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Related papers: Two-loop operator matrix elements for massive ferm…

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The two-loop QCD corrections to vector boson pair production at hadron colliders involve a new class of Feynman integrals: two-loop four-point functions with two off-shell external legs. We describe their reduction to a small set of master…

High Energy Physics - Phenomenology · Physics 2013-08-26 Thomas Gehrmann , Lorenzo Tancredi , Erich Weihs

In this article two-loop QED corrections to the muon decay and corrections of order $\alpha_s^2$ to the semileptonic decay of the bottom quark are considered. We compute the imaginary part of the four-loop diagrams contributing to the…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Steinhauser , T. Seidensticker

We calculate moments of the $O(\alpha_s^3)$ heavy flavor contributions to the Wilson coefficients of the structure function $F_2(x,Q^2)$ in the region $Q^2\gg m^2$. The massive Wilson coefficients are obtained as convolutions of massive…

High Energy Physics - Phenomenology · Physics 2009-07-16 I. Bierenbaum , J. Blümlein , S. Klein

We present the analytic evaluation of the second-order corrections to the massive form factors, due to two-loop vertex diagrams with a vacuum polarization insertion, with exact dependence on the external and internal fermion masses, and on…

High Energy Physics - Phenomenology · Physics 2024-01-24 Taushif Ahmed , Giulio Crisanti , Federico Gasparotto , Syed Mehedi Hasan , Pierpaolo Mastrolia

We report on recent progress in the calculation of the 3-loop massive Wilson coefficients in deep-inelastic scattering at general values of $N$ for neutral and charged current reactions in the asymptotic region $Q^2 \gg m^2$. Four new out…

High Energy Physics - Phenomenology · Physics 2013-12-03 A. Behring , J. Blümlein , A. De Freitas , T. Pfoh , C. Raab , M. Round , J. Ablinger , A. Hasselhuhn , C. Schneider , F. Wißbrock , A. von Manteuffel

Evanescent operators are a special class of operators that vanish in four-dimensional spacetime but are non-zero in $d=4-2\epsilon$ dimensions. In this paper, we continue our systematic study of the evanescent operators in the pure…

High Energy Physics - Theory · Physics 2023-02-14 Qingjun Jin , Ke Ren , Gang Yang , Rui Yu

We study two-loop anomalous dimension matrices in QCD and related gauge theories for products of Wilson lines coupled at a point. We verify by an analysis in Euclidean space that the contributions to these matrices from diagrams that link…

High Energy Physics - Phenomenology · Physics 2009-06-19 Alexander Mitov , George Sterman , Ilmo Sung

We compute the three-loop QCD corrections to the massive quark form factors with external vector, axial-vector, scalar and pseudo-scalar currents. All corrections with closed loops of massless fermions are included. The non-fermionic part…

High Energy Physics - Phenomenology · Physics 2018-07-04 Roman N. Lee , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

We present the ${\cal O}(\alpha_s^3)$ virtual QCD corrections to the process $h \rightarrow g+g+g$ due to interference of born and two-loop amplitudes, where $h$ is a massive spin-2 particle and $g$ is the gluon. We assume that the SM…

High Energy Physics - Phenomenology · Physics 2015-06-19 Taushif Ahmed , Maguni Mahakhud , Prakash Mathews , Narayan Rana , V. Ravindran

We compute the three-loop QCD corrections to the massive quark-anti-quark-photon form factors $F_1$ and $F_2$ involving a closed loop of massless fermions. This subset is gauge invariant and contains both planar and non-planar…

High Energy Physics - Phenomenology · Physics 2018-04-18 Roman N. Lee , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

We calculate the coefficients of operators with dimensions d <= 7 in the operator product expansion of correlators of q Gamma Q currents, for the effective field theory of an infinite-mass quark, Q. Exact two-loop results are obtained, with…

High Energy Physics - Phenomenology · Physics 2010-11-01 D. J. Broadhurst , A. G. Grozin

We find that unitarity cuts and the duality between color and kinematics are sufficient constraints to bootstrap $D$-dimensional QCD scattering amplitudes starting from three-particle tree-level. Specifically, we calculate tree level…

High Energy Physics - Theory · Physics 2024-09-25 John Joseph M. Carrasco , Aslan Seifi

Perturbative and non-perturbative results on the renormalization constants of the fermion field and the twist-2 fermion bilinears are presented with emphasis on the non-perturbative evaluation of the one-derivative twist-2 vector and axial…

High Energy Physics - Lattice · Physics 2011-04-01 C. Alexandrou , M. Constantinou , T. Korzec , H. Panagopoulos , F. Stylianou

We present the complete analytical result for the two-loop logarithmically enhanced contributions to the high energy asymptotic behavior of the vector form factor and the four-fermion cross section in a spontaneously broken SU(2) gauge…

High Energy Physics - Phenomenology · Physics 2014-11-18 Bernd Jantzen , Johann H. Kühn , Alexander A. Penin , Vladimir A. Smirnov

Recently exact results for the complete fermionic two-loop contributions to the prediction for the W-boson mass from muon decay in the electroweak Standard Model have been published [hep-ph/0007091]. This paper illustrates the techniques…

High Energy Physics - Phenomenology · Physics 2009-11-07 A. Freitas , W. Hollik , W. Walter , G. Weiglein

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

We compute the two-loop QCD corrections to the heavy quark form factors in case of the vector, axial-vector, scalar and pseudo-scalar currents up to second order in the dimensional parameter $\epsilon = (4-D)/2$. These terms are required in…

High Energy Physics - Phenomenology · Physics 2018-05-30 J. Ablinger , A. Behring , J. Blümlein , G. Falcioni , A. De Freitas , P. Marquard , N. Rana , C. Schneider

We compute the next-to-leading order virtual QCD corrections to Higgs pair production via gluon fusion. We present analytic results for the two-loop contributions to the spin-0 and spin-2 form factors in the amplitude. The reducible…

High Energy Physics - Phenomenology · Physics 2016-08-24 Giuseppe Degrassi , Pier Paolo Giardino , Ramona Gröber

We describe the calculation of the three-loop QCD corrections to quark and gluon form factors. The relevant three-loop Feynman diagrams are evaluated and the resulting three-loop Feynman integrals are reduced to a small set of known master…

High Energy Physics - Phenomenology · Physics 2023-11-15 T. Gehrmann , E. W. N. Glover , T. Huber , N. Ikizlerli , C. Studerus

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