Measurements of the absolute branching fractions of the doubly Cabibbo-suppressed decays $D^+\to K^+\pi^0$, $D^+\to K^+\eta$ and $D^+\to K^+\eta^{\prime}$

Abstract

Using $20.3\,\rm fb^{-1}$ 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 $D^+\to K^+\pi^0$, $D^+\to K^+\eta$ and $ D^+ \to K^+ \eta^{\prime}$ with the double-tag method, with significantly improved precision compared to the previous measurements. The statistical significance of each signal decay exceeds $10\sigma$. The branching fractions are determined to be ${\mathcal B}(D^+\to K^+ \pi^0) = (1.45 \pm 0.06 \pm 0.08)\times 10^{-4}$, ${\mathcal B}(D^+\to K^+ \eta) = (1.17 \pm 0.10 \pm 0.03)\times 10^{-4}$ and ${\mathcal B}(D^+\to K^+ \eta^{\prime}) = (1.88 \pm 0.15 \pm 0.11)\times 10^{-4}$, where the first uncertainties are statistical and the second systematic. The branching fractions of $D^+\to K^+\eta$ and $ D^+ \to K^+ \eta^{\prime}$ are consistent with the world average values. The reported branching fraction of $D^+\to K^+\pi^0$ deviates with the world average value by 3$\sigma$.