Amplitude analysis and branching-fraction measurement of Ds+ → π ⁺ π ⁰ η′

Using data collected with the BESIII detector in e⁺e⁻ collisions at center-of-mass energies between 4.178 and 4.226 GeV and corresponding to 6.32 fb⁻¹ of integrated luminosity, we report the amplitude analysis and branching-fraction measurement of the Ds+→ π⁺π⁰η′ decay. We find that the dominant intermediate process is Ds+→ ρ⁺η′ and the significances of other resonant and nonresonant processes are all less than 3σ. The upper limits on the branching fractions of S-wave and P-wave nonresonant components are set to 0.10% and 0.74% at the 90% confidence level, respectively. In addition, the branching fraction of the Ds+→ π⁺π⁰η′ decay is measured to be (6.15 ± 0.25(stat.) ± 0.18(syst.))%, which receives significant contribution only from Ds+→ ρ⁺η′ according to the amplitude analysis. [Figure not available: see fulltext.].