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Related papers: Two-loop electroweak contributions to $\Delta r$

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We present complete one-loop radiative corrections to the decay rate of a top quark into a charged Higgs boson and a bottom quark, and for the decay of a charged Higgs boson into leptons. The results are discussed in the framework of the…

High Energy Physics - Phenomenology · Physics 2009-10-22 Andrzej Czarnecki

A novel approach to study electroweak physics at one-loop level in generic ${\rm SU(2)_L \times U(1)_Y}$ theories is introduced. It separates the 1-loop corrections into two pieces: process specific ones from vertex and box contributions,…

High Energy Physics - Phenomenology · Physics 2008-11-26 K. Hagiwara , D. Haidt , C. S. Kim , S. Matsumoto

I present the two-loop self-energy functions and pole masses for fermions in an arbitrary renormalizable field theory, in the approximation that vector bosons are treated as massless. The calculations are done simultaneously in the…

High Energy Physics - Phenomenology · Physics 2009-11-11 Stephen P. Martin

The assumption that two-loop top corrections are well approximated by the $O(G_mu^2 mt^4)$ contribution is investigated. It is shown that in the case of the ratio neutral-to-charged current amplitudes at zero momentum transfer the $O(G_mu^2…

High Energy Physics - Phenomenology · Physics 2009-10-28 G. Degrassi , S. Fanchiotti , F. Feruglio , P. Gambino , A. Vicini

We investigated the electroweak corrections from one-loop diagrams involving the third generation (s)quarks to the decay width of process $\tilde{\chi}_1^+ \to W^+ \tilde{\chi}_1^{0}$ in the framework of the Minimal Supersymmetric Standard…

High Energy Physics - Phenomenology · Physics 2008-11-26 Zhang Ren-You , Ma Wen-Gan , Wan Lang-Hui

The off-shell two-loop correction to the massive quark propagator in an arbitrary covariant gauge is calculated and results for the bare and renormalized propagator are presented. The calculations were performed by means of a set of new…

High Energy Physics - Phenomenology · Physics 2009-10-31 J. Fleischer , F. Jegerlehner , O. V. Tarasov , O. L. Veretin

We discuss two-loop leading and angular-dependent next-to-leading logarithmic electroweak virtual corrections to arbitrary processes at energies above the electroweak scale. The relevant Feynman diagrams involving soft-collinear gauge…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ansgar Denner , Michael Melles , Stefano Pozzorini

Reaching a theoretical accuracy in the prediction of the lightest MSSM Higgs-boson mass, M_h, at the level of the current experimental precision requires the inclusion of momentum-dependent contributions at the two-loop level. Recently two…

High Energy Physics - Phenomenology · Physics 2015-09-30 S. Borowka , T. Hahn , S. Heinemeyer , G. Heinrich , W. Hollik

We present a detailed evaluation of the bosonic two-loop electroweak corrections to the muon's anomalous magnetic moment. We study the Higgs mass dependence and find agreement with a previous evaluation in the large Higgs mass limit. We…

High Energy Physics - Phenomenology · Physics 2009-11-11 T. Gribouk , A. Czarnecki

We review a recent calculation of the two-loop next-to-leading logarithmic electroweak corrections to the form factors for massless chiral fermions coupling to an SU(2)xU(1) singlet gauge boson.

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Pozzorini

Recent calculations of the two-loop electroweak effects enhanced by powers of the top mass have been implemented in the main electroweak libraries and have an important effect on the indirect determination of the Higgs mass MH. I briefly…

High Energy Physics - Phenomenology · Physics 2007-05-23 Paolo Gambino

We present a determination of a new class of three-loop Feynman diagrams describing heavy-to-light transitions. We apply it to find the O(alpha_s^2) corrections to the top quark decay t -> bW and to the distribution of lepton invariant mass…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ian Blokland , Andrzej Czarnecki , Maciej Slusarczyk , Fyodor Tkachov

The complete set of two-loop electroweak corrections to the decay width of the Higgs boson into two photons is presented. Two-loop contributions involving weak bosons and the top quark are computed in terms of an expansion in the Higgs…

High Energy Physics - Phenomenology · Physics 2010-04-05 Giuseppe Degrassi , Fabio Maltoni

We discuss a recent analysis of a dominant two-loop electroweak correction, of O(G_F M_t^2), to the partial width of the decay of an intermediate-mass Higgs boson into a pair of photons. The asymptotic-expansion technique was used in order…

High Energy Physics - Phenomenology · Physics 2007-05-23 Bernd A. Kniehl

A critical assessment of the available calculations of the top quark width is presented. QCD corrections, the finite mass of the $b$ quark and the effect of the $W$ width are included as well as the electroweak corrections. The relative…

High Energy Physics - Phenomenology · Physics 2014-11-17 M. Jeżabek , J. H. Kühn

Of the the three best-measured electroweak observables, $\alpha$, $G_\mu$ and $M_Z$, the first two are extracted from low-energy processes. Both $G_\mu$ and $M_Z$ are now known to an accuracy of about 2 parts in $10^5$ and there is a…

High Energy Physics - Phenomenology · Physics 2007-05-23 Robin G. Stuart

We compute the eighth-order fermionic corrections involving two and three closed massless fermion loops to the anomalous magnetic moment of the muon. The required four-loop on-shell integrals are classified and explicit analytical results…

High Energy Physics - Phenomenology · Physics 2015-06-12 Roman Lee , Peter Marquard , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

Two different two-loop relations between the pole- and the MS-mass of the top quark have been derived in the literature which were based on different treatments of the tadpole diagrams. In addition, the limit M_W^2/m_t^2 \to 0 was employed…

High Energy Physics - Phenomenology · Physics 2009-03-16 M. Faisst , J. H. Kuhn , O. Veretin

We provide a compendium of techniques that can be used to compute $O(N_f\alpha^2)$ corrections to low-energy electroweak processes. Specifically, these are the 2-loop electroweak corrections containing a light fermion loop. It is shown that…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. Akhoury , Paresh Malde , Robin G. Stuart

Two-loop QED corrections with closed fermion loops are calculated for the 1s bound-electron g factor. Calculations are performed to all orders in the nuclear binding strength parameter Z\alpha (where Z is the nuclear charge and \alpha is…

Atomic Physics · Physics 2015-06-16 V. A. Yerokhin , Z. Harman