Can the nature of a0(980) be tested in the Ds

Theoretical study of the process $D^+_s \to π^+ K^0_S K^0_S$ and the isovector partner of $f_0(1710)$

“…With the masses of these particles given in Table II, the branching fraction of Br(D + s → K0 K * + ) = (5.4± 1.2)% and the partial decay width K * + → K 0 π + quoted in the RPP [1], we obtain g Ds KK * = (1.05 ± 0.12) × 10 −6 and g K * Kπ = 3.26. Again, we assume that g Ds KK * and g K * Kπ are real and positive [43]. The uncertainty of g Ds KK * originates from the uncertainty of the branching fraction Br(D + s → K0 K * + ), while the uncertainty of g K * Kπ is ignored, since it is very small.…”

The role of meson interactions in the $D_s^{+}\rightarrow π^{+}π^{+}π^{-}η$ decay

“…An alternative explanation was provided in [11] through a triangle mechanism where one has D s → ρ + η, which proceed via external emission, followed by ρ → ππ and fusion of πη to give the a 0 (980) resonance. The same argumentation was followed in [20], where the work of [19] was discussed and other possible mechanisms were considered. What is clear is that with either of the mechanisms of [10,11,20] one does not need weakannihilation for the D s → πa 0 (980) production, and the strong interaction of the resulting mesons can lead to the desired final state.…”

“…The same argumentation was followed in [20], where the work of [19] was discussed and other possible mechanisms were considered. What is clear is that with either of the mechanisms of [10,11,20] one does not need weakannihilation for the D s → πa 0 (980) production, and the strong interaction of the resulting mesons can lead to the desired final state. We will find a similar situation in the present reaction, where considering mechanisms of external and internal emission of different intermediate particles and allowing them to make transitions through final state interaction, we can obtain the desired final state.…”