  We use gamma-ray observations by the Fermi Large Area Telescope (Fermi-LAT)
to impose limits on the properties of the hypothetical particle Weyl meson.
Such mesons arise in theories which display local scale invariance and act as
dark matter candidate. In a generalized locally scale invariant Standard Model
it can decay or annihilate to the photon pair through the Higgs channel. We
find that Fermi-LAT observations severely constrain the parameters of the Weyl
meson.
