75 research outputs found
On the prompt contribution to the atmospheric neutrino flux
The prompt contribution to the atmospheric neutrino flux is analyzed. It is
demonstrated that the corresponding theoretical uncertainties related to
perturbative treatment of charm production, notably, the ones stemming from the
low and high behavior of parton distribution functions, can be conveniently
studied at the level of charm quark production. Additionally, we discuss the
non-perturbative contribution to the prompt neutrino flux, related to the
intrinsic charm content of the proton, and analyze its main features.Comment: v2: accepted versio
Standard Model Higgs boson production in association with a top anti-top pair at NLO with parton showering
Forward production of prompt neutrinos from charm in the atmosphere and at high energy colliders
The high-energy atmospheric neutrino flux is dominated by neutrinos from the
decays of charmed hadrons produced in the forward direction by cosmic ray
interactions with air nuclei. We evaluate the charm contributions to the prompt
atmospheric neutrino flux as a function of the center-of-mass energy
of the hadronic collision and of the center-of-mass rapidity of the
produced charm hadron. Uncertainties associated with parton distribution
functions are also evaluated as a function of . We find that the
coverage of LHCb for forward heavy-flavour production, complemented by the
angular coverage of present and future forward neutrino experiments at the LHC,
bracket the most interesting regions for the prompt atmospheric neutrino
flux. At TeV foreseen for the HL-LHC phase, nucleon collisions in
air contribute to the prompt neutrino flux prominently below ~GeV. Measurements of forward charm and/or forward neutrinos produced in
hadron collisions up to TeV, which might become possible at the
FCC, are relevant for the prompt atmospheric neutrino flux up to
GeV and beyond.Comment: 29 pages, 11 figure
Impact of heavy-flavour production cross sections measured by the LHCb experiment on parton distribution functions at low x
The impact of recent measurements of heavy-flavour production in deep
inelastic scattering and in collisions on parton distribution
functions is studied in a QCD analysis in the fixed-flavour number scheme at
next-to-leading order. Differential cross sections of charm- and beauty-hadron
production measured by LHCb are used together with inclusive and heavy-flavour
production cross sections in deep inelastic scattering at HERA. The
heavy-flavour data of the LHCb experiment impose additional constraints on the
gluon and the sea-quark distributions at low partonic fractions of the
proton momentum, down to . This kinematic range is
currently not covered by other experimental data in perturbative QCD fits
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