f0(980) meson as a K bar K molecule in a phenomenological Lagrangian approach

Understand

We discuss a possible interpretation of the f0(980) meson as a hadronic molecule - a bound state of K and bar K mesons.

• Using a phenomenological Lagrangian approach we calculate the strong f0(980) to pi pi and electromagnetic f0(980) to gamma gamma decays.
• The compositeness condition provides a self-consistent method to determine the coupling constant between f0 and its constituents, K and bar K.
• Form factors governing the decays of the f0(980) are calculated by evaluating the kaon loop integrals.