Heavy-quark symmetry implies stable heavy tetraquark mesons $Q_i{Q}_j{\bar{q}}_k{\bar{q}}_l$

Estia J. Eichten, Chris Quigg

For very heavy quarks $Q$, relations derived from heavy-quark symmetry predict the existence of novel narrow doubly heavy tetraquark states of the form $Q_i{Q}_j{\bar{q}}_k{\bar{q}}_l$ (…