Evidence for the singly-Cabibbo-suppressed decay $Lambda_{c}^{+} to peta$ and search for $Lambda_{c}^{+} to ppi^{0}$

We study the singly-Cabibbo-suppressed decays $Lambda_c^{+}to peta$ and $Lambda_{c}^{+}to ppi^{0}$ using $Lambda_{c}^{+}Lambda_{c}^{+}$ pairs produced by $e^+e^-$ collisions at a center-of-mass energy of $sqrt{s} = 4.6; GeV$. The data sample was collected by the BESIII detector at the BEPCII collider and corresponds to an integrated luminosity of 567 $pb^{-1}$. We find the first evidence for the decay $Lambda_{c}^{+}to p eta$ with a statistical significance of $4.2sigma$ and measure its branching fraction to be $mathcal{B}(Lambda_c^+to peta)= (1.24pm0.28({rm{stat.}})pm0.10({rm{syst.}}))times10^{-3}$. No significant $Lambda_c^+ to ppi^0$ signal is observed. We set an upper limit on its branching fraction $mathcal{B}(Lambda_c^+ to ppi^{0}) < 2.7 times 10^{-4}$ at the 90% confidence level.