Observation of $D^{+}\to {\eta }^{\prime }{\mu }^{+}{\nu }_{\mu }$ and First Study of $D^{+}\to {\eta }^{\prime }{\ell }^{+}{\nu }_{\ell }$ Decay Dynamics

Abstract

Using $20.3\mathrm{f}{\mathrm{b}}^{-1}$ of $e^{+}{e}^{-}$ collision data collected at the center-of-mass energy 3.773\,GeV with the BESIII detector, we report the first observation of the semileptonic decay $D^{+}\to {\eta }^{\prime }{\mu }^{+}{\nu }_{\mu }$ with significance of $8.6\sigma$ including systematic uncertainties, and an improved measurement of $D^{+}\to {\eta }^{\prime }{e}^{+}{\nu }_e$. The branching fractions of $D^{+}\to {\eta }^{\prime }{\mu }^{+}{\nu }_{\mu }$ and $D^{+}\to {\eta }^{\prime }{e}^{+}{\nu }_e$ are determined to be $(1.92\pm 0.28_{\mathrm{stat}}\pm 0.08_{\mathrm{syst}})\times 10^{-4}$ and $(1.79\pm 0.19_{\mathrm{stat}}\pm 0.07_{\mathrm{syst}})\times 10^{-4}$, respectively. The ratio of the two branching fractions is determined to be ${\mathcal{R}}_{\mu /e}=1.07\pm 0.19_{\mathrm{stat}}\pm 0.03_{\mathrm{syst}}$, which agrees with the theoretical expectation of lepton flavor universality within the Standard Model.From an analysis of the $D^{+}\to {\eta }^{\prime }{\ell }^{+}{\nu }_{\ell }$ decay dynamics, the product of the hadronic form factor $f_{+}^{{\eta }^{\prime }}(0)$ and the CKM matrix element $|V_{cd}|$ is measured for the first time, giving $f_{+}^{{\eta }^{\prime }}(0)|V_{cd}|=(5.92\pm 0.56_{\mathrm{stat}}\pm 0.13_{\mathrm{syst}})\times 10^{-2}$. The $\eta -{\eta }^{\prime }$ mixing angle in the quark flavor basis is determined to be ${\varphi }_{\mathrm{P}}=(39.8\pm 0.8_{\mathrm{stat}}\pm 0.3_{\mathrm{syst}}{)}^{\circ }$.

References in corpus (15)

• Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm
• Measurement of the branching ratio of ${\bar{B}}^0\to D^{\ast +}{\tau }^{-}{\bar{\nu }}_{\tau }$ relative to ${\bar{B}}^0\to D^{\ast +}{\ell }^{-}{\bar{\nu }}_{\ell }$ decays with a semileptonic tagging method
• Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of 2021
• Isoscalar meson spectroscopy from lattice QCD
• The $\eta$ and ${\eta }^{\prime }$ mesons from Lattice QCD
• Branching fractions of semileptonic $D$ and $D_s$ decays from the covariant light-front quark model
• Recent Progress in Leptonic and Semileptonic Decays of Charmed Hadrons
• Measurement of the ratios of branching fractions $\mathcal{R}(D^{\ast })$ and $\mathcal{R}(D^0)$
• Semileptonic decays of $D$ and $D_s$ mesons in the relativistic quark model
• Measurement of the integrated luminosity of the data collected at 3.773 GeV by BESIII from 2021 to 2024
• Determination of the $\eta$-${\eta }^{\prime }$ mixing angle
• Precision Measurements of $D_s^{+}\to \eta e^{+}{\nu }_e$ and $D_s^{+}\to {\eta }^{\prime }{e}^{+}{\nu }_e$
• Observation of $D_s^{+}\to {\eta }^{\prime }{\mu }^{+}{\nu }_{\mu }$, Precision Test of Lepton Flavor Universality with $D_s^{+}\to {\eta }^{(\prime )}{\ell }^{+}{\nu }_{\ell }$, and First Measurements of $D_s^{+}\to {\eta }^{(\prime )}{\mu }^{+}{\nu }_{\mu }$ Decay Dynamics
• Properties of the ${\eta }_q$ leading-twist distribution amplitude and its effects to the $B/D^{+}\to {\eta }^{(\prime )}{\ell }^{+}{\nu }_{\ell }$ decays
• Improved measurements of $D^0\to K^{-}{\ell }^{+}{\nu }_{\ell }$ and $D^{+}\to {\bar{K}}^0{\ell }^{+}{\nu }_{\ell }$

Cited by in corpus (2)

• Exclusive semileptonic decays of $D$ and $D_s$ mesons into orbitally and radially excited states of strange and light mesons
• Observation of $D^{+}\to K_S^0{\pi }^0{\mu }^{+}{\nu }_{\mu }$, Test of Lepton Flavor Universality and First Angular Analysis of $D^{+}\to {\bar{K}}^{\ast }(892{)}^0{\ell }^{+}{\nu }_{\ell }$