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Related papers: Improved Approximations for the Three-Loop Splitti…

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We summarize recent results on the evolution of unpolarized parton densities and deep-inelastic structure functions in massless perturbative QCD. Due to last year's extension of the integer-moment calculations of the three-loop splitting…

High Energy Physics - Phenomenology · Physics 2008-11-26 W. L. van Neerven , A. Vogt

We compute the next-to-next-to-leading order (NNLO) contributions to the splitting functions governing the evolution of the unpolarized flavour-singlet parton densities in perturbative QCD. The exact expressions are presented in both…

High Energy Physics - Phenomenology · Physics 2010-04-05 A. Vogt , S. Moch , J. A. M. Vermaseren

We have computed the complete next-to-next-to-leading order (NNLO) contributions to the splitting functions governing the evolution of unpolarized parton densities in perturbative QCD. Our results agree with all partial results available in…

High Energy Physics - Phenomenology · Physics 2009-11-10 S. Moch , J. A. M. Vermaseren , A. Vogt

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

We have computed the next-to-next-to-leading-order (NNLO) contributions to the evolution of unpolarized parton distributions in perturbative QCD. In this talk, we briefly recall why this huge computation was necessary and outline how it was…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. Vogt , S. Moch , J. Vermaseren

We have calculated the complete matrix of three-loop helicity-difference (`polarized') splitting functions Delta P_ik^(2), i,k = q,g, in massless perturbative QCD. In this note we briefly discuss some properties of the polarized splitting…

High Energy Physics - Phenomenology · Physics 2014-05-15 A. Vogt , S. Moch , J. A. M. Vermaseren

Using forward matrix elements of local leading-twist operators, we present a determination of the isovector third Mellin moments $\left< x^2 \right>$ of nucleon unpolarized, polarized, and transversity parton distribution functions. Two…

We present the next-to-next-to-next-to-leading order (N^3LO) contributions to the non-singlet splitting functions for both parton distribution and fragmentation functions in perturbative QCD. The exact expressions are derived for the terms…

High Energy Physics - Phenomenology · Physics 2017-10-25 S. Moch , B. Ruijl , T. Ueda , J. A. M. Vermaseren , A. Vogt

We present the next-to-next-to-leading order (NNLO) contributions to the main splitting functions for the evolution of longitudinally polarized parton densities of hadrons in perturbative QCD. The quark-quark and gluon-quark splitting…

High Energy Physics - Phenomenology · Physics 2015-06-22 S. Moch , J. A. M. Vermaseren , A. Vogt

The scale evolution of parton distributions is governed by splitting functions. We compute the four-loop splitting functions in perturbative QCD that control the evolution of quark non-singlet distributions. We confirm previous partial…

High Energy Physics - Phenomenology · Physics 2026-04-27 Thomas Gehrmann , Andreas von Manteuffel , Vasily Sotnikov , Tong-Zhi Yang

These proceedings describe a computation of the large-$n_f$ terms contributing to the QCD splitting functions at the fourth order in the strong coupling constant $\alpha_s$. Using the FORCER package for the reduction of four-loop two-point…

High Energy Physics - Phenomenology · Physics 2017-09-04 Joshua Davies

We report on recent progress on the flavour non-singlet splitting functions in perturbative QCD. The~exact four-loop (N^3LO) contribution to these functions has been obtained in the planar limit of a large number of colours.…

High Energy Physics - Phenomenology · Physics 2018-01-19 A. Vogt , S. Moch , B. Ruijl , T. Ueda , J. A. M. Vermaseren

We have calculated the splitting functions governing the evolution of the unpolarized parton distributions of the photon at the next-to-next-to-leading order (NNLO) of massless perturbative QCD. The results, presented here mainly in terms…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. Vogt , S. Moch , J. Vermaseren

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 perform the analysis of the existing inclusive deep inelastic scattering (DIS) data within NNLO QCD approximation. The parton distributions functions (PDFs) and the value of strong coupling constant $\alpha_{s}(M_Z)=0.1143\pm0.0013…

High Energy Physics - Phenomenology · Physics 2015-06-25 Alekhin Sergey

We present results on the Mellin moments of the unpolarized parton distribution function (PDF) of the pion and kaon up to the fourth order. The computation is done using one $N_f=2+1+1$ gauge ensemble of twisted mass fermions with quark…

We review the status of the calculation of the time-like splitting functions for the evolution of fragmentation functions to the next-to-next-to-leading order in perturbative QCD. By employing relations between space-like and time-like…

High Energy Physics - Phenomenology · Physics 2008-07-03 S. Moch , A. Vogt

We have extended our previous computations of the even-N moments of the flavour-singlet four-loop splitting functions to N = 12 for the pure-singlet quark case and N = 10 for all other cases. These results, obtained using physical…

High Energy Physics - Phenomenology · Physics 2023-10-10 S. Moch , B. Ruijl , T. Ueda , J. Vermaseren , A. Vogt

Associated with the use of conventional integrated parton densities are kinematic approximations on parton momenta which result in unphysical differential distributions for final-state particles. We argue that it is important to reformulate…

High Energy Physics - Phenomenology · Physics 2007-05-23 John Collins , Hannes Jung

The second Mellin moments $\langle x\rangle$ of the nucleon's unpolarized, polarized, and transversity parton distribution functions (PDFs) are computed. Two lattice QCD ensembles at the physical pion mass are used: these were generated…

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