PARTITION-FUNCTIONS FOR HETEROTIC WZW CONFORMAL FIELD-THEORIES

Thus far in the search for, and classification of, ''physical'' modula r invariant partition functions SIGMAN(LR)chi(L)chi(R) the attention has been focused on the symmetric case where the holomorphic and anti- holomorphic sectors, and hence the characters chi(L) and chi(R), are a ssociated with the same Kac-Moody algebras g(L) = g(R) and levels k(L) = k(R). In this paper we consider the more general possibility where (g(L), k(L)) may not equal (g(R), k(R)). We discuss which choices of a lgebras and levels may correspond to well-defined conformal field theo ries, we find the ''smallest'' such heterotic (i.e. asymmetric) partit ion functions, and we give a method, generalizing the Roberts-Terao-Wa rner lattice method, for explicitly constructing many other modular in variants. We conclude the paper by proving that this new lattice metho d will succeed in generating all the heterotic partition functions, fo r all choices of algebras and levels.