Siegel superparticle, higher order fermionic constraints, and path integrals

We study Siegel superparticle moving in $R^{4|4}$ flat superspace. Canonical quantization is accomplished yielding the massless Wess-Zumino model as an effective field theory. Path integral representation for the corresponding superpropagator is constructed and proven to involve the Siegel action in a gauge fixed form. It is shown that higher order fermionic constraints intrinsic in the theory, though being a consequence of others in $d=4$, make a crucial contribution into the path integral.