  Multiparticle production at high energies is described in terms of color
strings stretched between the projectile and target. As the string density
increases, overlap in the transverse plane leads to cluster formation. At some
critical density a macroscopic cluster appears, spanning the entire system.
This marks the percolation phase transition. Data from $\sqrt{s_{NN}}$ = 200
GeV p+p, d+Au and Au+Au collisions at RHIC has been analyzed using the STAR
detector to obtain the percolation density parameter, $\eta$. The particle
p$_{T}$ spectrum from 200 GeV p+p data is parameterized using a power law.
Values of the fit parameters are used in the d+Au and Au+Au analysis. For 200
GeV Au+Au collisions, the value of $\eta$ is found to lie above the critical
percolation threshold, while for other collision systems and energies, it is
below the critical value. This supports the idea of string percolation, which
at high enough string density is a possible mechanism to explore the hadronic
phase transition to a quark-gluon plasma.
