摘要
实验上寻找超出传统夸克标准模型的激发态强子(也称为类粲偶素/类底偶素或XYZ粒子)已经很多年,建议过很多的激发态强子的候选者,包括胶球、混杂态、多夸克态、强子分子态等.自从B工厂运行以来,这方面的研究已经取得了巨大的进步.本文给出来自Belle实验的关于XYZ粒子的最新实验成果,包括(1)X态:首次观测到B0→X(3872)K+π-过程的信号以及B+→X(3872)K0π+过程存在的迹象;寻找Xb态;(2)Y态:更新的Y(4360)和Y(4660)共振参数的结果以及更新的测量e+e-→K+K-J/ψ和γχc J过程的散射截面;(3)Z态:发现带电的Zc(4050)±→π±ψ(2 S)存在的迹象以及在e+e-→K+K-J/ψ过程中寻找Zcs的态.
Exotic hadronic states beyond the conventional quark model( called charmoniumlike /bottomoniumlike states or XYZ particles) have been searched for and many candidates have been proposed including glueballs,hybrids,multi-quark states,hadron molecules,etc. Dramatic progress was made in the study of them after the running of the B-factories. The most recent results on the XYZ states at Belle are presented,including(1) X states: the first observation of B0→X(3872)K+π-and evidence for B+→X(3872)K0π+; search for the Xbstate;(2) Y states: the updated results for the Y( 4360) and Y( 4660) and cross section measurements of e+e-→K+K-J / ψ and γχc J;(3) Z states: the evidence for the Zc(4050)±→π±ψ(2 S); search for the Zcsin e+e-→K+K-J / ψ.
基金
Supported by National Natural Science Foundation of China(11575017)
