Measurement of the hadronic form factor in D0→K−e+νe decays

Abstract

The shape of the hadronic form factor f + ( q 2 ) in the decay D 0 → K − e + ν e has been measured in a model independent analysis and compared with theoretical calculations. We use 75 fb − 1 of data recorded by the BABAR detector at the PEP-II electron-positron collider. The corresponding decay branching fraction, relative to the decay D 0 → K − π + , has also been measured to be R D = B ( D 0 → K − e + ν e ( γ ) ) / B ( D 0 → K − π + ( γ ) ) = 0.927 ± 0.007 ± 0.012 . From these results, and using the present world average value for B ( D 0 → K − π + ) , the normalization of the form factor at q 2 = 0 is determined to be f + ( 0 ) = 0.727 ± 0.007 ± 0.005 ± 0.007 where the uncertainties are statistical, systematic, and from external inputs, respectively.