Related papers: ERBL and DGLAP kernels for transversity distributi…
Significant differences between transverse and longitudinal polarized parton distributions are found at low energies within a light-front covariant quark model of the nucleon. These differences are due to relativistic spin effects…
The evolution equations of the gauge and Yukawa couplings are derived for the two-loop renormalisation group equations in a five-dimensional SM compactified on a $S^1/Z_2$ to yield standard four space-time dimensions. Different…
Valence double parton distribution functions of the nucleon are evaluated in the framework of a simple model, where the conservation of the longitudinal momentum is taken into account. The leading-order DGLAP QCD evolution from the low…
By measuring Drell-Yan massive lepton-pair's angular distributions, we can identify the polarization of the virtual photon of invariant mass $Q$ which decays immediately into the lepton-pair. In terms of a modified QCD factorization formula…
I study the Feynman integrals needed to compute two-loop self-energy functions for general masses and external momenta. A convenient basis for these functions consists of the four integrals obtained at the end of Tarasov's recurrence…
We discuss diffractive hadron leptoproduction in terms of skewed gluon distributions and within two-gluon exchange model. Connection of the two-gluon approach with skewed gluon distributions is found. The double spin asymmetries for…
The duality relation between one-loop integrals and phase-space integrals, developed in a previous work, is extended to higher-order loops. The duality relation is realized by a modification of the customary +i0 prescription of the Feynman…
Nucleon spin structure functions have been investigated mainly by longitudinally-polarized ones for finding the origin of the nucleon spin. Other types of spin structure functions are transversely-polarized ones. In particular, quark…
We explore the electromagnetic gauge invariance of the hadron tensor of the Drell-Yan process with one transversely polarized hadron. The special role is played by the contour gauge for gluon fields. The prescription for the gluonic pole in…
A general procedure for the calculation of a class of two-loop Feynman diagrams is described. These are two-point functions containing three massive propagators, raised to integer powers, in the denominator, and arbitrary polynomials of the…
We consider a distributed system of a type which is encountered in the study of diffusion processes with memory and in viscoelasticity. The key feature of such system is the persistence in the future of the past actions due the memory…
A short review of problems with parton distribution functions in nucleons, non-polarized and polarized, is given. The main part is devoted to the transversity distribution its possible measurement and its first experimental probe via spin…
We predict readily experimentally measurable differences in the diffractive cross section in the coherent exclusive photoproduction of J/psi mesons in e + A collisions at eRHIC and LHeC energies for nuclear gluon distributions assumed to 1)…
Based on the non-local light-ray operator technique, we develop an algorithm for the computational calculation of evolution kernels for higher-twist operators in leading order of the perturbation theory. We compute the evolution kernel for…
Kwiecinski, Martin, Stasto [13] argue for inclusion of DGLAP terms into BFKL evolution of unintegrated gluon density. The equation was reformulated by Oliveira, Martin, Ryskin [6] employing the opening angle {\theta} = k/xp as the evolution…
We derive an evolution equation for the generating functional which accounts for processes for both gluon emission and recombination. In terms of color dipoles, the kernel of this equation describes evolution as a classical branching…
Within the framework of light-cone quantisation we derive the complete and exact overlap representation of skewed parton distributions for unpolarised and polarised quarks and gluons. Symmetry properties and phenomenological applications…
We extend existing dispersive approach in subloop insertion to the case of crossed two-loop box type topologies. Based on the ideas of the Feynman trick, mass shift approach and dispersive representation of two-point Passarino-Veltman…
The transverse polarization distribution of quarks $h_1(x)$ is computed in a confinement model, the chiral chromodielectric model. The flavor structure of $h_1$, its $Q^2$ evolution and Soffer's inequality are studied. The Drell--Yan double…
We discuss polarized parton distributions and their effects on spin asymmetries at RHIC. In particular, transversity distributions and transverse spin asymmetry are studied. First, we show the $Q^2$ evolution difference between a…