Related papers: IR-Renormalon Contribution to the Polarized Struct…
Using the framework of QCD sum rules we predict the twist-3 contribution to the second moment of the polarized nucleon structure function $g_2(x)$. As the relevant local operator depends explicitely on the gluon field, we employ a recently…
We show that when Bjorken $x_B$ is large, the leading order twist-four contributions to the structure functions can be expressed in terms of the derivatives of the normal twist-two parton distributions. Our analytical results are not only…
We present the complete twist-4 results for the semi-inclusive annihilation process $e^+ +e^- \to h+ \bar q+X$ at the tree level of perturbative quantum chromodynamics. The calculations are carried out by using the formalism obtained by…
Parity violating electron-deuteron scattering can potentially provide a clean access to electroweak couplings that are sensitive to physics beyond the Standard Model. However hadronic effects can contaminate their extraction from…
We discuss the role of nucleon and its excited state poles in the twist expansion of the nucleon structure function moments. We find that the nucleon pole contribution was overestimated in previous analyses by a factor of two. Inclusion of…
Estimates for longitudinal spin asymmetries which single out new polarized nucleon structure functions in deeply inelastic charged current interactions at HERA energies are given, exploiting their interpretation in terms of polarized quark…
Leading QCD vacuum polarization contributions to the electroweak parameter $\delta\rho$ are evaluated numerically using several different prescriptions for the gluon self-energy. Simple theoretical estimates of the asymptotic behavior are…
We discuss the small $x$ behaviour of the spin dependent structure function $g_1$. We find a contribution from the exchange of two non-perturbative gluons which behaves as $\sim ( 2 \ln {1 \over x} -1)$.
In the present paper we summarize our results on the structure function g_1 and present explicit expressions for the non-singlet and singlet components of g_1 which can be used at arbitrary x and Q^2. These expressions combine the…
The smallness of the deuteron tensor spin structure function is the necessary condition to extract neutron $g_1$ function neglecting the nuclear effects. The oscillating behavior of the quark tensor spin structure function leading to the…
We propose two new sources of a substantial tensor polarization of sea partons in the deuteron: the diffractive nuclear shadowing which depends on the alignment of nucleons in the polarized deuteron and the nuclear excess of pions in the…
We estimate the power corrections (infrared renormalon contributions) to the coefficient functions for the transverse, longitudinal and asymmetric fragmentation functions in $e^+e^-$ annihilation, using a method based on the analysis of…
We have re-analyzed the world data on inclusive polarized DIS including the very precise CLAS proton and deuteron data, as well as the latest COMPASS data on the asymmetry $A_1^d$, and have studied the impact of these data on polarized…
It is shown that in the special infinite momentum frame where photon has pure transverse components at $P\rightarrow\infty$ the spin-dependent deep inelastic structure function $ g_{2}(x)$ has a reasonable interpretation in terms of…
We calculate the contribution of the higher-twist Feynman diagrams to the large-$p_T$ inclusive gluon production cross-section in $\pi p$ collisions in case of the running coupling and frozen coupling approaches within perturbative and…
We calculate the twist-4 corrections to the integral of $g_1(x,Q^2)$ in the framework of QCD sum rules using an interpolating nucleon field which contains explicitly a gluonic degree of freedom. This information can be used together with…
We report on a high statistics quenched lattice QCD calculation of the deep-inelastic structure functions $F_1$, $F_2$, $g_1$ and $g_2$ of the proton and neutron. The theoretical basis for the calculation is the operator product expansion.…
The hard-gluonic contribution to the first moment of the polarized proton structure function $g_1^p(x)$ is dependent of the factorization convention chosen in defining the quark spin density and the hard cross section for photon-gluon…
We propose a new method for extracting neutron structure functions from inclusive structure functions of nuclei. Unlike earlier approaches, the new method is applicable to both spin-averaged and spin-dependent structure functions. We test…
We consider the effect of nuclear shadowing in polarized deep inelastic scattering (DIS) on ^6LiD at small Bjorken x and its relevance to the extraction of the deuteron spin structure function g_{1}^{d}(x,Q^2). Using models, which describe…