Heavy quarkonia, heavy-light tetraquarks, and the chiral quark-soliton model

We apply the chiral quark-soliton model, used previously to describe baryons with one heavy quark, to the case of heavy tetraquarks. We argue that the model is insensitive to the nature of the heavy object bound by the soliton, i.e., to its mass and spin. Therefore, a heavy quark can be replaced by an antidiquark without modifying the soliton background. Diquark dynamics is taken into account by means of the nonrelativistic Schrödinger equation with the Cornell potential. We fix the Cornell potential parameters from the charmonia and bottomonia spectra. We first compute <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msub><a:mi>B</a:mi><a:mi>c</a:mi></a:msub></a:math>-meson masses to check our fitting procedure, and then compute diquark masses by appropriately rescaling color factors in the Cornell potential. We then compute tetraquark masses and confirm previous findings that only <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mi>b</c:mi><c:mi>b</c:mi></c:math> tetraquarks are bound.