Doubly heavy tetraquarks in a chiral-diquark picture

Abstract

Energy spectrum of doubly heavy tetraquarks, $T_{QQ}$ ($QQ\bar{q}\bar{q}$ with $Q=c,b$ and $q=u,d,s$), is studied in the potential chiral-diquark model. Using the chiral effective theory of diquarks and the quark-diquark-based potential model, the $T_{bb}$, $T_{cc}$, and $T_{cb}$ tetraquarks are described as a three-body system composed of two heavy quarks and an antidiquark. We find several $T_{bb}$ bound states, while no $T_{cc}$ and $T_{cb}$ (deep) bound state is seen. We also study the change of the $T_{QQ}$ tetraquark masses under restoration of chiral symmetry.

Comments: 16 pages, 14 Figures, 10 Tables