Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Right-handed Neutrinos as Superheavy Dark Matter   We propose that right-handed neutrinos are very long-lived dark matter. The
long lifetime is realized by the separation of the wavefunction of right-handed
neutrinos and that of other fermions in an extra dimension. Such long-lived and
superheavy dark matter can naturally explain observed ultra high energy cosmic
rays above the GZK cutoff (5 * 10^{19} eV) and huge amounts of cold dark matter
simultaneously. Furthermore, the exponentially suppressed Yukawa couplings of
right-handed neutrinos leads to the high predictablilty on the mass parameter
of the neutrinoless double beta decay, as all the models which predict very
small neutrino mass of one generation.

21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat