Abstract
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 Xb state; 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 γχcJ; ③ Z states: the evidence for the Zc(4050)±→π± ψ(2S); search for the Zcs in e+e-→K+K-J/ψ.
Abstract
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 Xb state; 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 γχcJ; ③ Z states: the evidence for the Zc(4050)±→π± ψ(2S); search for the Zcs in e+e-→K+K-J/ψ.