摘要
最近国际上几个合作组都在各自的实验中发现了X(2175)共振态,实验中一个主要的衰变产物是(1 020)和f0(980),理论上如何解释它的结构是目前一直关注的问题.在手征幺正理论中认为f0(980)主要是由KK构成的分子态,所以很自然地认为应该研究三体系统KK的相互作用.通过求解三体系统的法捷耶夫方程,理论上的确得到了这个共振态,但是这一计算过程极其复杂,因而理论上希望找到一个简单的近似方法来处理某些特殊的三体系统,即其中的两个粒子关联在一起的情况.法捷耶夫方程的固定中心近似法(FCA)在处理很多这样的问题时取得了相当的成功,但是这一方法有其限制条件.以X(2175)为例,利用FCA近似法具体讨论了KK系统,结果表明这一方法不适合描述KK系统,并指出了FCA有效的可能适用条件.
Recently,some collaborations including BES discovered experimentally the X（2175） state, and one of the main decay particles are （1020） and f0（980） in these reactions.How to explain the X（2175） state has been attached much attention.As we know,in the chiral unitary theory,the f0（980） state is considered as a KK resonance.Thus,it is natural to consider the X（2175） state as a three-body system of KK.Indeed,they obtained a neat resonance peak around a total mass of 2150 MeV by solving the Faddeev equation in the chiral unitary theory,in which an invariant mass for the KK system around 970 MeV,very close to the f0（980） mass.However,the calculation for solving three-body Faddeev equation is extremely complicated.Therefore,we hope to find the simple approximation for some special three-body systems where two particles are strongly correlated.Fixed Center Approximation（FCA） has achieved considerable success for some cases.However,this method has some limits to application.Here for X（2175）,for example,where the KK are strongly correlated.We discuss the FCA method to the Faddeev equation and apply it to study the KK system.The results show that although the FCA is easy way for the special three-body system,it might be effective only when two particles are strongly correlated with the negative or low energy.
出处
《辽宁师范大学学报（自然科学版）》
CAS
2011年第4期442-446,共5页
Journal of Liaoning Normal University:Natural Science Edition
基金
国家自然科学基金项目(10975068)
辽宁省教育厅创新团队项目(2009T055)
关键词
手征幺正理论
法捷耶夫方程
固定中心近似法
三体系统
chiral unitary theory
Faddeev equations
the fixed center approximation
three body system
