Scalar resonances in the D+ →k-K+K+ decay

Abstract

We study theoretically the resonant structure of the double Cabibbo suppressed D+→K-K+K+ decay. We start from an elementary production diagram, considered subleading in previous approaches, which cannot produce a final K-K+ pair at the tree level but which we show to be able to provide the strength of the decay through final meson-meson state interaction. The different meson-meson elementary productions are related through SU(3), and the final rescattering is implemented from a suitable implementation of unitary extensions of chiral perturbation theory, which generate dynamically the scalar resonances f0(980) and a0(980). We obtain a good agreement with recent experimental data from the LHCb Collaboration with a minimal freedom in the fit and show the dominance of the a0(980) contribution close to the threshold of the K-K+ spectrum.