Searching for the QCD critical point through constant entropy density contours

We propose a novel method to locate the QCD critical point by constructing an expansion along contours of constant entropy density. Applying two independent analysis of lattice QCD data at zero baryon chemical potential, we find a critical point at $T_c=114\pm 7$ MeV and ${\mu }_{B_c}=602\pm 62$ MeV for an expansion truncated at order ${\mu }_B^2$. This approach is consistent with recent lattice QCD results up to ${\mu }_B\mathrm{/}T\le 3$. A more precise determination of the required expansion coefficients from lattice simulations will be essential for reliably establishing the location of the QCD critical endpoint.