120259220
ATLAS computing and the GRID
At the most conservative estimates, ATLAS will produce over 1 Pb of data per year requiring 1-2M SpecInt95 of CPU to process and analyse, and to generate large Monte Carlo datasets. The collaboration is worldwide, and only Grids will allow all collaborators must have access to the full datasets. Atlas must develop an intercontinental distributed computing and data Grid with a user interface to shield the user from the Grid middleware and the distributed nature of the processing; we must develop automated production systems using the Grid tools; and we must provide tools that automatically distribute, install and verify the required experimental software and run-time environment to remote sites to avoid the problems of chaotic and multi-site management. Bookkeeping, replication and monitoring are also required. All of these topics are being addressed within the collaboration, with Grid tools being used for large-scale Data Challenges.
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.
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.
65296691
ATLAS computing: Technical design report.
126069786
Physics and detector performance measurements with the decays B0(s) ---> J/Psi Phi and B0(d) ---> J/Psi K0* with early data
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.
17515691
The classical action for a Bianchi VI_h model
An estimate for the classical action for a Bianchi VI_h homogeneous spatially closed cosmology is presented as a function of b, a parameter of the model that is proportional to the relative rotation of the average inertial frame and the bulk of matter in the universe. It is assumed (through the equation of state) that a relativistic early universe is followed by a matter-dominated late universe. The action is used in a saddlepoint approximation to a semiclassical estimate for the wave function in quantum cosmology to explain why our inertial frame seems not to rotate relative to the stars. The saddlepoint is at b=0, as would be expected. Application of the saddlepoint approximation leads to the result that only those classical geometries whose action differs from the saddlepoint value for the action by an amount less than Planck's constant contribute significantly to the integration to give the present value of the wave function. Using estimates for our universe implies that only those classical geometries for which the present relative rotation rate of inertial frames and matter are less than about 10^(-130) radians per year contribute significantly to the integration. This is well below the limit set by experiment. The result depends on the ratio of the Hubble distance to the Planck length, but does not depend on the details of the theory of quantum gravity.
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.