We study the composition of nuclear matter at sub-saturation densities, non-zero temperatures, and isospin asymmetry, under the conditions characteristic of binary neutron star mergers, stellar collapse, and low-energy heavy-ion collisions. The composition includes light clusters with mass number \(A\le 4\), a heavy nucleus (\(^{56}{Fe}\)), the \(\varDelta \)-resonances, the isotriplet of pions, as well as the \(\Lambda \) hyperon. The nucleonic mean-fields are computed from a zero-range density functional, whereas the pion-nucleon interactions are treated to leading order in chiral perturbation theory. We show that with increasing temperature and/or density the composition of matter shifts from light-cluster to heavy baryon dominated one, the transition taking place nearly independent of the magnitude of the isospin. Our findings highlight the importance of simultaneous treatment of light clusters and heavy baryons in the astrophysical and heavy-ion physics contexts.

我们研究了在双饱和中子星合并，恒星坍塌和低能重离子碰撞的特征下，在亚饱和密度，非零温度和同位旋不对称下的核物质组成。组成包括质量数为\（A \ le 4 \）的轻簇，重核（\（^ {56} {Fe} \）），\（\ varDelta \）-共振，介子的三重态。以及\（\ Lambda \）Hyperon。从零范围密度泛函计算出核子平均场，而手性扰动理论中将π-核子相互作用处理为先导。我们表明，随着温度和/或密度的增加，物质的组成从轻簇转变为重质重子，转变几乎与同位旋的大小无关。我们的发现凸显了在天体物理和重离子物理环境中同时处理轻团簇和重质重子的重要性。