Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Vector-like family extension of the standard model and the light quark
  masses and mixings   The standard model extended with the pairs of the vector-like families is
studied. The model independent analysis for an arbitrary case and an explicit
realization for the case with one pair of the heavy vector-like families are
considered. The mixing matrices of the light quarks for the left- and
right-handed charged currents, as well as those for the flavour changing
neutral currents, both the Z and Higgs mediated, are found.

2
The categories of this paper are: math
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics