Based on a data sample corresponding to an integrated luminosity of 6.4~fb$^{ -1}$ of $e^+e^-$ annihilation and collected with the BESIII detector at 13 center-of-mass energy points ranging between 4.600~GeV and 4.950~GeV, we report the first observation of the singly Cabibbo-suppressed decay $\Lambda_c^+ \to \Sigma^0 K_S^0 \pi^+$ with a statistical significance of 5.9$\sigma$. The branching fraction is determined to be $\mathcal{ B}(\Lambda_c^+ \to \Sigma^0 K_S^0 \pi^+) = (0.58 \pm 0.14_{ \rm stat.} \pm 0.04_{ \rm syst.}) \times 10^{ -3}$. In addition, the decay $\Lambda_c^+\to\Sigma^0K_{ S}^{ 0} K^+$ has also been investigated, and the first evidence for this decay is obtained with a statistical significance of 3.7$\sigma$.
Categories: hep-ex