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Atomic, Molecular and Optical Physics

Kennesaw State University

Resummation

Articles 1 - 5 of 5

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.


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 …


Higher-Order Soft Gluon Corrections In Single Top Quark Production At The Cern Lhc, Nikolaos Kidonakis Apr 2007

Higher-Order Soft Gluon Corrections In Single Top Quark Production At The Cern Lhc, Nikolaos Kidonakis

Faculty and Research Publications

I present a calculation of soft-gluon corrections to single top-quark production in pp collisions at the LHC via the standard model partonic processes in the t and s channels and associated top quark and W boson production. Higher-order soft-gluon corrections through next-to-next-to-next-to-leading order (NNNLO) are calculated at next-to-leading logarithmic (NLL) accuracy. The soft-gluon corrections in the s channel and in tW production are large and dominant, while in the t channel they are not a good approximation of the complete QCD corrections.


Next-To-Next-To-Next-To-Leading-Order Soft-Gluon Corrections In Hard-Scattering Processes Near Threshold, Nikolaos Kidonakis Feb 2006

Next-To-Next-To-Next-To-Leading-Order Soft-Gluon Corrections In Hard-Scattering Processes Near Threshold, Nikolaos Kidonakis

Faculty and Research Publications

I present a unified calculation of soft-gluon corrections to hard-scattering cross sections through next-to-next-to-next-to-leading order (NNNLO). Master formulas are derived, from a threshold resummation formalism, that can be applied to total and differential cross sections for hard-scattering processes in hadron colliders. I also present numerical results for charged Higgs production at the LHC where these corrections are large, and for top quark production at the Tevatron where these corrections greatly reduce the scale dependence of the cross section.


Collinear And Soft Resummation In The Large-X Limit, Nikolaos Kidonakis Jun 2005

Collinear And Soft Resummation In The Large-X Limit, Nikolaos Kidonakis

Faculty and Research Publications

I discuss general unified formulas for resumming collinear and soft contributions to QCD hard scattering cross sections at laxge x. Expansions of the resummed cross sections to next-to-next-to-next-to-leading order are also shown along with applications of the formalism.