Related papers: DIS coefficient functions at four loops in QCD and…
The anomalous dimensions of planar N=4 SYM theory operators like tr(Phi D^S Phi) expanded in large spin S have the asymptotics \gamma= f ln S + f_c + 1/S (f_11 ln S + f_10) + ..., where f (the universal scaling function or cusp anomaly),…
We reanalyze deep inelastic scattering data of BCDMS Collaboration by including proper cuts of ranges with large systematic errors. We perform also the fits of high statistic deep inelastic scattering data of BCDMS, SLAC, NM and BFP…
The low energy mass spectrum of QCD in the large $N_C$ limit is computed. The low-lying states in the meson spectrum are explicitly evaluated up to the fourth order in the strong coupling perturbative expansion. The 't Hooft limit is smooth…
We give an asymptotic formula for the number of $D_4$ quartic extensions of a function field with discriminant equal to some bound, essentially reproducing the analogous result over number fields due Cohen, Diaz y Diaz, and Olivier, but…
We present the result of a calculation for the third and fourth moments of the non-singlet four-loop anomalous dimension of Wilson twist-2 operators in QCD with full color and flavour structures. We discuss also a general expressions for…
The expression for the dynamical mass of fermions in QED in a magnetic field is obtained for a large number of the fermion flavor N in the framework of 1/N expansion. The existence of a threshold value N_{thr}, dividing the theories with…
Non-compact QED(3) with four-component fermion flavor content larger than or equal to two is studied numerically near the chiral limit to understand its chiral symmetry breaking features. We monitor discretization and finite size effects on…
We perform pQCD analysis of the existing DIS data for charged leptons with account of corrections up to the NNLO. The parton distributions, value of strong coupling constant, and high-twist terms are extracted and their stability with…
We present calculations of the structure functions F_2(x,Q^2) and F_L(x,Q^2), concentrating on small x. After discussing the standard expansion of the structure functions in powers of \alpha_s(Q^2) we consider a leading-order expansion in…
The breaking of flavor SU(3) symmetry in the axial couplings and magnetic moments of baryons is analyzed in the $1/N_c$ expansion. A simple meson loop graph which is known to be of order $\sqrt{m_s}$ and leading order in $1/N_c$ correctly…
The massive 3-loop fermion-loop corrections $\propto C_A N_f T_F^2$ and $C_F N_f T_F^2$ to the massive operator matrix elements $A_{Qg}$, $A_{Qq}^{\rm{PS}}$, $A_{qq,Q}^{\rm{PS}}$, $A_{qq,Q}^{\rm{NS}}$ and $A_{qq,Q}^{\rm{NS,TR}} have been…
An important ``observable'' of planar N=4 SYM theory is the scaling function f(lambda) that appears in the anomalous dimension of large spin twist 2 operators and also in the cusp anomaly of light-like Wilson loops. The non-trivial relation…
We discuss the interplay of low-x physics and QCD scaling violations by extending the unified approach describing inclusive structure functions and diffractive production in $\gamma* p$ interactions proposed in previous papers, to large…
A systematic expansion in 1/N is constructed for baryons in QCD. Predictions of the 1/N expansion at leading and subleading order for baryon axial current coupling constant ratios such as F/D, baryon masses and magnetic moments are derived.…
The subject of this thesis is the construction of an approximation for the next-to-next-to-next-to leading order (N^3LO) deep inelastic scattering (DIS) massive coefficient function of the gluon for F2 in heavy quark pair production.…
In this paper we discuss effective strong coupling constants. Those are well behaved in the low-Q^2 domain, contrarily to alpha_s from pQCD. We present an extraction of an effective strong coupling constant from Jefferson Lab polarized data…
Power-law sensitivity to initial conditions at the edge of chaos provides a natural relation between the scaling properties of the dynamics attractor and its degree of nonextensivity as prescribed in the generalized statistics recently…
We calculate the massive Wilson coefficients for the heavy flavor contributions to the non-singlet charged current deep-inelastic scattering structure functions $F_L^{W^+}(x,Q^2)-F_L^{W^-}(x,Q^2)$ and $F_2^{W^+}(x,Q^2)-F_2^{W^-}(x,Q^2)$ in…
Conformal symmetry of QCD is restored at the Wilson-Fisher critical point in noninteger $4-2\epsilon$ space-time dimensions. Correlation functions of multiplicatively renormalizable operators with different anomalous dimensions at the…
We present our most recent results on the calculation of the heavy flavor contributions to deep-inelastic scattering at 3-loop order in the large $Q^2$ limit, where the heavy flavor Wilson coefficients are known to factorize into light…