4,090 research outputs found
Searches at LEP2 latest results
Searches for the Higgs boson of the Standard Model and supersymmetric models have been performed by the four LEP experiments in the data collected over almost 12 years (August/1989 until November/2000) at centre-of-mass energies varying from 91.2 GeV to 209 GeV. An excess of candidates for the process e/sup +/e/sup -/ to Z* to Z/sup 0/H/sup 0/ was found for Higgs masses near 114 GeV. (9 refs)
Refactoring, reengineering and evolution: paths to Geant4 uncertainty quantification and performance improvement
Ongoing investigations for the improvement of Geant4 accuracy and
computational performance resulting by refactoring and reengineering parts of
the code are discussed. Issues in refactoring that are specific to the domain
of physics simulation are identified and their impact is elucidated.
Preliminary quantitative results are reported.Comment: To be published in the Proc. CHEP (Computing in High Energy Physics)
201
Quantifying the unknown: issues in simulation validation and their experimental impact
The assessment of the reliability of Monte Carlo simulations is discussed,
with emphasis on uncertainty quantification and the related impact on
experimental results. Methods and techniques to account for epistemic
uncertainties, i.e. for intrinsic knowledge gaps in physics modeling, are
discussed with the support of applications to concrete experimental scenarios.
Ongoing projects regarding the investigation of epistemic uncertainties in the
Geant4 simulation toolkit are reported.Comment: To be published in the Proceedings of the 13th ICATPP Conference on
Astroparticle, Particle, Space Physics and Detectors for Physics
Applications, Villa Olmo, Como, 3-7 October 201
Research in Geant4 electromagnetic physics design, and its effects on computational performance and quality assurance
The Geant4 toolkit offers a rich variety of electromagnetic physics models;
so far the evaluation of this Geant4 domain has been mostly focused on its
physics functionality, while the features of its design and their impact on
simulation accuracy, computational performance and facilities for verification
and validation have not been the object of comparable attention yet, despite
the critical role they play in many experimental applications. A new project is
in progress to study the application of new design concepts and software
techniques in Geant4 electromagnetic physics, and to evaluate how they can
improve on the current simulation capabilities. The application of a
policy-based class design is investigated as a means to achieve the objective
of granular decomposition of processes; this design technique offers various
advantages in terms of flexibility of configuration and computational
performance. The current Geant4 physics models have been re-implemented
according to the new design as a pilot project. The main features of the new
design and first results of performance improvement and testing simplification
are presented; they are relevant to many Geant4 applications, where
computational speed and the containment of resources invested in simulation
production and quality assurance play a critical role.Comment: 4 pages, 4 figures and images, to appear in proceedings of the
Nuclear Science Symposium and Medical Imaging Conference 2009, Orland
Geant4-related R&D for new particle transport methods
A R&D project has been launched in 2009 to address fundamental methods in
radiation transport simulation and revisit Geant4 kernel design to cope with
new experimental requirements. The project focuses on simulation at different
scales in the same experimental environment: this set of problems requires new
methods across the current boundaries of condensed-random-walk and discrete
transport schemes. An exploration is also foreseen about exploiting and
extending already existing Geant4 features to apply Monte Carlo and
deterministic transport methods in the same simulation environment. An overview
of this new R&D associated with Geant4 is presented, together with the first
developments in progress.Comment: 4 pages, to appear in proceedings of the Nuclear Science Symposium
and Medical Imaging Conference 2009, Orland
Estimating preferences for controlling beach erosion in Sicily
This study applied discrete-choice experiments to estimate preferences for a program aimed at reducing the retreatment of the sandy beach at "Lido di Noto", a renowned Sicilian bathing resort close to Noto (Italy). Econometric analysis of data was based on Multinomial Logit (MNL), Latent Class (LC) and Mixed Logit (MXL) models. Findings shown that users appreciated the advancement of the current coastline through nourishment, and negatively perceived the construction of emerged sea barriers. MXL and LC models revealed that preferences were heterogeneous
R&D on co-working transport schemes in Geant4
A research and development (R&D) project related to the extension of the
Geant4 toolkit has been recently launched to address fundamental methods in
radiation transport simulation. The project focuses on simulation at different
scales in the same experimental environment; this problem requires new methods
across the current boundaries of condensed-random-walk and discrete transport
schemes. The new developments have been motivated by experimental requirements
in various domains, including nanodosimetry, astronomy and detector
developments for high energy physics applications.Comment: To be published in the Proceedings of the CHEP (Computing in High
Energy Physics) 2009 conferenc
Inter-Comparison and Validation of Geant4 Photon Interaction Models
A R&D project, named Nano5, has been recently launched to study an
architectural design in view of addressing new experimental issues related to
particle transport in high energy physics and other related physics disciplines
with Geant4. In this frame, the first step has involved the redesign of the
photon interaction models currently available in Geant4; this task has
motivated a thorough investigation of the physics and computational features of
these models, whose first results are presented here.Comment: 4 pages, 7 figures and images, 2 tables, to appear in proceedings of
the Nuclear Science Symposium and Medical Imaging Conference 2009, Orland
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