English
Related papers

Related papers: The Two-Loop Massless Off-Shell QCD Operator Matri…

200 papers

We consider the anomalous dimension of the flavor non-singlet twist-two quark operator of arbitrary Lorentz spin N at four loops in QCD and construct its contribution proportional to zeta(3) in analytic form by applying advanced methods of…

High Energy Physics - Phenomenology · Physics 2025-03-27 B. A. Kniehl , V. N. Velizhanin

We compute the two-mass contributions to the polarized massive operator matrix element $A_{gg,Q}^{(3)}$ at third order in the strong coupling constant $\alpha_s$ in Quantum Chromodynamics analytically. These corrections are important…

High Energy Physics - Phenomenology · Physics 2020-05-27 J. Ablinger , J. Blümlein , A. De Freitas , A. Goedicke , M. Saragnese , C. Schneider , K. Schönwald

The inclusive four-particle phase space integral of any $1\to 4$ matrix element in massless QCD contains divergences due to the soft and collinear emission of up to two particles in the final state. We show that any term appearing in this…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Gehrmann-De Ridder , T. Gehrmann , G. Heinrich

The angle-dependent cusp anomalous dimension governs divergences coming from soft gluon exchanges between heavy particles, such as top quarks. We focus on the matter-dependent contributions and compute the first truly non-planar terms. They…

High Energy Physics - Theory · Physics 2021-01-20 Robin Brüser , Christoph Dlapa , Johannes M. Henn , Kai Yan

A number of exact results for two-loop three-point diagrams with massless internal particles and arbitrary (off-shell) external momenta are presented. Divergent contributions are calculated in the framework of dimensional regularization.

High Energy Physics - Phenomenology · Physics 2009-10-28 N. I. Ussyukina , A. I. Davydychev

We study the electromagnetic on-shell form factor of quarks in massless perturbative QCD. We derive the complete pole part in dimensional regularization at three loops, and extend the resummation of the form factor to the…

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

The asymptotic structure of the QCD perturbative relation between the on-shell and $\overline{\rm{MS}}$ heavy quark masses is studied. We estimate the five and six-loop contributions to this relation by three different techniques. First,…

High Energy Physics - Phenomenology · Physics 2020-12-01 A. L. Kataev , V. S. Molokoedov

We calculate the two-loop $10 \times 10$ anomalous dimension matrix ${\cal O}(\alpha_s^{2})$ involving current-current operators, QCD penguin operators, and electroweak penguin operators especially relevant for $\Delta S=1$ weak…

High Energy Physics - Phenomenology · Physics 2009-10-22 Andrzej J. Buras , Matthias Jamin , Markus E. Lautenbacher , Peter H. Weisz

We analyse matrix elements of Delta B=2 operators by combining QCD results with the ones obtained in the static limit of HQET. The matching of all the QCD operators to HQET is made at NLO order. To do that we have to include the anomalous…

High Energy Physics - Lattice · Physics 2009-11-07 D. Becirevic , V. Gimenez , G. Martinelli , M. Papinutto , J. Reyes

We calculate the massive polarized three-loop pure singlet operator matrix element $A_{Qq}^{(3), \rm PS}$ in the single mass case in the Larin scheme. This operator matrix element contributes to the massive polarized three-loop Wilson…

High Energy Physics - Phenomenology · Physics 2020-02-12 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. von Manteuffel , C. Schneider , K. Schönwald

The contributions $\propto n_f$ to the $O(\alpha_s^3)$ massive operator matrix elements describing the heavy flavor Wilson coefficients in the limit $Q^2 \gg m^2$ are computed for the structure function $F_2(x,Q^2)$ and transversity for…

High Energy Physics - Phenomenology · Physics 2016-08-14 J. Ablinger , J. Blümlein , S. Klein , C. Schneider , F. Wißbrock

We present the result of a full direct component calculation for the first three even moments of the non-planar contribution into the four-loop anomalous dimension of twist-2 operators in maximally extended N=4 supersymmetric Yang-Mills…

High Energy Physics - Theory · Physics 2011-02-01 V. N. Velizhanin

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…

High Energy Physics - Phenomenology · Physics 2009-10-31 S. Moch , J. A. M. Vermaseren

The three-loop QCD contributions to the vacuum polarization functions of the $Z$ and $W$ bosons at zero momentum are calculated. The top quark is considered to be massive and the other quarks massless. Using these results, we calculate the…

High Energy Physics - Phenomenology · Physics 2011-01-13 L. Avdeev , J. Fleischer , S. Mikhailov , O. Tarasov

We report on the analytic calculation of the second-order QCD corrections to semi-inclusive hadron production in electron-positron annihilation. The calculation of the single-particle inclusive cross-section in time-like kinematics is…

High Energy Physics - Phenomenology · Physics 2014-12-22 Alexander Mitov , Sven-Olaf Moch

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

We calculate the collinear anomalous dimensions in massless four-loop QCD and $\mathcal{N} = 4$ supersymmetric Yang-Mills theory from the infrared poles of vertex form factors. We give very precise numerical approximations and a conjecture…

High Energy Physics - Phenomenology · Physics 2021-07-14 Bakul Agarwal , Andreas von Manteuffel , Erik Panzer , Robert M. Schabinger

Three loop ladder and $V$-topology diagrams contributing to the massive operator matrix element $A_{Qg}$ are calculated. The corresponding objects can all be expressed in terms of nested sums and recurrences depending on the Mellin variable…

High Energy Physics - Phenomenology · Physics 2016-04-20 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. von Manteuffel , C. Schneider

We present a generalisation of the double-logarithmic equation for the anomalous dimension of the non-singlet unpolarized twist-2 operators in QCD. Using the known three-loop result, this generalisation allows to predict a small x expansion…

High Energy Physics - Phenomenology · Physics 2017-12-01 V. N. Velizhanin

Various of the single scale quantities in massless and massive QCD up to 3-loop order can be expressed by iterative integrals over certain classes of alphabets, from the harmonic polylogarithms to root-valued alphabets. Examples are the…

High Energy Physics - Phenomenology · Physics 2017-11-28 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , E. Imamoglu , M. van Hoeij A. von Manteuffel , C. G. Raab , C. -S. Radu , C. Schneider