Energy scan by φ mesons and threshold energy for the confinement-deconfinement phase transition

We argue that the ratio of $\phi$ mesons multiplicity over cube of the mean $p_T$ is proportional to the degeneracy of the medium produced in ultra-relativistic heavy ion collisions. The ratio extracted from the existing $\phi$ meson data in the energy range $\sqrt{s}$=6.3-200 GeV, indicate that beyond a threshold energy $\sqrt{s}_{th}=15.74\pm 8.10$ GeV, the medium crosses over from a confined phase to a deconfined phase.