Stability of dimesons

Using only the known short-distance behavior of quantum chromodynamics it is possible to prove that, for sufficiently large quark mass m, and fixed antiquark mass, the dimeson ($Q^2$q¯ ${}_{}{}^2{}_{}{}^{}$) must be stable against strong decay into two mesons. The binding energy is (1/9m${\alpha }_s^2$[1+O($m^{\mathrm{-}1}$)]. We then study systems in which Q is c or b, using the many-body confining interaction that comes from a Born-Oppenheimer approximation to the MIT bag model. The calculations were performed using the Green’s-function Monte Carlo method. The $1^{+}$ isoscalar dimeson T(bbūd¯) is bound by ∼70 MeV with respect to two B mesons; it can only decay weakly, therefore. The calculations of the dimesons (ccq¯ q¯’) and (bcq¯ q¯ ’) are more uncertain, but indicate that the latter may also be bound.