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Related papers: Three loop QCD corrections to heavy quark form fac…

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Light quark masses can be determined through lattice simulations in regularization invariant momentum-subtraction(RI/MOM) schemes. Subsequently, matching factors, computed in continuum perturbation theory, are used in order to convert these…

High Energy Physics - Phenomenology · Physics 2011-05-04 Leandro G. Almeida , Christian Sturm

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…

High Energy Physics - Phenomenology · Physics 2014-09-08 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. Hasselhuhn , A. von Manteuffel , C. Raab , M. Round , S. Schneider , F. Wißbrock

We compute corrections of order $\alpha_s^3$ to the decay $b \to c \ell \bar\nu$ taking into account massive charm quarks. In the on-shell scheme large three-loop corrections are found. However, in the kinetic scheme the three-loop…

High Energy Physics - Phenomenology · Physics 2021-07-16 Matteo Fael , Kay Schönwald , Matthias Steinhauser

We calculate the one loop renormalisation parameters for the heavy-light axial-vector and vector currents using lattice perturbation theory. We use NonRelativistic QCD (NRQCD) heavy quarks and the Highly Improved Staggered Quark (HISQ)…

High Energy Physics - Lattice · Physics 2012-11-28 Christopher Monahan , Christine Davies , Ron Horgan , G. Peter Lepage , Heechang Na , Junko Shigemitsu

We report on the status of the calculation of the massive Wilson coefficients and operator matrix elements for deep-inelastic scatterung to three-loop order. We discuss both the unpolarized and the polarized case, for which all the…

High Energy Physics - Phenomenology · Physics 2024-07-03 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. von Manteuffel , C. Schneider , K. Schoenwald

We develop a perturbative QCD factorization theorem which is compatible with effective field theory. The factorization involves three scales: an infrared cutoff of order $\Lambda_{\rm QCD}$, a hard scale of order the $B$ meson mass, and an…

High Energy Physics - Phenomenology · Physics 2011-07-19 Chia-Hung V. Chang , Hsiang-nan Li

We report on recent progress for the QCD corrections to top quark pair plus jet production. In particular, we discuss a recent computation for the two-loop master integrals associated to a two-loop five-point pentagon-box integral…

High Energy Physics - Phenomenology · Physics 2023-10-17 Matteo Becchetti

We present the two-mass QCD contributions to the pure singlet operator matrix element at three loop order in x-space. These terms are relevant for calculating the structure function $F_2(x,Q^2)$ at $O(\alpha_s^3)$ as well as for the…

High Energy Physics - Phenomenology · Physics 2018-02-01 J. Ablinger , J. Blümlein , A. De Freitas , C. Schneider , K. Schönwald

I report on an implementation of an algorithm for the automated numerical calculation of spin- and colour-correlated Born matrix elements in QCD. These spin- and colour-correlated matrix elements are needed for NLO calculations in…

High Energy Physics - Phenomenology · Physics 2009-01-07 Stefan Weinzierl

The modelling of the ultraviolet contributions to the quark determinant in lattice QCD in terms of a small number of Wilson loops is examined. Complete Dirac spectra are obtained for sizeable ensembles of SU(3) gauge fields at $\beta$=5.7…

High Energy Physics - Lattice · Physics 2016-08-25 A. Duncan , E. Eichten , R. Roskies , H. Thacker

The Wilson contour integral approach is applied to resum the soft gluon radiative correctins to the quark form factors in the Sudakov regime. The one-loop order results for the quark-photon (color singlet form factor) and quark-gluon (color…

High Energy Physics - Phenomenology · Physics 2007-05-23 Igor O. Cherednikov

We compute the differential equations for the two remaining integral topologies contributing to the leading colour two-loop amplitudes for $pp \rightarrow t\bar{t}j$. We derive differential equations for the master integrals by solving the…

High Energy Physics - Phenomenology · Physics 2024-05-01 Simon Badger , Matteo Becchetti , Nicolò Giraudo , Simone Zoia

We present the three-loop QCD+QED mixed corrections to the on-shell quark mass and wave-function renormalization constants through orders $\mathcal{O}(\alpha_s^m\alpha^n)$ with $m+n=3$. We further derive the three-loop relation between the…

High Energy Physics - Phenomenology · Physics 2026-02-24 Long Chen , Hong-Yang Han , Zhe Li , Marco Niggetiedt

We analytically compute all four-loop QCD corrections to the photon-quark and Higgs-gluon form factors involving a closed massless fermion loop. Our calculation of non-planar vertex integrals confirms a previous conjecture for the…

We present new algorithms to detect and correct errors in the lower-upper factorization of a matrix, or the triangular linear system solution, over an arbitrary field. Our main algorithms do not require any additional information or…

Symbolic Computation · Computer Science 2019-01-31 Jean-Guillaume Dumas , Joris Van Der Hoeven , Clément Pernet , Daniel Roche

In this paper we consider the matching coefficients up to two loops between Quantum Chromodynamics (QCD) and Non-Relativistic QCD (NRQCD) for the vector, axial-vector, scalar and pseudo-scalar currents. The structure of the effective theory…

High Energy Physics - Phenomenology · Physics 2009-11-11 B. A. Kniehl , A. Onishchenko , J. H. Piclum , M. Steinhauser

This is the first in a series of papers, in which we compute the third-order QCD corrections to top-antitop production near threshold in e+ e- collisions. The present paper provides a detailed outline of the strategy of computation in the…

High Energy Physics - Phenomenology · Physics 2024-09-11 M. Beneke , Y. Kiyo , K. Schuller

We compute the three-loop QCD corrections to the vertex function for the Yukawa coupling of a Higgs boson to a pair of bottom quarks in the limit of vanishing quark masses. This QCD form factor is a crucial ingredient to third-order QCD…

High Energy Physics - Phenomenology · Physics 2014-10-07 Thomas Gehrmann , Dominik Kara

In this talk I review the calculation of the third order corrections to the heavy quarkonium spectrum in the nonrelativistic effective theory framework and its application to the phenomenology of top quark threshold production.

High Energy Physics - Phenomenology · Physics 2009-11-07 A. A. Penin

We determine the three-loop form factor parameterising the amplitude for the production of an off-shell Higgs boson in gluon fusion in QCD with a single massive quark. The result is obtained via a numerical solution of a system of…

High Energy Physics - Phenomenology · Physics 2020-06-04 M. Czakon , M. Niggetiedt