  The Color String Percolation Model (CSPM) is used to determine the equation
of state (EOS) of the QGP produced in central Au-Au collisions at
$\sqrt{s_{NN}}$ = 200 A GeV using STAR data at RHIC. When the initial density
of interacting colored strings exceeds the 2D percolation threshold a cluster
is formed, which defines the onset of color deconfinement. These interactions
also produce fluctuations in the string tension which transforms the Schwinger
particle (gluon) production mechanism into a maximum entropy thermal
distribution. The single string tension is determined by identifying the known
value of the universal hadron limiting temperature $T_{c}$ = 167.7 $\pm$ 2.6
MeV with the CSPM percolation temperature at the critical threshold $\xi_{c}$
=1.2. At mid-rapidity the initial Bjorken energy density and the initial
temperature determine the number of degrees of freedom consistent with the
formation of a $\sim$ 2+1 flavor QGP. An analytic expression for the equation
of state, the sound velocity $C_{s}^{2}(\xi)$ is obtained in CSPM. The CSPM
$C_{s}^{2}(\xi)$ and the bulk thermodynamic values $\varepsilon /T^{4}$ and $s
/T^{3}$ are in excellent agreement in the phase transition region with recent
lattice QCD simulations (LQCD) by the HotQCD Collaboration.

Nuclear Experiment;High Energy Physics - Phenomenology