Few-body correlations in nuclear systems

轻元素（2H, 3H, 3He, 4He）嵌入核介质后，其性质发生改变。在准粒子方法中，星团的能量取决于质心动量以及密度、温度和周围介质的不对称性。目前，这些准粒子的能量位移是在一个不相关的介质中计算的。我们以一种自洽的方式计算位移，考虑到介质（即成分）中的相关性。介质中少核子相关的精确计算是评价核物质组成和状态方程的重要组成部分。它可以应用于天体物理学来描述紧凑的物体（超新星、中子星），也可以应用于重离子碰撞的研究。少核子相关，特别是α聚类，在核结构物理中引起了人们的兴趣。我们研究了重核表面附近的类α相关性（四重奏）。特别地，计算了重核（例如钋同位素）α衰变的α预形成因子。

The properties of light elements (2H, 3H, 3He, 4He) are modified when they are imbedded in a nuclear medium. Within a quasiparticle approach, the energies of the clusters are dependent on the center of mass momentum as well as the density, the temperature, and the asymmetry of the surrounding medium. At present, these quasiparticle energy shifts are calculated assuming an uncorrelated medium. We calculate the shifts taking into account correlations in the medium (i.e. the composition) in a self-consistent way. A precise calculation of in-medium few-nucleon correlations is an important ingredient for the evaluation of the composition and the equations of state of nuclear matter. It can be applied in astrophysics to describe compact objects (supernovae, neutron stars) as well as in the investigation of heavy-ion collisions. Few-nucleon correlations, in particular alpha clustering, is of interest in nuclear structure physics. We investigate alpha-like correlations (quartets) near the surface of heavy nuclei. In particular, the alpha preformation factor is calculated for the alpha-decay of heavy nuclei, e.g., of the polonium isotopes.