ON BOSONIZATION OF 2D CONFORMAL FIELD-THEORIES

We show how bosonic (free field) representations for so-called degener ate conformal theories are built by singular vectors in Verma modules. Based on this construction, general expressions of conformal blocks a re proposed. As an example, we describe new modules for the SL(2) Wess -Zumino-Witten model. They are, in fact, the simplest nontrivial modul es in a full set of bosonized highest weight representations of the sl (2), algebra. The Verma and Wakimoto modules appear as boundary module s of this set. Our construction also yields a new kind of bosonization in 2d conformal field theories.