Measurements of the branching fractions of Ξ0c→ΛK0S, Ξ0c→Σ0K0S, and Ξ0c→Σ+K- decays at Belle

Physical Review D - Particles, Fields, Gravitation and Cosmology. 2022. Vol. 105. No. 1. Article L011102.

Li Y., Cui J. X., Jia S., Shen C. P., Adachi I., Ahn J. K., Aihara H., T. Aushev, D. Bodrov, R. Mizuk, G. Pakhlova, V. Popov

Using the entire data sample of 980  fb−1 collected with the Belle detector at the KEKB asymmetric-energy e+e− collider, we present measurements of the branching fractions of the Cabibbo-favored decays Ξ0c→ΛK0S, Ξ0c→Σ0K0S, and Ξ0c→Σ+K−. Taking the decay Ξ0c→Ξ−π+ as the normalization mode, we measure the branching fraction ratio B(Ξ0c→ΛK0S)/B(Ξ0c→Ξ−π+)=0.229±0.008±0.012 with improved precision, and measure the branching fraction ratios B(Ξ0c→Σ0K0S)/B(Ξ0c→Ξ−π+)=0.038±0.006±0.004 and B(Ξ0c→Σ+K−)/B(Ξ0c→Ξ−π+)=0.123±0.007±0.010 for the first time. Taking into account the branching fraction of the normalization mode, the absolute branching fractions are determined to be B(Ξ0c→ΛK0S)=(3.27±0.11±0.17±0.73)×10−3, B(Ξ0c→Σ0K0S)=(0.54±0.09±0.06±0.12)×10−3, and B(Ξ0c→Σ+K−)=(1.76±0.10±0.14±0.39)×10−3. The first and second uncertainties above are statistical and systematic, respectively, while the third ones arise from the uncertainty of the branching fraction of Ξ0c→Ξ−π+.

Keywords: Belle detector

Publication based on the results of: Search for Physics beyond the Standard Model in the decays of heavy leptons and hadrons at Belle and Belle II experiments (2022)