Related papers: Higher-twist corrections to nucleon structure func…
We perform a calculation of the relativistic corrections to the electromagnetic elastic form factors of the nucleon obtained with various Constituent Quark Models. With respect to the non relativistic calculations a substantial improvement…
Form factors of the nucleon have been extracted from experiment with high precision. However, lattice calculations have failed so far to reproduce the observed dependence of form factors on the momentum transfer. We have embarked on a…
We present a computation of nucleon mass corrections to nucleon structure functions for polarized deep-inelastic scattering. We perform a fit to existing data including mass corrections at first order in $m^2/Q^2$ and we study the effect of…
We present a detailed discussion of the elastic scattering of a supersymmetric neutralino off a nucleon or nucleus, with emphasis on the spin--independent interaction. We carefully treat QCD effects on the squark exchange contribution. In…
We analyze higher twist effect in photoproduction of quarkonium, where the quarkonium is a spin-triplet, S-wave state. We find that the nonperturbative effect of next-to-leading twist is contained in three correlation functions related to…
Nonperturbative QCD corrections are important to many low-energy electroweak observables, for example the muon magnetic moment. However, hadronic corrections also play a significant role at much higher energies due to their impact on the…
The recent high statistics NMC data on the Tin to Carbon structure function ratio seems to indicate, for the first time, a significant $Q^2$ dependence, especially at small values of Bjorken $x$, $x < 0.05$, and $Q^2 > 1 GeV^2$. Pure…
We study polarized inelastic electron-nucleon scattering at low momentum transfer in the Witten-Sakai-Sugimoto model of holographic QCD, focusing on resonance production contributions to the nucleon spin structure functions. Our analysis…
Some aspects of recent QCDSF-UKQCD nucleon moments of structure function computations (both quenched and unquenched) are reviewed in an effort to explore the light quark mass regime, lattice spacing effects and quenching artefacts.
Recent results presented in the structure functions working group are briefly summarized for the following topics: The theoretical treatment of heavy quarks in structure functions, higher-order corrections for the leading-twist evolution…
We extract the high-twist contribution to the neutrino-nucleon structure function $xF_3^{(\nu+\bar{\nu})N}$ from the analysis of the data collected by the IHEP-JINR Neutrino Detector in the runs with the focused neutrino beams at the IHEP…
We study the effect of various perturbative and nonperturbative QCD corrections on the free nucleon structure functions ($F_{iN}^{WI}(x,Q^2); ~i=1-3$) and their implications in the determination of nuclear structure functions. The…
Power corrections to the Q**2 behaviour of the low-order moments of both the longitudinal and transverse structure functions of proton and deuteron have been investigated using available phenomenological fits of existing data in the Q**2…
We investigate the Q^2 evolution of parton distributions at small x values, obtained in the case of flat initial conditions. The contributions of twist-two and (renormalon-type) higher-twist operators of the Wilson operator product…
The structure of neutrons, protons, and other strongly interacting particles is now being calculated in full, unquenched lattice QCD with quark masses entering the chiral regime. This talk describes selected examples, including the nucleon…
We analyze the CCFR collaboration iron target data on the xF3 structure function making particular emphasis on the extraction of the higher twist contributions from data. Corrections for nuclear effects are applied in order to extract data…
Deep-inelastic scattering, in the laboratory and on the lattice, is most instructive for understanding how the nucleon is built from quarks and gluons. The long-term goal is to compute the associated structure functions from first…
We summarize recent developments in the understanding of nucleon structure. New data on F2, R and F2c, over a wide range of Q2 and x, are described. Conventional leading twist NLO perturbative QCD gives an excellent account of all the new…
We present explicit expressions for the tree-level "kinematic" twist-three contributions to the nucleon matrix elements of gauge-invariant nonlocal quark-antiquark operators which can be used in lattice calculations of generalized parton…
In this letter we address issues involved in quarkonium production near the boundaries of phase space. It is shown that higher-order non-perturbative contributions are enhanced in this kinematic region and lead to a breakdown of the…