Millions of standard models on ℤ₆′?

Abstract

Using previous results on the statistics of intersecting D6-brane models on T 6 /Z ′ 6 we analyse solutions that resemble the gauge group and matter content of the supersymmetric standard model. In particular the structure of the hidden sector, the gauge coupling constants and chiral exotic matter content are computed and classified for all possible standard model-like configurations on this background. It turns out that the number of chiral exotics, Higgses and values of gauge couplings are strongly correlated. Some examples with the chiral spectrum of the supersymmetric standard model plus vector-like states and a massless U(1) B−L are discussed in detail.fgmeiner@nikhef.nl Gabriele.Honecker@cern.ch

Rigid D6-branes on $ {{{{T^6}}} \left/ {{\left( {{Z_2} \times {Z_{2M}} \times \Omega \mathcal{R}} \right)}} \right.} $ with discrete torsion

“…These two sectors are (up to normalisation and permutation of tori) equivalent to the exceptional three-cycles at Z 2 fixed points on the T 6 /Z 6 orbifold discussed in [68,69].…”

“…The twist sectors of T 6 /Z 2 × Z 2M are inherited from various underlying T 4 /Z N and T 6 /Z N cases as discussed in appendix D. This is on the one hand of interest in view of the fact that intersecting D6-branes on T 6 /Z 6 and T 6 /Z 6 have been discussed before in [70,71] and [68,69], respectively, and on the other hand when one considers the blow-up of orbifold singularities as discussed e.g. in [81].…”

“…Also two of the three Z (i) 2 twisted sectors of T 6 /Z 2 × Z 6 with discrete torsion are inherited from the two T 6 /Z 6 subsectors, as discussed in detail in table 62 in appendix D. This correspondence allows for using partial results, e.g. the classification of supersymmetric bulk three-cycles, from the well-studied T 6 /Z 6 orbifold [68,69] in order to construct D6-brane models on the T 6 /Z 2 × Z 6 orbifold with discrete torsion. It also gives reason to hope that on this product orbifold, new phenomenologically appealing spectra with three Standard Model generations will be found.…”

“…The second case 2M = 6 has T 6 /Z 6 as a subsector, which has proven to be able to accommodate the SM gauge group and chiral spectrum [68,69], however, always with some adjoint matter. The last case 2M = 6 has T 6 /Z 6 as a subsector, for which also three generation models with some adjoint matter content are known [70,71].…”

Asymmetric Gepner models (revisited)

“…However, previous studies of family number distributions seem to suggest that in fact precisely the number three is difficult to obtain. In the area of orientifolds, systematic studies have been done for a variety of Standard Model features [19,20,21,17,22]. Although most of this work has focused on getting the Standard Model itself, a number of conclusions can be drawn about distributions of certain parameters and discrete properties in its neighbourhood, such as coupling constants, the presence of various kinds of GUTs, the number of families, or the presence of fractional charges.…”