Measurements of the C P -even fractions of D 0 → π + π − π 0 and D 0 → K + K − π 0 at BESIII

The C P -even fractions ( F + ) of the decays D 0 → π + π − π 0 and D 0 → K + K − π 0 are measured with a quantum-correlated ψ ( 3770 ) → D D ¯ data sample collected by the BESIII experiment corresponding to an integrated luminosity of 7.93 fb − 1 . The results are F + π + π − π 0 = 0.9406 ± 0.0055 ± 0.0033 and F + K + K − π 0 = 0.631 ± 0.014 ± 0.011 , where the first uncertainties are statistical and the second systematic. These measurements are consistent with the previous determinations, and the uncertainties for F + π + π − π 0 and F + K + K − π 0 are reduced by factors of 2.6 and 2.6, respectively. The reported results provide important inputs for the precise measurement of the angle γ of the Cabibbo-Kobayashi-Maskawa matrix and indirect C P violation in charm mixing.