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We update the calculation of γZ interference corrections to the weak charge of the proton. We show how constraints from parton distributions, together with new data on parity-violating electron scattering in the resonance region, significantly reduce the uncertainties on the corrections compared to previous estimates. [ABSTRACT FROM AUTHOR]

Constraining the d PDF at large values of x has traditionally relied, in part, on the use of deeply inelastic lepton deuterium scattering data. In order to utilize such data, one must include nuclear corrections which account for Fermi motion, binding, and off-shell effects. The impact of these corrections in the context of a global fit are examined. The uncertainties due to these nuclear effects are large. [ABSTRACT FROM AUTHOR]

I review quark momentum distributions in the nucleon at large momentum fractions x. Particular attention is paid to the impact of nuclear effects in deuterium on the d/u quark distribution ratio as x→1. A new global study of parton distributions, using less restrictive kinematic cuts in Q2 and W2, finds strong suppression of the d quark distribution once nuclear corrections are accounted for. [ABSTRACT FROM AUTHOR]

A project to perform global fits for parton distribution functions (PDFs) with an emphasis on the large-x region is described. An overview of the aims of the project, the techniques used, and some preliminary results are all discussed. [ABSTRACT FROM AUTHOR]

We discuss recent developments in the study of structure functions at low Q2, focusing in particular on the issue of target mass corrections (TMC) to nucleon structure functions. We summarize the standard TMC implementation, and contrast this with a new formulation which has the correct kinematic threshold behavior at finite Q2 in the x→1 limit. [ABSTRACT FROM AUTHOR]

On the basis of the phenomenological model for baryon resonance production in lepton–nucleon and lepton–nucleus scattering we investigate to what extent quark–hadron duality is applicable to the neutrino structure functions and how it compares with duality in electron scattering. [ABSTRACT FROM AUTHOR]

We present a new model for the hyperon-nucleon (ΛN, &Zigma;N) interaction, derived within the meson exchange framework. The model incorporates the standard one boson exchange contributions of the lowest pseudoscalar and vector meson multiplets with coupling constants fixed by SU(6) symmetry relations. In addition — as the main feature of the new model — the exchange of two correlated pions or kaons, both in the scalar-isoscalar (σ) and vector-isovector (ρ) channels, is included. [ABSTRACT FROM AUTHOR]

Quark-hadron duality addresses some of the most fundamental issues in strong interaction physics, in particular the nature of the transition from the perturbative to non-perturbative regions of QCD. I summarize recent developments in quark-hadron duality in lepton-hadron scattering, and outline how duality can be studied at future high-luminosity facilities such as the electron-hadron collider, EPIC. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Abstract. We consider the non-analytic behaviour of ...(x) - ...(x) and s(x) - ...(x) as a function of the quark mass. Using the fact that such non-analytic behaviour is a unique characteristic of Goldstone boson loops, we establish two features of the nucleon sea in a model independent fashion. First we establish the unambiguous role of the pion cloud of the nucleon in the observed excess of ... over ... quarks in the proton. Second, we establish that s(x) cannot in general be equal to ...(x). [ABSTRACT FROM AUTHOR]

Asymmetries in the quark momentum distributions in the proton reveal fundamental aspects of strong interaction physics. Differences between ü and &dline; quarks in the proton sea provide insight into the dynamics of the pion cloud around the nucleon and the nature of chiral symmetry breaking. Polarized flavor asymmetries allow the effects of pion clouds to be disentangled from those of antisymmetrization. Asymmetries between s and &sline; quark distributions in the nucleon are also predicted from the chiral properties of QCD. [ABSTRACT FROM AUTHOR]

We present an explicit quantum field theoretical calculation of two-photon exchange contribution to elastic electron-proton scattering and to Δ resonance production in electron-proton collisions. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]