New measurements of the and branching ratios

Using a large sample of charm semileptonic decays collected by the FOCUS photoproduction experiment at Fermilab, we present new measurements of two semileptonic branching ratios. We obtain values of Γ(D + → K ∗0 μ + ν) Γ(D + →K − π + π + ) =0.602±0.010( stat )±0.021( sys ) and Γ(D s + →φμ + ν) Γ(D s + →φπ + ) =0.54±0.033( stat )±0.048( sys ) . Our D + → K ∗0 μ + ν result includes the effects of the s-wave interference discussed in Phys. Lett. B 535 (2002) 43.