The role of the $f_0(1710)$ and $a_0(1710)$ resonances in the $D^0 \to ρ^0 φ$, $ωφ$ decays
Natsumi Ikeno, Wen-Hao Jia, Wei-Hong Liang, Eulogio Oset
TL;DR
This work explains why D^0 → ρ^0 φ occurs more readily than D^0 → ω φ by invoking an indirect production path: external emission creates K^{*+}K^{*-}, which then rescatter into VV final states via strong interactions described by the local hidden gauge approach. The resulting coupled-channel dynamics generate the resonances f_0(1710) and a_0(1710), whose couplings to ρ^0 φ and ω φ dominate the transitions, respectively; solving the Bethe–Salpeter equation yields T ≈ [I − VG]^{−1}V with poles matching these states. The calculated ratio R_b = Γ_{D^0→ρφ} / Γ_{D^0→ωφ} improves from ~1.5–2.0 to ≈ 1.97 when the VV channels are fully treated, and a further ρ-mass convolution brings R_b to ≈ 1.47, in line with experimental measurements within uncertainties. The results underscore the significant role of the a_0(1710) in shaping D^0 decay patterns and offer a pathway to constrain its mass and couplings through future precision data.
Abstract
We study the $D^0 \to ρ^0 φ$, $ωφ$ decays which proceed in a direct mode via internal emission with equal rates. Yet, the experimental branching ratio for the $ρ^0 φ$ mode is twice as big as that for the $ωφ$ mode. We find a natural explanation based on the extra indirect mechanism where $K^{*+} K^{*-}$ is produced via external emission and that channel undergoes final state interaction with other vector--vector channels to lead to the $ρ^0 φ$, $ωφ$ final states, with transition amplitudes dominated by the $a_0(1710)$ resonance, recently discovered, and $f_0(1710)$ respectively. The large coupling of the $a_0(1710)$ to the $ρ^0 φ$ channel is mostly responsible for this large ratio of the production rates.
