Harold A. Riggs

Twist points as branch points for the QCD2 string

Abstract We show that the string representation of the QCD 2 partition function satisfies, by virtue of a Young-tableau-transposition symmetry, the topological constraint that any branched covering of an orientable or nonorientable surface without boundary must have an even branch point multiplicity. This statement holds for each chiral sector and requires multiple branch point behavior for the twist points, since cross-terms appear that couple twist points with odd powers of simple branch points. We obtain the same result for the complete partition function of SO( N ) and Sp( N ) Yang-Mills 2 theory.