526 research outputs found
String Parton Models in Geant4
Dual parton and quark gluon string model are the by now almost standard
theoretical techniques by which one can arrive at precision description of high
energy, soft, inclusive reactions. These reactions make the part of jets at
energies that contribute strongly to discovery channels such as HWWjj, or
search for compositeness at the highest transverse momenta. The above modeling
approach is available with Geant4 for nucleon induced reactions since the first
release. Its object oriented design and parameter set was recently extended to
allow for simulation of pion and kaon induced reactions, as well as heavy ion
reactions. We will briefly describe the theory and algorithmic approaches that
underly the modeling, show the object oriented designs and component structure
of the string parton sub-systems of Geant4, present validation/verification
results pertaining to these models, as well as results concerning their usage
in calorimeter simulation.Comment: Computing in High Energy and Nuclear Physics, La Jolla, California,
March 24-28, 2003 1 tar fil
Electro and gamma nuclear physics in Geant4
Adequate description of electro and gamma nuclear physics is of utmost
importance in studies of electron beam-dumps and intense electron beam
accelerators. I also is mandatory to describe neutron backgrounds and
activation in linear colliders. This physics was elaborated in Geant4 over the
last year, and now entered into the stage of practical application.
In the {\sc Geant4} Photo-nuclear data base there are at present about 50
nuclei for which the Photo-nuclear absorption cross sections have been
measured. Of these, data on 14 nuclei are used to parametrize the gamma nuclear
reaction cross-section The resulting cross section is a complex, factorized
function of and , where is the energy of the
incident photon.
Electro-nuclear reactions are so closely connected with Photo-nuclear
reactions that sometimes they are often called ``Photo-nuclear''. The
one-photon exchange mechanism dominates in Electro-nuclear reactions, and the
electron can be substituted by a flux of photons. Folding this flux with the
gamma-nuclear cross-section, we arrive at an acceptable description of the
electro-nuclear physics.
Final states in gamma and electro nuclear physics are described using chiral
invariant phase-space decay at low gamma or equivalent photon energies, and
quark gluon string model at high energies.
We will present the modeling of this physics in {\sc Geant4}, and show
results from practical applications.Comment: Computing in High Energy and Nuclear Physics, La Jolla, California,
March 24-28, 2003 1 tar fil
Bertini intra-nuclear cascade implementation in Geant4
We present here a intra-nuclear cascade model implemented in Geant4 5.0. The
cascade model is based on re-engineering of INUCL code. Models included are
Bertini intra-nuclear cascade model with exitons, pre-equilibrium model,
nucleus explosion model, fission model, and evaporation model. Intermediate
energy nuclear reactions from 100 MeV to 3 GeV energy are treated for proton,
neutron, pions, photon and nuclear isotopes. We represent overview of the
models, review results achieved from simulations and make comparisons with
experimental data.Comment: Computing in High Energy and Nuclear Physics, La Jolla, California,
March 24-28, 2003 1 tar fil
SCRAM: Software configuration and management for the LHC Computing Grid project
Recently SCRAM (Software Configuration And Management) has been adopted by
the applications area of the LHC computing grid project as baseline
configuration management and build support infrastructure tool.
SCRAM is a software engineering tool, that supports the configuration
management and management processes for software development. It resolves the
issues of configuration definition, assembly break-down, build, project
organization, run-time environment, installation, distribution, deployment, and
source code distribution. It was designed with a focus on supporting a
distributed, multi-project development work-model.
We will describe the underlying technology, and the solutions SCRAM offers to
the above software engineering processes, while taking a users view of the
system under configuration management.Comment: Computing in High Energy and Nuclear Physics, La Jolla, California,
March 24-28, 2003 1 tar fil
The Geant4 Hadronic Verification Suite for the Cascade Energy Range
A Geant4 hadronic process verification suite has been designed to test and
optimize Geant4 hadronic models in the cascade energy range. It focuses on
quantities relevant to the LHC radiation environment and spallation source
targets. The general structure of the suite is presented, including the user
interface, stages of verification, management of experimental data, event
generation, and comparison of results to data. Verification results for the
newly released Binary cascade and Bertini cascade models are presented.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics
(CHEP03), La Jolla, Ca, USA, March 2003, 5 pages, LaTeX, 3 eps figures. PSN
MOMT00
GEANT4 : a simulation toolkit
Abstract Geant4 is a toolkit for simulating the passage of particles through matter. It includes a complete range of functionality including tracking, geometry, physics models and hits. The physics processes offered cover a comprehensive range, including electromagnetic, hadronic and optical processes, a large set of long-lived particles, materials and elements, over a wide energy range starting, in some cases, from 250 eV and extending in others to the TeV energy range. It has been designed and constructed to expose the physics models utilised, to handle complex geometries, and to enable its easy adaptation for optimal use in different sets of applications. The toolkit is the result of a worldwide collaboration of physicists and software engineers. It has been created exploiting software engineering and object-oriented technology and implemented in the C++ programming language. It has been used in applications in particle physics, nuclear physics, accelerator design, space engineering and medical physics. PACS: 07.05.Tp; 13; 2
Neutral-Current Atmospheric Neutrino Flux Measurement Using Neutrino-Proton Elastic Scattering in Super-Kamiokande
Recent results show that atmospheric oscillate with eV and , and that
conversion into is strongly disfavored. The Super-Kamiokande (SK)
collaboration, using a combination of three techniques, reports that their data
favor over . This distinction
is extremely important for both four-neutrino models and cosmology. We propose
that neutrino-proton elastic scattering () in water
\v{C}erenkov detectors can also distinguish between active and sterile
oscillations. This was not previously recognized as a useful channel since only
about 2% of struck protons are above the \v{C}erenkov threshold. Nevertheless,
in the present SK data there should be about 40 identifiable events. We show
that these events have unique particle identification characteristics, point in
the direction of the incoming neutrinos, and correspond to a narrow range of
neutrino energies (1-3 GeV, oscillating near the horizon). This channel will be
particularly important in Hyper-Kamiokande, with times higher rate.
Our results have other important applications. First, for a similarly small
fraction of atmospheric neutrino quasielastic events, the proton is
relativistic. This uniquely selects (not ) events,
useful for understanding matter effects, and allows determination of the
neutrino energy and direction, useful for the dependence of oscillations.
Second, using accelerator neutrinos, both elastic and quasielastic events with
relativistic protons can be seen in the K2K 1-kton near detector and MiniBooNE.Comment: 10 pages RevTeX, 8 figure
A GPU implementation of a track-repeating algorithm for proton radiotherapy dose calculations
An essential component in proton radiotherapy is the algorithm to calculate
the radiation dose to be delivered to the patient. The most common dose
algorithms are fast but they are approximate analytical approaches. However
their level of accuracy is not always satisfactory, especially for
heterogeneous anatomic areas, like the thorax. Monte Carlo techniques provide
superior accuracy, however, they often require large computation resources,
which render them impractical for routine clinical use. Track-repeating
algorithms, for example the Fast Dose Calculator, have shown promise for
achieving the accuracy of Monte Carlo simulations for proton radiotherapy dose
calculations in a fraction of the computation time. We report on the
implementation of the Fast Dose Calculator for proton radiotherapy on a card
equipped with graphics processor units (GPU) rather than a central processing
unit architecture. This implementation reproduces the full Monte Carlo and
CPU-based track-repeating dose calculations within 2%, while achieving a
statistical uncertainty of 2% in less than one minute utilizing one single GPU
card, which should allow real-time accurate dose calculations
Energy Flow in the Hadronic Final State of Diffractive and Non-Diffractive Deep-Inelastic Scattering at HERA
An investigation of the hadronic final state in diffractive and
non--diffractive deep--inelastic electron--proton scattering at HERA is
presented, where diffractive data are selected experimentally by demanding a
large gap in pseudo --rapidity around the proton remnant direction. The
transverse energy flow in the hadronic final state is evaluated using a set of
estimators which quantify topological properties. Using available Monte Carlo
QCD calculations, it is demonstrated that the final state in diffractive DIS
exhibits the features expected if the interaction is interpreted as the
scattering of an electron off a current quark with associated effects of
perturbative QCD. A model in which deep--inelastic diffraction is taken to be
the exchange of a pomeron with partonic structure is found to reproduce the
measurements well. Models for deep--inelastic scattering, in which a
sizeable diffractive contribution is present because of non--perturbative
effects in the production of the hadronic final state, reproduce the general
tendencies of the data but in all give a worse description.Comment: 22 pages, latex, 6 Figures appended as uuencoded fil
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