Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Rare muon and tau decays in A4 Models   We analyze the most general dimension six effective Lagrangian, invariant
under the flavour symmetry A4 x Z3 x U(1) proposed to reproduce the near
tri-bimaximal lepton mixing observed in neutrino oscillations. The effective
Lagrangian includes four-lepton operators that violate the individual lepton
numbers in the limit of exact flavor symmetry and allow unsuppressed processes
satisfying the rule |Delta L_e x Delta L_mu x Delta L_tau| = 2. The most
stringent bounds on the strength of the new interactions come from the observed
universality of leptonic muon and tau decays, from the agreement between the
Fermi constant measured in the muon decay and that extracted from the mW/mZ
ratio, and from the limits on the rare decays tau^- -> mu^+ e^- e^- and tau^-
-> e^+ mu^- mu^-. We also investigate these effects in a specific
supersymmetric (SUSY) realization of the flavour symmetry and we find large
suppression factors for all the processes allowed by the selection rule. We
explain why this rule is violated in the SUSY context and we provide a complete
picture of lepton flavour violation in the SUSY version of A4 x Z_3 x U(1).

9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol