Study of the semileptonic charm decays D0→π-e+νe, D+→π0e+νe, D0→K-e+νe, and D+→(K)over-bar0e+νe

Using a sample of 1.8 million D (D) over bar mesons collected at the psi(3770) with the CLEO-c detector, we study the semileptonic decays D-0 ->pi(-)e(+)nu(e), D+ -> pi(0)e(+)nu(e), D-0 -> K(-)e(+)nu(e), and D+ -> (K) over bar (0)e(+)nu(e). For the total branching fractions we find B(D-0 ->pi(-)e(+)nu(e))=0.299(11)(9)%, B(D+ -> pi(0)e(+)nu(e))=0.373(22)(13)%, B(D-0 -> K(-)e(+)nu(e))=3.56(3)(9)%, and B(D+ -> (K) over bar (0)e(+)nu(e))=8.53(13)(23)%, where the first error is statistical and the second systematic. In addition, form factors are studied through fits to the partial branching fractions obtained in five q(2) ranges. By combining our results with recent unquenched lattice calculations, we obtain |V-cd| = 0.217(9)(4)(23) and |V-cs| = 1.015(10)(11)(106), where the final error is theoretical.