New measurements of the D+→φμ+ν form factor ratios

Using a large sample of D s + → φμ + ν decays collected by the FOCUS photoproduction experiment at Fermilab, we present new measurements of two semileptonic form factor ratios: r v and r 2 . We find r v =1.549±0.250±0.148 and r 2 =0.713±0.202±0.284. These values are consistent with r v and r 2 form factors measured for the process D + → K ∗0 l + ν l .