  The strict analogy between scalar-tensor theories of gravity and high order
gravity is well known in literature. In this paper it is shown that, from a
particular high order gravity theory known in literature, it is possible to
produce, in the linearized approch, particles which can be seen like massive
scalar modes of gravitational waves and the response of interferometers to this
type of particles is analyzed. The presence of the mass generates a
longitudinal force in addition of the transverse one which is proper of the
massless gravitational waves and the response of an arm of an interferometer to
this longitudinal effect in the frame of a local observer is computed. This
longitudinal response function is directly connected with the function of the
Ricci scalar in the particular action of this high order theory. Important
conseguences from a theoretical point of view could arise from this approach,
because it opens to the possibility of using the signals seen from
interferometers to understand which is the correct theory of gravitation.
