  An analytical solution of the Mott transition is obtained for the Hubbard
model on the Bethe lattice in the large coordination number ($z$) limit. The
excitonic binding of doublons (doubly occupied sites) and holons (empty sites)
is shown to be the origin of a continuous Mott transition between a metal and
an emergent quantum spin liquid insulator. The doublon-holon binding theory
enables a different large-$z$ limit and a different phase structure than the
dynamical meanfield theory by allowing intersite spinon correlations to lift
the $2^N$-fold degeneracy of the local moments in the insulating phase. We show
that the spinons are coupled to doublons/holons by a dissipative compact U(1)
gauge field that is in the deconfined phase, stabilizing the spin-charge
separated gapless spin liquid Mott insulator.
