61 research outputs found
Impact of Beauty and Charm H1-ZEUS Combined Measurements on PDFs and Determination of the Strong Coupling
In this QCD analysis, we investigate the impact of recent measurements of
heavy-flavor charm and beauty cross sections data sets on the simultaneous
determination of Parton Distribution Functions (PDFs) and the strong coupling,
. We perform three different fits based on Variable-Flavour
Number Scheme (VFNS) at the Leading Order (LO) and Next-to-Leading Order (NLO)
and choose the full HERA run I and II combined data as a new measurement of
inclusive Deep Inelastic Scattering (DIS) cross sections for our base data set.
We show that including charm and beauty cross sections data reduces the
uncertainty of gluon distribution and improves the fit quality up to 4.1\% from
leading order to next-to-leading order and up to 1.7\% for only NLO without and
with beauty and charm data contributions.Comment: 20 pages, 4 figures. arXiv admin note: text overlap with
arXiv:1709.0840
The impact of the LHCb production cross-section on parton distribution functions and determining the mass of heavy quarks
In this work, the impact of recent measurements of heavy-flavour production
in collisions on parton distribution functions (PDFs) and their
uncertainties is studied. In this regard, the absolute and normalised cross
sections of beauty hadron production measured by LHCb at center-of-mass energy
of 7 TeV and 13 TeV are separately included in the next-to-leading order (NLO)
global QCD analysis together with the measurements of the inclusive and
heavy-flavour production cross sections at HERA. It is illustrated that the
heavy-flavour data of the LHCb experiment impose additional constraints on the
PDFs, especially on the gluon distribution at low partonic fractions of the
proton momentum. One of the most important results of the present analysis is
the significant reduction of the gluon uncertainties in the region less than
that can play a crucial rule in many areas of high energy physics
investigations.Comment: 36 pages, 8 figures, has been accepted for publication in Nuclear
Physics
Polarized Deeply Inelastic Scattering (DIS) Structure Functions for Nucleons and Nuclei
We extract parton distribution functions (PDFs) and structure functions from
recent experimental data of polarized lepton-DIS on nucleons at next-to-leading
order (NLO) Quantum Chromodynamics. We apply the Jacobi polynomial method to
the DGLAP evolution as this is numerically efficient. Having determined the
polarized proton and neutron spin structure, we extend this analysis to
describe 3He and 3H polarized structure functions, as well as various sum
rules. We compare our results with other analyses from the literature.Comment: LaTeX, 12 pages, 11 figures, 6 tables. Update to match published
versio
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