  We present a new application of affine Lie algebras to massive quantum field
theory in 2 dimensions, by investigating the $q\to 1$ limit of the q-deformed
affine $\hat{sl(2)}$ symmetry of the sine-Gordon theory, this limit occurring
at the free fermion point. We describe how radial quantization leads to a
quasi-chiral factorization of the space of fields. The conserved charges which
generate the affine Lie algebra split into two independent affine algebras on
this factorized space, each with level 1, in the anti-periodic sector. The
space of fields in the anti-periodic sector can be organized using level-$1$
highest weight representations, if one supplements the $\slh$ algebra with the
usual local integrals of motion. Using the integrals of motion, a momentum
space bosonization involving vertex operators is formulated. This leads to a
new way of computing form-factors, as vacuum expectation values in momentum
space. The problem of non-trivial correlation functions in this model is also
discussed; in particular it is shown how space-time translational anomalies
which arise in radial quantization can be used to compute the short distance
expansion of some simple correlation functions.
