RESONANT AND NONRESONANT D-]K- PI(+)L(+) NU(L) SEMILEPTONIC DECAYS - ART. NO. 054009()

We analyze the semileptonic decay D+ --> K- pi(+)l(+)nu(l) using an ef fective Lagrangian developed previously to describe the decays D --> P l nu(l) and D --> Vl nu(l). Light vector mesons are included in the mo del which combines the heavy quark effective Lagrangian and chiral per turbation theory approach. The nonresonant and resonant contributions are compared. With no new parameters the model correctly reproduces th e measured ratio Gamma(nres)/Gamma(nres +) (res). We also present usef ul nonresonant decay distributions. Finally, a similar model, but with a modified current which satisfies the soft pion theorems at the expe nse of introducing another parameter, is analyzed and the results of t he models are compared. [S0556-2821(98)02017-7]