Gauge theory of gravity requires massive torsion field

One of the greatest unsolved issues of the physics of this century is to fi nd a quantum field theory of gravity. According to a vast amount of literat ure, unification of quantum field theory and gravitation requires a gauge t heory of gravity which includes torsion and an associated spin held. Variou s models including either massive or massless torsion fields have been sugg ested. We present arguments for a massive torsion field, where the probable rest mass of the corresponding spin three gauge boson is the Planck mass.