Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Flavour Hierarchy and See-Saw Neutrinos from Bulk Masses in 5d
  Orbifold GUTs   In supersymmetric grand unified theories (GUTs) based on S^1/(Z_2 x Z'_2)
orbifold constructions in 5 dimensions, Standard Model (SM) matter and Higgs
fields can be realized in terms of 5d hypermultiplets. These hypermultiplets
can naturally have large bulk masses, leading to a localization of the zero
modes at one of the two branes or to an exponential suppression of the mass of
the lowest-lying non-zero mode. We demonstrate that these dynamical features
allow for the construction of an elegant 3-generation SU(5) model in 5
dimensions that explains all the hierarchies between fermion masses and CKM
matrix elements in geometrical terms. Moreover, if U(1)_\chi (where SU(5) x
U(1)_\chi \subset SO(10)) is gauged in the bulk, but broken by the orbifold
action at the SM brane, the right-handed neutrino mass scale is naturally
suppressed relative to M_GUT. Together with our construction in the charged
fermion sector this leads, via the usual see-saw mechanism, to a realistic
light neutrino mass scale and large neutrino mixing angles.

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The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
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The categories of this paper are: math-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
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The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
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The categories of this paper are: q-bio
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The categories of this paper are: bayes-an
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The categories of this paper are: solv-int
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-lat
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The categories of this paper are: nucl-ex
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The categories of this paper are: stat
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The categories of this paper are: acc-phys