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We review the calculations of form factors and coupling constants in vertices with charm mesons in the framework of QCD sum rules. We first discuss the motivation for this work, describing possible applications of these form factors to…

High Energy Physics - Phenomenology · Physics 2015-05-27 M. E. Bracco , M. Chiapparini , F. S. Navarra , M. Nielsen

A general one-loop scattering amplitude may be expanded in terms of master integrals. The coefficients of the master integrals can be obtained from tree-level input in a two-step process. First, use known formulas to write the coefficients…

High Energy Physics - Phenomenology · Physics 2009-01-14 Ruth Britto , Bo Feng , Gang Yang

The three-loop master integrals for ladder-box diagrams with one massive leg are computed from an eighty-five by eighty-five system of differential equations, solved by means of Magnus exponential. The results of the considered box-type…

High Energy Physics - Phenomenology · Physics 2015-06-22 Stefano Di Vita , Pierpaolo Mastrolia , Ulrich Schubert , Valery Yundin

Three--loop contributions to massive QED vacuum polarization are evaluated by a combination of analytical and numerical techniques. The first three Taylor coefficients, at small $q^2$, are obtained analytically, using $d$\/--dimensional…

High Energy Physics - Phenomenology · Physics 2007-05-23 P. A. Baikov , D. J. Broadhurst

We obtain full-color three-loop three-point form factors of the stress-tensor supermultiplet and also of a length-3 half-BPS operator in N=4 SYM based on the color-kinematics duality and on-shell unitarity. The integrand results are…

High Energy Physics - Theory · Physics 2021-11-08 Guanda Lin , Gang Yang , Siyuan Zhang

Leading (large) logarithms in non-renormalizable theories have been investigated in the recent past. Besides some general considerations, explicit results for the expansion coefficients (in terms of leading logarithms) of partial wave…

High Energy Physics - Phenomenology · Physics 2018-08-15 B. Ananthanarayan , Shayan Ghosh , Alexey Vladimirov , Daniel Wyler

We calculate the two-mass three-loop contributions to the unpolarized and polarized massive operator matrix elements $\tilde{A}_{Qg}^{(3)}$ and $\Delta \tilde{A}_{Qg}^{(3)}$ in $x$-space for a general mass ratio by using a semi-analytic…

High Energy Physics - Phenomenology · Physics 2025-10-13 J. Ablinger , J. Blümlein , A. De Freitas , A. von Manteuffel , C. Schneider , K. Schönwald

We review theoretical approaches to form factors that arise in heavy-meson decays and are hadronic expressions of non-perturbative QCD. After motivating their origin in QCD factorisation, we retrace their evolution from quark-model…

Nuclear Theory · Physics 2014-11-20 B. El-Bennich , M. A. Ivanov , C. D. Roberts

In this article, we present analytical expansion results of two single mass scale four-loop vacuum integrals in d=3-2*ep dimensions. After finding hypergeometric representations with half-integer coefficients, we use algorithms which we…

High Energy Physics - Phenomenology · Physics 2009-03-24 E. Bejdakic

We calculate all contributions $\propto T_F$ to the polarized three-loop anomalous dimensions in the M-scheme using massive operator matrix elements and compare to results in the literature. This includes the complete anomalous dimensions…

High Energy Physics - Phenomenology · Physics 2019-09-25 A. Behring , J. Blümlein , A. De Freitas , A. Goedicke , S. Klein , A. von Manteuffel , C. Schneider , K. Schönwald

For the first time, we compute three-loop contributions to all triple vertices in QCD at the symmetric point. The analytic results are obtained in massless QCD with an arbitrary color group in the Landau gauge. All new loop integrals are…

High Energy Physics - Phenomenology · Physics 2020-04-15 Alexander Bednyakov , Andrey Pikelner

We discuss recent results on the three-loop (next-to-next-to-leading order, NNLO) time-like splitting functions of QCD and the two-loop (NNLO) coefficient functions in one-particle inclusive e+e- annihilation. These results form the basis…

High Energy Physics - Phenomenology · Physics 2009-11-11 A. Mitov , S. Moch , A. Vogt

The quark form factor is known to exponentiate within the framework of dimensionally regularized perturbative QCD. The logarithm of the form factor is expressed in terms of integrals over the scale of the running coupling. I show that these…

High Energy Physics - Phenomenology · Physics 2009-10-31 Lorenzo Magnea

In this talk I report on the results of a recent calculation of the \alpha_s corrections to a three-point correlation function at the three-loop level in QCD perturbation theory, which allows one to extract the matrix element of B^0 -\bar…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. A. Pivovarov

Virtual two-loop corrections to scattering amplitudes are a key ingredient to precision physics at collider experiments. We compute the full set of planar master integrals relevant to five-point functions in massless QCD, and use these to…

High Energy Physics - Phenomenology · Physics 2016-04-18 T. Gehrmann , J. M. Henn , N. A. Lo Presti

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 present the analytic calculation of two-loop master integrals that are relevant for $tW$ production at hadron colliders. We focus on the integral families with only one massive propagator. After choosing a canonical basis, the…

High Energy Physics - Phenomenology · Physics 2021-12-08 Long-Bin Chen , Jian Wang

We show that the QCD factorization approach for $B$-meson decays to charmless hadronic two-body final states can be extended to include electromagnetic corrections. The presence of electrically charged final-state particles complicates the…

High Energy Physics - Phenomenology · Physics 2020-12-02 Martin Beneke , Philipp Böer , Jan-Niklas Toelstede , K. Keri Vos

It is shown that for every problem within dimensional regularization, using the Integration-By-Parts method, one is able to construct a set of master integrals such that each corresponding coefficient function is finite in the limit of…

High Energy Physics - Phenomenology · Physics 2008-11-26 K. G. Chetyrkin , M. Faisst , C. Sturm , M. Tentyukov

We present a computation of the one-loop QCD corrections to top-quark pair production in association with a $W$ boson, including terms up to order $\varepsilon^2$ in dimensional regularization. Providing a first glimpse into the complexity…

High Energy Physics - Phenomenology · Physics 2025-11-05 Matteo Becchetti , Maximilian Delto , Sara Ditsch , Philipp Alexander Kreer , Mattia Pozzoli , Lorenzo Tancredi