Observation of the Singly Cabibbo-Suppressed Decay ${\Lambda }_c^{+}\to n{\pi }^{+}$

Abstract

The singly Cabibbo-suppressed decay ${\Lambda }_c^{+}\to n{\pi }^{+}$ is observed for the first time with a statistical significance of $7.3\sigma$ by using 3.9 ${\mathrm{fb}}^{-1}$ of $e^{+}{e}^{-}$ collision data collected at center-of-mass energies between 4.612 and 4.699 GeV with the BESIII detector at BEPCII. The branching fraction of ${\Lambda }_c^{+}\to n{\pi }^{+}$ is measured to be $(6.6\pm 1.2_{\mathrm{stat}}\pm 0.4_{\mathrm{syst}})\times 10^{-4}$. By taking the upper limit of branching fractions of ${\Lambda }_c^{+}\to p{\pi }^0$ from the Belle experiment, the ratio of branching fractions between ${\Lambda }_c^{+}\to n{\pi }^{+}$ and ${\Lambda }_c^{+}\to p{\pi }^0$ is calculated to be larger than 7.2 at the 90% confidence level, which disagrees with the current predictions of available phenomenological models. In addition, the branching fractions of the Cabibbo-favored decays ${\Lambda }_c^{+}\to \Lambda {\pi }^{+}$ and ${\Lambda }_c^{+}\to {\Sigma }^0{\pi }^{+}$ are measured to be $(1.31\pm 0.08_{\mathrm{stat}}\pm 0.05_{\mathrm{syst}})\times 10^{-2}$ and $(1.22\pm 0.08_{\mathrm{stat}}\pm 0.07_{\mathrm{syst}})\times 10^{-2}$, respectively, which are consistent with previous results.

18 pages,7 figures

References in corpus (7)

• Study of the Standard Model with weak decays of charmed hadrons at BESIII
• Non-leptonic two-body weak decays of ${\Lambda }_c(2286)$
• Two-body hadronic weak decays of antitriplet charmed baryons
• Singly Cabibbo suppressed decays of ${\Lambda }_c^{+}$ with SU(3) flavor symmetry
• Measurements of the branching fractions of ${\Lambda }_c^{+}\to p\eta$ and ${\Lambda }_c^{+}\to p{\pi }^0$ decays at Belle
• Search for ${\Lambda }_c^{+}\to \varphi p{\pi }^0$ and branching fraction measurement of ${\Lambda }_c^{+}\to K^{-}{\pi }^{+}p{\pi }^0$
• Study of $J/\psi$ and $\psi (3686)$ decays to ${\pi }^{+}{\pi }^{-}{\eta }^{\prime }$

Cited by in corpus (14)

• Charmed Baryon Physics Circa 2021
• ${\Lambda }_c$ semileptonic decays
• Search for a massless dark photon in ${\Lambda }_c^{+}\to p{\gamma }^{\prime }$ decay
• Observations of the Cabibbo-Suppressed decays ${\Lambda }_c^{+}\to n{\pi }^{+}{\pi }^0$, $n{\pi }^{+}{\pi }^{-}{\pi }^{+}$ and the Cabibbo-Favored decay ${\Lambda }_c^{+}\to n{K}^{-}{\pi }^{+}{\pi }^{+}$
• Topological amplitudes of charmed baryon decays in the $SU(3{)}_F$ limit
• Measurement of the absolute branching fraction of the singly Cabibbo suppressed decay ${\Lambda }_c^{+}\to p{\eta }^{\prime }$
• Evidence of the Singly Cabibbo Suppressed decay ${\Lambda }_c^{+}\to p{\pi }^0$
• A novel method for searching the ${\Xi }_c^{0/+}$-${\Xi }_c^{\prime 0/+}$ mixing effect in the angular distribution analysis of a four-body ${\Xi }_c^{0/+}$ decay
• First observation of ${\Lambda }_c^{+}\to \Lambda K^{+}{\pi }^0$ and evidence of ${\Lambda }_c^{+}\to \Lambda K^{+}{\pi }^{+}{\pi }^{-}$
• Measurement of the absolute branching fraction of the inclusive decay ${\bar{\Lambda }}_c^{-}\to \bar{n}+X$
• Observation of the Singly Cabibbo-Suppressed Decay ${\Lambda }_c^{+}\to p{\pi }^0$
• Measurement of the absolute branching fraction of the three-body decay ${\Lambda }_c^{+}\to {\Xi }^0{K}^{+}{\pi }^0$ and search for ${\Lambda }_c^{+}\to n{K}^{+}{\pi }^0$, ${\Sigma }^0{K}^{+}{\pi }^0$ and $\Lambda K^{+}{\pi }^0$
• Baryons and baryoniums in the perspective of QCD sum rules
• Observation of the Singly Cabibbo-Suppressed Decay ${\Lambda }_c^{+}\to {\Sigma }^{-}{K}^{+}{\pi }^{+}$