Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Lepton Flavour Violation in Models with A4 Flavour Symmetry   We analyze lepton flavour violating transitions, leptonic magnetic dipole
moments (MDMs) and electric dipole moments (EDMs) in a class of models
characterized by the flavour symmetry A4 x Z3 x U(1)_{FN}, whose choice is
motivated by the approximate tri-bimaximal mixing observed in neutrino
oscillations. We construct the relevant low-energy effective Lagrangian where
these effects are dominated by dimension six operators, suppressed by the scale
M of new physics. All the flavour breaking effects are universally described by
the vacuum expectation values <Phi> of a set of spurions. We separately analyze
both a supersymmetric and a general case. While the observed discrepancy delta
a_mu in the anomalous MDM of the muon suggests M of order of a few TeV, several
data require M above 10 TeV, in particular the limit on EDM of the electron. In
the general case also the present limit on BR(mu -> e gamma) requires M >10
TeV, at least. The branching ratios for mu -> e gamma, tau -> mu gamma and tau
-> e gamma are all expected to be of the same order. In the supersymmetric case
the constraint from mu -> e gamma is softened and it can be satisfied by a
smaller scale M. In this case both the observed delta a_mu and the current
bound on BR(mu -> e gamma) can be satisfied, at the price of a rather small
value for |<Phi>|, of the order of a few percents, that reflects on a similar
value for theta_{13}.

19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th