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Related papers: Calculation of Massive 2-Loop Operator Matrix Elem…

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We describe the calculation of all planar master integrals that are needed for the computation of NNLO QCD corrections to the production of two off-shell vector bosons in hadron collisions. The most complicated representatives of integrals…

High Energy Physics - Phenomenology · Physics 2015-06-18 Johannes M. Henn , Kirill Melnikov , Vladimir A. Smirnov

We present a method to calculate the $x$--space expressions of massless or massive operator matrix elements in QCD and QED containing local composite operator insertions, depending on the discrete Mellin index $N$, directly, without…

High Energy Physics - Phenomenology · Physics 2023-07-05 A. Behring , J. Blümlein , K. Schönwald

We calculate the quarkonic $O(\alpha_s^2)$ massive operator matrix elements $\Delta A_{Qg}(N), \Delta A_{Qq}^{\rm PS}(N)$ and $\Delta A_{qq,Q}^{\rm NS}(N)$ for the twist--2 operators and the associated heavy flavor Wilson coefficients in…

High Energy Physics - Phenomenology · Physics 2023-02-15 I. Bierenbaum , J. Blümlein , A. De Freitas , A. Goedicke , S. Klein , K. Schönwald

In the Catani-Ciafaloni-Hautmann high-energy factorization approach a cross section is expressed as a convolution of unintegrated gluon densities and a gauge-invariant hard process, in which two incoming gluons are off-shell with momenta…

High Energy Physics - Phenomenology · Physics 2013-09-23 Piotr Kotko

Processes involving only massless or massive quarks at tree-level get corrections from massive (lighter, heavier, or equal-mass) secondary quarks starting at two-loop order, generated by a virtual gluon splitting into a massive quark…

High Energy Physics - Phenomenology · Physics 2024-05-15 Alejandro Bris , Vicent Mateu

We calculate the O($\eps$)--term of the two--loop massive operator matrix elements for twist 2--operators, which contribute to the heavy flavour Wilson coefficients in unpolarized deep--inelastic scattering in the asymptotic limit $Q^2 \gg…

High Energy Physics - Phenomenology · Physics 2009-01-07 I. Bierenbaum , J. Blümlein , S. Klein

We calculate the $O(\alpha_s^3)$ heavy flavor contributions to the Wilson coefficients of the structure function $F_2(x,Q^2)$ and the massive operator matrix elements (OMEs) for the twist--2 operators of unpolarized deeply inelastic…

High Energy Physics - Phenomenology · Physics 2009-07-22 Isabella Bierenbaum , Johannes Blümlein , Sebastian Klein

We present the two-loop corrected operator matrix elements calculated in N-dimensional regularization up to the finite terms which survive in the limit $\epsilon = N - 4 \to 0 $. The anomalous dimensions of the local operators have been…

High Energy Physics - Phenomenology · Physics 2009-10-31 Y. Matiounine , J. Smith , W. L. van Neerven

Starting at 3-loop order, the massive Wilson coefficients for deep-inelastic scattering and the massive operator matrix elements describing the variable flavor number scheme receive contributions of Feynman diagrams carrying quark lines…

High Energy Physics - Phenomenology · Physics 2017-08-23 J. Ablinger , J. Blümlein , A. De Freitas , A. Hasselhuhn , C. Schneider , F. Wißbrock

The logarithmic contributions to the massive twist-2 operator matrix elements for deep-inelastic scattering are calculated to $O(\alpha_s^3)$for general values of the Mellin variable $N$.

High Energy Physics - Phenomenology · Physics 2010-11-19 I. Bierenbaum , J. Blümlein , S. Klein

We compute the master integrals for massless two-loop vertex graphs with three off-shell legs. These master integrals are relevant for the QCD corrections to H to V*V* (where V = W, Z) and for two-loop studies of the triple gluon (and…

High Energy Physics - Phenomenology · Physics 2008-11-26 T. G. Birthwright , E. W. N. Glover , P. Marquard

The calculation of exclusive observables beyond the one-loop level requires elaborate techniques for the computation of multi-leg two-loop integrals. We discuss how the large number of different integrals appearing in actual two-loop…

High Energy Physics - Phenomenology · Physics 2008-11-26 T. Gehrmann , E. Remiddi

A general method is described for finding algebraic expressions for matrix elements of any one- and two-particle operator for an arbitrary number of subshells in an atomic configuration, requiring neither coefficients of fractional…

Atomic Physics · Physics 2009-11-10 G. Gaigalas , Z. Rudzikas , C. Froese Fischer

We compute angular phase-space integrals with three and four denominators analytically, working within dimensional regularisation via the Mellin-Barnes (MB) representation. The approach converts multifold MB integrals into real parametric…

High Energy Physics - Phenomenology · Physics 2026-04-03 Taushif Ahmed , Syed Mehedi Hasan , Andreas Rapakoulias

We summarize two geometrical approaches to analytically evaluate higher-fold Mellin-Barnes (MB) integrals in terms of hypergeometric functions. The first method is based on intersections of conic hulls, while the second one, which is more…

High Energy Physics - Theory · Physics 2024-07-30 Sumit Banik , Samuel Friot

Analytic results for the complete set of two-loop self-energy master integrals on shell with one mass are calculated.

High Energy Physics - Phenomenology · Physics 2009-10-31 J. Fleischer , M. Yu. Kalmykov , A. V. Kotikov

We first propose a general method to construct the complete set of on-shell operator bases involving massive particles with any spins. To incorporate the non-abelian little groups of massive particles, the on-shell scattering amplitude…

High Energy Physics - Phenomenology · Physics 2024-06-07 Zi-Yu Dong , Teng Ma , Jing Shu

We obtain for the first time the two-loop amplitudes for Higgs plus three gluons in Higgs effective field theory including dimension-seven operators. This provides the S-matrix elements for the top mass corrections for Higgs plus a jet…

High Energy Physics - Theory · Physics 2018-09-11 Qingjun Jin , Gang Yang

This letter introduces a novel analytical approach to calculating phase-space integrals, crucial for precision in particle physics. We develop a method to compute angular components using multifold Mellin-Barnes integrals, yielding results…

High Energy Physics - Phenomenology · Physics 2024-10-25 Taushif Ahmed , Syed Mehedi Hasan , Andreas Rapakoulias

We report on the three-loop unpolarized and polarized massive operator matrix elements, with single- and two-mass corrections, and the associated deep-inelastic massive Wilson coefficients in the region $Q^2 \gg m_Q^2$, the calculation of…

High Energy Physics - Phenomenology · Physics 2026-02-12 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. von Manteuffel , C. Schneider , K. Schönwald