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Faculty and Research Publications

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Full-Text Articles in Physics

Two-Loop Soft Anomalous Dimensions For Single Top Quark Associated Production With A W- Or H-, Nikolaos Kidonakis Sep 2010

Two-Loop Soft Anomalous Dimensions For Single Top Quark Associated Production With A W- Or H-, Nikolaos Kidonakis

Faculty and Research Publications

I present results for the two-loop soft anomalous dimensions for associated production of a single top quark with a W boson or a charged Higgs boson. The calculation uses expressions for the massive cusp anomalous dimension, which are presented in different forms, and it allows soft-gluon resummation at next-to-next-to-leading-logarithm (NNLL) accuracy. From the NNLL resummed cross section I derive approximate NNLO cross sections for bg→tW- and bg→tH- at LHC energies of 7, 10, and 14 TeV.


Two-Loop Soft Anomalous Dimensions And Next-To-Next-To-Leading-Logarithm Resummation For Heavy Quark Production, Nikolaos Kidonakis Jun 2009

Two-Loop Soft Anomalous Dimensions And Next-To-Next-To-Leading-Logarithm Resummation For Heavy Quark Production, Nikolaos Kidonakis

Faculty and Research Publications

I present results for two-loop soft anomalous dimensions for heavy quark production which control soft-gluon resummation at next-to-next-to-leading-logarithm accuracy. I derive an explicit expression for the exact result and study it numerically for top quark production via e(+) e(-) -> t (t) over bar t, and I construct a surprisingly simple but very accurate approximation. I show that the two-loop soft anomalous dimensions with massive quarks display a simple proportionality relation to the one-loop result only in the limit of vanishing quark mass. I also discuss the extension of the calculation to single top and top pair production in hadron …


Theoretical Top Quark Cross Section At The Fermilab Tevatron And The Cern Lhc, Nikolaos Kidonakis, Ramona Vogt Oct 2008

Theoretical Top Quark Cross Section At The Fermilab Tevatron And The Cern Lhc, Nikolaos Kidonakis, Ramona Vogt

Faculty and Research Publications

We present results for the top quark pair cross section at the Tevatron and the LHC. We use the resummed double differential cross section, employing the fully kinematics-dependent soft-anomalous-dimension matrices, to calculate the soft-gluon contributions at next-to-next-to-leading order (NNLO). We improve and update our previous estimates by refining our methods, including further subleading terms, and employing the most recent parton distribution function sets. The NNLO soft corrections significantly enhance the NLO cross section while considerably reducing the scale dependence. We provide a detailed discussion of all theoretical uncertainties in our calculation, including kinematics, scale, and parton distribution uncertainties, and clarify …