  We study the broad emission line blazars detected in the gamma-ray band by
the Large Area Telescope onboard the Fermi satellite and with the optical
spectrum studied by Shaw et al. (2012, 2013). The observed broad line strength
provides a measure of the ionizing luminosity of the accretion disk, while the
gamma-luminosity is a proxy for the bolometric non-thermal beamed jet emission.
The resulting sample, composed by 217 blazars, is the best suited to study the
connection between accretion and jet properties. We compare the broad emission
line properties of these blazars with those of radio-quiet and radio-loud
quasars present in the Sloan Digital Sky Survey, to asses differences and
similarities of the disc luminosity and the virial black hole mass. For most
sources, we could derive the black hole mass by reproducing the IR-optical-UV
data with a standard accretion disc spectrum, and we compared the black hole
masses derived with the two methods. The distributions of the masses estimated
in the two ways agree satisfactorily. We then apply a simple, one-zone,
leptonic model to all the 217 objects of our sample. The knowledge of the black
hole mass and disc luminosity helps to constrain the jet parameters. On average
they are similar to what found by previous studies of smaller samples of
sources.
