  The nonlocal implementation of the dispersive optical model (DOM) provides
all the ingredients for distorted-wave impulse-approximation (DWIA)
calculations of the $(e,e'p)$ reaction. It provides both the overlap function,
including its normalization, and the outgoing proton distorted wave. This
framework is applied to describe the knockout of a proton from the
$0\textrm{d}\frac{3}{2}$ and $1\textrm{s}\frac{1}{2}$ orbitals in ${}^{40}$Ca
with fixed normalizations of 0.71 and 0.60, respectively. Data were obtained in
parallel kinematics for three outgoing proton energies: 70, 100, and 135 MeV.
Agreement with the data is as good as, or better than, previous descriptions
employing local optical potentials and overlap functions from Woods-Saxon
potentials - both with standard nonlocality corrections - whose normalization
(spectroscopic factor) and radius were fitted to the data. The present analysis
suggests that slightly larger spectroscopic factors are obtained when nonlocal
optical potentials are employed than those generated with local potentials. The
results further suggest that the chosen kinematical window around 100 MeV
proton energy provides the best and cleanest method to employ the DWIA for the
analysis of this reaction. The conclusion that substantial ground-state
correlations cannot be ignored when describing a closed-shell atomic nucleus is
therefore confirmed in detail. To reach these conclusions, it is essential to
have a complete description of the nucleon single-particle propagator that
accounts for all elastic nucleon-scattering observables in a wide energy domain
up to 200 MeV. The current nonlocal implementation of the DOM fulfills this
requirement.
