Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Precision determination of the small-$x$ gluon from charm production at
  LHCb   The small-$x$ gluon in global fits of parton distributions is affected by
large uncertainties from the lack of direct experimental constraints. In this
work we provide a precision determination of the small-$x$ gluon from the
exploitation of forward charm production data provided by LHCb for three
different centre-of-mass (CoM) energies: 5~TeV, 7~TeV and 13~TeV. The LHCb
measurements are included in the PDF fit by means of normalized distributions
and cross-section ratios between data taken at different CoM values, $R_{13/7}$
and $R_{13/5}$. We demonstrate that forward charm production leads to a
reduction of the PDF uncertainties of the gluon down to $x\simeq 10^{-6}$ by up
to an order of magnitude, with implications for high-energy colliders, cosmic
ray physics and neutrino astronomy.

15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat