  In scalar-tensor theories, spontaneous scalarization is a phase transition
that can occur in ultra-dense environments such as neutron stars. The scalar
field develops a non-trivial configuration once the stars exceeds a compactness
threshold. We recently pointed out that, if the scalar exhibits some additional
coupling to matter, it could give rise to significantly different microphysics
in these environments. In this work we study, at the non-perturbative level, a
toy model in which the photon is given a large mass when spontaneous
scalarization occurs. Our results demonstrate clearly the effectiveness of
spontaneous scalarization as a Higgs-like mechanism in neutron stars.
