Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Leptogenesis with Heavy Majorana Neutrinos Reexamined   The mass term for Majorana neutrinos explicitly violates lepton number.
Several authors have used this fact to create a lepton asymmetry in the
universe by considering CP violating effects in the one loop self-energy
correction for the decaying heavy Majorana neutrino. We compare and comment on
the different approaches used to calculate the lepton asymmetry including those
using an effective Hamiltonian and resummed propagators. We also recalculate
the asymmetry in the small mass difference limit.

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The categories of this paper are: q-bio
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The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
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The categories of this paper are: solv-int
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The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-th
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The categories of this paper are: funct-an
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The categories of this paper are: math-ph
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The categories of this paper are: nlin
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The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
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The categories of this paper are: gr-qc