Fig. 1. (color online) Sketch of conjectured QCD phase diagram with crossover (black dashed line), order phase transition boundary (black solid lines), and QCD critical point (red solid circle, MeV). A hypothetical system evolution trajectory (red dashed lines) is also plotted and ends with the chemical freeze-out point (blue solid circle).

Fig. 2. (color online) Time evolution of , , and ratios along ocusing trajectory.

Fig. 3. (color online) UrQMD calculations for dependence of average emission time of p and at mid-rapidity in Au+Au collisions at 19.6.

Fig. 4. (color online) , , and as a function of from UrQMD and UrQMD + QCP focusing effect. Shaded band represents range of from 0.5 to 2 GeV/c. A depicts the mass number of light nuclei.

Fig. 5. (color online) dependence of 0%–5% central (left) and 0%–10% central (right) are derived from the spectra in Au+Au collisions measured by the STAR experiment at RHIC-BES energies [34-36]. Dashed lines depict the linear fit. Error bars shown in the figure combine both systematic and statistical errors.