Rigour and Rigidity: Systematics on particle physics D6-brane models on Z(2)xZ(6)

TL;DR

This paper systematically searches for string theory models with intersecting D-branes on a specific orientifold, classifying gauge groups and matter content, and identifies viable GUT and Pati-Salam models with three generations.

Contribution

It provides a comprehensive classification of D6-brane configurations on T6/Z(2)xZ(6) orientifold, including gauge groups, matter representations, and three-generation conditions, advancing model-building efforts.

Findings

Classified gauge groups and matter representations for D-branes.

Excluded certain GUT models based on three-generation and matter content.

Identified Pati-Salam models with minimal exotic matter.

Abstract

We launch a systematic search for phenomenologically appealing string vacua with intersecting D-branes on the promising T6/Z(2)xZ(6)xOR orientifold with discrete torsion. The number of independent background lattices is reduced from six to two by new symmetries. The occurrence of USp(2N) and SO(2N) versus U(N) gauge groups is classified as well as D-branes without matter in the adjoint and/or symmetric representation. Supersymmetric fractional D6-branes allowing for RR tadpole cancellation are fully classified in terms of all possible values of the one complex structure modulus inherited from the underlying six-torus. We then systematically investigate the conditions for three particle generations at pairwise intersections of two D6-branes. Global SU(5) GUT models on T6/Z(2)xZ(6)xOR are excluded by demanding three generations and no exotic matter in the 15 representation. Two prototypes of global Pati-Salam models with a mild amount of vector-like exotic matter are found.