Study of the semileptonic charm decays D0→π-l+ν and D0→K-l+ν -: art. no. 011802

We investigate the decays D-0-->pi(-)l(+)nu and D-0-->K(-)l(+)nu, where l is e or mu, using approximately 7 fb(-1) of data collected with the CLEO III detector. We find R-0=B(D-0-->pi(-)e(+)nu)/B(D-0-->K(-)e(+)nu)=0.082+/-0.006+/-0.005. Fits to the kinematic distributions of the data provide parameters describing the form factor of each mode. Combining the form factor results and R-0 gives |f(+)(pi)(0)|(2)|V-cd|(2)/|f(+)(K)(0)|(2)|V-cs|(2)=0.038(-0.007-0.003)(+0.006+0.005).