Abelian discrete symmetries Z_{N} and Z_{nR} from string orbifolds

Abstract

We show that Abelian discrete symmetries Z_{N} and Z_{nR} from string orbifolds result by assigning vacuum expectation values(VEVs) only to specified singlets. These singlets obtaining VEVs carry the gauge charges (of the covering U(1) gauge group) as multiples of N for Z_N and n for Z_{nR}. We explicitly show this realization in a Z_{12-I} orbifold model.

Comments: 8 pages, 2 figures, to appear in Phys. Letters B