N_{part}$> for $\sqrt{s_{NN}}$ =200 GeV (Au-Au) and for $\sqrt{s_{NN}}$ =2.76 TeV and $\sqrt{s_{NN}}$ =5.02 TeV (Pb-Pb). A comparison in terms of Bjorken energy density times formation time ($\varepsilon_{Bj}\cdot\tau$) and particle density per unit of rapidity and overlapping area ($(dN/dy)/S_{\perp}$) is presented.
