Search for the semileptonic decays ${\Xi }_c^0\to {\Xi }^0{\ell }^{+}{\ell }^{-}$ at Belle

Abstract

Using the full data sample of 980 ${\mathrm{fb}}^{-1}$ collected with the Belle detector at the KEKB asymmetric energy electron-positron collider, we report the results of the first search for the rare semileptonic decays ${\Xi }_c^0\to {\Xi }^0{\ell }^{+}{\ell }^{-}$ ($\ell =e$ or $\mu )$. No significant signals are observed in the ${\Xi }^0{\ell }^{+}{\ell }^{-}$ invariant-mass distributions. Taking the decay ${\Xi }_c^0\to {\Xi }^{-}{\pi }^{+}$ as the normalization mode, we report 90\% credibility upper limits on the branching fraction ratios $\mathcal{B}({\Xi }_c^0\to {\Xi }^0{e}^{+}{e}^{-})/\mathcal{B}({\Xi }_c^0\to {\Xi }^{-}{\pi }^{+})<6.7\times 10^{-3}$ and $\mathcal{B}({\Xi }_c^0\to {\Xi }^0{\mu }^{+}{\mu }^{-})/\mathcal{B}({\Xi }_c^0\to {\Xi }^{-}{\pi }^{+})<4.3\times 10^{-3}$ based on the phase-space assumption for signal decays. The 90\% credibility upper limits on the absolute branching fractions of $\mathcal{B}({\Xi }_c^0\to {\Xi }^0{e}^{+}{e}^{-})$ and $\mathcal{B}({\Xi }_c^0\to {\Xi }^0{\mu }^{+}{\mu }^{-})$ are found to be $9.9\times 10^{-5}$ and $6.5\times 10^{-5}$, respectively.

arXiv comment8 pages, 4 figures, submitted to PRD

References in corpus (25)

• High-Energy-Physics Event Generation with PYTHIA 6.1
• Test of lepton universality using $B^{+}\to K^{+}{\ell }^{+}{\ell }^{-}$ decays
• Test of lepton universality with $B^0\to K^{\ast 0}{\ell }^{+}{\ell }^{-}$ decays
• Kernel Estimation in High-Energy Physics
• Search for lepton-universality violation in $B^{+}\to K^{+}{\ell }^{+}{\ell }^{-}$ decays
• Test of lepton universality in beauty-quark decays
• Measurement of $CP$-averaged observables in the $B^0\to K^{\ast 0}{\mu }^{+}{\mu }^{-}$ decay
• Electron Identification in Belle
• TopoAna: A generic tool for the event type analysis of inclusive Monte-Carlo samples in high energy physics experiments
• Observation of the Baryonic Flavor-Changing Neutral Current Decay Lambda_b -> Lambda mu+ mu-
• Test of lepton universality in $b\to s{\ell }^{+}{\ell }^{-}$ decays
• Flavour Changing Neutral Current Decays of Heavy Baryons: The Case ${\Lambda }_b\to \Lambda \gamma$
• Angular analysis of the $B^{+}\to K^{\ast +}{\mu }^{+}{\mu }^{-}$ decay
• Rare Decays of Λ_b->Λ+ γand Λ_b ->Λ+ l^{+} l^{-} in the Light-cone Sum Rules
• Evidence for the Decay Sigma+ -> p mu+ mu-
• Searches for Rare or Forbidden Semileptonic Charm Decays
• Measurement of the differential branching fraction of the decay ${\Lambda }_b^0\to \Lambda {\mu }^{+}{\mu }^{-}$
• Photon polarization from helicity suppression in radiative decays of polarized Lambda_b to spin-3/2 baryons
• Global Decay Chain Vertex Fitting at B-Factories
• Search for the rare decay ${\Lambda }_c^{+}\to p{\mu }^{+}{\mu }^{-}$
• Studying ${\mathcal{B}}_1({\frac{1}{2}}^{+})\to {\mathcal{B}}_2({\frac{1}{2}}^{+}){\ell }^{+}{\ell }^{-}$ Semi-leptonic Weak Baryon Decays with the SU(3) Flavor Symmetry
• Measurement of Branching Fractions of Hadronic Decays of the ${\Omega }_c^0$ Baryon
• First observation and branching fraction and decay parameter measurements of the weak radiative decay Xi0 --> Lambda e+e-
• Measurements of branching fractions of ${\Lambda }_c^{+}\to {\Sigma }^{+}\eta$ and ${\Lambda }_c^{+}\to {\Sigma }^{+}{\eta }^{\prime }$ and asymmetry parameters of ${\Lambda }_c^{+}\to {\Sigma }^{+}{\pi }^0$, ${\Lambda }_c^{+}\to {\Sigma }^{+}\eta$, and ${\Lambda }_c^{+}\to {\Sigma }^{+}{\eta }^{\prime }$
• Measurement of the Resonant and Non-Resonant Branching Ratios in ${\Xi }_c^0\to {\Xi }^0{K}^{+}{K}^{-}$