Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hard probes in heavy ion collisions at the LHC: PDFs, shadowing and $pA$
  collisions   This manuscript is the outcome of the subgroup ``PDFs, shadowing and $pA$
collisions'' from the CERN workshop ``Hard Probes in Heavy Ion Collisions at
the LHC''. In addition to the experimental parameters for $pA$ collisions at
the LHC, the issues discussed are factorization in nuclear collisions, nuclear
parton distributions (nPDFs), hard probes as the benchmark tests of
factorization in $pA$ collisions at the LHC, and semi-hard probes as
observables with potentially large nuclear effects. Also, novel QCD phenomena
in $pA$ collisions at the LHC are considered. The importance of the $pA$
program at the LHC is emphasized.

8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
5
The categories of this paper are: gr-qc