Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ordinary atom-mirror atom bound states: A new window on the mirror world   Mirror symmetry is a plausible candidate for a fundamental symmetry of
particle interactions which can be exactly conserved if a set of mirror
particles exist. The properties of the mirror particles seem to provide an
excellent candidate to explain the inferred dark matter of the Universe and
might also be responsible for a variety of other puzzles in particle physics,
astrophysics, meteoritics and planetary science. One such puzzle -- the
orthopositronium lifetime problem -- can be explained if there is a small
kinetic mixing of ordinary and mirror photons. We show that this kinetic mixing
implies the existence of ordinary atom - mirror atom bound states with
interesting terrestrial and astrophysical implications. We suggest that
sensitive mass spectroscopic studies of ordinary samples containing heavy
elements such as lead might reveal the presence of these bound states, as they
would appear as anomalously heavy elements. In addition to the effects of
single mirror atoms, collective effects from embedded fragments of mirror
matter (such as mirror iron microparticles) are also possible. We speculate
that such mirror matter fragments might explain a mysterious UV photon burst
observed coming from a laser irradiated lead target in a recent experiment.

23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
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The categories of this paper are: q-fin