Role of scalar mesons a0(980) and a0(1710) in the Ds plus → π0K+K0S decay

Recently, the BESIII Collaboration has measured the D+s -> pi 0K+K0S decay and reported the observation of scalar meson a0(1710)+ in the K+K0S invariant mass spectrum. Based on the previous study about such a state in the D+s ->pi+K0SK0S decay, we perform a theoretical study of a0(1710)+ in the process D+s -> pi 0a0(1710)+-> pi 0K+K0S. In addition to the a0(1710) state, the contributions of K* and a0(980) are also taken into account. Firstly, we consider the contributions from the tree diagrams of K*+ -> K+ pi 0 and over bar K*0 -> pi 0 over bar K0. Secondly, we describe the final state interaction of KK over bar in the chiral unitary approach to study the contribution of a0(980), while the a0(1710) state is dynamically generated from the K* over bar K* interaction, and then decays into K+ over bar K0. Since the final K+K0S state is in pure isospin I = 1, the D+s -> pi 0K+K0 S decay is an ideal process to study the a0(1710)+ and a0(980)+ resonances. It is found that the recent BESIII experimental measurements on the K+K0S, pi 0K+, and pi 0K0S invariant mass distributions can be well reproduced, which supports the molecular K* over bar K* nature of the scalar a0(1710) resonance.

Automated summary

Recently, the BESIII Collaboration observed the scalar meson a0(1710)+ in the K+K0S invariant mass spectrum in the D+s -> pi 0K+K0S decay. They performed a theoretical study of a0(1710)+ in the process D+s -> pi 0a0(1710)+-> pi 0K+K0S and considered the contributions of K* and a0(980). The study supported the molecular K* over bar K* nature of the scalar a0(1710) resonance, as the recent BESIII experimental measurements can be well reproduced.