Theoretical study of the D^0 rightarrow K^- pi ^+ eta reaction

Genaro Toledo,Eulogio Oset,Natsumi Ikeno

doi:10.1140/epjc/s10052-021-09058-z

Abstract

We develop a model to study the D^0 rightarrow K^- pi ^+ eta weak decay, starting with the color favored external emission and Cabibbo favored mode at the quark level. A less favored internal emission decay mode is also studied as a source of small corrections. Some pairs of quarks are allowed to hadronize producing two pseudoscalar mesons, which posteriorly are allowed to interact to finally provide the K^- pi ^+ eta state. The chiral unitary approach is used to take into account the final state interaction of pairs of mesons, which has as a consequence the production of the kappa (K^*_0(700)) and the a_0(980) resonances, well visible in the invariant mass distributions. We also introduce the bar{K}^{*0} eta production in a phenomenological way and show that the s-wave pseudoscalar interaction together with this vector excitation mode are sufficient to provide a fair reproduction of the experimental data. The model provides the relative weight of the a_0(980) to the kappa excitation, and their strength is clearly visible in the low energy part of the K pi spectrum.

Highlights

In a different formalism as the one followed here, the rescattering with the third particle is taken into account inRefs. [15,16] and shown to be relevant in some kinematical regions
We have studied the D0 → K −π +η decay, recently measured by the Belle collaboration, and found that it provides valuable information on the scalar mesons a0(980) and κ (K0∗(700))
We find that while the K −π +η state can be produced in a primary stage, prior to any final state interaction consideration, the interaction of mesons, and the final ones, gives rise to two resonances, the κ in the final Kπ channel and the a0(980) in

Summary

Introduction

In a different formalism as the one followed here, the rescattering with the third particle is taken into account in. K1(1270) resonances [28,29], much in resemblance with the two (1405) states [30,31,32,33,34] Taking this into account, predictions for the production of these two resonances were done in [35] in the decay of D0 → π + plus ρ K or K ∗π. Our study, using the chiral unitary approach, shows how the two s-wave signals are related in the theoretical scheme and comparison with the data allows a theoretical interpretation of the results, showing the value of the reaction to provide information on the meson meson interaction and indirectly on the nature of the a0(980)

Formalism

Full mechanism with s- and p-waves

Results

Conclusions