506 research outputs found
Multiparticle amplitudes at one-loop: an algebraic/numeric approach
We discuss algebraic/numeric methods to compute one-loop corrections for
multiparticle/jet production cross sections. By using efficient reduction
algorithms a compact expression for the ggg\gamma\gamma -> 0 amplitude is
obtained. Further a numerical approach for 6-point 1-loop diagrams is
presented.Comment: 5 pages, Talk given at the 7th DESY Workshop On Elementary Particle
Theory: Loops And Legs In Quantum Field Theory, Zinnowitz, Germany, 25-30 Apr
200
Towards LHC phenomenology at the loop level: A new method for one-loop amplitudes
A precise understanding of LHC phenomenology requires the inclusion of
one-loop corrections for multi-particle final states. In this talk we describe
a semi-numerical method to compute one-loop amplitudes with many external
particles and present first applications.Comment: 5 pages latex, 1 ps fig., 1 eps fig., Conference Proceedings Radcor
200
New one-loop techniques and first applications to LHC phenomenology
In this talk we describe our approach for the computation of multi-leg
one-loop amplitudes and present some first results relevant for LHC
phenomenology.Comment: 5 pages, to appear in the proceedings of the conference "Loops and
Legs", Eisenach, 200
Six-Photon Amplitudes
We present analytical results for all six-photon helicity amplitudes. For the
computation of this loop induced process two recently developed methods, based
on form factor decomposition and on multiple cuts, have been used. We obtain
compact results, demonstrating the applicability of both methods to one-loop
amplitudes relevant to precision collider phenomenology.Comment: replaced by published versio
Influence of strongly coupled, hidden scalars on Higgs signals
To investigate the possible effects of a light hidden sector on Higgs boson
detection, we discuss a model of scalar singlets coupled to the Standard Model.
The model effectively makes the Higgs width a free parameter due to additional
invisible decay modes. This width can become arbitrarily large. Theoretical and
experimental bounds on model parameters are presented. It is shown, how
Standard Model predictions change and that in the case of large coupling, Higgs
signals will be diluted. We study, to which extent such a strongly coupled,
hidden sector can be excluded by present and future Higgs search experiments.Comment: 22 pages, Latex, 12 figures embedded with epsf.sty and epsfig.sty, to
appear in Z. Phys.
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