Polarized Antimatter in the Proton from Global QCD Analysis

Abstract

We present the first simultaneous global QCD analysis of spin-dependent parton distribution functions alongside their spin-averaged counterparts and pion, kaon, and unidentified hadron fragmentation functions. This analysis includes all data relevant for constraining the polarized light quark sea asymmetry $\Delta \bar{u}-\Delta \bar{d}$, in particular the latest polarized $W$-lepton production data from the STAR collaboration at RHIC and semi-inclusive deep inelastic scattering data from COMPASS, allowing the most robust extraction available with minimal theoretical assumptions. We also extract a self-consistent set of antiquark polarization ratios $\Delta \bar{u}/\bar{u}$ and $\Delta \bar{d}/\bar{d}$ and determine the signs of the truncated contributions to the proton spin from the light antiquarks.

arXiv comment4 figures

References in corpus (56)

• The Spin Structure of the Nucleon
• Improved Measurement of the $\bar{d}/\bar{u}$ Asymmetry in the Nucleon Sea
• Measurements of the Proton and Deuteron Spin Structure Functions g1 and g2
• Extraction of Spin-Dependent Parton Densities and Their Uncertainties
• The angular momentum controversy: What's it all about and does it matter?
• Precise determination of the spin structure function ${\mathbf{g}}_1$ of the proton, deuteron and neutron
• A first unbiased global determination of polarized PDFs and their uncertainties
• Precision Determination of the Neutron Spin Structure Function g1n
• Evidence for polarization of gluons in the proton
• QCD Constrains on the Shape of Polarized Quark and Gluon Distributions
• Measurement of the Neutron Spin Structure Function $g_1^n$ with a Polarized ^3He Target
• Measurement of the Light Antiquark Flavor Asymmetry in the Nucleon Sea
• The Deuteron Spin-dependent Structure Function g1d and its First Moment
• Deep Inelastic Scattering of Polarized Electrons by Polarized ${}^3$He and the Study of the Neutron Spin Structure
• Measurements of the $Q^2$-Dependence of the Proton and Neutron Spin Structure Functions g1p and g1n
• Quark helicity distributions in the nucleon for up, down, and strange quarks from semi--inclusive deep--inelastic scattering
• First simultaneous extraction of spin-dependent parton distributions and fragmentation functions from a global QCD analysis
• Measurement of the Deuteron Spin Structure Function g_1^d(x) for 1 (GeV/c)^2 < Q^2 < 40 (GeV/c)^2
• The Spin-dependent Structure Function of the Proton g_1^p and a Test of the Bjorken Sum Rule
• Polarised Quark Distributions in the Nucleon from Semi-Inclusive Spin Asymmetries
• Longitudinal double-spin asymmetry and cross section for inclusive jet production in polarized proton collisions at sqrt(s) = 200 GeV
• Flavor Decomposition of the Polarized Quark Distributions in the Nucleon from Inclusive and Semi-inclusive Deep-inelastic Scattering
• Unpolarized and polarized quark distributions in the large-Nc limit
• Iterative Monte Carlo analysis of spin-dependent parton distributions
• Complete flavor decomposition of the spin and momentum fraction of the proton using lattice QCD simulations at physical pion mass
• Precision Measurement of the Longitudinal Double-spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at $\sqrt{s}=200$ GeV
• Simultaneous Monte Carlo analysis of parton densities and fragmentation functions
• Strange quark suppression from a simultaneous Monte Carlo analysis of parton distributions and fragmentation functions
• The Asymmetry of Antimatter in the Proton
• Measurement of longitudinal spin asymmetries for weak boson production in polarized proton-proton collisions at RHIC
• Monte Carlo sampling variant of the DSSV14 set of helicity parton densities
• Flavour Separation of Helicity Distributions from Deep Inelastic Muon-Deuteron Scattering
• Parton momentum and helicity distributions in the nucleon
• First Monte Carlo analysis of fragmentation functions from single-inclusive $e^{+}{e}^{-}$ annihilation
• Impact of hadronic and nuclear corrections on global analysis of spin-dependent parton distributions
• Flavor Structure of the Nucleon Sea
• Longitudinal double-spin asymmetry for inclusive jet and dijet production in $pp$ collisions at $\sqrt{s}=510$ GeV
• Measurement of the parity-violating longitudinal single-spin asymmetry for $W^{\pm }$ boson production in polarized proton-proton collisions at $\sqrt{s}=500$GeV
• New developments in the statistical approach of parton distributions: tests and predictions up to LHC energies
• Bayesian Reweighting for Global Fits
• How well do we know the gluon polarization in the proton?
• Constraints on spin-dependent parton distributions at large x from global QCD analysis
• Measurement of parity-violating spin asymmetries in W${}^{\pm }$ production at midrapidity in longitudinally polarized $p$$+$$p$ collisions
• Measurement of the longitudinal spin asymmetries for weak boson production in proton-proton collisions at $\sqrt{s}$ = 510 GeV
• Can $\overline{\mathrm{MS}}$ parton distributions be negative?
• Isovector EMC effect from global QCD analysis with MARATHON data
• Positivity and renormalization of parton densities
• Event Structure and Double Helicity Asymmetry in Jet Production from Polarized p+p Collisions at sqrt(s) = 200 GeV
• Non-perturbative structure of the polarized nucleon sea
• The Sea of Quarks and Antiquarks in the Nucleon: a Review
• Longitudinal double-spin asymmetry for inclusive jet and dijet production in polarized proton collisions at $\sqrt{s}=200$ GeV
• Cross section and longitudinal single-spin asymmetry $A_L$ for forward $W^{\pm }\to {\mu }^{\pm }\nu$ production in polarized $p$$+$$p$ collisions at $\sqrt{s}=510$ GeV
• Do we expect light flavor sea-quark asymmetry also for the spin-dependent distribution functions of the nucleon?
• Single-Spin Asymmetries in W Boson Production at Next-to-Leading Order
• Revisiting quark and gluon polarization in the proton at the EIC
• Bayesian Monte Carlo extraction of sea asymmetry with SeaQuest and STAR data

Cited by in corpus (17)

• 50 Years of Quantum Chromodynamics
• The Present and Future of QCD
• Generalized parton distributions through universal moment parameterization: non-zero skewness case
• Transversity distributions and tensor charges of the nucleon: extraction from dihadron production and their universal nature
• First simultaneous global QCD analysis of dihadron fragmentation functions and transversity parton distribution functions
• Tomography of pions and protons via transverse momentum dependent distributions
• Strong Interaction Physics at the Luminosity Frontier with 22 GeV Electrons at Jefferson Lab
• Non-singlet quark helicity PDFs of the nucleon from pseudo-distributions
• $O({\alpha }_s^2$) Polarized Heavy Flavor Corrections}to Deep-Inelastic Scattering at $Q^2\gg m^2$
• Global analysis of polarized DIS & SIDIS data with improved small-$x$ helicity evolution
• Resonant contributions to polarized proton structure functions
• Polarized fragmenting jet functions in Inclusive and Exclusive Jet Production
• High precision measurements of alpha_s at the future EIC
• Flavor asymmetry from the non-perturbative nucleon sea
• Analysis of HERA data with a PDF parametrization inspired by quantum statistical mechanics
• Quantum stress and torsion distributions in the deuteron
• Unveiling Light-Quark Yukawa Flavor Structure via Dihadron Fragmentation at Lepton Colliders