  Previous extensive studies on the dependence of the average transverse
momentum, its slope as a function of the hadron mass and the average transverse
expansion on the particle multiplicity per unit rapidity and unit transverse
overlap area of the colliding partners are extended to the ratio of the energy
density to the entropy density.
  The behaviour of the ratio between the average transverse momentum and the
square root of the particle multiplicity per unit rapidity and unit transverse
overlap area $\langle p_T \rangle/\sqrt{\langle dN/dy\rangle/S_{\perp}}$ as a
function of collision energy for a given centrality or as a function of
centrality for a given collision energy supports the predictions of CGC and
percolation based approaches. The dependence of the ratio of the energy density
$\langle dE_{T}/dy\rangle/S_{\perp}$ to the entropy density $\langle
dN/dy\rangle/S_{\perp}$ at different collision centralities for A-A collisions
from AGS, SPS, RHIC and LHC energies is presented. The trend of this ratio
towards a plateau at the highest RHIC energies followed by a steep rise at LHC
energies is in agreement with theoretical predictions made 40 years ago that
indicate this behaviour as a signature of a phase transition. This pattern
strongly depends on the collision geometry, converging towards the dependence
that characterizes the pp minimum bias (MB) collisions for the most peripheral
A-A collisions. Expected similarities between pp and Pb-Pb collisions at LHC
energies are confirmed.

High Energy Physics - Phenomenology