Measurements of the absolute branching fractions of the doubly Cabibbo-suppressed decays D+ → K+π0, D+ → K+η and D+ → K+η′

Using 20.3 fb − 1 of e + e − collision data collected at a center-of-mass energy of 3.773 GeV with the BESIII detector, we present the measurements of the absolute branching fractions of the doubly Cabibbo-suppressed decays D + → K + π 0 , D + → K + η and D + → K + η′ with the double-tag method, with significantly improved precision compared to the previous measurements. The statistical significance of each signal decay exceeds 10 σ . The branching fractions are determined to be ℬ( D + → K + π 0 ) = (1.45 ± 0.06 ± 0.08) × 10 − 4 , ℬ( D + → K + η ) = (1.17 ± 0.10 ± 0.03) × 10 − 4 and ℬ( D + → K + η′ ) = (1.88 ± 0.15 ± 0.11) × 10 − 4 , where the first uncertainties are statistical and the second systematic. The branching fractions of D + → K + η and D + → K + η′ are consistent with the world average values. The reported branching fraction of D + → K + π 0 deviates with the world average value by 3 σ .