%0 Journal Article
%T An Orientifold of Type-IIB Theory on $K3$
%A Atish Dabholkar
%A Jaemo Park
%J Physics
%D 1996
%I arXiv
%R 10.1016/0550-3213(96)00199-X
%X A new orientifold of Type-IIB theory on $K3$ is constructed that has $N=1$ supersymmetry in six dimensions. The orientifold symmetry consists of a $Z_2$ involution of $K3$ combined with orientation-reversal on the worldsheet. The closed-string sector in the resulting theory contains nine tensor multiplets and twelve neutral hypermultiplets in addition to the gravity multiplet, and is anomaly-free by itself. The open-string sector contains only 5-branes and gives rise to maximal gauge groups $SO(16)$ or $U(8)\times U(8)$ at different points in the moduli space. Anomalies are canceled by a generalization of the Green-Schwarz mechanism that involves more than one tensor multiplets.
%U http://arxiv.org/abs/hep-th/9602030v2