Decoupling the chiral dynamics in the canonical approach to the WZNW model
requires an extended phase space that includes left and right monodromy
variables. Earlier work on the subject, which traced back the quantum qroup
symmetry of the model to the Lie-Poisson symmetry of the chiral symplectic
form, left some open questions: - How to reconcile the monodromy invariance of
the local 2D group valued field (i.e., equality of the left and right
monodromies) with the fact that the latter obey different exchange relations? -
What is the status of the quantum group symmetry in the 2D theory in which the
chiral fields commute? - Is there a consistent operator formalism in the chiral
and in the extended 2D theory in the continuum limit? We propose a constructive
affirmative answer to these questions for G=SU(2) by presenting the chiral
quantum fields as sums of chiral vertex operators and q-Bose creation and
annihilation operators.Comment: 18 pages, LATE