56701
GANGA: a user-Grid interface for Atlas and LHCb
Author(s): Harrison, K; Lavrijsen, WTLP; Mato, P; Soroko, A; Tan, CL; Tull, CE; Brook, N; Jones, RWL | Abstract: The Gaudi/Athena and Grid Alliance (GANGA) is a front-end for the configuration, submission, monitoring, bookkeeping, output collection, and reporting of computing jobs run on a local batch system or on the grid. In particular, GANGA handles jobs that use applications written for the Gaudi software framework shared by the Atlas and LHCb experiments. GANGA exploits the commonality of Gaudi-based computing jobs, while insulating against grid-, batch- and framework-specific technicalities, to maximize end-user productivity in defining, configuring, and executing jobs. Designed for a python-based component architecture, GANGA has a modular underpinning and is therefore well placed for contributing to, and benefiting from, work in related projects. Its functionality is accessible both from a scriptable command-line interface, for expert users and automated tasks, and through a graphical interface, which simplifies the interaction with GANGA for beginning and c1asual users. This paper presents the GANGA design and implementation, the development of the underlying software bus architecture, and the functionality of the first public GANGA release.
121691932
W mass measurements at LEP and the Tevatron
The prospects for precise tests of the standard model by measuring the mass of the W boson at LEP II and the Tevatron are considered. The limiting systematic effects are discussed.
65296691
ATLAS computing: Technical design report.
120991534
B-physics in the p-p collisions at the LHC
The LHC provides an excellent opportunity for B-physics studies, providing both high statistics and a wide range of kinematic conditions. This paper summarises the prospects for the ATLAS, CMS and LHCb experiments, with an emphasis on the QCD aspects. The rather different programme of the heavy-ions experiment ALICE is not addressed. The experiments will probe both the production and decay of B-hadrons. The various trigger strategies are presented, after which the production measurements are considersed and are shown to provide stringent test of QCD, as well as providing vital information of the backgrounds to searches. After this, the studies of B-decays are presented. The measurements of CP-violation are shown to have a good potential for discovering signatures of new physics. B s mixing will also open a window on new physics, and Δ| Gamma s will be measurable. Finally, the prospects for rare deacys are considered, especially for the decays to muons.
9457823
Ganga user interface for job definition and management
Ganga is a frontend for job definition and management in a distributed environment. It is being developed in the context of two high-energy physics experiments, ATLAS and LHCb, but is a component-based system that can readily be extended to meet the needs of other user communities. Ganga allows the user to specify the software to run, which may include user code, to set values for any configurable parameters, to select data for processing, and to submit jobs to a variety of local batch queues and Grid-based systems, hiding Grid technicalities. After jobs are submitted, ganga monitors their status, and takes care of saving any output. Ganga offers a Command-Line Interface in Python (CLIP), possibilities for scripting, and a Graphical User Interface (GUI), which significantly simplifies basic tasks. This paper describes the job model and architecture of ganga, and illustrates ganga’s main features as a user interface.
126069786
Physics and detector performance measurements with the decays B0(s) ---> J/Psi Phi and B0(d) ---> J/Psi K0* with early data
17352400
The criteria for a solution of the field equations to be a classical limit of a quantum cosmology
If the gravitational field is quantized, then a solution of Einstein's field equations is a valid cosmological model only if it corresponds to a classical limit of a quantum cosmology. To determine which solutions are valid requires looking at quantum cosmology in a particular way. Because we infer the geometry by measurements on matter, we can represent the amplitude for any measurement in terms of the amplitude for the matter fields, allowing us to integrate out the gravitational degrees of freedom. Combining that result with a path-integral representation for quantum cosmology leads to an integration over 4-geometries. Even when a semiclassical approximation for the propagator is valid, the amplitude for any measurement includes an integral over the gravitational degrees of freedom. The conditions for a solution of the field equations to be a classical limit of a quantum cosmology are: (1) The effect of the classical action dominates the integration, (2) the action is stationary with respect to variation of the gravitational degrees of freedom, and (3) only one saddlepoint contributes significantly to each integration.
14899076
On star formation in primordial protoglobular clouds.
Using a new physical model for star formation (Padoan 1995) we have tested the possibility that globular clusters (GCs) are formed from primordial mass fluctuations, whose mass scale (10 8 - 10 9 M⊙) is selected out of a CDM spectrum by the mechanism of non-equilibrium formation of H2.
20354147
Possible Phase Loop for the Global Decoupling
The two eigentunes Q<inf>I</inf>and Q<inf>II</inf>, two eigenmode amplitude ratios R<inf>I</inf>and R<inf>II</inf>, and two eignmode phase differences Δφ<inf>I</inf>and Δφ<inf>II</inf>, are defined as the coupling observables for the linear weak difference betatron coupling. Simulations were carried out to investigate their behaviors in global decoupling scans. It was found that the amplitude ratios R<inf>I</inf>,<inf>II</inf>are more sensitive than the tune split when the decoupling scan is approaching the global uncoupled point, and that the phase differences Δφ<inf>I</inf>,<inf>II</inf>tell the right global decoupling direction, the right strength combination of the skew quadrupoles or families. The analytical solution to these six coupling observables is calculated through both the strict matrix approach and the perturbation Hamiltonian approach. The constant phase differences in the right decoupling direction hint a possible global decoupling phase loop. Dedicated beam experiments were carried out at the Relativistic Heavy Ion Collider (RHIC). The preliminary results from the beam experiments are presented. These six parameters can be used for the global decoupling in feedback mode, especially on the non-stop energy ramp.