Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dirac neutrinos in a $SU(2)$ left-right symmetric model   In a left-right symmetric model, with the scalar sector consisting of several
bi-doublets and two doublets, neutrinos remain as Dirac fermions in all order
in perturbation theory. Although with only two bi-doublets the neutrino masses
need still a fine tuning, this is not the case when a third bi-doublet is
added. One of the scalar doublet may be of the inert type since it is protected
by the left-right symmetry.

1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
4
The categories of this paper are: cond-mat
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th