Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gauge symmetry breaking in orbifold model building   We review the gauge symmetry breaking mechanism due to orbifold projections
in orbifold model building. We explicitly show the existence of a scale of
breaking if such a symmetry breaking is due to freely-acting orbifold operators
only, i.e. in case the breaking is realized non-locally in the internal space.
We show that such a scale is related to the compactification moduli only, and
that there are no extra continuous parameters, at least in semirealistic models
with N=1 SUSY in four dimensions. In this sense, the mechanism is peculiarly
different from the standard Higgs (or Hosotani) symmetry breaking mechanism. We
show that the mechanism also differs from that present in standard orbifold
models where, even in presence of discrete Wilson lines, a scale of breaking is
generically missing, since the breaking is localized in specific points in the
internal space.
  We review a set of background geometries where the described non-local
breaking is realized, both in the case of two and six extra dimensions. In the
latter case, relevant in string model building, we consider both heterotic and
open string compactifications.

17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ