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

• Published in: The European physical journal. C, Particles and fields Particles and fields, 2021-03, Vol.81 (3), Article 268
• Main Authors: Toledo, Genaro, Ikeno, Natsumi, Oset, Eulogio
• Format: Article
• Language: English
• ISSN: 1434-6044; 1434-6052
• DOI: 10.1140/epjc/s10052-021-09058-z

We develop a model to study the $$D^0 \rightarrow K^- \pi ^+ \eta $$ D 0 → K - π + η 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 $$K^- \pi ^+ \eta $$ K - π + η 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 $$\kappa $$ κ ( $$K^*_0(700)$$ K 0 ∗ ( 700 ) ) and the $$a_0(980)$$ a 0 ( 980 ) resonances, well visible in the invariant mass distributions. We also introduce the $$\bar{K}^{*0} \eta $$ K ¯ ∗ 0 η 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 $$a_0(980)$$ a 0 ( 980 ) to the $$\kappa $$ κ excitation, and their strength is clearly visible in the low energy part of the $$K \pi $$ K π spectrum.