Measurement of B(D+->(K)over-bar(*0)l(+)nu(l))

Abstract

Using 13.53 fb(-1) of CLEO data, we have measured the ratios of the branching fractions R-e(+),R-mu(+) and the combined branching fraction ratio R-l(+), defined by R-l(+)=[B(D+-->(K) over bar (*0)l(+)nu(l))]/[B(D+-->K(-)pi(+)pi(+))]. We find R-e(+)=0.74+/-0.04+/-0.05, R-mu(+)=0.72+/-0.10+/-0.05, and R-l(+)=0.74+/-0.04+/-0.05, where the first and second errors are statistical and systematic, respectively. The known branching fraction B(D+-->K(-)pi(+)pi(+)) leads to B(D+-->(K) over bar (*0)e(+)nu(e))=(6.7+/-0.4+/-0.5+/-0.4)%, B(D+-->(K) over bar (*0)mu(+)nu(mu))=(6.5+/-0.9+/-0.5+/-0.4)%, and B(D+-->(K) over bar (*0)l(+)nu(l))=(6.7+/-0.4+/-0.5+/-0.4)%, where the third error is due to the uncertainty in B(D+-->K(-)pi(+)pi(+)).