High-energy phase diagrams with charge and isospin axes under heavy-ion collision and stellar conditions

We investigate the phase transition from hadron to quark matter in the general case without the assumption of chemical equilibrium. The effects of net strangeness on charge and isospin fractions, chemical potentials, and temperature are studied in the context of the Chiral Mean Field (CMF) model that incorporates chiral symmetry restoration and deconfinement. The extent to which these quantities are probed during deconfinement in conditions expected to exist in protoneutron stars, binary neutron-star mergers, and heavy-ion collisions is analyzed via the construction of 3-dimensional phase diagrams.

Figure 1

Top panels: the temperature T vs baryon chemical potential ${\mu }_B$ vs charge fraction $Y_Q$ phase diagram for nonstrange matter $Y_S=0$ on the hadronic-phase side of the deconfinement phase transition coexistence region (left panel) and on the quark-phase side (right panel). Bottom panel: the temperature T vs free energy $\tilde{\mu }$ vs charge fraction $Y_Q$ phase diagram for nonstrange matter either on the hadronic or quark-phase side of the deconfinement phase transition coexistence region. All curves were calculated varying the charge fraction between $Y_Q=0$ and $Y_Q=0.5$.

Figure 2

Same as Fig. 1 but showing the charged chemical potential ${\mu }_Q$. The separate bottom panels show the hadronic phase (left panel) and quark phase (right panel) sides of the deconfinement phase transition coexistence region.

Figure 3

Equivalent to Fig. 1 (top panels) and Fig. 2 (bottom panels) but only showing results along the deconfinement coexistence line for 0 (left panels) and 160 MeV (right panels) temperatures. Green, red and brown lines (all grey in black and white print) show results already discussed for nonstrange matter, while black lines show new results for strange matter.

Figure 4

Same as the top panels of Fig. 3 but showing the isospin fraction $Y_I$. Equivalent isospin chemical potential panels would be exactly like the charged chemical potential bottom panels of Fig. 3.

Figure 5

Same as Fig. 1 but showing the isospin charge fraction $Y_I$.

Figure 6

Same as Fig. 2 but showing the isospin chemical potential ${\mu }_I$.