Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Model of leptons from $SO(3) \to A_4$   The lepton sector masses and mixing angles can be explained in models based
on $A_4$ symmetry. $A_4$ is a non-Abelian discrete group. Therefore, one issue
in constructing models based on it is explaining the origin of $A_4$. A
plausible mechanism is that $A_4$ is an unbroken subgroup of a continuous group
that is broken spontaneously. We construct a model of leptons where the $A_4$
symmetry is obtained by spontaneous symmetry breaking of SO(3).

19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex