English
Related papers

Related papers: Two-loop Calculations in the MSSM with FeynArts

200 papers

We calculate the one- and two-loop matching corrections in the Standard Model effective field theory (SMEFT) that impact electroweak precision measurements and flavour physics observables, focusing on the contributions of third-generation…

High Energy Physics - Phenomenology · Physics 2025-01-17 Ulrich Haisch , Luc Schnell

The program package GoSam is presented which aims at the automated calculation of one-loop amplitudes for multi-particle processes. The amplitudes are generated in terms of Feynman diagrams and can be reduced using either D-dimensional…

High Energy Physics - Phenomenology · Physics 2015-06-03 G. Cullen , N. Greiner , G. Heinrich , G. Luisoni , P. Mastrolia , G. Ossola , T. Reiter , F. Tramontano

We compute two-loop electroweak corrections to Higgs boson pair and Higgs plus jet production, taking into account all sectors of the Standard Model. All diagrams with virtual top quarks are computed in an expansion for large top quark mass…

High Energy Physics - Phenomenology · Physics 2023-10-10 Joshua Davies , Kay Schönwald , Matthias Steinhauser , Hantian Zhang

The potential of present and anticipated future electroweak precision data, including the Higgs boson and top quark masses, for testing quantum effects of the electroweak theory is investigated in the context of the Minimal Supersymmetric…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Heinemeyer , G. Weiglein

We reemphasize the importance of discriminating fermion-loop and bosonic electroweak corrections in the analysis of electroweak precision data. Most recent data are indeed precise enough to require corrections beyond (trivial) fermion…

High Energy Physics - Phenomenology · Physics 2007-05-23 Dieter Schildknecht

The behaviour of two-loop two-point diagrams at non-zero thresholds corresponding to two-particle cuts is analyzed. The masses involved in a cut and the external momentum are assumed to be small as compared to some of the other masses of…

High Energy Physics - Phenomenology · Physics 2009-10-28 F. A. Berends , A. I. Davydychev , V. A. Smirnov

We present in this paper our new program package ewN2HDECAY for the calculation of the partial decay widths and branching ratios of the Higgs bosons of the Next-to-Minimal 2-Higgs Doublet Model (N2HDM). The N2HDM is based on a general…

High Energy Physics - Phenomenology · Physics 2020-01-23 M. Krause , M. Mühlleitner

With a key improvement, the auxiliary mass flow method is now able to compute Feynman integrals encountered in cutting-edge collider processes. We have successfully applied it to compute some integrals involved in two-loop electroweak…

High Energy Physics - Phenomenology · Physics 2022-03-16 Xiao Liu , Yan-Qing Ma

The electroweak corrections of order ${\cal O}(\alpha_{\rm em} m^2_{t,b}/m^2_w)$ and ${\cal O}(\alpha_{\rm em} m^3_{t,b}/m^3_w)$ to Higgs boson associated production with top quark pair are calculated at $e^+e^-$ colliders in the standard…

High Energy Physics - Phenomenology · Physics 2007-05-23 Xiao-Hong Wu , Chong Sheng Li , Jian Jun Liu

We present the NNLO QCD virtual corrections for qurak-antiquark -> gluon photon, quark-antiquark -> photon photon and the NNLO QED virtual corrections for electron positron -> photon photon and all processes related by crossing symmetry. We…

High Energy Physics - Phenomenology · Physics 2008-11-26 C. Anastasiou , E. W. N. Glover , M. E. Tejeda-Yeomans

The radiatively-induced splitting of masses in electroweak multiplets is relevant for both collider phenomenology and dark matter. Precision two-loop corrections of $\mathcal{O}$(MeV) to the triplet mass splitting in the wino limit of the…

High Energy Physics - Phenomenology · Physics 2018-04-03 James McKay , Pat Scott

We present a determination of a new class of Feynman diagrams relevant for second-order QCD corrections to the top quark decay t -> b W. Modern computing techniques allow us to perform a reduction of the original loop integrals to master…

High Energy Physics - Phenomenology · Physics 2017-08-23 Maciej Slusarczyk

The rare decays $\bar B\rightarrow X_s\gamma$ and $B_s^0\rightarrow \mu^+\mu^-$ are important to research new physics beyond standard model. In this work, we investigate two loop electroweak corrections to $\bar B\rightarrow X_s\gamma$ and…

High Energy Physics - Phenomenology · Physics 2018-09-10 Jin-Lei Yang , Tai-Fu Feng , Hai-Bin Zhang , Rong-Fei Zhu , Shu-Min Zhao , Xiu-Yi Yang

We present the prediction of the electroweak $\rho$ parameter and the $W$ boson mass in the CP-violating Next-to-Minimal Supersymmetric extension of the Standard Model (NMSSM) at the two-loop order. The $\rho$ parameter is calculated at the…

High Energy Physics - Phenomenology · Physics 2023-08-09 Thi Nhung Dao , Martin Gabelmann , M. Margarete Mühlleitner

We present the full $\mathcal{O}(\alpha_s)$ supersymmetric QCD corrections for gaugino annihilation and co-annihilation into light and heavy quarks in the Minimal Supersymmetric Standard Model (MSSM). We demonstrate that these channels are…

High Energy Physics - Phenomenology · Physics 2014-06-18 B. Herrmann , M. Klasen , K. Kovarik , M. Meinecke , P. Steppeler

We compute the two-loop mixed QCD-Electroweak corrections to $q \overline{q} \to H g$ and its crossed channels $q g \to H q$, $\overline{q} g \to H \overline{q}$, limiting ourselves to the contribution of light virtual quarks. We compute…

High Energy Physics - Phenomenology · Physics 2022-07-18 Marco Bonetti , Erik Panzer , Lorenzo Tancredi

We compute the exact two-loop matching coefficients for the strong coupling constant alpha_s and the bottom-quark mass m_b within the Minimal Supersymmetric Standard Model (MSSM), taking into account O(alpha_s^2) contributions from…

High Energy Physics - Phenomenology · Physics 2010-04-15 A. Bauer , L. Mihaila , J. Salomon

We show that in the framework of the pinch technique the universal part of the $\rho$ parameter can be meaningfully defined, beyond one loop. The universal part so obtained satisfies the crucial requirements of gauge-independence,…

High Energy Physics - Phenomenology · Physics 2011-01-13 Joannis Papavassiliou , Kostas Philippides , Ken Sasaki

We give an algorithm for obtaining expansions of massive two-loop Feynman graphs in powers of the external momentum around a finite, nonzero value of the momentum. This is based on our general two-loop formalism to reduce massive two-loop…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. Ghinculov , Y. P. Yao

We discuss the renormalization of the electric charge at the two-loop level in the Standard Model of the electroweak interactions. We explicitly calculate the expression of the complete on-shell two-loop counterterm using the Background…

High Energy Physics - Phenomenology · Physics 2009-11-10 Giuseppe Degrassi , Alessandro Vicini