We present results for the next-to-leading order calculation of single-top Wt-channel production interfaced to Shower Monte Carlo programs, implemented according to the POWHEG method. A comparison with MC@NLO is carried out. Results obtained using the PYTHIA shower are also shown and the effect of typical cuts is briefly discussed.

/pdf/single-top-wt-channel-production-matched-with-parton-showers-5e6h3zl0el.pdf

Single-top Wt-channel production matched with parton showers using the POWHEG method

We present a new version of the CompHEP program (version 4.4). We describe shortly new issues implemented in this version, namely, simplification of quark flavor combinatorics for the evaluation of hadronic processes, Les Houches Accord-based CompHEP-PYTHIA interface, processing the color configurations of events, implementation of MSSM, symbolical and numerical batch modes, etc. We discuss how the CompHEP program is used for preparing event generators for various physical processes. We mention a few concrete physics examples for CompHEP-based generators prepared for the LHC and Tevatron.

CompHEP 4.4 - Automatic Computations from Lagrangians to Events

I present the next-to-next-to-leading-logarithm (NNLL) resummation of soft and collinear gluon corrections to single top quark production in the s channel. Attaining NNLL accuracy involves the calculation of the two-loop soft anomalous dimension for the partonic subprocesses. Finite-order expansions of the resummed cross section are calculated through next-to-next-to-leading order. Numerical results are presented for s-channel single top quark production at the Tevatron and the LHC, including the dependence of the cross sections on the top quark mass and the uncertainties in the theoretical prediction. The higher-order corrections are significant for energies at both colliders and they decrease the theoretical uncertainty.

/pdf/next-to-next-to-leading-logarithm-resummation-for-s-channel-m4xj0rf2rr.pdf

Next-to-next-to-leading logarithm resummation for s -channel single top quark production

We present a next-to-leading order calculation of single-top production interfaced to Shower Monte Carlo programs, implemented according to the POWHEG method. A detailed comparison with MC@NLO and PYTHIA is carried out for several observables, for the Tevatron and LHC colliders.

https://iopscience.iop.org/article/10.1088/1126-6708/2009/09/111/pdf

Erratum: NLO single-top production matched with shower in POWHEG: s - and t -channel contributions

https://escholarship.org/content/qt7653f3f2/qt7653f3f2.pdf?t=paoixg

Physics interplay of the LHC and the ILC

We present a new next-to-leading order calculation for fully dieren tial single-topquark nal states. The calculation is performed using phase space slicing and dipole subtraction methods. The results of the methods are found to be in agreement. The dipole subtraction method calculation retains the full spin dependence of the nal state particles. We show a few numerical results to illustrate the utility and consistency of the resulting computer implementations.

The fully differential single-top-quark cross section in next-to-leading order QCD

The phase space slicing method of two cutoffs for next-to-leading-order Monte Carlo style QCD corrections has been applied to many physics processes. The method is intuitive, simple to implement, and relies on a minimum of process dependent information. Although results for specific applications exist in the literature, there is not a full and detailed description of the method. Herein such a description is provided, along with illustrative examples; details, which have not previously been published, are included so that the method may be applied to additional hard scattering processes.

/pdf/two-cutoff-phase-space-slicing-method-88x6080738.pdf

B. W. Harris

Papers

The fully differential single-top-quark cross section in next-to-leading order QCD

Two cutoff phase space slicing method