1,048 research outputs found
Scale Evolution of Unintegrated Distributions and the p_t Spectrum of Gauge Bosons
We present predictions for the -boson -spectrum at Tevatron within
the framework of unintegrated distributions evolved according to evolution
equations recently proposed by us. We discuss the dependence of the results on
the choice of non-perturbative parameters, the coupling constant and the impact
of soft gluon resummation.Comment: proceedings of the workshop "Recent Advances in Perturbative QCD and
Hadronic Physics", 20-25 July 2009, ECT*, Trento (Italy), in Honor of Prof.
Anatoly Efremov's 75th Birthday Celebratio
Event generators: New developments.
After an introduction to event generators we give an overview of developments
in the field of joining matrix elements with parton showers. Starting with
matrix element corrections, we also discuss implementations that match LO and
NLO matrix elements with parton shower results correctly. Finally, the new
Monte Carlo program Herwig++ is described. We report on its status of
development and some major physics improvements.Comment: 12 pages, 11 Figs, invited talk at the 14th Topical Conference on
Hadron Collider Physics (HCP2002), Karlsruhe, Germany, 30 Sep--4 Oct 2002, to
appear in the proceeding
The new Monte Carlo Event Generator Herwig++
We present results obtained with the new Monte Carlo event generator
Herwig++. In its first version (1.0), Herwig++ is capable of simulating e+e-
Annihilation events. We compare results for different distributions with a vast
amount of available data from e+e- annihilation.Comment: Proceedings of the XIIth International Workshop on Deep Inelastic
Scattering (DIS04), Strbske Pleso, Slovakia, April 14-18 200
Know about Your Home Country
Postcard from Emma Gieseke, during the Linfield College Semester Abroad Program at the University of Heidelberg in German
Analysis of nonlinear structures via mode synthesis
An effective procedure for NASTRAN was developed that permits any number of substructures of any size to be synthesized for the purpose of developing normal modes of vibration of the complete structural system. The technique is extended to permit modal transient analysis of the subdivided system. This latter procedure permits the use of NASTRAN's ability to include nonlinear forces in the problem. The five-phase process is accomplished using standard NASTRAN rigid formats with problem-independent alter packages and DMAP sequences
A Positive-Weight Next-to-Leading-Order Monte Carlo for e+e- Annihilation to Hadrons
We apply the positive-weight Monte Carlo method of Nason for simulating QCD
processes accurate to Next-To-Leading Order to the case of e+e- annihilation to
hadrons. The method entails the generation of the hardest gluon emission first
and then subsequently adding a `truncated' shower before the emission. We have
interfaced our result to the Herwig++ shower Monte Carlo program and obtained
better results than those obtained with Herwig++ at leading order with a matrix
element correction.Comment: 21 pages, 11 figures, 2 tables Reason for replacement: minor
corrections, typos and 1 changed referenc
A model of non-perturbative gluon emission in an initial state parton shower
We consider a model of transverse momentum production in which
non-perturbative smearing takes place throughout the perturbative evolution, by
a simple modification to an initial state parton shower algorithm. Using this
as the important non-perturbative ingredient, we get a good fit to data over a
wide range of energy. Combining it with the non-perturbative masses and cutoffs
that are a feature of conventional parton showers also leads to a reasonable
fit. We discuss the extrapolation to the LHC.Comment: 14 pages, 6 figures; version accepted by JHE
The Photon Wave Function in Non-forward Diffractive Scattering with Non-vanishing Quark Masses
The light-cone Photon wave function in explicit helicity states, valid for
massive quarks and in both momentum and configuration space, is presented by
considering the leading order photon-proton hard scattering, i.e., the
splitting quark pair scatters with the proton in the Regge limit. Further we
apply it to the diffractive scattering at nonzero momentum transfer and reach a
similar factorization as in the case of zero momentum transfer.Comment: 11 pages LaTeX, 2 figures, version to appear in Phys. Rev.
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