Search for the semi-leptonic decays ${\Lambda }_c^{+}\to \Lambda {\pi }^{+}{\pi }^{-}{e}^{+}{\nu }_e$ and ${\Lambda }_c^{+}\to p{K}_S^0{\pi }^{-}{e}^{+}{\nu }_e$

Abstract

We search for the semi-leptonic decays ${\Lambda }_c^{+}\to \Lambda {\pi }^{+}{\pi }^{-}{e}^{+}{\nu }_e$ and ${\Lambda }_c^{+}\to p{K}_S^0{\pi }^{-}{e}^{+}{\nu }_e$ in a sample of 4.5 ${\mathrm{fb}}^{-1}$ of $e^{+}{e}^{-}$ annihilation data collected in the center-of-mass energy region between 4.600 GeV and 4.699 GeV by the BESIII detector at the BEPCII. No significant signals are observed, and the upper limits on the decay branching fractions are set to be $\mathcal{B}({\Lambda }_c^{+}\to \Lambda {\pi }^{+}{\pi }^{-}{e}^{+}{\nu }_e)<3.9\times 10^{-4}$ and $\mathcal{B}({\Lambda }_c^{+}\to p{K}_S^0{\pi }^{-}{e}^{+}{\nu }_e)<3.3\times 10^{-4}$ at the 90% confidence level, respectively.

11 pages, 3 figures