Measurements of the branching fractions of Λc+ → pη and Λc+ → pπ0 decays at Belle

We report measurements of the branching fractions of singly Cabibbo-suppressed decays Λc+ → pη and Λc+ → pπ0 using the full Belle data sample corresponding to an integrated luminosity of 980.6 fb−1. The data were collected by the Belle detector at the KEKB e+ e− asymmetric energy collider. A clear Λ + c signal is seen in the invariant mass distribution of p η . The fitted number of signal events of the Λc+ → pη process is 7734 ± 263 ; from this, we measure the ratio of branching fractions B ( Λc+→ pη ) / B ( Λc+ → pK− π+ ) = [ 2.258 ± 0. 077 ( stat ) ± 0.122 ( syst ) ] × 10 − 2 , from which we infer the branching fraction B ( Λc+ → pη ) = [ 1.42 ± 0.05 ( stat ) ± 0.11 ( syst ) ] × 10−3. In addition, no significant signal for Λc+ → pπ0 is found, so an upper limit on the branching fraction of B ( Λc+ → pπ0) < 8.0 × 10−5 at a 90% credibility level is set, more than 3 times better than the best current upper limit.