Search for the Rare Decays $D_s^{+}\to h^{+}(h^0)e^{+}{e}^{-}$

Abstract

Using 7.33~fb${}^{-1}$ of $e^{+}{e}^{-}$ collision data collected by the BESIII detector at center-of-mass energies in the range of $\sqrt{s}=4.128-4.226$~GeV, we search for the rare decays $D_s^{+}\to h^{+}(h^0)e^{+}{e}^{-}$, where $h$ represents a kaon or pion. By requiring the $e^{+}{e}^{-}$ invariant mass to be consistent with a $\varphi (1020)$, $0.98<M(e^{+}{e}^{-})<1.04$ ~GeV/$c^2$, the decay $D_s^{+}\to {\pi }^{+}\varphi ,\varphi \to e^{+}{e}^{-}$ is observed with a statistical significance of 7.8$\sigma$, and evidence for the decay $D_s^{+}\to {\rho }^{+}\varphi ,\varphi \to e^{+}{e}^{-}$ is found for the first time with a statistical significance of 4.4$\sigma$. The decay branching fractions are measured to be $\mathcal{B}(D_s^{+}\to {\pi }^{+}\varphi ,\varphi \to e^{+}{e}^{-})=(1.17_{-0.21}^{+0.23}\pm 0.03)\times 10^{-5}$, and $\mathcal{B}(D_s^{+}\to {\rho }^{+}\varphi ,\varphi \to e^{+}{e}^{-})=(2.44_{-0.62}^{+0.67}\pm 0.16)\times 10^{-5}$, where the first uncertainties are statistical and the second systematic. No significant signal for the three four-body decays of $D_s^{+}\to {\pi }^{+}{\pi }^0{e}^{+}{e}^{-},D_s^{+}\to K^{+}{\pi }^0{e}^{+}{e}^{-}$, and $D_s^{+}\to K_S^0{\pi }^{+}{e}^{+}{e}^{-}$ is observed. For $D_s^{+}\to {\pi }^{+}{\pi }^0{e}^{+}{e}^{-}$, the $\varphi$ mass region is vetoed to minimize the long-distance effects. The 90$\%$ confidence level upper limits set on the branching fractions of these decays are in the range of $(7.0-8.1)\times 10^{-5}$.

10 pages, 2 figures, 1 table

References in corpus (33)

• Design and Construction of the BESIII Detector
• The Precision Monte Carlo Event Generator KK For Two-Fermion Final States In e+e- Collisions
• Coherent Exclusive Exponentiation For Precision Monte Carlo Calculations
• Test of lepton universality in beauty-quark decays
• Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of 2021
• Rare Charm Decays in the Standard Model and Beyond
• Method for detector description transformation to Unity and application in BESIII
• Test of lepton universality in $b\to s{\ell }^{+}{\ell }^{-}$ decays
• Measurement of Charm Production Cross Sections in e+e- Annihilation at Energies between 3.97 and 4.26 GeV
• Prospects of discovering new physics in rare charm decays
• Flavor & new physics opportunities with rare charm decays into leptons
• Recent Progress in Leptonic and Semileptonic Decays of Charmed Hadrons
• Searches for Rare or Forbidden Semileptonic Charm Decays
• Measurement of integrated luminosities at BESIII for data samples at center-of-mass energies between 4.0 and 4.6 GeV
• On $D\to X_u{l}^{+}{l}^{-}$ within the Standard Model and Frameworks like the Littlest Higgs Model with T Parity
• Observation of the Dalitz Decay ${\eta }^{\prime }\to \gamma e^{+}{e}^{-}$
• Standard Model prediction and new physics tests for D0 -> h+h-l+l- (h=π,K; l=e,μ)
• Null tests from angular distributions in $D\to P_1{P}_2{l}^{+}{l}^{-}$, $l=e,\mu$ decays on and off peak
• Rare radiative charm decays within the standard model and beyond
• Measurements of the center-of-mass energies of $e^{+}{e}^{-}$ collisions at BESIII
• Observation of $D^0$ meson decays to ${\pi }^{+}{\pi }^{-}{\mu }^{+}{\mu }^{-}$ and $K^{+}{K}^{-}{\mu }^{+}{\mu }^{-}$ final states
• Amplitude analysis and branching fraction measurement of $D_s^{+}\to K^{+}{K}^{-}{\pi }^{+}$
• Theoretical and experimental status of rare charm decays
• Measurement of the Dynamics of the Decays $D_s^{+}\to {\eta }^{(\prime )}{e}^{+}{\nu }_e$
• Manifestations of Warped Extra Dimension in Rare Charm Decays and Asymmetries
• Search for the rare decays $D\to h(h^{\prime })e^{+}{e}^{-}$
• First observation of the decay $D^0\to K^{-}{\pi }^{+}{\mu }^{+}{\mu }^{-}$ in the ${\rho }^0$-$\omega$ region of the dimuon mass spectrum
• Search for rare and forbidden decays of charm and charmed-strange mesons to final states h^+- e^-+ e^+
• Measurement of the absolute branching fraction of inclusive semielectronic $D_s^{+}$ decays
• Observation of the decay $D^0\to K^{-}{\pi }^{+}{e}^{+}{e}^{-}$
• Observation of the $W$-Annihilation Decay $D_s^{+}\to \omega {\pi }^{+}$ and Evidence for $D_s^{+}\to \omega K^{+}$
• Amplitude analysis and branching-fraction measurement of $D_s^{+}\to K_S^0{K}^{-}{\pi }^{+}{\pi }^{+}$
• Measurements of the branching fraction ratio $\mathcal{B}(\varphi \to {\mu }^{+}{\mu }^{-})/\mathcal{B}(\varphi \to e^{+}{e}^{-})$ with charm meson decays