Interacting 2D Field-Theoretic Model for Hodge Theory

We take up the St${\ddot u}$ckelberg-modified version of the two (1+1)-dimensional (2D) Proca theory, in interaction with the Dirac fields, to study its various continuous and discrete symmetry transformations and show that this specific interacting 2D field-theoretic model provides a tractable example for the Hodge theory because its symmetries (and corresponding conserved charges) provide the physical realizations of the de Rham cohomological operators of differential geometry at the algebraic level. The physical state of this theory is chosen to be the harmonic state (of the Hodge decomposed state) in the quantum Hilbert space which is annihilated by the conserved and nilpotent (anti-)BRST as well as (anti-)co-BRST charges. A physical consequence of this study is an observation that the 2D anomaly, at the quantum level, does not lead to any problem as far as the consistency and unitarity of our present 2D theory is concerned. In other words, our present 2D field-theoretic model is amenable to particle interpretation despite the presence of the local chiral symmetry (which is associated with the nilpotent (anti-)co-BRST symmetry transformations) besides the presence of the nilpotent (anti-)BRST symmetries (which are connected with the local gauge symmetry). The physicality condition with the (anti-)co-BRST charges implies that the 2D anomaly term is trivial in our present theory. Hence, our 2D theory is consistent, unitary and amenable to particle interpretation.