In-medium Meson properties and Nuclear Exotres.

通过假设N -N体系的N^*(1535)优势得到的光势，研究了原子核相互作用的性质及其实验结果。基于N^*(1535)的不同图像，用两种手性有效模型对核介质中的N^*(1535)性质进行了评价。我们发现这两种模型提供了质量上不同的eta介子光学势，反映了这些模型中N^*(1535)的介质性质。为了在物理观测中比较这些模型，我们计算了与不同靶核形成eta介核的（d,3He）反应谱。我们表明，在这些模型中得到的（d,3He）光谱有很大的不同，并且有望在实验中区分。我们还探索了通过（d,t）和（d,^3He）反应在核的标量等标量（sigma）通道中观察到增强的2 π相关的可能性，以获得关于核介质中部分恢复手性对称性的新信息。研究了反应谱对核介质中手性凝聚物变化的敏感性。

The properties of eta-nucleus interaction and their experimental consequences are investigated with eta-nucleus optical potentials obtained by postulating the N^*(1535) dominance for eta-N system. The N^*(1535) properties in nuclear medium are evaluated by two kinds of chiral effective models based on distinct pictures of N^*(1535). We find that these two models provide qualitatively different optical potentials of the eta meson, reflecting the in-medium properties of N^*(1535) in these models. In order to compare these models in physical observables, we calculate spectra of (d,3He) reactions for the eta mesic nucleus formation with various kinds of target nuclei. We show that the (d,3He) spectra obtained in these models are significantly different and are expected to be distinguishable in experiments.We also explore the possibility to observe an enhanced 2pi correlation in the scalar iso-scalar (sigma) channel in nuclei by (d,t) and (d,^3He) reactions to obtain new information on the partial restoration of chiral symmetry in the nuclear medium. The sensitivity of the reaction spectra on the change of the chiral condensate in the nuclear medium is examined.