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Related papers: Two-loop master integrals for the mixed QCD-electr…

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Multi-loop integrals can be evaluated numerically using Mellin-Barnes representations. Here this technique is applied to the calculation of electroweak two-loop correction with closed fermion loops for two observables: the effective weak…

High Energy Physics - Phenomenology · Physics 2013-10-14 A. Freitas , Yi-Cheng Huang

We present the analytic computation of all the planar master integrals which contribute to the two-loop scattering amplitudes for Higgs$\to 3$ partons, with full heavy-quark mass dependence. These are relevant for the NNLO corrections to…

High Energy Physics - Phenomenology · Physics 2017-02-01 Roberto Bonciani , Vittorio Del Duca , Hjalte Frellesvig , Johannes M. Henn , Francesco Moriello , Vladimir A. Smirnov

We compute the master integrals relevant for the two-loop corrections to pseudo-scalar quarkonium and leptonium production and decay. We present both analytic and high-precision numerical results. The analytic expressions are given in terms…

High Energy Physics - Phenomenology · Physics 2022-11-18 Samuel Abreu , Matteo Becchetti , Claude Duhr , Melih A. Ozcelik

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

We have recently presented the complete O(alpha_s^2) corrections to the semileptonic decay width of the b quark at maximal recoil. Here we discuss various technical aspects of that calculation and further applications of similar methods. In…

High Energy Physics - Phenomenology · Physics 2016-08-25 Andrzej Czarnecki , Kirill Melnikov

We consider the two-loop amplitude of $gg\rightarrow HH$ mediated by bottom quarks, which provides a correction of percent level at leading order in the low invariant mass region. In order to compute the corresponding master integrals, we…

High Energy Physics - Phenomenology · Physics 2025-08-19 Zhenghong Hu , Tao Liu , Jin Min Yang

We compute the two-loop QCD corrections to the neutral Higgs-boson masses in the MSSM, including the effect of non-vanishing external momenta in the self-energies. We obtain corrections of O(alpha_t*alpha_s) and O(alpha*alpha_s), i.e., all…

High Energy Physics - Phenomenology · Physics 2015-06-23 G. Degrassi , S. Di Vita , P. Slavich

The two-loop QCD radiative corrections to the $B_c$ meson leptonic decay rate are calculated in the framework of NRQCD factorization formalism. Two types of master integrals appearing in the calculation are obtained analytically for the…

High Energy Physics - Phenomenology · Physics 2015-07-29 Long-Bin Chen , Cong-Feng Qiao

The leading heavy-top two-loop corrections to the \Zbb~vertex are determined from a direct evaluation of the corresponding Feynman diagrams in the large \Mt~limit. %The calculation is done in the naive %dimensional regularization scheme…

High Energy Physics - Phenomenology · Physics 2009-09-25 A. Denner , W. Hollik , B. Lampe

We compute the dominant logarithmically enhanced two-loop electroweak corrections to the electron-positron scattering differential cross section in the high energy limit for large scattering angles. Depending on the scattering angle and…

High Energy Physics - Phenomenology · Physics 2011-12-12 A. A. Penin , G. Ryan

We consider the full set of master integrals with internal top-and $W$-propagators contributing to the three-loop Higgs self-energy diagrams of order ${\mathcal O}(\alpha^2 \alpha_s)$. We split the master integrals into a system relevant to…

High Energy Physics - Phenomenology · Physics 2022-11-30 Ekta Chaubey , Ina Hönemann , Stefan Weinzierl

We compute the two-loop electroweak correction to the production of the Higgs boson in gluon fusion to higher orders in the dimensional-regularization parameter $\epsilon = (d-4)/2$. We employ the method of differential equations to compute…

High Energy Physics - Phenomenology · Physics 2017-03-08 Marco Bonetti , Kirill Melnikov , Lorenzo Tancredi

Using the asymptotic-expansion technique, we compute the dominant two-loop electroweak corrections, of O(G_F m_t^2), to production and decay via a pair of photons or gluons of the CP-odd Higgs boson A^0 in a two-Higgs-doublet model with…

High Energy Physics - Phenomenology · Physics 2008-11-26 Joachim Brod , Frank Fugel , Bernd A. Kniehl

We analytically calculate the dominant two-loop electroweak correction, of O(G_F^2 m_t^4), to the partial width of the decay of a Higgs boson, with mass M_H << m_t, into a bottom-quark pair, and describe the most important conceptual and…

High Energy Physics - Phenomenology · Physics 2008-11-26 Mathias Butenschoen , Frank Fugel , Bernd A. Kniehl

We compute the complete two-loop electroweak corrections to the Higgsstralung process $e^+e^-\rightarrow HZ$ at the future Higgs factory. The Feynman integrals involved in the computation are decomposed into linear combinations of a minimal…

High Energy Physics - Phenomenology · Physics 2023-07-12 Xiang Chen , Xin Guan , Chuan-Qi He , Zhao Li , Xiao Liu , Yan-Qing Ma

We present the analytic computation of the master integrals associated to certain two-loop non-planar topologies, which are needed to complete the evaluation of the last two color coefficients for the top-pair production in the…

High Energy Physics - Phenomenology · Physics 2019-12-13 Matteo Becchetti , Roberto Bonciani , Valerio Casconi , Andrea Ferroglia , Simone Lavacca , Andreas von Manteuffel

We present the results for two-loop MSSM corrections to the relation between pole and running masses of heavy quarks up to the order O(as^2). The running masses are defined in the DR scheme, usually used in multiloop calculations in…

High Energy Physics - Phenomenology · Physics 2009-01-07 A. Bednyakov , A. Onishchenko , V. Velizhanin , O. Veretin

The three-loop QCD contributions to the vacuum polarization functions of the $Z$ and $W$ bosons at zero momentum are calculated. The top quark is considered to be massive and the other quarks massless. Using these results, we calculate the…

High Energy Physics - Phenomenology · Physics 2011-01-13 L. Avdeev , J. Fleischer , S. Mikhailov , O. Tarasov

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

We present an analytic formula for the $O(\alpha_s)$ corrections to the decay $t\to H^+b$ for nonzero $m_H$ and $m_b$. The Equivalence Theorem is used to relate these corrections to those for the process $t\to W^+b$. Contrary to previously…

High Energy Physics - Phenomenology · Physics 2009-10-22 Andrzej Czarnecki , Sacha Davidson