Measurement of the absolute branching fraction of D + → K 0 e + ν e via K 0 → π 0 π 0

Abstract

By analyzing 2.93 fb$^{-1}$ data collected at the center-of-mass energy $\\sqrt s=3.773$ GeV with the BESIII detector, we measure the absolute branching fraction of the semileptonic decay $D^+\\rightarrow\\bar K^0 e^{+}\\nu_{e}$ to be ${\\mathcal B}(D^{+}\\rightarrow\\bar K^0 e^{+}\\nu_{e})=(8.59 \\pm 0.14 \\pm 0.21)\\%$ using $\\bar K^0\\to K^0_S\\to \\pi^0\\pi^0$, where the first uncertainty is statistical and the second systematic. Our result is consistent with previous measurements within uncertainties.