Is the Equation of State of Strongly Interacting Matter Observable ?

The equation of state (EOS) is a nontrivial relation linking the thermodynamic variables specifying the state of a physical system . The best known example of EOS is Boyle’s ideal gas law, stating that the pressure of a collection of N noninteracting, pointlike classical particles, enclosed in a volume Ω, grows linearly with the temperature T and the average particle density n = N/Ω. The ideal gas law provides a good description of very dilute systems. In general, the EOS can be written as an expansion of the pressure, P , in powers of the density (we use units such that Boltzmann’s constant is KB = 1):