相关论文: The 3-Loop Non-Singlet Heavy Flavor Contributions …
A physically defined effective charge can incorporate quark masses analytically at the flavor thresholds. Therefore, no matching conditions are required for the evolution of the strong coupling constant through these thresholds. In this…
We compare the recent results on the higher twist (HT) contribution to the nonsinglet combination $g_1^p - g_1^n$ of the polarized proton and neutron structure functions with that one to the unpolarized structure function $F_3$ using the…
We investigate the gravitational form factors (GFFs) of the nucleon and the baryon octet, decomposed into their flavor components, utilizing a pion mean-field approach grounded in the large $N_c$ limit of Quantum Chromodynamics (QCD). Our…
We present the results of our QCD analysis for non-singlet unpolarized quark distributions and structure function $F_2(x,Q^2)$ up to N$^3$LO. In this regards 4-loop anomalous dimension can be obtain from the Pad\'e approximations. The…
We present the first complete next-to-next-to-next-to-leading-order calculation of the matching coefficients that link unpolarized flavor non-singlet parton distribution functions with lattice QCD computable correlation functions. By using…
We present the analytic calculation of the Mellin moments of the structure functions F_2, F_3 and F_L in perturbative QCD up to second order corrections and in leading twist approximation. We calculate the 2-loop contributions to the…
By using $\k$-factorization, we derive resummation formulas for the non-abelian $q\bar{q}$ contributions to both heavy flavour production by gluon fusion, and to the next-to-leading BFKL kernel. By combining this result with previous ones…
I use a direct method to extract the longitudinal structure function in the next-to-leading order approximation with respect to the number of active flavor from the parametrization of parton distributions. The contribution of charm and…
We re-examine the estimates of the higher twist contributions to the integral of $g_1$, the polarised structure function of the nucleon, based on QCD sum rules. By including corrections both to the perturbative contribution and to the low…
Starting from fixed-order perturbation theory (FOPT) we derive expressions for the heavy-flavour components of the deep-inelastic structure functions FL and F2 in the variable-flavour number scheme (VFNS). These expressions are valid in all…
At low Q^2, charm production in deep-inelastic scattering is adequately described by assuming generation in electroweak boson-light parton scattering (dominantly boson-gluon fusion) which naturally incorporates the correct threshold…
We evaluate analytically higher terms of the epsilon-expansion of the three-loop master integrals corresponding to three-loop quark and gluon form factors and to the three-loop master integrals contributing to the electron g-2 in QED up to…
We report on recent results obtained for the massive operator matrix elements which contribute to the massive Wilson coefficients in deep-inelastic scattering for $Q^2 \gg m_i^2$ in case of sub-processes with two fermion lines and different…
In the semiclassical approach, inclusive and diffractive quark and gluon distributions are expressed in terms of correlation functions of Wilson loops. Each Wilson loop integrates the colour field strength in the area between the…
The $O(\alpha_s^3 T_F^2 C_F (C_A))$ contributions to the transition matrix element $A_{gg,Q}$ relevant for the variable flavor number scheme at 3--loop order are calculated. The corresponding graphs contain two massive fermion lines of…
An estimation of the higher twist contribution to the polarized nonsinglet structure function $g_1$ is given. Its first moment is generally assumed to be small but this could be due to a cancellation of its contribution in different…
We compute 2-loop QCD corrections to the hard coefficient functions which arise in the factorization formula for B -> X_u l nu decays in the shape-function region. Our calculation provides the last missing piece required for a NNLO analysis…
The behaviour of the quark coefficient functions in deep-inelastic scattering is investigated for large values of the Bjorken variable x. By combining results of soft-gluon resummation and fixed-order calculations, we determine the…
The spin-dependent structure functions g_2 (x, Q^2) are investigated within the framework of the chiral quark soliton model. It turns out that the twist-3 part of g_2 (x, Q^2) gives nonnegligible contributions to the total distributions at…
We present for numerical use the analytic continuations to complex arguments of those basic Mellin transforms, which build the harmonic sums contributing to the 3--loop anomalous dimensions. Eight new basic functions contribute in addition…