Signature of QCD critical point: Anomalous transverse velocity dependence of antiproton-proton ratio

Abstract

We formulate the QCD critical point focusing effect on transverse velocity ($β_{t}$) dependence of antiproton to proton ($\bar{p}/p$) ratio, which was recently proposed by Asakawa {\it et al.} as an experimental signature of QCD critical point in high energy heavy ion collisions (HICs). For quantitative analysis, Ultra-relativistic Quantum Molecular Dynamics (UrQMD) transport model and THERMal heavy-IoN generATOR (THERMINATOR) are applied to calculate the corresponding $β_{t}$ dependence of $\bar{p}/p$ ratio for three gedanken focused isentropic trajectories with different focusing degree on QCD phase diagram. Finally, we obtained an observable anomaly in $β_{t}$ dependence of $\bar{p}/p$ ratio, which can be employed as a signature of QCD critical point.