Transverse velocity dependence of the proton-antiproton ratio as a signature of the QCD critical point

The presence of a critical point in the QCD phase diagram can deform the trajectories describing the evolution of the expanding fireball in the mu(B)-T phase diagram. If the average emission time of hadrons is a function of transverse velocity, as microscopic simulations of the hadronic freeze-out dynamics suggest, the deformation of the hydrodynamic trajectories will change the transverse velocity (beta(T)) dependence of the proton-antiproton ratio when the fireball passes in the vicinity of the critical point. An unusual beta(T) dependence of the (p) over bar /p ratio in a narrow beam energy window would thus signal the presence of the critical point.