Toward Realistic Intersecting D-Brane Models

Self Cite

128

287

Most intersecting D-brane vacua in the literature contain additional massless adjoint fields in their low energy spectrum. The existence of these additional fields make it difficult to obtain negative beta functions and, eventually, asymptotic freedom. We address this important issue for N = 1 intersecting D-brane models, rephrasing the problems in terms of (open string) moduli stabilization. In particular, we consider a Z 2 × Z 2 orientifold construction where D6-branes wrap rigid 3-cycles and such extra adjoint fields do not arise. We derive the model building rules and consistency conditions for intersecting branes in this background, and provide N = 1 chiral vacua free of adjoint fields. More precisely, we construct a Pati-Salam-like model whose SU (4) gauge group is asymptotically free. We also comment on the application of these results for obtaining gaugino condensation in chiral D-brane models. Finally, we embed our constructions in the framework of flux compactification, and construct new classes of N = 1 and N = 0 chiral flux vacua. † Permanent address

Section: An N = 1 Pati-salam-like Examplementioning

confidence: 99%

Chiral D-brane Models with Frozen Open String Moduli

Blumenhagen

Cvetič

Marchesano

et al. 2005

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128

287

“…If χ I is a massless character which starts with the complex scalar field Z I , one can conclude that the tree-level gauge coupling is given by 6) to lowest order in Z I . In particular the dilaton dependence, measuring the tension of the brane, is given by n a B 0 a Z 0 where Z 0 = S to adhere to standard notation.…”

Section: Tadpole Cancellation and Gauge Couplingsmentioning

confidence: 99%

On gauge couplings and thresholds in Type I Gepner models and otherwise

Anastasopoulos¹,

Bianchi²,

Sarkissian³

et al. 2007

We derive general formulae for tree level gauge couplings and their oneloop thresholds in Type I models based on genuinely interacting internal N = 2 SCFT's, such as Gepner models. We illustrate our procedure in the simple yet non-trivial instance of the Quintic. We briefly address the phenomenologically more relevant issue of determining the Weinberg angle in this class of models. Finally we initiate the study of the correspondence between 'magnetized' or 'coisotropic' D-branes in Gepner models and twisted representations of the underlying N = 2 SCA.

“…The classes of models that have been discussed in most detail are certainly E 8 × E 8 heterotic string compactifications (e.g. [1][2][3]) and Type II orientifold models with intersecting/magnetised D-branes (for references we refer to the most recent review [4]). …”

Section: Introductionmentioning

confidence: 99%

One in a billion: MSSM-like D-brane statistics

Gmeiner¹,

Blumenhagen²,

Honecker³

et al. 2006

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184

253

Continuing our recent work hep-th/0411173, we study the statistics of fourdimensional, supersymmetric intersecting D-brane models in a toroidal orientifold background. We have performed a vast computer survey of solutions to the stringy consistency conditions and present their statistical implications with special emphasis on the frequency of Standard Model features. Among the topics we discuss are the implications of the K-theory constraints, statistical correlations among physical quantities and an investigation of the various statistical suppression factors arising once certain Standard Model features are required. We estimate the frequency of an MSSM like gauge group with three generations to be one in a billion.