$\bar{d}-\bar{u}$ asymmetry and semi-inclusive production of pions in DIS

Abstract

We investigate unambiguities in the extraction of the $\bar{d}-\bar{u}$ asymmetry from semi-inclusive production of pions in DIS. The role of several effects beyond the quark-parton model (QPM) which lead to $N_p^{{\pi }^{+}}\ne N_n^{{\pi }^{+}}$ and $N_p^{{\pi }^{-}}\ne N_n^{{\pi }^{-}}$ and may therefore cloud such an extraction is studied. The results are discussed in the context of the recent HERMES data. We find that the interaction of the resolved photon with the nucleon significantly modifies the observed $\bar{d}-\bar{u}$ asymmetry. The exclusive elastic production of $\rho$ mesons plays a similar role for the large-$z$ data sample. Our estimate shows a rather small effect of the spectator mechanism. Nuclear effects in the deuteron also look potentially important but are difficult to estimate quantitatively. Throughout the paper we make in addition several general remarks concerning semi-inclusive and exclusive production of mesons.

arXiv comment47 pages, LaTeX with 19 eps figures

References in corpus (28)

• Deeply Virtual Compton Scattering
• Factorization for hard exclusive electroproduction of mesons in QCD
• Deeply virtual electroproduction of photons and mesons on the nucleon : leading order amplitudes and power corrections
• Measurement of the Light Antiquark Flavor Asymmetry in the Nucleon Sea
• Flavor Asymmetry of Antiquark Distributions in the Nucleon
• The Flavor Asymmetry of the Light Quark Sea from Semi-inclusive Deep-inelastic Scattering
• Next-to-Leading Order Fragmentation Functions for Pions and Kaons
• Elastic Electroproduction of rho Mesons at HERA
• Pion and Kaon Production in $e^{+}{e}^{-}$ and $ep$ Collisions at Next-to-Leading Order
• Exclusive Electroproduction of ${\rho }^0$ and $J/\psi$ Mesons at HERA
• Exclusive vector meson production at HERA
• Do the E866 Drell Yan data change our picture of the chiral structure of the nucleon ?
• Quark correlation functions in deep inelastic semi-inclusive processes
• Single spin asymmetries in inclusive high energy hadron-hadron collision processes
• Production of $\omega$-mesons in proton-proton collisions
• Next to leading order determination of pion fragmentation functions
• Hard Leptoproduction of Charged Vector Mesons
• Vector-Meson Electroproduction from Generalized Vector Dominance
• Measurement of Angular Distributions and R= sigma_L/sigma_T in Diffractive Electroproduction of rho^0 Mesons
• Nonpartonic components in the nucleon structure functions at small Q^2 in a broad range of x
• Production of vector mesons by real and virtual photons at high energies
• Inclusive Hadron Photoproduction from Longitudinally Polarized Protons and Deuterons
• Soft Contributions to Hard Pion Photoproduction
• Testing the Meson Cloud Model in Inclusive Meson Production
• Off-diagonal helicity density matrix elements for heavy vector mesons inclusively produced in N-N, gamma-N, l-N interactions
• On the range of validity of the QCD-improved parton model
• Asymmetry in omega meson photoproduction and the phase of omega-pi-gamma coupling
• Light-Cone Meson-Baryon Fluctuations and Single-Spin Asymmetries

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• Has HERA reached a new QCD regime?