Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Constraints on the intrinsic charm content of the proton from recent
  ATLAS data   Constraints on the intrinsic charm probability $\wccm = P_{{\mathrm{c}\bar
\mathrm{c}} / \mathrm{p}}$ in the proton are obtained for the first time from
LHC measurements. The ATLAS Collaboration data for the production of prompt
photons, accompanied by a charm-quark jet in pp collisions at $\sqrt s = 8 $
TeV, are used. The upper limit \mbox{$\wccm < 1.93$~\%} is obtained at the
68~\% confidence level. This constraint is primarily determined from the
theoretical scale and systematical experimental uncertainties. Suggestions for
reducing these uncertainties are discussed. The implications of intrinsic heavy
quarks in the proton for future studies at the LHC are also discussed.

14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph