Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The High Quality QCD Axion and the LHC   The QCD axion provides an elegant solution to the Strong CP Problem. While
the minimal realization is vulnerable to the so-called "Axion Quality Problem",
we will consider a more robust realization in the presence of a mirror sector
related to the Standard Model by a (softly broken) $\mathbb{Z}_2$ symmetry. We
point out that the resulting "heavy" axion, while satisfying all theoretical
and observational constraints, has a large and uncharted parameter space which
allows it to be probed at the LHC as a Long-Lived Particle (LLP). The small
defining axionic coupling to gluons results in a challenging hadronic decay
signal which we argue can be distinguished against the background in such a
long-lived regime, and yet, the same coupling allows for sufficient production
at hadron colliders thanks to the large gluon parton luminosity. Our study
opens up a new window towards accelerator observable axions, and more
generally, singly produced LLPs.

24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin