  The propagation of boson particles in a gravitational field described by the
Brans-Dicke theory of gravity is analyzed. We derive the wave function of the
scalar particles, and the effective potential experienced by the quantum
particles considering the role of the varying gravitational coupling. Besides,
we calculate the probability to find the scalar particles near the region where
a naked singularity is present. The extremely high energy radiated in such a
situation could account for the huge emitted power observed in Gamma Ray
Bursts.
