Isovector EMC effect from global QCD analysis with MARATHON data

Abstract

We report the results of a Monte Carlo global QCD analysis of unpolarized parton distribution functions (PDFs), including for the first time constraints from ratios of ${}^3$He to ${}^3$H structure functions recently obtained by the MARATHON experiment at Jefferson Lab. Our simultaneous analysis of nucleon PDFs and nuclear effects in $A=2$ and $A=3$ nuclei reveals the first indication for an isovector nuclear EMC effect in light nuclei. We find that while the MARATHON data yield relatively weak constraints on the $F_2^n/F_2^p$ neutron to proton structure function ratio and on the $d/u$ PDF ratio, they suggest an enhanced nuclear effect on the $d$-quark PDF in the bound proton, questioning the assumptions commonly made in nuclear PDF analyses.

6 pages, 3 figures

References in corpus (13)

• Measurement of the inclusive jet cross section in $p\bar{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$
• Longitudinal double-spin asymmetry and cross section for inclusive jet production in polarized proton collisions at sqrt(s) = 200 GeV
• Covariant spectator theory of np scattering: Phase shifts obtained from precision fits to data below 350 MeV
• Measurement of the shape of the boson rapidity distribution for p\bar{p}-> Z/gamma*-> e+e- +X events produced at sqrt(s) of 1.96 TeV
• Parton Distributions in Nucleons and Nuclei
• Direct Measurement of the $W$ Production Charge Asymmetry in $\ppbar$ Collisions at $\sqrt{s}=1.96$ TeV
• Measurement of the electron charge asymmetry in inclusive W production in pp collisions at sqrt(s) = 7 TeV
• The Asymmetry of Antimatter in the Proton
• Isovector EMC effect explains the NuTeV anomaly
• Measurements of $W$ and $Z/{\gamma }^{\ast }$ cross sections and their ratios in $p+p$ collisions at RHIC
• Nuclear effects in the proton-deuteron Drell-Yan process
• Single-Spin Asymmetries in W Boson Production at Next-to-Leading Order
• What does kinematical target mass sensitivity in DIS reveal about hadron structure?

Cited by in corpus (20)

• 50 Years of Quantum Chromodynamics
• The Present and Future of QCD
• Progress in understanding short-range structure in nuclei: an experimental perspective
• Polarized Antimatter in the Proton from Global QCD Analysis
• How well do we know the gluon polarization in the proton?
• Valence quark ratio in the proton
• Transversity distributions and tensor charges of the nucleon: extraction from dihadron production and their universal nature
• Tomography of pions and protons via transverse momentum dependent distributions
• Sensitivity of Parity-violating Electron Scattering to a Dark Photon
• Nuclear effects in the deuteron and global QCD analyses
• Target mass corrections in lepton--nucleus DIS: theory and applications to nuclear PDFs
• On the determination of uncertainties in parton densities
• Off-shell effects in bound nucleons and parton distributions from ${}^1$H, ${}^2$H, ${}^3$H and ${}^3$He data
• Systematic uncertainties from higher-twist corrections in DIS at large x
• Extraction of the neutron F2 structure function from inclusive proton and deuteron deep-inelastic scattering data
• The European Muon Collaboration effect in Light-Front Hamiltonian Dynamics
• Octet and decuplet baryon $\sigma$-terms and mass decompositions
• Physical Implications of the Extrapolation and Statistical Bootstrap of the Nucleon Structure Function Ratio $\frac{F_2^n}{F_2^p}$ for Mirror Nuclei ${}^3$He and ${}^3$H
• Helicity-dependent distribution of strange quarks in the proton from nonlocal chiral effective theory
• Multiprocess imaging of nuclear modifications on parton distributions in proton-nucleus collisions