2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/207278Using data collected by the fixed target Fermilab experiment FOCUS, we measure the branching ratios of the Cabibbo favored decays $Ξ_c^+ \to Σ^+K^-π^+$, $Ξ_c^+ \to Σ^+ \bar{K}^{*}(892)^0$, and $Ξ_c^+ \to Λ^0K^-π^+π^+$ relative to $Ξ_c^+ \to Ξ^-π^+π^+$ to be $0.91\pm0.11\pm0.04$, $0.78\pm0.16\pm0.06$, and $0.28\pm0.06\pm0.06$, respectively. We report the first observation of the Cabibbo suppressed decay $Ξ_c^+ \to Σ^+K^+K^-$ and we measure the branching ratio relative to $Ξ_c^+ \to Σ^+K^-π^+$ to be $0.16\pm0.06\pm0.01$. We also set 90% confidence level upper limits for $Ξ_c^+ \to Σ^+ ϕ$ and $Ξ_c^+ \to Ξ^*(1690)^0(Σ^+ K^-) K^+$ relative to $Ξ_c^+ \to Σ^+K^-π^+$ to be 0.12 and 0.05, respectively. We find an indication of the decays $Ξ_c^+ \to Ω^-K^{+}π^+$ and $Ξ_c^+ \to Σ^{*}(1385)^+ \bar{K}^0$ and set 90% confidence level upper limits for the branching ratios with respect to $Ξ_c^+ \to Ξ^-π^+π^+$ to be 0.12 and 1.72, respectively. Finally, we determine the 90% C.L. upper limit for the resonant contribution $Ξ_c^+ \to Ξ^{*}(1530)^0 π^+$ relative to $Ξ_c^+ \to Ξ^-π^+π^+$ to be 0.10.14 pages, 8 figuresHigh Energy Physics - Experimenttext