144 research outputs found
Event generation with SHERPA 1.1
In this paper the current release of the Monte Carlo event generator Sherpa,
version 1.1, is presented. Sherpa is a general-purpose tool for the simulation
of particle collisions at high-energy colliders. It contains a very flexible
tree-level matrix-element generator for the calculation of hard scattering
processes within the Standard Model and various new physics models. The
emission of additional QCD partons off the initial and final states is
described through a parton-shower model. To consistently combine multi-parton
matrix elements with the QCD parton cascades the approach of Catani, Krauss,
Kuhn and Webber is employed. A simple model of multiple interactions is used to
account for underlying events in hadron--hadron collisions. The fragmentation
of partons into primary hadrons is described using a phenomenological
cluster-hadronisation model. A comprehensive library for simulating tau-lepton
and hadron decays is provided. Where available form-factor models and matrix
elements are used, allowing for the inclusion of spin correlations; effects of
virtual and real QED corrections are included using the approach of Yennie,
Frautschi and Suura.Comment: 47 pages, 21 figure
The BlackHat Library for One-Loop Amplitudes
We present recent next-to-leading order (NLO) results in perturbative QCD
obtained using the BlackHat software library. We discuss the use of n-tuples to
separate the lengthy matrix-element computations from the analysis process. The
use of n-tuples allows many analyses to be carried out on the same phase-space
samples, and also allows experimenters to conduct their own analyses using the
original NLO computation.Comment: Talk given at ACAT 2013, Beijing, China, May 16--21, 2013; 6 pages, 2
figures; added reference
Universality in W+Multijet Production
We study -boson production accompanied by multiple jets at 7 TeV at the
LHC. We study the jet-production ratio, of total cross sections for +- to
+()-jet production, and the ratio of distributions in the total
transverse hadronic jet energy . We use the ratios to
extrapolate the total cross section, and the differential distribution in
, to +6-jet production. We use the BlackHat software
library in conjunction with SHERPA to perform the computations.Comment: Merge of Moriond 2014 and Loops & Legs 2014 proceedings, 6 pages, 2
figure
NLO vector boson production with light jets
In this contribution we present recent progress in the computation of
next-to-leading order (NLO) QCD corrections for the production of an
electroweak vector boson in association with jets at hadron colliders. We focus
on results obtained using the virtual matrix element library BLACKHAT in
conjunction with SHERPA, focusing on results relevant to understanding the
background to top production.Comment: 4+2 epsilon pages, Submitted for the proceedings of TOP2011 - 4th
International Workshop on Top Quark Physics, 25-30th September 2011, Sant
Feliu de Guixols, Spai
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