17317284
CMS Monte Carlo production in the WLCG computing Grid
Monte Carlo production in CMS has received a major boost in performance and 
scale since the past CHEP06 conference. The production system has been re-engineered in order 
to incorporate the experience gained in running the previous system and to integrate production 
with the new CMS event data model, data management system and data processing framework. 
The system is interfaced to the two major computing Grids used by CMS, the LHC Computing 
Grid (LCG) and the Open Science Grid (OSG). 
Operational experience and integration aspects of the new CMS Monte Carlo production 
system is presented together with an analysis of production statistics. The new system 
automatically handles job submission, resource monitoring, job queuing, job distribution 
according to the available resources, data merging, registration of data into the data 
bookkeeping, data location, data transfer and placement systems. Compared to the previous 
production system automation, reliability and performance have been considerably improved. A 
more efficient use of computing resources and a better handling of the inherent Grid unreliability 
have resulted in an increase of production scale by about an order of magnitude, capable of 
running in parallel at the order of ten thousand jobs and yielding more than two million events 
per day.
59576416
CDF SILICON VERTEX TRACKER: TEVATRON RUN II PRELIMINARY RESULTS
The Online Silicon Vertex Tracker (SVT) is the unique new trigger processor dedicated to the 2-D reconstruction of charged particle trajectories at Level 2 of the CDF trigger. The SVT has been successfully built, installed and operated during the 2000 and 2001 CDF data taking runs. The
204003557
Study of Hadronic Events in $e^{+} e^{-}$ Collisions using Detector at Large Electron Positron (LEP) Collider at CERN
110456171
Real-time dataflow and workflow with the CMS tracker data
The Tracker detector took data with cosmics rays at the Tracker Integration Facility (TIF) at CERN. First on-line monitoring tasks were executed at the Tracker Analysis Centre (TAC) which is a dedicated Control Room at TIF with limited computing resources. A set of software agents were developed to perform the real-time data conversion in a standard format, to archive data on tape at CERN and to publish them in the official CMS data bookkeeping systems. According to the CMS computing and analysis model, most of the subsequent data processing has to be done in remote Tier-1 and Tier-2 sites, so data were automatically transferred from CERN to the sites interested to analyze them, currently Fermilab, Bari and Pisa. Official reconstruction in the distributed environment was triggered in real-time by using the tool currently used for the processing of simulated events. Automatic end-user analysis of data was performed in a distributed environment, in order to derive the distributions of important physics variables. The tracker data processing is currently migrating to the Tier-0 CERN as a prototype for the global data taking chain. Tracker data were also registered into the most recent version of the data bookkeeping system, DBS-2, by profiting from the new features to handle real data. A description of the dataflow/workflow and of the tools developed is given, together with the results about the performance of the real-time chain. Almost 7.2 million events were officially registered, moved, reconstructed and analyzed in remote sites by using the distributed environment.
118143564
The Dependence of Muon-Size on Shower Size and the Composition of Cosmic Ray Primaries
119023076
The CDF Analysis Farm
Since the beginning of Run II in 2001 the Fermilab Tevatron has been delivering proton‐antiproton collisions to CDF with a steadily increasing performance. By the end of Run II up to 8 fb−1 of integrated luminosity are expected to be available on tape. In order to provide the CDF Collaboration members with adequate computing resources for analyzing those data, a globally distributed pool of dedicated PC farms has been commissioned and is currently being successfully deployed. This paper describes the main features of the CDF Analysis Farm with particular attention to the user perspective. The last part is devoted to a brief overview of the more relevant technical details on the farm implementation and, finally, the future developments toward its integration in the GRID framework are outlined.
118221775
Comment on `High spin structure of the neutron-rich nuclei I-137 and Cs-139'
S. H. Liu et al. [Phys. Rev. C 80, 044314 (2009)] have demonstrated that an accurate description of $^{137}\mathrm{I}$ may be obtained within the shell model. It seems that they have missed one of the shell model calculations done earlier. They have also missed the earlier theoretical results for $^{139}\mathrm{Cs}$, where some of the levels observed in their work were predicted.
110266088
The preliminary laser control system for the TRIUMF optically pumped polarized ion source
A system to provide detailed information on control parameters for the lasers used in the optically pumped polarized ion source at TRIUMF has been constructed. The authors describe the overall structure of the system and give details of the instrumentation used. Test and control programs to operate some of the devices and implement a slow spin-flipping operation have been developed and run on the workstation. During initial tests laser beam positions were found to be more stable than expected, and the requirement for controlling mirror motors and beam position detectors has been dropped from the final system. Laser frequency drift was less in the temperature-controlled laser room than in initial tests. >
119598948
Asymptotic analysis of the Boltzmann equation for dark matter relics
This paper presents an asymptotic analysis of the Boltzmann equations (Riccati differential equations) that describe the physics of thermal dark-matter-relic abundances. Two different asymptotic techniques are used, boundary-layer theory, which makes use of asymptotic matching, and the delta expansion, which is a powerful technique for solving nonlinear differential equations. Two different Boltzmann equations are considered. The first is derived from general relativistic considerations and the second arises in dilatonic string cosmology. The global asymptotic analysis presented here is used to find the long-time behavior of the solutions to these equations. In the first case, the nature of the so-called freeze-out region and the post-freeze-out behavior is explored. In the second case, the effect of the dilaton on cold dark-matter abundances is calculated and it is shown that there is a large-time power-law fall off of the dark-matter abundance.
119400581
Probing models of quantum decoherence in particle physics and cosmology
In this review we discuss the string theoretical motivations for induced decoherence and deviations from ordinary quantum-mechanical behaviour; this leads to intrinsic CPT violation in the context of an extended class of quantum-gravity models. We proceed to a description of precision tests of CPT symmetry and quantum mechanics using mainly neutral kaons and neutrinos. We emphasize the possibly unique role of neutral meson factories in providing tests of models where the quantum-mechanical CPT operator is not well-defined, leading to modifications of Einstein-Podolsky-Rosen particle correlators. Finally, we discuss experimental probes of decoherence in cosmology, including studies of dissipative relaxation models of dark energy in non-critical (non-equilibrium) string theory and the associated modifications of the Boltzmann equation for the evolution of species abundances.
53492385
Mechanical prototype of tracking chamber in station 2 in dimuon spectrometer of ALICE
To explore the physics of ultra-relativistic heavy-ion collision, a large ion collider experiment (ALICE) [1] is proposed to carry out at large hadron collider (LHC). Forward muon spectrometer (FMS) [2] is included in ALICE to look for the signals of quark gluon plasma (QGP) using dileptonic decay of heavy quarkonia (J=ψ , γ) produced in the collision as a probe. The production of these states will be suppressed in a deconfined medium of QGP which can be estimated from the invariant mass spectrum of dimuonic decay channel. The spectrometer is designed to track down the flight path of the dimuons with the help of five tracking stations from which the opening angle of the pair can be known by reconstruction and extrapolation of their tracks. The momenta of the pairs can be obtained from the deviation of the tracks in a dipole magnetic field. The invariant mass of the pair can be determined from the opening angle and momenta of dimuon pairs. Each of the five tracking stations is equipped with two planes of cathode pad chamber each divided into four quadrants to detect the position of the dimuon passing through them and reconstruct their tracks from their positions. The tracking chambers are designed following the basic feature of a position sensitive multi-wire proportional counter (MWPC) where an anode wire plane is interposed between two cathode planes and a high electric field is maintained near the anode with respect to the cathodes. The chambers are capable of providing X, Y position readout of an event from the charge distribution induced over the cathode planes equipped with pad matrices due to the avalanche produced in the gaseous medium. However, the mechanical design of the large chamber (diameter 2 m) for the second tracking station is a challenging task as it concerns good surface planarity to achieve position resolution better than 100 μm (necessary to meet mass resolution about 100 MeV) as well as minimum usage of material to keep radiation length low (2–3% of X0) in order to minimise the energy loss and scattering of the incident lepton. The calculation was carried out at IPN, Orsay to simulate a full scale quadrant with different design parameters and materials to study its mechanical characteristics [3,4]. In the simulation, various options in material and design aspects were studied to seek an optimum design for the chamber to enhance its mechanical