Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Three-Family Standard-like Orientifold Model: Yukawa Couplings and
  Hierarchy   We discuss the hierarchy of Yukawa couplings in a supersymmetric three family
Standard-like string Model. The model is constructed by compactifying Type IIA
string theory on a Z_2 x Z_2 orientifold in which the Standard Model matter
fields arise from intersecting D6-branes. When lifted to M theory, the model
amounts to compactification of M-theory on a G_2 manifold. While the actual
fermion masses depend on the vacuum expectation values of the multiple Higgs
fields in the model, we calculate the leading worldsheet instanton
contributions to the Yukawa couplings and examine the implications of the
Yukawa hierarchy.

17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph