Structures of the f0(980), a0(980) mesons and the strong coupling constants gf0K+K-, ga0K+K- with light-cone QCD sum rules

Making the assumption of explicit isospin violation arising from f0(980)-a0(980) mixing, we take the point of view that the scalar mesons f0(980) and a0(980) have both strange and non-strange quark-antiquark components and evaluate the strong coupling constants gf0K+K- and ga0K+K- within the framework of the light-cone QCD sum rules approach. The large strong scalar-KK couplings through both the n anti n and s anti s components g antinnf0K+K-, g antissf0K+K-, g antinna0K+K- and g antissa0K+K- will support the hadronic dressing mechanism; furthermore, in spite of the constituent structure differences between the f0(980) and a0(980) mesons, the strange components have larger strong coupling constants with the K+K- state than the corresponding non-strange ones, gf0K+K-antiss∼√(2)gf0K+K-antinn and ga0K+K-antiss∼√(2)ga0K+K-antinn. From the existing controversial values, we cannot reach a general consensus on the strong coupling constants gf0K+K-, ga0K+K- and the mixing angles. (orig.)