Amplitude analysis of ψ (3686)→ γ KS⁰KS⁰

A bstract Using (2712 ± 14) × 10 6 ψ (3686) events collected with the BESIII detector, we perform the first amplitude analysis of the radiative decay ψ (3686)→ γ KS⁰KS⁰ ψ 3686 → γ K S 0 K S 0 within the mass region M_KS⁰KS⁰<2.8 M K S 0 K S 0 < 2.8 GeV/ c 2 . Employing a one-channel K-matrix approach for the description of the dynamics of the KS⁰KS⁰ K S 0 K S 0 system, the data sample is well described with four poles for the f 0 -wave and three poles for the f 2 -wave. The determined pole positions are consistent with those of well-established resonance states. The observed f 0 and f 2 states are found to be in agreement with those produced in radiative J/ψ decays. The production behaviors of f 0 and f 2 poles in ψ (3686)→ γ KS⁰KS⁰ ψ 3686 → γ K S 0 K S 0 are qualified with their residues and the converted branching fractions. By comparing with J/ψ → γ KS⁰KS⁰ J / ψ → γ K S 0 K S 0 decay, the ratios B(ψ (3686)→ γ f0,2)B(J/ψ → γ f0,2) B ψ 3686 → γ f 0 , 2 B J / ψ → γ f 0 , 2 are determined, which provides crucial experimental inputs on the internal structure of the f 0 , 2 states, especially their potential mixing with glueball components.