Strong decays of double-charmed pseudoscalar and scalar cc(u)over-bar(d)over-bar tetraquarks

The strong decays of the pseudoscalar and scalar double-charmed tetraquarks T-cc;(u) over bar(d) over bar(+) and (T) over tilde (+)(cc;(u) over bar(d) over bar) are investigated in the framework of the QCD sum rule method. The mass and coupling of these exotic four-quark mesons are calculated in the framework of the QCD two-point sum rule approach by taking into account vacuum condensates of the quark, gluon, and mixed local operators up to dimension 10. Our results for masses m(T) = (4130 +/- 170) MeV and m((T) over tilde) = (3845 +/- 175) MeV demonstrate that these tetraquarks are strong-interaction unstable resonances and decay to conventional mesons through the channels T-cc;(u) over bar(d) over bar(+)-> D+D*(2007)(0), (DD)-D-0*(2010)(+) and (T) over tilde (+)(cc;(u) over bar(d) over bar) -> (D+D0).Key quantities necessary to compute the cc partial width of these decay modes, i.e., the strong couplings of two D mesons and a corresponding tetraquark g(i), i = 1, 2, and G, are extracted from the QCD three-point sum rules. The full width Gamma(T) = (129.9 +/- 23.5) MeV demonstrates that the tetraquark T-cc;(u) over bar(d) over bar(+) is a broad resonance, whereas the scalar exotic meson with Gamma((T) over tilde)= (12.4 +/- 3.1) MeV can be classified as a relatively narrow state.