Evidence for the singly Cabibbo-suppressed decay Ωc0 → Ξ−π+ and search for Ωc0 → Ξ−K+ and Ω−K+ decays at Belle

Journal of High Energy Physics. 2023. Vol. 2023. No. 1. Article 55.

Han X., Jia S., Yuan L., Shen C. P., Adachi I., Ahn J. K., Aihara H., T. Aushev, D. Bodrov, R. Mizuk, G. Pakhlova, T. Uglov

Using a data sample of 980 fb(-1) collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider, we study for the first time the singly Cabibbo-suppressed decays omega(0)(c) -(sic) -pi(+) and omega K--(+) and the doubly Cabibbo-suppressed decay omega(0)(c) -(sic)K--(+). Evidence for an Q0 c signal in the omega(0)(c) -E-pi+ mode is reported with a significance of 4.5 sigma including systematic uncertainties. The ratio of branching fractions to the normalization mode omega(0)(c) -omega(-)pi(+ )is measured to beB(omega(0)(c) -(sic)(-)pi(+))/B(omega(0)(c) -Q-pi+) = 0.253 +/- 0.052(stat.) +/- 0.030(syst.).No significant signals of omega(0)(c) -(sic)K--(+) and omega K--(+) modes are found. The upper limits at 90% confidence level on ratios of branching fractions are determined to be B(omega(0)(c) -> (sic)K--(+))/B(omega(0)(c) -> omega-pi(+)) < 0.070 and B(omega(0)(c) -> omega K--(+))/B(omega(0)(c) -> omega-pi(+)) < 0.29.

Keywords: Belle detector, Branching fraction, Charm physics, Particle and resonance production

Publication based on the results of: Development of new methods for searching for physics beyond the Standard Model in experiments at the Super Charm-Tau Factory and Belle at the KEKB B-Factory (2023)