  The Mott metal-insulator transition in the two-band Hubbard model in infinite
dimensions is studied by using the linearized dynamical mean-field theory. The
discontinuity in the chemical potential for the change from hole to electron
doping is calculated analytically as a function of the on-site Coulomb
interaction $U$ at the $d$-orbital and the charge-transfer energy $\Delta$
between the $d$- and $p$-orbitals. Critical behaviour of the quasiparticle
weight is also obtained analytically as a function of $U$ and $\Delta$. The
analytic results are in good agreement with the numerical results of the exact
diagonalization method.
