  The presence of a critical point in the QCD phase diagram can deform the
trajectories describing the evolution of the expanding fireball in the QCD
phase diagram. The deformation of the hydrodynamic trajectories will change the
transverse velocity dependence of the proton-antiproton ratio when the fireball
passes in the vicinity of the critical point. An unusual transverse velocity
dependence of the anti-proton/proton ratio in a narrow beam energy window would
thus signal the presence of the critical point.
