Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Getting just the Standard Model at Intersecting Branes   We present what we believe are the first specific string (D-brane)
constructions whose low-energy limit yields just a three generation
$SU(3)\times SU(2)\times U(1)$ standard model with no extra fermions nor U(1)'s
(without any further effective field theory assumption). In these constructions
the number of generations is given by the number of colours. The Baryon, Lepton
and Peccei-Quinn symmetries are necessarily gauged and their anomalies
cancelled by a generalized Green-Schwarz mechanism.
  The corresponding gauge bosons become massive but their presence guarantees
automatically proton stability. There are necessarily three right-handed
neutrinos and neutrino masses can only be of Dirac type. They are naturally
small as a consequence of a PQ-like symmetry. There is a Higgs sector which is
somewhat similar to that of the MSSM and the scalar potential parameters have a
geometric interpretation in terms of brane distances and intersection angles.
Some other physical implications of these constructions are discussed.

15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
19
The categories of this paper are: eess
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio