Hamiltonian formulation of a gauge-invariant massive spin-(3/2 theory)

A gauge-invariant theory describing a free massive spin-(3/2 particle, obtained previously by dimensional reduction of a massless theory, is quantized using Dirac's procedure. The quantum theory is shown to be free from negative-norm states despite the absence of constraints obtained from differentiating the Lagrangian equations of motion (i.e., "secondary constraints"). This is in direct contrast to all other half-integral-spin theories avoiding secondary constraints, which invariably have indefinite metric