  In this work, we investigate the quasinormal modes for a massive scalar field
with a nonminimal coupling with gravity in the spacetime of a loop quantum
black hole, known as the Self-Dual Black Hole. In this way, we have calculated
the characteristic frequencies using the WKB approach, where we can verify a
strong dependence on the mass of scalar field, the parameter of nonminimal
coupling with gravity, and the parameters of the Loop Quantum Gravity. From our
results, we can check that the Self-Dual Black Hole is stable under the scalar
perturbations when assuming small values for the parameters. Also, such results
tell us that the quasinormal modes assume different values for the cases where
the mass of field is null and the nonminimal coupling assumes $\xi=0$ and
$\xi=1/6$, i.e., a possible breaking of the conformal invariance can be seen in
the context of Self-Dual Black Hole.
