The Nucleon's Virtual Meson Cloud and Deep Inelastic Lepton Scattering

Abstract

We address the question whether the nucleon's antiquark sea can be attributed entirely to its virtual meson cloud and, in essence, whether there exists a smooth transition between hadronic and quark-gluon degrees of freedom. We take into account contributions from $\pi$ and $K$ mesons and compare with the nucleon's antiquark distributions which serve as a non-perturbative input to the QCD evolution equations. We elucidate the different behavior in the flavor singlet and non-singlet channels and study the dependence of our results on the scale $Q^2$. The meson-nucleon cut-offs that we determine give not only an indication on the size of the region within which quarks are confined in a nucleon, but we find that the scale of these form factors is closely related to the four-momentum transfer, $Q^2$, where gluons are resolved by a high energy probe, and that large meson loop momenta, $|\mathbf{k}|\approx 0.8$ GeV, contribute significantly to the sea quark distributions. While the agreement of our calculations with data-based parametrizations is satisfactory and scale independent for the flavor breaking share of the nucleon's antiquark sea, the flavor singlet component is quite poorly described. This hints the importance of gluon degrees of freedom.

34 pages, RevTeX, 6 figures optionally included using epsfig.sty

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Cited by in corpus (51)

• Improved Measurement of the $\bar{d}/\bar{u}$ Asymmetry in the Nucleon Sea
• Flavor Asymmetry of Antiquark Distributions in the Nucleon
• dbar/ubar Asymmetry and the Origin of the Nucleon Sea
• Dynamics of Light Antiquarks in the Proton
• Light-Cone Models for Intrinsic Charm and Bottom
• Transversity distributions in the nucleon in the large-N_c limit
• High-Energy Hadron-Induced Dilepton Production from Nucleons and Nuclei
• D and rho Mesons: Who resolves whom?
• Virtual meson cloud of the nucleon and generalized parton distributions
• Next-to-leading order corrections in exclusive meson production
• Hidden dibaryons in one- and two-pion production in NN collisions
• Deeply virtual Compton scattering on a virtual pion target
• Chiral dynamics and the growth of the nucleon's gluonic transverse size at small x
• Observation of Events with an Energetic Forward Neutron in Deep Inelastic Scattering at HERA
• Polarized light-antiquark distributions in a meson-cloud model
• Taming the Pion Cloud of the Nucleon
• Omega Meson Cloud and the Proton's Light Anti-Quark Distribution
• Chiral dynamics and partonic structure at large transverse distances
• Nonperturbative versus perturbative effects in generalized parton distributions
• Mapping the Proton's Fluctuating Waistline
• Chiral Light Front Perturbation Theory and the Flavor Dependence of the Light-Quark Nucleon Sea
• Polarized rho mesons and the asymmetry between Delta d^bar(x) and Delta u^bar(x) in the sea of the nucleon
• Sea quark contents of octet baryons
• Manifestation of the $P$-wave diproton resonance in single-pion production in $pp$ collisions
• Exclusive channels in semi-inclusive production of pions and kaons
• To the nature of nuclear force
• Polarized antiquark flavor asymmetry: Pauli blocking vs. the pion cloud
• Pions in the nuclear medium and Drell-Yan scattering
• Flavor structure of the unpolarized and longitudinally-polarized sea-quark distributions in the nucleon
• Collinear parton distributions and the structure of the nucleon sea in a light-front meson-cloud model
• Covariant propagator of the Rarita-Schwinger field in the nuclear medium
• Parton distributions in the proton and pion
• Orbital Angular Momentum in the Nucleon
• Sigma Meson Cloud and Proton's Light Flavor Sea Quarks
• Exclusive vector meson production with a leading neutron in photon - hadron interactions at hadronic colliders
• Soft-hard interplay and factorization for baryon production in the target fragmentation region in ep collisions
• Testing the Meson Cloud Model in Inclusive Meson Production
• Physics of the Nucleon Sea Quark Distributions
• Sivers function of sea quarks in the light-cone model
• Pion-Exchange and Fermi-Motion Effects on the Proton-Deuteron Drell-Yan Process
• Mesonic and Binding Contributions to the Nuclear Drell-Yan Process
• Pions in Proton Structure and Everywhere Else
• $P$-wave dibaryon resonances in $pp$ elastic scattering and near-threshold pion production
• Pion fluctuation in deep inelastic scattering
• Phenomenological analysis of nucleon strangeness and meson-nucleon sigma terms
• Deuteron Structure Functions in the Context of Few-Body Physics
• Gluonic effects in vector meson photoproduction at large momentum transfers
• Meson exchange and nucleon polarizabilities in the quark model
• Exclusive vector meson photoproduction with a leading baryon in photon - hadron interactions at hadronic colliders
• Non-singlet structure function of the 3He-3H system and divergence of the Gottfried integral
• The Skyrme Model piNN Form Factor and the Sea Quark Distribution of the Nucleon