Amplitude analysis and branching fraction measurement of D+ → π+π0π0

A bstract We present the first amplitude analysis of the hadronic decay D + → π + π 0 π 0 , using e + e − collision data collected with the BESIII detector at a center-of-mass energy of 3.773 GeV, corresponding to an integrated luminosity of 20.3 fb − 1 . The fit fractions of the intermediate processes are measured, in which the D + → ρ (770) + π 0 component is found to be dominant with a branching fraction of (3.08 ± 0.10 stat . ± 0.07 syst . ) × 10 − 3 . Based on the amplitude analysis, the branching fraction of D + → π + π 0 π 0 is measured to be (4.84 ± 0.05 stat . ± 0.05 syst . ) × 10 − 3 . In addition, the CP asymmetries, both for specific amplitudes and integrated over the entire phase space, are measured.