Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Flavor Violating Lepton Family U(1)$_\lambda$   The Standard Model is extended minimally with a new flavor-violating family
symmetry ${\rm U(1)}_\lambda$, which acts only on leptons including the
right-handed neutrinos. The model is anomaly free with family-dependent ${\rm
U(1)}_\lambda$ charges, and consistent with the observed neutrino mixing
angles. It predicts charged lepton flavor-violating processes mediated by a new
gauge boson. Under certain conditions, the smallness of $\theta_{13}$ of
neutrino mixing can be justified in terms of the muon-to-tau mass ratio, at the
same time explaining the electron-to-tau large mass hierarchy.

16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
18
The categories of this paper are: econ