Liquid-gas phase transition in hypernuclei

The fragmentation of excited hypernuclear systems formed in heavy ion collisions has been described by the canonical thermodynamical model extended to three-component systems. The multiplicity distribution of the fragments has been analyzed in detail and it has been observed that the hyperons tend to get attached to the heavier fragments. Another important observation is the phase coexistence of the hyperons, a phenomenon which is linked to the liquid-gas phase transition in strange matter.

Figure 1

Distribution of hyperfragments produced from the fragmentation of $A_0=128,Z_0=50$, and $H_0=8$ at $T=3$ MeV (black dotted line), 5 MeV (red dashed line), 7 MeV (green solid line), and 10 MeV (blue dash-dotted line).

Figure 2

Mass distribution $h=0$, 2, 4, 6, and 8 hyperfragments produced from the fragmentation of $A_0=128,Z_0=50$, and $H_0=8$ at $T=3$ and 6 MeV.

Figure 3

Temperature dependence of intermediate mass fragments containing different strangeness produced from the fragmentation of $A_0=128,Z_0=50$, and $H_0=8$.

Figure 4

Temperature dependence of higher mass fragments containing different strangeness produced from the fragmentation of $A_0=128,Z_0=50$, and $H_0=8$.

Figure 5

Average mass of the fragments $\left(\langle a_h\rangle \right)$ with different strangeness $\left(h\right)$ due to fragmentation of $A_0=128,Z_0=50$, and $H_0=8$ at $T=3$ MeV (red dashed line) and 7 MeV (blue dotted line).

Figure 6

Mass distribution of hyperfragments (and/or fragments) produced at $T=3$ MeV from the fragmentation of two different sources having the same $A_0=128$ and $Z_0=50$ but different $H_0=8$ (black dotted line) and $H_0=0$ (red dashed line).