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Related papers: Three-loop QCD corrections and b-quark decays

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Recent developments in the calculation of the NNLO corrections to the Bhabha scattering differential cross section in pure QED are briefly reviewed and discussed.

High Energy Physics - Phenomenology · Physics 2009-11-11 R. Bonciani , A. Ferroglia

We study the next-to-next-to-leading order (NNLO) evolution of flavour non-singlet quark densities and structure functions in massless perturbative QCD. Present information on the corresponding three-loop splitting functions is used to…

High Energy Physics - Phenomenology · Physics 2008-11-26 W. L. van Neerven , A. Vogt

We review the status of the calculation of next-to-next-to-leading order corrections to large angle Bhabha scattering in pure QED. After discussing the electron-loop and photonic corrections, we focus on the recently calculated two-loop…

High Energy Physics - Phenomenology · Physics 2008-11-07 R. Bonciani , A. Ferroglia

By means of a heavy-top-quark effective Lagrangian, we calculate the three-loop corrections of O(alpha_s^2 G_F M_t^2) to the H->bb-bar partial decay width of the standard-model Higgs boson with intermediate mass M_H<<2M_t. We take advantage…

High Energy Physics - Phenomenology · Physics 2009-10-30 K. G. Chetyrkin , B. A. Kniehl , M. Steinhauser

We present $O(\alpha_s^2)$ QCD corrections to the fully-differential decay rate of a $b$-quark into inclusive semileptonic charmless final states. Our calculation provides genuine two-loop QCD corrections, beyond the…

High Energy Physics - Phenomenology · Physics 2015-06-12 Mathias Brucherseifer , Fabrizio Caola , Kirill Melnikov

I present higher-order results for $s$-channel single-top-quark production that are derived from soft-gluon resummation. I show that the soft-gluon corrections provide the dominant contribution to the QCD corrections, and that they…

High Energy Physics - Phenomenology · Physics 2026-02-20 Nikolaos Kidonakis

We compute the three-loop QCD corrections to the quark chromomagnetic moment and thus obtain the matching coefficient and the anomalous dimension of the chromomagnetic interaction in HQET. As a byproduct we obtain the three-loop corrections…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. G. Grozin , P. Marquard , J. H. Piclum , M. Steinhauser

I discuss the status of the computation of the two-loop QCD corrections to top-quark pair production associated with a jet at hadron colliders. This amplitude is a missing ingredient for next-to-next-to-leading order (NNLO) QCD predictions.…

High Energy Physics - Phenomenology · Physics 2024-11-19 Colomba Brancaccio

We show the three-loop calculation of the matching coefficients $\mathcal{C}_J$ for the four heavy flavor-changing currents in nonrelativistic Quantum Chromodynamics effective theory and confirm the surprising observation of the…

High Energy Physics - Phenomenology · Physics 2023-10-19 Wei Tao , Zhen-Jun Xiao , Ruilin Zhu

One of the most troublesome contributions to the NNLO QCD corrections to B -> X_s gamma originates from three-loop matrix elements of four-quark operators. A part of this contribution that is proportional to the QCD beta-function…

High Energy Physics - Phenomenology · Physics 2008-11-26 Mikolaj Misiak , Matthias Steinhauser

We compute the 1-loop (alpha_s^2) correction to hard spectator scattering in non-leptonic B decay tree amplitudes. This forms part of the NNLO contribution to the QCD factorization formula for hadronic B decays, and introduces a new…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Beneke , S. Jager

In this contribution three-loop QCD corrections to current correlators are considered. The application of the large momentum procedure, which provides a systematic expansion in $(m^2/q^2)^n$, allows the computation of terms up to $n=6$ for…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Steinhauser

We calculate the two-loop QCD correction to the form factors of on-shell b-quark decay to an energetic massless quark, which constitutes the last missing piece required for an O(alpha_s^2) determination of |V_ub| from inclusive…

High Energy Physics - Phenomenology · Physics 2014-11-18 M. Beneke , T. Huber , Xin-Qiang Li

We present the O(alpha_s) corrections to the cross section for the reaction e+e- --> gamma^* --> Q \bar Q in the energy region close to the threshold. We assume that the energy of the reaction is such that both the perturbative expansion in…

High Energy Physics - Phenomenology · Physics 2009-10-30 Andrzej Czarnecki , Kirill Melnikov

We present the first full analytic results of next-to-next-to-leading order (NNLO) QCD corrections to the top-quark decay width $\Gamma(t\to Wb)$ by calculating the imaginary part of three-loop top-quark self-energy diagrams. The results…

High Energy Physics - Phenomenology · Physics 2023-09-08 Long-Bin Chen , Hai Tao Li , Jian Wang , Yefan Wang

At the end of 2016, we computed the five-loop (N$^4$LO) contributions to the beta function in perturbative Quantum Chromodynamics (QCD), its generalization to non-Abelian gauge theories with a simple compact Lie group, and for Quantum…

High Energy Physics - Phenomenology · Physics 2025-10-31 F. Herzog , B. Ruijl , T. Ueda , J. Vermaseren , A. Vogt

We consider QCD radiative corrections to $W^+W^-b {\bar b}$ production with leptonic decays and massive bottom quarks at the LHC. We perform an exact next-to-leading order (NLO) calculation within the $q_T$-subtraction formalism and…

High Energy Physics - Phenomenology · Physics 2025-07-17 Luca Buonocore , Massimiliano Grazzini , Stefan Kallweit , Jonas M. Lindert , Chiara Savoini

We compute three-loop QCD corrections to the scattering amplitude of a Higgs boson and three partons interfered with its tree level counterpart. Specifically, we derive our results in the generalized leading color limit. Our results are…

High Energy Physics - Phenomenology · Physics 2025-04-10 Xiang Chen , Xin Guan , Bernhard Mistlberger

We compute three-loop virtual corrections to the associated production of a Higgs boson with a $Z$ boson in the large-$m_t$ limit. We describe in detail the application of the asymptotic expansion and provide, for all form factors, analytic…

High Energy Physics - Phenomenology · Physics 2025-12-02 Joshua Davies , Dominik Grau , Kay Schönwald , Matthias Steinhauser , Daniel Stremmer

We present the two-loop ${\cal O}(\alpha_sG_Fm_t^2)$ correction to the $b\bar b$ decay rate of the Stan\-dard-Model Higgs boson, assuming that the $t$ quark is much heavier than the Higgs boson. Apart from the universal correction connected…

High Energy Physics - Phenomenology · Physics 2009-10-28 Bernd A. Kniehl , Michael Spira