First observation of Cabibbo-suppressed Xi(0)(c) decays

Abstract

We report the first observation of the Cabibbo-suppressed decays Xi(0)(c) -> Xi K--(+), Xi(0)(c) -> Lambda K+K- and Xi(0)(c) -> Lambda phi, using a data sample of 711 fb(-1) collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We measure the ratios of branching fractions to be B(Xi(0)(c)->Xi K--(+))/B(Xi(0)(c)->Xi(-)pi(+)) = (2.75 +/- 0.51 +/- 0.25) x 10(-2), B(Xi(0)(c)->Lambda K+K-)/B(Xi(0)(c)->Xi(-)pi(+)) = (2.86 +/- 0.61 +/- 0.37) x 10(-2) and B(Xi(0)(c)->Lambda phi)/B(Xi(0)(c)->Xi(-)pi(+)) = (3.43 +/- 0.58 +/- 0.32) X 10(-2), where the first uncertainty is statistical and the second is systematic.