2025/09/21 by Wang, Yan-Li, Cai, Shu-Ting, Hsiao, Yu-Kuo
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2509.16879
We investigate two-body non-leptonic D→ SS weak decays, where S denotes a light scalar meson such as a0/a0(980), f0/f0(980), or σ0/f0(500). Short-distance topologies from W-boson emission and annihilation (exchange) are found to be negligible, while long-distance final-state interactions provide the dominant contributions. In particular, triangle rescattering processes, D → πη(′) → σ0 a0 and D → a1(1260)η→ σ0 a0, mediated by pion exchange in πη(′) and a1(1260)η scatterings, respectively, are identified as the leading mechanisms. Our calculations yield branching fractions \cal B(Ds+ → σ0 a0+) = (1.0 ± 0.2+0.1-0.2) × 10-2, \cal B(D+ → σ0 a0+) = (1.1 ± 0.2+0.1-0.2) × 10-3, and \cal B(D0 → σ0 a00) = (0.9 ± 0.2+0.2-0.3) × 10-5. For the Cabibbo-allowed decay mode Ds+ → f0 a0+, the near-threshold condition mDs≃ mf0+ma0 limits the phase space, suppressing the branching fraction to (3.4±0.3+0.4-0.9)× 10-4. These results highlight rescattering-induced D→ SS decays as promising channels for experimental studies at BESIII, Belle(-II), and LHCb.