Lifetime of kaonium

The kaon-antikaon system is studied in both the atomic and the strongly interacting sector. We discuss the influence of the structures of the f(0)(980) and the a(0)(980) mesons on the lifetime of kaonium. The strong interactions are generated by vector meson exchange within the framework of the standard SU(3)(V)xSU(3)(A) invariant effective Lagrangian. In the atomic sector, the energy levels and decay widths of kaonium are determined by an eigenvalue equation of the Kudryavtsev-Popov type, with the strong interaction effects entering through the complex scattering length for K (K) over bar scattering and annihilation. The presence of two scalar mesons f(0)(980) and a(0)(980) leads to a ground state energy for the kaonium atom that is shifted above the point Coulomb value by a few hundred eV. The effect on the lifetime for the kaonium decay into two pions is much more dramatic. This lifetime is reduced by two orders of magnitude from 1.2x10(-16) sec for annihilation in a pure Coulomb field down to 3.2x10(-18) sec when the strong interactions are included. The analysis of the two photon decay width of the f(0)(980) suggests a generalization of the molecular picture which reduces the lifetime of kaonium still further to 1.1x10(-18) sec.