806 research outputs found
W+n-jet predictions at NLO matched with a parton shower
The MC@NLO method as implemented in the Sherpa MC generator is presented
using the production of W-bosons in conjunction with up to three jets as an
example. Corresponding results computed at next-to leading order in QCD and
including parton shower corrections are compared to recent experimental data
from the Large Hadron Collider.Comment: 4 pages, 2 figures. To appear in the proceedings of DIS 201
Next-to-leading order matrix elements and truncated showers
An algorithm is presented that combines the ME+PS approach to merge sequences
of tree-level matrix elements into inclusive event samples with the POWHEG
method, which combines exact next-to-leading order matrix elements with parton
showers. The quality of the approach and its implementation in Sherpa are
exemplified by results for e+e- annihilation into hadrons at LEP, for Drell-Yan
lepton-pair production at the Tevatron and for Higgs-boson and W+W- production
at LHC energies.Comment: 5 pages, 8 figures; To appear in the proceedings of Physics at the
LHC 2010, DESY, Hamburg, 7-12 June 201
The conceptualisation and measurement of pedagogical content knowledge and content knowledge in the COACTIV study and their impact on student learning
An ongoing question is the extent to which teachers' professional knowledge has an impacton their teaching and, in particular, on their students' achievement. The COACTIV1 studysurveyed and tested the mathematics teachers of the classes sampled for PISA 2003/04 inGermany. The study’s key components were newly developed tests of teachers’ pedagogicalcontent knowledge and content knowledge. This article gives a report of theconceptualisation and operationalisation of both domains of knowledge and describes theconstruction of the COACTIV tests. Findings from the tests show that there are differenceswith respect to both knowledge domains regarding teachers’ school types, but thatpedagogical content knowledge and content knowledge astoundingly both do not depend onteaching experience. Furthermore we show that the two domains of knowledge correlatepositively with constructivist teachers’ subjective beliefs, on the one hand, and with somecrucial aspects of their instruction, on the other hand. Finally, we show that pedagogicalcontent knowledge – but not pure content knowledge per se – significantly contributes tostudents’ learning gains
Resolved Photons in Sherpa
We present the first complete simulation framework, in the Sherpa event
generator, for resolved photon interactions at next-to leading order accuracy.
It includes photon spectra obtained through the equivalent-photon
approximation, parton distribution functions to parametrize the hadronic
structure of quasi-real photons, the matching of the parton shower to next-to
leading order QCD calculations for resolved photon cross sections, and the
modelling of multiple-parton interactions. We validate our framework against a
wide range of photo-production data from LEP and HERA experiments, observing
good overall agreement. We identify important future steps relevant for
high-quality simulations at the planned Electron-Ion Collider
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