First Observation of $D^{+}\to \eta {\mu }^{+}{\nu }_{\mu }$ and Measurement of its Decay Dynamics

Abstract

By analyzing a data sample corresponding to an integrated luminosity of $2.93{\mathrm{fb}}^{-1}$ collected at a center-of-mass energy of 3.773 GeV with the BESIII detector, we measure for the first time the absolute branching fraction of the $D^{+}\to \eta {\mu }^{+}{\nu }_{\mu }$ decay to be ${\mathcal{B}}_{D^{+}\to \eta {\mu }^{+}{\nu }_{\mu }}=(10.4\pm 1.0_{\mathrm{stat}}\pm 0.5_{\mathrm{syst}})\times 10^{-4}$. Using the world averaged value of ${\mathcal{B}}_{D^{+}\to \eta e^{+}{\nu }_e}$, the ratio of the two branching fractions is determined to be ${\mathcal{B}}_{D^{+}\to \eta {\mu }^{+}{\nu }_{\mu }}/{\mathcal{B}}_{D^{+}\to \eta e^{+}{\nu }_e}=0.91\pm 0.13$, which agrees with the theoretical expectation of lepton flavor universality within uncertainty. Here, the uncertainty is the sum in quadrature of the statistical and systematic uncertainties. By studying the differential decay rates in five four-momentum transfer intervals, we obtain the product of the hadronic form factor $f_{+}^{\eta }(0)$ and the $c\to d$ Cabibbo-Kobayashi-Maskawa matrix element $|V_{cd}|$ to be $f_{+}^{\eta }(0)|V_{cd}|=0.087\pm 0.008_{\mathrm{stat}}\pm 0.002_{\mathrm{syst}}$. Taking the input of $|V_{cd}|$ from the global fit in the standard model, we determine $f_{+}^{\eta }(0)=0.39\pm 0.04_{\mathrm{stat}}\pm 0.01_{\mathrm{syst}}$. On the other hand, using the value of $f_{+}^{\eta }(0)$ calculated in theory, we find $|V_{cd}|=0.242\pm 0.022_{\mathrm{stat}}\pm 0.006_{\mathrm{syst}}\pm 0.033_{\mathrm{theory}}$.

10 pages, 3 figures

References in corpus (11)

• On the B to D* tau nu Sensitivity to New Physics
• Explaining $h\to {\mu }^{\pm }{\tau }^{\mp }$, $B\to K^{\ast }{\mu }^{+}{\mu }^{-}$ and $B\to K{\mu }^{+}{\mu }^{-}/B\to K{e}^{+}{e}^{-}$ in a two-Higgs-doublet model with gauged $L_{\mu }-L_{\tau }$
• 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
• Implications of lepton flavor universality violations in B decays
• $B_{(s)},D_{(s)}\to \pi ,K,\eta ,\rho ,K^{\ast },\omega ,\varphi$ Transition Form Factors and Decay Rates with Extraction of the CKM parameters $|V_{ub}|$, $|V_{cs}|$, $|V_{cd}|$
• Branching fractions of semileptonic $D$ and $D_s$ decays from the covariant light-front quark model
• Measurement of $\mathcal{R}(D)$ and $\mathcal{R}(D^{\ast })$ with a semileptonic tagging method
• Semileptonic decays of $D$ and $D_s$ mesons in the relativistic quark model
• Discerning new physics in charm meson leptonic and semileptonic decays
• Dalitz plot analyses of $B^0\to D^{-}{D}^0{K}^{+}$ and $B^{+}\to {\overline{D}}^0{D}^0{K}^{+}$ decays
• Observation of the semi-muonic decay $D^{+}\to \omega {\mu }^{+}{\nu }_{\mu }$

Cited by in corpus (13)

• Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of 2021
• Recent Progress in Leptonic and Semileptonic Decays of Charmed Hadrons
• Hints of Natural Supersymmetry in Flavor Anomalies?
• Search for the semileptonic decay $D^{0(+)}\to b_1(1235{)}^{-(0)}{e}^{+}{\nu }_e$
• Observation of the Doubly Cabibbo-Suppressed Decay $D^{+}\to K^{+}{\pi }^{+}{\pi }^{-}{\pi }^0$ and Evidence for $D^{+}\to K^{+}\omega$
• Search for baryon and lepton number violating decays $D^0\to \bar{p}{e}^{+}$ and $D^0\to p{e}^{-}$
• Determination of the absolute branching fractions of $D^0\to K^{-}{e}^{+}{\nu }_e$ and $D^{+}\to {\bar{K}}^0{e}^{+}{\nu }_e$
• Observation of the Decay $D^0\to {\rho }^{-}{\mu }^{+}{\nu }_{\mu }$
• Measurements of the absolute branching fractions of $D^{0(+)}\to K\bar{K}\pi \pi$ decays
• Observation of $D^{0(+)}\to K_S^0{\pi }^{0(+)}\omega$ and improved measurement of $D^0\to K^{-}{\pi }^{+}\omega$
• Semileptonic Decay of ${\Omega }_c^0\to {\Xi }^{-}{l}^{+}{\nu }_l$ From Light-Cone Sum Rules
• Exclusive semileptonic decays of $D$ and $D_s$ mesons into orbitally and radially excited states of strange and light mesons
• Status of the $D_s^{+}\to \varphi {\ell }^{+}{\nu }_{\ell }$ decay with a chiral-odd $\varphi$-meson light-cone distribution amplitude