62187956
CMS analysis operations
During normal data taking CMS expects to support potentially as many as 2000 analysis users. Since the beginning of 2008 there have been more than 800 individuals who submitted a remote analysis job to the CMS computing infrastructure. The bulk of these users will be supported at the over 40 CMS Tier-2 centres. Supporting a globally distributed community of users on a globally distributed set of computing clusters is a task that requires reconsidering the normal methods of user support for Analysis Operations. In 2008 CMS formed an Analysis Support Task Force in preparation for large-scale physics analysis activities. The charge of the task force was to evaluate the available support tools, the user support techniques, and the direct feedback of users with the goal of improving the success rate and user experience when utilizing the distributed computing environment. The task force determined the tools needed to assess and reduce the number of non-zero exit code applications submitted through the grid interfaces and worked with the CMS experiment dashboard developers to obtain the necessary information to quickly and proactively identify issues with user jobs and data sets hosted at various sites. Results of the analysis group surveys were compiled. Reference platforms for testing and debugging problems were established in various geographic regions. The task force also assessed the resources needed to make the transition to a permanent Analysis Operations task. In this presentation the results of the task force will be discussed as well as the CMS Analysis Operations plans for the start of data taking.
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.
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.
117065404
Energy Spectrum of Primary Cosmic Rays from Air Shower Observations at Sea Level
111351794
A Job Monitoring and Accounting Tool for the LSF Batch System
This paper presents a web based job monitoring and group-and-user accounting tool for the LSF Batch System. The user oriented job monitoring displays a simple and compact quasi real-time overview of the batch farm for both local and Grid jobs. For Grid jobs the Distinguished Name (DN) of the Grid users is shown. The overview monitor provides the most up-to-date status of a batch farm at any time. The accounting tool works with the LSF accounting log files. The accounting information is shown for a few pre-defined time periods by default. However, one can also compute the same information for any arbitrary time window. The tool already proved to be an extremely useful means to validate more extensive accounting tools available in the Grid world. Several sites have already been using the present tool and more sites running the LSF batch system have shown interest. We shall discuss the various aspects that make the tool essential for site administrators and end-users alike and outline the current status of development as well as future plans.
107947607
RECENT DEVELOPMENTS IN THE TRIUMF CONTROL SYSTEM
The principle ideas and underlying architecture of the TRIUMF Central Control System have not changed since its commissioning in 1974. As described elsewhere 1,2,3 the system consists of a number of Data General minicomputers which communicate using a proprietary Data General parallel direct memory access interprocessor bus, and which share access to a common multiported memory containing a limited descriptive data base of device addresses and pointers to acquisition and conversion routines (Figure 1). The most important idea of the TRIUMF Control System design, and one which has in large measure determined the manner of its evolution, is the use of the executive crate, by means of which all central system computers share direct and immediate access to the entire seven parallel branch CAM.4C system, which in turn interfaces all accelerator devices and most of the main Control Room console devices. Expansion of the Control System to date has been realized on one hand by the addition of CAM.4C crates, and on the other by the addition of minicomputers to the executive crate interface. With the use of active extenders. the executive crate has been extended to three CAMAC crates. and could in principle clcctrically support as many as 1500 sources. In practice, this number is limited to a.bout 30 sources by bandwidth considerations, and to even fewer by the geographical requirement that sources be located physically within about 50 ft. (I/O bus length limitation) of the executive crate. This paper describes three recent developments in the TRIIJMF system whose designs have been influenced by its multisourced architecture. These are:
16744767
Absence of M2 Retardation in $^{35}Cl$: Evidence for Stronger Isospin-Mixing Effects in A=35 Mirror Nuclei
The lifetime of the 3163 keV, 7/2$^-$ isomeric state in $^{35}Cl$ that decays by a stretched M2 transition to the $3/2^+$ ground state, has been re-measured using the Doppler Shift Attenuation Method, by gating on the 1185 keV transition which directly feeds this state. This eliminates the uncertainties in the measurement arising from the direct feedings from the continuum. A mean life of 0.6$^{+0.5}_{-0.2}$ ps has been obtained from the present work. This is considerably smaller than the adopted value 45.3(6) ps. Implication of this major reduction in the lifetime has been pointed out.
115620347
The Schwinger mechanisms in non-abelian gauge theories
Abstract An alternative to the Higgs-Kibble mechanism for the formulation of spontaneously broken gauge theories has been recently proposed. It is shown how the new procedures can be generalised to the case when non-Abelian gauge groups are present.
54602717
Experience with the TRIUMF Main Tank Vacuum Control System
The TRIUMF Main Tank Vacuum Control System was upgraded in 1984. The earlier system, which consisted of a collection of hardwired relay logic boxes housed in three standard instrumentation racks, was replaced with a compact and flexible microprocessor-based control system. The user interface, previously distributed over the three racks, was consolidated into a single hardwired control and mimic panel. Since 1984, the Main Tank Vacuum System has undergone a series of changes in configuration and vacuum pumping hardware with necessary changes being implemented in the control system logic. Corresponding changes to the user interface were sometimes difficult to implement and in time exhausted the spare input/output capacity which had been built in to the panel. The availability of inexpensive personal computers with adequate graphics capability and the ease of modifying, or adding to a programmable user interface precipitated the retirement of the hardwired panel and its replacement by a PC-based graphics user interface. System configuration, safety considerations, the hardware and the software implementation using the 'C' programming language are described. The evolution of the control system and its performance, both over the years and in adapting to the vacuum system changes, are discussed.<<ETX>>
123143461
Interacting holographic dark energy with variable deceleration parameter and tachyon scalar field dark energy model in LRS Bianchi type-II universe
In this work, we have considered the spatially homogeneous and anisotropic Bianchi type-II universe filled with two interacting fluids; dark matter and holographic dark energy components. Assuming the proportionality relation between one of the components of shear scalar and expansion scalar which yields time dependent deceleration parameter, an exact solution to Einstein’s field equations in Bianchi type-II line element is obtained. We have investigated geometric and kinematics properties of the model and the behaviour of the holographic dark energy. It is observed that the mean anisotropic parameter is uniform through the whole evolution of the universe and the coincidence parameter increases with increasing time. The solutions are also found to be in good agreement with the results of recent observations. We have applied the statefinder diagnostics method to study the behaviour of different stages of the universe and to differentiate the proposed dark energy model from the ΛCDM model. We have also established a correspondence between the holographic dark energy model and the tachyon scalar field dark energy model. We have reconstructed the potential and the dynamics of the tachyon scalar field, which describes accelerated expansion of the universe.