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 [over]p/p ratio in a narrow beam energy window would thus signal the presence of the critical point.
Asakawa
M
M
Department of Physics, Osaka University, Toyonaka, Japan.
Bass
S A
SA
Müller
B
B
Nonaka
C
C