We have investigated the composition of nuclear matter under thermodynamic conditions relevant for the core-collapse of massive stars, with a focus on quantum-statistical effects for light clusters. We find that deviations in the number densities of light clusters between Boltzmann and quantum statistics are small at sub-nuclear densities and temperatures 1–3 MeV, ≈0.2% at most. The formation of heavy clusters in stellar matter leads to a reduction in the number densities of light clusters. As a result, quantum-statistical effects such as the Bose–Einstein condensation of deuterons and α-particles are suppressed. The condensation of α-particles in iso-symmetric nuclear matter is predicted under the assumptions that it is composed solely of nucleons and light clusters and that no heavy clusters are present. We also find that Coulomb screening hardly affects the critical baryon densities for alpha condensation, although it modifies the masses and chemical potentials of the α-particles.

我们研究了与大质量恒星坍塌有关的热力学条件下核物质的组成，重点研究了光团的量子统计效应。我们发现，在亚核密度和1–3 MeV的温度下，玻耳兹曼和量子统计之间的光簇数密度的偏差很小，最多≈0.2％。恒星物质中重团簇的形成导致轻团簇的数量密度降低。结果，抑制了氘核和α粒子的玻色-爱因斯坦凝聚等量子统计效应。α的缩合在以下假设条件下预测了等对称核质中的α-粒子：它仅由核子和轻簇组成，并且不存在重簇。我们还发现，库仑筛分几乎可以改变α凝聚的临界重子密度，尽管它可以改变α粒子的质量和化学势。