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We compute the next-to-next-to-leading order (NNLO) contributions to the three splitting functions governing the evolution of unpolarized non-singlet combinations of quark densities in perturbative QCD. Our results agree with all partial…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Moch , J. A. M. Vermaseren , A. Vogt

Using a recursive algorithm to solve the renormalization group equations of N=1 QCD (DGLAP), we describe the most general supersymmetric evolution of the parton distributions. The analysis involves the regular DGLAP evolution, a partial…

High Energy Physics - Phenomenology · Physics 2007-05-23 Claudio Coriano

Splitting amplitudes are universal functions governing the collinear behavior of scattering amplitudes for massless particles. We compute the two-loop g -> gg splitting amplitudes in QCD, N=1, and N=4 super-Yang-Mills theories, which…

High Energy Physics - Phenomenology · Physics 2010-03-25 Zvi Bern , Lance J. Dixon , David A. Kosower

QCD in non-integer d=4-2 epsilon space-time dimensions possesses a nontrivial critical point and enjoys exact scale and conformal invariance. This symmetry imposes nontrivial restrictions on the form of the renormalization group equations…

High Energy Physics - Phenomenology · Physics 2015-06-19 V. M. Braun , A. N. Manashov

We have studied the recently completed analytic all-N expressions for the four-loop anomalous dimensions corresponding to the next-to-next-to-next-to-leading order splitting functions for the non-singlet quark distribution in perturbative…

High Energy Physics - Phenomenology · Physics 2026-05-06 S. Moch , A. Vogt

The scale evolution of parton distributions is determined by universal splitting functions. As a milestone towards the computation of these functions to four-loop order in QCD, we compute all contributions to the pure-singlet quark-quark…

High Energy Physics - Phenomenology · Physics 2024-12-02 Thomas Gehrmann , Andreas von Manteuffel , Vasily Sotnikov , Tong-Zhi Yang

Explicit diagrammatic calculation of evolution equations for high-twist correlation functions is a challenge already at one-loop order in QCD coupling. The main complication being quite involved mixing pattern of the so-called…

High Energy Physics - Phenomenology · Physics 2015-06-23 Yao Ji , A. V. Belitsky

We revisit the Next-to-Leading Order (two-loop) contributions to the Anomalous Dimensions of $\Delta F = 1$ four-quark operators in QCD. We devise a test for anomalous dimensions, that we regard as of general interest, and by means of which…

High Energy Physics - Phenomenology · Physics 2025-06-19 Pol Morell , Javier Virto

We study the scale dependence of twist-3 distributions defined with chirality-odd quark-gluon operators. To derive the scale dependence we explicitly calculate these distributions of multi-parton states instead of a hadron. Taking one-loop…

High Energy Physics - Phenomenology · Physics 2015-06-11 J. P. Ma , Q. Wang , G. P. Zhang

We consider two-loop renormalization of high-dimensional Lorentz scalar operators in the gluonic sector of QCD. These operators appear also in the Higgs effective theory obtained by integrating out the top quark loop in the gluon fusion…

High Energy Physics - Phenomenology · Physics 2021-05-05 Qingjun Jin , Ke Ren , Gang Yang

We investigate the renormalization of the twist-3 operators which are relevant for the spin-dependent structure function $g_{2}(x, Q^{2})$. We derive the anomalous dimension for the non-singlet part by calculating the off-shell Green's…

High Energy Physics - Phenomenology · Physics 2009-10-28 Jiro Kodaira , Yoshiaki Yasui , Kazuhiro Tanaka , Tsuneo Uematsu

The solution of DGLAP evolution equation for the twist-3 gluon operators is obtained in the Double Logarithmic Approximation of QCD perturbation theory. The method used for the solution is similar to the reggeon field theory. The…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. G. Shuvaev

A complete description of the calculation of anomalous dimensions (GLAP splitting functions) is given for parton distributions which appear in space-like processes. The calculation is performed in the light-cone gauge. The results are in…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. K. Ellis , W. Vogelsang

We describe the evaluation of the anomalous dimensions of twist-2 deep inelastic light cone operators to O(1/N_f) as a check on future perturbative calculations. In particular we present recent results for the singlet gluonic operator…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. F. Bennett , J. A. Gracey

We report on recent progress on the splitting functions for the evolution of parton distributions and related quantities, the (lightlike) cusp anomalous dimensions, in perturbative QCD. New results are presented for the four-loop…

High Energy Physics - Phenomenology · Physics 2018-08-29 A. Vogt , F. Herzog , S. Moch , B. Ruijl , T. Ueda , J. A. M. Vermaseren

We formulate and numerically solve the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi~(DGLAP) evolution equations at next-to-leading order in perturbation theory directly for a basis of 6 physical, observable structure functions in deeply…

High Energy Physics - Phenomenology · Physics 2025-09-03 Tuomas Lappi , Heikki Mäntysaari , Hannu Paukkunen , Mirja Tevio

We study the scale dependence of the twist-3 quark-gluon parton distributions using the observation that in the multi-color limit the corresponding QCD evolution equations possess an additional integral of motion and turn out to be…

High Energy Physics - Phenomenology · Physics 2023-06-29 S. E. Derkachov , G. P. Korchemsky , A. N. Manashov

Renormalization group evolution equations describing the scale dependence of quantities in quantum chromodynamics (QCD) play a central role in the interpretation of experimental data. Arguably the most important evolution equations for…

High Energy Physics - Phenomenology · Physics 2022-10-20 Hao Chen , Max Jaarsma , Yibei Li , Ian Moult , Wouter J. Waalewijn , Hua Xing Zhu

In this work, we study the renormalization of nonlocal quark bilinear operators containing an asymmetric staple-shaped Wilson line at the one-loop level in both lattice and continuum perturbation theory. These operators enter the…

High Energy Physics - Lattice · Physics 2024-06-10 Gregoris Spanoudes , Martha Constantinou , Haralambos Panagopoulos

We analyze the twist-4 contributions to Bjorken and Ellis-Jaffe sum rules for spin-dependent structure function $g_1(x, Q^2 )$. We investigate the anomalous dimensions of the twist-4 operators which determine the logarithmic correction to…

High Energy Physics - Phenomenology · Physics 2007-05-23 Hiroyuki Kawamura