Related papers: Generalized Sum Rules for Spin-Dependent Structure…
Deep inelastic scattering data on $F_2$ structure function obtained in the fixed-target experiments were analysed in the valence quark approximation with a next-to-next-to-leading-order accuracy. Parton distribution functions are…
We generalize the sum rules for the nucleon electric plus magnetic polarizability $\Sigma=\alpha+\beta$ and for the nucleon spin-polarizability $\gamma$, to virtual photons with $Q^2>0$. The dominant low energy cross sections are…
We extract a set of values for the Gross-Llewellyn Smith sum rule at different values of 4-momentum transfer squared ($Q^{2}$), by combining revised CCFR neutrino data with data from other neutrino deep-inelastic scattering experiments for…
We prove that regulating infrared divergencies generates power (~1/(Q^2)^k) corrections to the spin structure function g_1 at small x and large Q^2. At the same time it leads to the corrections ~(Q^2)^k at small Q^2. We present the explicit…
The Drell-Hearn-Gerasimov (DHG) sum rule relates the helicity structure of the photoabsorption cross section to the anomalous magnetic moment of the nucleon. It is based on Lorentz and gauge invariance, crossing symmetry, causality and…
The twist three contributions to the $Q^2$-evolution of the spin-dependent structure function $g_2(x_{Bj},Q^2)$ are considered in the non-local operator product approach. Defining appropriate twist three distribution function we derive…
Predictions for the spin dependent structure function $g_1$ of the nucleon are presented. We use an unified approach incorporating the LO DGLAP evolution and the resummation of double logarithmic terms $ln^2(x)$. We show, that the singular…
In this paper we study QCD and power corrections to sum rules which show up in deep inelastic lepton-hadron scattering. Furthermore we will make a distinction between fundamental sum rules which can be derived from quantum field theory and…
The neutron longitudinal and transverse asymmetries $A^n_1$ and $A^n_2$ have been extracted from deep inelastic scattering of polarized electrons by a polarized $^3$He target at incident energies of 19.42, 22.66 and 25.51 GeV. The…
We have measured the spin structure functions g2p and g2d and the virtual photon asymmetries A2p and A2d over the kinematic range 0.02 < x < 0.8 and 1.0 < Q^2 < 30(GeV/c)^2 by scattering 38.8 GeV longitudinally polarized electrons from…
I review what is known about the quark and gluon spin distributions in the nucleon. I discuss in some detail (a) the existence of sum rules for angular momentum; (b) the interpretation and possible measurement of the nucleon's transversity…
In the framework of light-cone QCD sum rules, we study the valence quark distribution function $q(x_B)$ of a pion for moderate $x_B$. The sum rule with the leading twist-2 wave function gives $q(x_B)=\varphi_\pi(x_B)$. Twist-4 wave…
We present predictions for the spin structure functions of the proton and the neutron in the framework of a unitary isobar model for one-pion photo- and electroproduction. Our results are compared with recent experimental data from SLAC.…
The possibility of the first measurement of Bjorken unpolarized sum rule for $F_1$ structure function of $\nu N$ deep-inelastic scattering at Neutrino Factories is commented. The brief summary of various theoretical contributions to this…
In a spin-1 hadron, tensor-polarized parton distribution functions (PDFs) exist. The twist-2 function is $f_{1LL}$ and a twist-3 one is $f_{LT}$. Because an experiment is under preparation at the Thomas Jefferson National Accelerator…
Recently, Son and Stephanov have considered an "open moose" as a possible dual model of a QCD-like theory of chiral symmetry breaking. In this note we demonstrate that although the Weinberg sum rules are satisfied in any such model, the…
We analyse the proton and deutron data on spin dependent asymmetry $A_1(x,Q^2)$ supposing the DIS structure functions $g_1(x,Q^2)$ and $F_3(x,Q^2)$ have the similar $Q^2$-dependence. As a result, we have obtained $\Gamma_1^p - \Gamma_1^n =…
In this talk I report on recent progress in a few areas closely related to the virtual Compton scattering studies. In particular, I discuss the quark-hadron duality estimate of the $\gamma^* p \to \Delta^+$ transition, QCD sum rule…
We present a QCD sum rule calculation of the spin-symmetry violating universal function $\chi_2(v\cdot v')$, which appears at order $1/m_Q$ in the heavy quark expansion of meson form factors. This function vanishes in the standard…
Quantum statistical distributions for the partons provide a fair description of deep inelastic scattering data at $Q^2 = 3$ and $10 (GeV/c)^2$. The study of the polarized structure functions seems to suggest an alternative possible solution…