  We extend previous results in spherically symmetric gravitational systems
coupled with a massless scalar field within the loop quantum gravity framework.
As starting point, we take the Schwarzschild spacetime. The results presented
here rely on the uniform discretization method. We are able to minimize the
associated discrete master constraint using a variational method. The trial
state for the vacuum consists of a direct product of a Fock vacuum for the
matter part and a Gaussian centered around the classical Schwarzschild
solution. This paper follows the line of research presented by Gambini, Pullin
and Rastgoo and a comparison between their result and the one given in this
work is made.
