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Related papers: NNLO Computational Techniques: the Cases H -> gamm…

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We calculate the O(alpha_s) corrections to the double differential decay width dGamma_{77}/(ds_1 ds_2) for the process B -> X_s gamma gamma originating from diagrams involving the electromagnetic dipole operator O_7. The kinematical…

High Energy Physics - Phenomenology · Physics 2014-06-11 H. M Asatrian , C. Greub

We derive logarithmically enhanced two-loop virtual electroweak corrections for arbitrary fermion-scattering processes at the TeV scale. This extends results previously obtained for massless fermion scattering to processes that involve also…

High Energy Physics - Phenomenology · Physics 2009-11-19 Ansgar Denner , Bernd Jantzen , Stefano Pozzorini

We review the techniques necessary for the calculation of virtual electroweak and soft photonic corrections at the one-loop level. In particular we describe renormalization, calculation of one-loop integrals and evaluation of one-loop…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ansgar Denner

In many extensions of the Standard Model, finite temperature computations are complicated by a hierarchy of zero temperature mass scales, in addition to the usual thermal mass scales. We extend the standard thermal resummations to such a…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Laine , M. Losada

We evaluate the three-loop matching conditions for the dimension-five operators that are relevant for the b -> s gamma decay. Our calculation completes the first out of three steps (matching, mixing and matrix elements) that are necessary…

High Energy Physics - Phenomenology · Physics 2010-04-05 Mikolaj Misiak , Matthias Steinhauser

A summary of recent results obtained for higher-order corrections to precision observables in the Standard Model and the Minimal Supersymmetric Standard Model is given. In the Standard Model electroweak two-loop results valid for arbitrary…

High Energy Physics - Phenomenology · Physics 2011-03-02 G. Weiglein

In part I and II of this series of papers all elements have been introduced to extend, to two loops, the set of renormalization procedures which are needed in describing the properties of a spontaneously broken gauge theory. In this paper,…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Actis , G. Passarino

In this work we compute the leading logarithmic corrections to the b -> s gamma decay in a dimensional scheme which does not require any definition of the gamma5 matrix. The scheme does not exhibit unconsistencies and it is therefore a…

High Energy Physics - Phenomenology · Physics 2009-10-28 G. Cella , G. Curci , G. Ricciardi , A. Vicere'

The Higgs decay $H\to \gamma\gamma$ duo to the virtual $W$-loop effect is revisited in the unitary gauge by using the symmetry-preserving and divergent-behavior-preserving loop regularization method, which is realized in the four…

High Energy Physics - Phenomenology · Physics 2012-04-12 Da Huang , Yong Tang , Yue-Liang Wu

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

Complete electroweak two-loop corrections to the process $gg \to H$ are presented and discussed in a Standard Model with a fourth generation of heavy fermions. The latter is studied at the LHC to put exclusion limits on a fourth generation…

High Energy Physics - Phenomenology · Physics 2015-05-30 Giampiero Passarino , Christian Sturm , Sandro Uccirati

The virtual two-loop corrections for Higgs production in gluon fusion are calculated analytically in QCD for arbitrary Higgs and quark masses. Both scalar and pseudo-scalar Higgs bosons are considered. The results are obtained by expanding…

High Energy Physics - Phenomenology · Physics 2016-09-06 Robert Harlander , Philipp Kant

We present the dominant two-loop electroweak corrections to the partial decay widths to gluon jets and prompt photons of the neutral CP-odd Higgs boson A^0, with mass M_{A^0} < 2 M_W, in the two-Higgs-doublet model for low to intermediate…

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

We present the calculation of the mixed two-loop QCD/electroweak corrections to hadronic W boson decays within the Standard Model. The optical theorem is applied to the W boson two-point function. The multi-scale integrals are computed with…

High Energy Physics - Phenomenology · Physics 2015-12-01 Dominik Kara

We consider the production of a Higgs boson via gluon-fusion and its decay into two photons. We compute the NLO virtual QCD corrections to these processes in a general framework in which the coupling of the Higgs boson to the external…

High Energy Physics - Phenomenology · Physics 2010-10-27 U. Aglietti , R. Bonciani , G. Degrassi , A. Vicini

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

We compute analytically the complete electroweak two-loop corrections to the $B^0-{\bar B}^0$ mixing. These corrections fix the normalization of the electroweak coupling employed in the extraction of $|V_{td}|$ and reduce the theoretical…

High Energy Physics - Phenomenology · Physics 2009-10-31 P. Gambino , A. Kwiatkowski , N. Pott

We present a method to numerically evaluate infrared-finite one- and two-loop integrals within the Four-Dimensional Regularization/Renormalization approach, in which a small mass serves as regulator. Typical integrals exhibit a logarithmic…

High Energy Physics - Phenomenology · Physics 2016-02-08 Tom Zirke

Inspired by the recent observation of the Higgs boson radiative decay into $Z^0$ by {\tt ATLAS} and {\tt CMS} Collaborations, we investigate the next-to-leading-order (NLO) electroweak correction to this rare decay process in Standard Model…

High Energy Physics - Phenomenology · Physics 2024-09-23 Wen-Long Sang , Feng Feng , Yu Jia

We present a completely numerical method of calculating one-loop amplitudes. Our approach is built upon two different existing methods: the contour deformation and the extrapolation methods. Taking the best features of each of them, we…

High Energy Physics - Phenomenology · Physics 2017-02-01 Goran Duplancic , Bruno Klajn