Amplitude analysis and branching fraction measurement of the decay D⁰→ KS⁰π⁰π⁰

A bstract An amplitude analysis of the decay D⁰→ KS⁰π⁰π⁰ 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→ KS⁰π⁰π⁰ 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→ K̄(892)⁰(→ KS⁰π⁰)π⁰ 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 .