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We present O(alpha) YFS exponentiated results for wide angle Bhabha scattering at LEP/SLC energies using a new Monte Carlo event generator BHWIDE 1.xx. Our calculations include two options for the pure weak corrections, as presented in…

High Energy Physics - Phenomenology · Physics 2009-10-28 S. Jadach , W. Placzek , B. F. L. Ward

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

A combination of algebraical and numerical techniques for calculating two-loop top-quark and Higgs-boson corrections to electroweak precision observables like $\Delta r$ or the $\rho$-parameter is presented. The renormalization is performed…

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

Using an effective potential approach, we compute two-loop radiative corrections to the MSSM lightest ${\cal CP}$-even Higgs boson mass $M_{h^0}$ to ${\cal O}(\alpha_t^2)$ for arbitrary left-right top-squark mixing and $\tan\beta$. We find…

High Energy Physics - Phenomenology · Physics 2011-01-13 Jose Ramon Espinosa , Ren-Jie Zhang

Measurements of electroweak precision observables at future electron-positron colliders, such as the CEPC, FCC-ee, and ILC, will be sensitive to physics at multi-TeV scales. To achieve this sensitivity, precise predictions for the Standard…

High Energy Physics - Phenomenology · Physics 2021-04-07 Lisong Chen , Ayres Freitas

Recent results for higher-order corrections to the relation between the vector-boson masses in the Standard Model and Supersymmetry are summarized. In the Standard Model, the Higgs-mass dependence of the two-loop contributions to Delta r is…

High Energy Physics - Phenomenology · Physics 2011-03-17 G. Weiglein

At the LHC a precise measurement of the Higgs boson mass (if discovered), at the level of 0.1-1%, will be possible through the channel g g --> H --> 4l for a wide range of Higgs mass values. To match such an accuracy, the systematic effects…

High Energy Physics - Phenomenology · Physics 2009-11-11 C. M. Carloni Calame , M. Moretti , G. Montagna , O. Nicrosini , F. Piccinini , A. D. Polosa

We complete the effective potential calculation of the two-loop, top/bottom Yukawa corrections to the Higgs boson masses in the Minimal Supersymmetric Standard Model, by computing the O(at^2 + at*ab + ab^2) contributions for arbitrary…

High Energy Physics - Phenomenology · Physics 2008-11-26 Athanasios Dedes , Giuseppe Degrassi , Pietro Slavich

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

We evaluate the two-loop corrections to Bhabha scattering from fermion loops in the context of pure Quantum Electrodynamics. The differential cross section is expressed by a small number of Master Integrals with exact dependence on the…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Actis , M. Czakon , J. Gluza , T. Riemann

I discuss the importance of the $O(g^4 m_t^2/\mw^2)$ corrections to the effective electroweak angle and Mw in the indirect determination of the Higgs mass. I emphasize the r\^ole of a very precise Mw measurement on the Mh estimate.

High Energy Physics - Phenomenology · Physics 2007-05-23 Giuseppe Degrassi

We compute the two-loop corrections of O(alpha_s^2) to the Yukawa couplings in the framework of the Minimal Supersymmetric Standard Model (MSSM). The calculation is performed using the effective Lagrangian approach under the approximation…

High Energy Physics - Phenomenology · Physics 2014-11-21 L. Mihaila , C. Reisser

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 present three-loop (NNNLO) corrections to the heavy-to-heavy quark transitions in the limit of equal initial and final quark masses. In analogy with the previously found NNLO corrections, the bulk of the result is due to the beta_0^2…

High Energy Physics - Phenomenology · Physics 2011-01-25 John Paul Archambault , Andrzej Czarnecki

In this article we give a calculation of the two-loop $\sigma$-model corrections to the T-duality map in string theory. We use the effective action approach, and analyze two-loop corrections in a specific subtraction scheme. Focusing on…

High Energy Physics - Theory · Physics 2009-10-30 Nemanja Kaloper , Krzysztof Meissner

Perturbation theory at finite temperature suffers from well-known infrared problems. In the standard model, as a result, one cannot calculate the effective potential for arbitrarily small values of $\phi$, the Higgs expectation value.…

High Energy Physics - Phenomenology · Physics 2011-07-19 John Bagnasco , Michael Dine

Hard processes at the TeV scale exhibit enhanced (double log) EW corrections, that need resummation in view of the high level of precision of Next Linear Colliders. The fact that the weak sector is spontaneously broken causes some…

High Energy Physics - Phenomenology · Physics 2007-05-23 P. Ciafaloni

We present the first calculation of the two-loop electroweak fermionic correction to the flavour-dependent effective weak-mixing angle for bottom quarks, sin^2 theta_{eff}^{b anti-b}. For the evaluation of the missing two-loop vertex…

High Energy Physics - Phenomenology · Physics 2010-04-21 M. Awramik , M. Czakon , A. Freitas , B. A. Kniehl

We present a complete $O(\alpha_s^2)$ correction to the differential width of the inclusive semileptonic decay $b\to cl\nu_l$ at the kinematical point of vanishing invariant mass of the leptons, $q^2=0$. Together with the recently computed…

High Energy Physics - Phenomenology · Physics 2014-11-17 Andrzej Czarnecki , Kirill Melnikov

Precision electroweak data allow one to test the standard model, constrain its parameters, and search for the effects of some kinds of new physics. The results of the most recent data from LEP, SLC, and elsewhere are described, as are their…

High Energy Physics - Phenomenology · Physics 2007-05-23 Paul Langacker
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