  The anomalous dimensions of the Planck mass and the cosmological constant are
calculated in a renormalizable quantum conformal gravity with a single
dimensionless coupling, which is formulated using dimensional regularization on
the basis of Hathrell's works for conformal anomalies. The dynamics of the
traceless tensor field is handled by the Weyl action, while that of the
conformal-factor field is described by the induced Wess-Zumino actions,
including the Riegert action as the kinetic term. Loop calculations are carried
out in Landau gauge in order to reduce the number of Feynman diagrams as well
as to avoid some uncertainty. Especially, we calculate two-loop quantum gravity
corrections to the cosmological constant. It suggests that there is a dynamical
solution to the cosmological constant problem.
