Basics of doubly heavy tetraquarks

Abstract

We outline the most important results regarding the stability of doubly heavy tetraquarks $QQ\bar{q}\bar{q}$ with an adequate treatment of the four-body dynamics. We consider both color-mixing and spin-dependent effects. Our results are straightforwardly applied to the case of all-heavy tetraquarks $QQ\bar{Q}\bar{Q}$. We conclude that the stability is favored in the limit $M_Q/m_q\gg 1$ pointing to the stability of the $bb\bar{u}\bar{d}$ state and the instability of all-heavy tetraquarks.

Comments: To appear in the Proc. of the Workshop "XIII International Conference on Beauty, Charm and Hyperon Hadrons", Peniche (Portugal), June 17-23, 2018. To be published by IOP Conference Series