2026/07/30 by Jun He, JUn He
Physics and Astronomy · #hep-ph
10 pages, 6 figures
arxiv created 2026/07/31 · arxiv updated 2026/08/03
In this work, we theoretically investigate the decay mechanism of Ds+ → π+ π0 π0 η based on BESIII data, considering two mechanisms: the production of two dynamically generated resonances, Ds+ → a0(980)+ f0(500,980), and a process with one dynamically generated resonance, Ds+ → a1(1260)+η. In the first mechanism, the interactions π+η and K+K0 are included to generate the a0(980)+, while coupled-channel interactions involving π+π-, π0π0, K+K-, K0K0, ηη, and π0η are adopted to generate the f0(500) as well as the f0(980). For the second mechanism, the πρ and K^*K - K^*K channels are included to generate the a1(1260). With these interactions, the amplitudes are calculated in the chiral unitary approach and used to compute the invariant mass spectra of Ds+ → π+ π0 π0 η. The results suggest that the peak near 1000~MeV in the π+η invariant mass spectrum can be well interpreted as the a0(980)+ arising from a cusp effect. The f0(980), generated together with the f0(500), is responsible for the small structure near 1000 MeV in the π0π0 spectrum. The a1(1260)+ and its decay to ρ+π0 followed by the subsequent ρ+ decay provide a good description of the π+π0π0 and π+π0 mass spectra. The inclusion of an additional resonance near 800 MeV in the π+η spectrum leads to only a marginal improvement of the fit.