New measurements of the {Γ(D +→ overlineK∗0μ +ν) }/{Γ(D +→K -π +π +) } and {Γ(D s+→φμ +ν) }/{Γ(D s+→φπ +) } 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 ⁺→ overlineK^∗0μ ⁺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 ⁺→ overlineK^∗0μ ⁺ν result includes the effects of the s-wave interference discussed in Phys. Lett. B 535 (2002) 43.