41 research outputs found
MSSM corrections to the top-antitop quark forward-backward asymmetry at the Tevatron
We study the effects of the complete supersymmetric QCD and electroweak
one-loop corrections to the ttbar forward-backward asymmetry at the Fermilab
Tevatron collider. We work in the complex Minimal Supersymmetric Standard Model
(MSSM), only restricted by the condition of minimal flavor violation (MFV). We
perform a comprehensive scan over the relevant parameter space of the complex
MFV-MSSM and determine the maximal possible contributions of these MSSM loop
corrections to the forward-backward asymmetry in the ttbar center-of-mass
frame.Comment: 25 pages, 9 figure
Radiative corrections to W gamma gamma production at the LHC
Radiative W production at hadron colliders is an important testing ground for
the Standard Model. We consider W gamma gamma production which is sensitive to
the quartic WW gamma gamma coupling. Furthermore the Standard Model amplitude
for this process contains a radiation zero. We present a calculation of the NLO
QCD corrections for W gamma gamma production at the LHC.Comment: 6 pages, talk given at RADCOR 2009 - 9th International Symposium on
Radiative Corrections (Applications of Quantum Field Theory to Phenomenology)
October 25-30 2009, Ascona, Switzerlan
Electroweak Radiative Corrections to Resonant Charged Gauge Boson Production
The electroweak O(alpha) contribution to the resonant single W production in
a general 4-fermion process is discussed with particular emphasis on a gauge
invariant decomposition into a QED-like and weak part. The cross section in the
vicinity of the resonance can be represented in terms of a convolution of a
`hard' Breit-Wigner-cross section, comprising the (m_t,M_H)-dependent weak
1-loop corrections, with an universal radiator function. The numerical impact
of the various contributions on the W line shape are discussed, together with
the concepts of s-dependent and constant width approach. Analytic formulae for
the W decay width are also provided including the 1-loop electroweak and QCD
corrections.Comment: 49 pages, LaTeX source and 17 postscript figures, revised version
with few minor changes, accepted for publication in Phys.Rev.
Higgs boson production in association with top quarks in the POWHEG BOX
We present results from the analytic calculation of top+antitop+Higgs
hadronic production at Next-to-Leading Order in QCD interfaced with
parton-shower Monte Carlo event generators in the POWHEG BOX framework. We
consider kinematic distributions of the top quark and Higgs boson at the 8 TeV
Large Hadron Collider and study the theoretical uncertainties due to specific
choices of renormalization/factorization scales and parton-showering
algorithms, namely PYTHIA and HERWIG. The importance of spin-correlations in
the production and decay stages of a top/antitop quark is discussed on the
example of kinematic distributions of leptons originating from the top/antitop
decays. The corresponding code is now part of the public release of the POWHEG
BOX.Comment: 15 pp, 14 figure