Fixed point resolution in extensions of permutation orbifolds

Abstract

We determine the simple currents and fixed points of the orbifold theory CFT ⊗ CFT / Z 2 , given the simple currents and fixed point of the original CFT. We see in detail how this works for the SU ( 2 ) k WZW model, focusing on the field content (i.e. h-spectrum of the primary fields) of the theory. We also look at the fixed point resolution of the simple current extended orbifold theory and determine the S J matrices associated to each simple current for SU ( 2 ) 2 and for the B ( n ) 1 and D ( n ) 1 series.