Amplitude analysis and branching fraction measurement of the decay D⁰ KS⁰⁰⁰

A bstract An amplitude analysis of the decay D⁰ KS⁰⁰⁰ D 0 → K S 0 π 0 π 0 is performed to determine the relative magnitudes and phases of different intermediate processes. The analysis uses e + e − collision data collected at the center-of-mass energy of 3. 773 GeV by the BESIII detector corresponding to an integrated luminosity of 20. 3 fb − 1. The absolute branching fraction of D⁰ KS⁰⁰⁰ D 0 → K S 0 π 0 π 0 is measured to be (1. 026 ± 0. 008 stat. ± 0. 009 syst. ) %. The dominant intermediate process is D⁰ K^ (892) ⁰ (KS⁰⁰) ⁰ D 0 → K ¯ ∗ 892 0 → K S 0 π 0 π 0, with a branching fraction of (4. 10 ± 0. 10 stat. ± 0. 07 syst. ) × 10 − 3.