Related papers: Spin dependent structure function $g_1$ at small $…
The Standard Approach (SA) for description of the structure function g_1 combines the DGLAP evolution equations and Standard Fits for the initial parton densities. The DGLAP equations describe the region of large Q^2 and large x, so there…
The spin structure functions g_1 for the proton and the deuteron have been measured over a wide kinematic range in x and Q2 using 1.6 and 5.7 GeV longitudinally polarized electrons incident upon polarized NH_3 and ND_3 targets at Jefferson…
I begin with a general discussion about importance of constructing a picture of the nucleon in terms of QCD degrees of freedom, emphasizing the role of spin structure functions. I then give a short overview on the theoretical and…
We present an update of a phenomenological model for the spin dependent structure functions $g_1(x,Q^2)$ of the proton and neutron. This model is based on a broken SU(6) wavefunction parametrized by the unpolarized structure functions. The…
We will discuss recent results for the spin structure functions, with an emphasis on g2 . High precision g2 data allows for tests of the Burkhardt-Cottingham sum rule, and is needed to consistently evaluate higher twist effects.
I investigate the behavior of spin-dependent parton distribution functions in the regions of small and large momentum fractions $x$. I present a systematic comparison between predictions for relevant observables obtained with various models…
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…
The spin dependent deuteron structure functions are investigated in the relativistic model of deuteron. It is shown that the deuteron structure function $g_{2}(X)$ can be considered properly only in the infinite momentum frame where the…
The spin structure functions g1 and g2 have been calculated in the resonance region and for small and intermediate momentum transfer. The calculation is based on a gauge-invariant and unitary model for one-pion photo- and electroproduction.…
We derive relations between spin-dependent nuclear and nucleon g_1 and g_2 structure functions within the nuclear impulse approximation, which are valid at all Q^2, and in both the resonance and deep inelastic regions. We apply the…
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 target mass corrections to the twist-2 contributions of the spin-dependent structure functions are calculated using operator product expansion in lowest order in QCD. The influence of such corrections to the different relations between…
We have measured the spin-dependent structure function $g_1^p$ of the proton in deep inelastic scattering of polarized muons off polarized protons, in the kinematic range $0.003<x<0.7$ and $1\,\mbox{GeV}^2<Q^2<60\,\mbox{GeV}^2$. Its first…
Nonsinglet structure function g_2(x) for deep inelastic scattering of a lepton on a constituent quark is calculated in the double logarithmic approximation at x<<1. Small-x asymptotics of g_2 is shown to have the same singular behaviour as…
A review on the theoretical aspects and the experimental results of polarized deep inelastic scattering and of other hard scattering processes is presented. The following items are discussed: longitudinally polarized structure functions,…
QCD predictions on the low-$x$ behaviour of the structure functions are reviewed and compared with the recent measurements of $F_2(x,Q^2)$ at HERA. The present theoretical accuracy of these predictions is discussed.
I review the spin dependent structure functions which control dominant (twist-2) and sub-dominant (twist-3) phenomena in hard processes. Novel effects associated with chirally odd parton distributions and with transverse polarization are…
The spin-dependent structure functions $g_1(x)$, $g_2(x)$, ${g}_2^{WW}(x)$ and ${\bar g}_2(x)$ and their moments are studied in the CM bag model. The results show that (i) $\int_0^1g_2(x)dx=0$, i.e. the Burkhardt-Cottingham sum rule holds,…
The spin dependent structure function, g2ww(x,Q^2), is calculated in the valon model. A simple approach is given for the determination of the twist-3 part of the g2(x, Q^2) in Mellin space; thus, enabling us to obtain the full transverse…
The small-x behavior of the singlet contributions to the polarized structure function g_2(x,Q^2) is calculated in the double-logarithmic approximation of perturbative QCD. The dominant contribution is due to the gluons which, in contrast to…