From the paper "Fermi-Bose Transmutations Induced by Gauge Fields" by Polyakov,
http://inspirehep.net/record/22956/citations
the theory in 3D,
L=2∑k=1|∂μzk+iAμzk|2+θ16π2ϵμνρAμ∂νAρ
with a constraint |z1|2+|z2|2=1 for z1(x0,x1,x2) and z2(x0,x1,x2),
has the transition amplitude given by
G(x,y)=∫Dxe−m∫ds⟨exp{i∫dxμAμ}⟩
where the average is given by
⟨exp{i∫dxμAμ}⟩=∫DAexp{i∫dxμAμ}exp{iSCS[A]}
How to derive this two-point function?