Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Three Generations in Type I Compactifications   Generalizing the recent work on three-family Type I compactifications, we
classify perturbative Type I vacua obtained via compactifying on the T^6/Z_2 X
Z_2 X Z_3 orbifold with all possible Wilson lines. In particular, we
concentrate on models with gauge groups containing the Standard Model gauge
group SU(3)_c X SU(2)_w X U(1)_Y as a subgroup. All of the vacua we obtain
contain D5-branes and are non-perturbative from the heterotic viewpoint. The
models we discuss have three-chiral families. We study some of their
phenomenological properties, and point out non-trivial problems arising in
these models in the phenomenological context.

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The categories of this paper are: ao-sci
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The categories of this paper are: solv-int
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The categories of this paper are: eess
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The categories of this paper are: q-bio
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The categories of this paper are: q-alg
4
The categories of this paper are: cond-mat
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The categories of this paper are: chem-ph
3
The categories of this paper are: physics
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The categories of this paper are: quant-ph
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The categories of this paper are: stat
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The categories of this paper are: patt-sol
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The categories of this paper are: plasm-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: mtrl-th
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The categories of this paper are: hep-ex
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The categories of this paper are: nucl-th