On the critical end point of QCD

Abstract

We investigate the critical end point of QCD with two flavours of light dynamical quarks at finite lattice cutoff a=¼T using a Taylor expansion of the baryon number susceptibility. We find a strong volume dependence of its radius of convergence. In the large volume limit we obtain μ_B/T≈1.1 as the radius of convergence at T/T_c≈0.95 where T_c is the crossover temperature at zero chemical potential. Since this estimate is a lower bound on the critical end point of QCD, the above small value of μ may place it in the range of observability in energy scans at the Relativistic Heavy-Ion Collider (RHIC).