Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: CP violation in neutral lepton transition dipole moment   The $CP$ violation in the neutrino transition electromagnetic dipole moment
is discussed in the context of the Standard Model with an arbitrary number of
right-handed singlet neutrinos. A full one-loop calculation of the neutrino
electromagnetic form factors is performed in the Feynman gauge. A non-zero $CP$
asymmetry is generated by a required threshold condition for the neutrino
masses along with non-vanishing $CP$ violating phases in the lepton flavour
mixing matrix. We follow the paradiagm of $CP$ violation in neutrino
oscillations to parametrise the flavour mixing contribution into a series of
Jarlskog-like parameters. This formalism is then applied to a minimal seesaw
model with two heavy right-handed neutrinos denoted $N_1$ and $N_2$. We observe
that the $CP$ asymmetries for decays into light neutrinos $N\to \nu\gamma$ are
extremely suppressed, maximally around $10^{-17}$. However the $CP$ asymmetry
for $N_2 \to N_1 \gamma$ can reach of order unity. Even if the Dirac $CP$ phase
$\delta$ is the only source of $CP$ violation, a large $CP$ asymmetry around
$10^{-5}$-$10^{-3}$ is comfortably achieved.

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The categories of this paper are: chao-dyn
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The categories of this paper are: adap-org
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The categories of this paper are: solv-int
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The categories of this paper are: dg-ga
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The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
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The categories of this paper are: econ
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The categories of this paper are: q-fin
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The categories of this paper are: math-ph
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The categories of this paper are: stat
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The categories of this paper are: gr-qc
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The categories of this paper are: math
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The categories of this paper are: nucl-th
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The categories of this paper are: ao-sci
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The categories of this paper are: q-alg
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The categories of this paper are: alg-geom