Scalar resonances in the $D^+\to K^-K^+K^+$ decay

TL;DR

This paper presents a theoretical study of the scalar resonance contributions, particularly the $a_0(980)$, in the decay $D^+ o K^- K^+ K^+$, using unitarized ChPT to match recent LHCb data.

Contribution

It introduces a novel approach starting from a subleading elementary production diagram and employs unitarized ChPT to dynamically generate scalar resonances in the decay process.

Findings

Good agreement with LHCb data achieved

Dominance of $a_0(980)$ near the $K^- K^+$ threshold

Minimal parameter fitting required

Abstract

We study theoretically the resonant structure of the double Cabibbo suppressed $D^+\to K^- K^+K^+$ 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 ChPT which generate dynamically the scalar resonances $f_0(980)$ and $a_0(980)$. 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 $a_0(980)$ contribution close to the threshold of the $K^- K^+$ spectrum.