Exotic $bc\bar q\bar q$ four-quark states

Understand

We carry out a systematic study of exotic $QQ^\prime \bar q\bar q$ four-quark states containing distinguishable heavy flavors, $b$ and $c$.

• Different generic constituent models are explored in an attempt to extract general conclusions.
• The results are robust, predicting the same sets of quantum numbers as the best candidates to lodge bound states independently of the model used, the isoscalar $J^P=0^+$ and $J^P=1^+$ states.
• The first state would be strong and electromagnetic-interaction stable while the second would decay electromagnetically to $\bar B D \gamma$.