2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/206079We present an analysis of the decay $D^0 \to K^+π^-$ based on FOCUS data. From a sample of 234 signal events, we find a branching ratio of $\frac{Γ(D^0 \to K^+π^-)}{Γ(D^0 \to K^-π^+)} = (0.429^{+0.063}_{-0.061}\pm 0.027)%$ under the assumptions of no mixing and no CP violation. Allowing for CP violation, we find a branching ratio of $(0.429 \pm 0.063 \pm 0.028)%$ and a \textit{CP} asymmetry of $0.18 \pm 0.14 \pm 0.04$. The branching ratio for the case of mixing with no CP violation is $(0.381^{+0.167}_{-0.163} \pm 0.092)%$. We also present limits on charm mixing.As accepted by Physics Letters BHigh Energy Physics - Experimenttext