Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High-density QCD with CMS at the LHC   The capabilities of the CMS experiment to explore the rich heavy-ion physics
programme offered by the CERN Large Hadron Collider (LHC) are summarised.
Various representative measurements in Pb-Pb collisions at sqrt(s) = 5.5 TeV
are covered. These include "bulk" observables (charged hadron multiplicity,
low-pT inclusive hadron spectra and elliptic flow) which provide information on
the collective properties of the system; as well as perturbative processes
(high-pT hadrons, jets, gamma-jet and quarkonium production) which yield
"tomographic" information of the densest phases of the reaction.

29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
2
The categories of this paper are: math
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
16
The categories of this paper are: stat
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga