^(182)Os核yrast带结构SU(3)→U(5)→SU(3)形状相变的有序性研究

Nuclear shape phase transition SU(3)→U(5)→SU(3) of the yrast-band structure in ^(182)Os from nucleonic order

对于发生在同一个原子核中的转动诱导发生基准态结构的量子相变,可以理解为一种从高有序激发模式向着低有序激发模式的演化:被布居到高角动量态的高有序激发核,以E2跃迁的方式先行退耦到yrast带,再退耦到共存区(或临界点)时释放了有序的结构能,诱发价核子对耦合强度改变,重新组合出低有序的激发模式基准态,实现了基准态结构的过渡.对核量子相变的这种描述,与朗道经典热相变理论之间有了某些相似的术语和物理内涵.本文把这种理解推广到了相继的二次相变中.以182Os核为例作了说明,并展示了核结合能对核结构的极端敏感性.

That quantum phase transition （ QPT） that occurs at the same nucleus causing the change of the basic state by rotation can be understood as an evolution from a higher-ordered and high-excitation model to another lower-ordered and high-excitation one,which implies a nucleus populated at high-momentum state decoupling firstly to the yrast-band with some E2-trasitions mode,then to the coexist region （or critical point）,wherein the structure-energy is released. The change of the nucleon coupling intensity is caused,finally the basic state of the lower-ordered excitation model is reconstructed,the evolution of basic states structure is accomplished. This description of nuclear QPTs has endowed them with some similar to Landau＇s classical quantum thermal phase transition in terminology and physical significance. This standpoint is generalized into the phase transitions that occur at the same nucleus one after an other. As an example,for the 182Os nucleus,the problem is discussed carefully,and the enhanced sensitivity of nuclear binging energy to collective structure is demonstrated.