Intrinsic charm in the nucleon and charm production at large rapidities in collinear, hybrid and $k_T$-factorization approaches

Abstract

We discuss the role of intrinsic charm (IC) in the nucleon for forward production of $c$-quark (or $\bar{c}$-antiquark) in proton-proton collisions for low and high energies. The calculations are performed in collinear-factorization approach with on-shell partons, $k_T$-factorization approach with off-shell partons as well as in a hybrid approach using collinear charm distributions and unintegrated (transverse momentum dependent) gluon distributions. For the collinear-factorization approach we use matrix elements for both massless and massive charm quarks/antiquarks. The distributions in rapidity and transverse momentum of charm quark/antiquark are shown for a few different models of IC. Forward charm production is dominated by $gc$-fusion processes. The IC contribution dominates over the standard pQCD (extrinsic) $gg$-fusion mechanism of $c\bar{c}$-pair production at large rapidities or Feynman-$x_F$. We perform similar calculations within leading-order and next-to-leading order $k_T$-factorization approach. The $k_T$-factorization approach leads to much larger cross sections than the LO collinear approach. At high energies and large rapidities of $c$-quark or $\bar{c}$-antiquark one tests gluon distributions at extremely small $x$. The IC contribution has important consequences for high-energy neutrino production in the Ice-Cube experiment and can be, to some extent, tested at the LHC by the SHIP and FASER experiments by studies of the ${\nu }_{\tau }$ neutrino production.

31 pages, 23 figures

References in corpus (12)

• An Introduction to PYTHIA 8.2
• Parton distributions in the LHC era: MMHT 2014 PDFs
• Prompt neutrino fluxes from atmospheric charm
• The Charm Parton Content of the Nucleon
• Forward Jet Production at the Large Hadron Collider
• Far-forward neutrinos at the Large Hadron Collider
• Constraints on charm-anticharm asymmetry in the nucleon from lattice QCD
• Hard scale dependent gluon density, saturation and forward-forward dijet production at the LHC
• Hadroproduction of scalar $P$-wave quarkonia in the light-front $k_T$-factorization approach
• On relation between Parton Branching Approach and CCFM evolution
• QCD predictions for open charm meson production at the LHCb in fixed-target experiment
• A new parton fragmentation procedure for heavy hadron production in proton-proton collisions

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• Neutrino Detection without Neutrino Detectors: Discovering Collider Neutrinos at FASER with Electronic Signals Only
• Impact of the LHCb $p+{}^{4}He$ fixed-target $D^0/\overline{D^0}$ data on the intrinisic $c\bar{c}$ component in the nucleon
• On the prompt contribution to the atmospheric neutrino flux
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