$\bar{B}_s \to f_0(980)$ form factors and the width effect from light-cone sum rules

In this paper we calculate the $$\bar{B}_s \rightarrow f_0(980)$$ form factors from light-cone sum rules with B meson DAs. With adopting the quark–antiquark configuration of light scalar mesons, the high twist two-particle and the three-particle contributions are found to be $$\sim 25\%$$ individual, and totally they give about $$50\%$$ correction to certain form factors in the considered energy regions. We further explore the light-cone sum rules approach to study the $$S-$$wave $$\bar{B}_s \rightarrow KK$$ form factors, the $$f_0+f'_0+f''_0$$ resonance model is proposed and the result shows that the background effect from $$f'_0+f''_0$$ accounts $$\sim 5\%$$. As a by-product, we extract the strong coupling $$|g_{f_0 KK }| = 1.08^{+0.05}_{-0.14}$$ GeV with taking the $$\bar{B}_s \rightarrow f_0(980)$$ form factors calculated previous under the narrow width approximation.