Installing and Configuring Application Software on the LHC Computing Grid

The management of application software is major scientific and practical challenge for designers of large-scale production Grids The Large Hadron Collider Computing Grid is unique in the sense that coupling between application scientists and the resource providers is extremely loose, thus adding even more complexity to the software management problem. After an analysis of the requirements for a Grid software management service from users and site administrators perspective, we give an overview of the solution adopted by the LHC Grid infrastructure to support High Energy Physics experiments, highlighting features and current limitations. Tank&Spark is our server-client solution that extends the LHC Grid application software system and tackles some of its limitations. Tank&Spark can be used as a stand-alone service also in other Grid infrastructures. Here we illustrate the design, deployment and preliminary results obtained

Integrated optical waveplates for arbitrary operations on polarization-encoded single-qubits

Integrated photonic technologies applied to quantum optics have recently enabled a wealth of breakthrough experiments in several quantum information areas. Path encoding was initially used to demonstrate operations on single or multiple qubits. However, a polarization encoding approach is often simpler and more effective. Two-qubits integrated logic gates as well as complex interferometric structures have been successfully demonstrated exploiting polarization encoding in femtosecond-laser-written photonic circuits. Still, integrated devices performing single-qubit rotations are missing. Here we demonstrate waveguide-based waveplates, fabricated by femtosecond laser pulses, capable to effectively produce arbitrary single-qubit operations in the polarization encoding. By exploiting these novel components we fabricate and test a compact device for the quantum state tomography of two polarization-entangled photons. The integrated optical waveplates complete the toolbox required for a full manipulation of polarization-encoded qubits on-chip, disclosing new scenarios for integrated quantum computation, sensing and simulation, and possibly finding application also in standard photonic devices

Nuisance <i>Didymosphenia geminata</i> blooms in the Argentinean Patagonia : Status and current research trends

Large nuisance blooms of Didymosphenia geminata have become increasingly widespread in Patagonia. Although the first published account for South America was in 1964, reports of large growths in Chile and Argentina commenced around 2010. Since then, these blooms have been observed all along the Andes region to the south of parallel 42 S. General surveys are needed to help provide an explanation. Possibilities include one or more new genetic variants or responses of local populations to global environmental changes. Electron microscopy of material from the Argentinean Patagonia revealed marked differences between regions, though it is unclear how much local factors and/or variations in life cycle contribute. Thus, we are approaching the problem from a molecular perspective, which we hope will help to overcome this limitation. Initial studies showed that D. geminata seems to be highly recalcitrant to DNA extraction, thus hindering the survey of molecular markers. We have now developed an improved DNA extraction technique for Didymosphenia mats, which markedly outperforms other techniques. However, endpoint polymerase chain reaction analyses suggest the persistence of polymerase chain reaction inhibitors in the samples, highlighting the need of further improvements for quantitative studies.Facultad de Ciencias Naturales y Muse

Study of radiation damage and substrate resistivity effects from beam test of silicon microstrip detectors using LHC readout electronics

We present the beam test results of single-sided silicon microstrip detectors, with different substrate resistivities. The effects of radiation damage are studied for a detector irradiated to a fluence of 2.4 multiplied by 10**1**4 n/cm**2. The detectors are read out with the APV6 chip, which is compatible with the 40 MHz LHC clock. The performance of different detectors and readout modes are studied in terms of signal-to-noise ratio and efficiency

Experience Supporting the Integration of LHC Experiments Software Framework with the LCG Middleware

The LHC experiments are currently preparing for data acquisition in 2007 and because of the large amount of required computing and storage resources, they decided to embrace the grid paradigm. The LHC Computing Project (LCG) provides and operates a computing infrastructure suitable for data handling, Monte Carlo production and analysis. While LCG offers a set of high level services, intended to be generic enough to accommodate the needs of different Virtual Organizations, the LHC experiments software framework and applications are very specific and focused on the computing and data models. The LCG Experiment Integration Support team works in close contact with the experiments, the middleware developers and the LCG certification and operations teams to integrate the underlying grid middleware with the experiment specific components. The strategical position between the experiments and the middleware suppliers allows EIS team to play a key role at communications level between the customers and the service providers. This activity is the source of many improvements on the middleware side, especially by channelling the experience and the requirements of the LHC experiments. The scope of the EIS activity encompasses several areas: 1) Understanding of the experiment needs 2) Identify open issues and possible solutions 3) Develop specific interfaces, services and components (when missing in or not yet satisfactory) 4) Provide operational support during Data Challenges, Service Challenges and massive productions. 5) Provide and maintain the user documentation; 6) Provide tutorial for the users community In the last year, the focus has been extended also to non High-Energy Physics communities like Biomed, GEANT4 and UNOSAT. In this work we discuss the EIS experience, describing the issues raising in the organization of the Virtual Organization support and the achievements, together with the lessons learned. This activity will continue in the framework of EGEE II, an

First Study of the CMS Sensitivity to the Neutrinoless Decay Tau Rightarrow mu^+ mu^+ mu^-

Recent results from Super Kamiokande suggest nu_tau-nu_mu mixing and hence lepton flavor violation. Since then this subject became an important topic of investigation. An improvement of experimental sensitivity on the Branching Ratio for process involving a cross-generation change in the charged lepton sector is thus of interest, either in a discovery search or in a study for the exclusion limit. It can also bring information on the SUSY scenario potentially at work in such processes. We have undertaken a study of the possibility to observe in CMS the Standard Model forbidden decay tau rightarrow 3 mu exploiting the signal from the most important sources of tau leptons at LHC. A study of taus originating from W and Z boson decays, as well as from b-quark mesons is discussed in this note. We used the GEANT3 detector simulation program it cmsim 122 and the current C++ reconstruction progra m for CMS (ORCA version 5_3_2). We also report a comparison of the results obtained with a fast simulation based analysis for signal events from W in the barrel region. The main goal of this comparison is to check the validity of the final results and the performances foreseen for the CMS sub-detectors involved in the study of this channel. At this stage this study shows that CMS should be able to improve on the present experimental limit set by CLEO II by about a factor of 50 with 30 fb^-1 of integrated luminosity

New developments on the LHCb bookkeeping

The LHCb Bookkeeping is the service which aims to keep the data of the LHCb experiment coherently organised. It provides information on the provenance of data and all kinds of metadata to allow for the characterisation of the data. This service is undergoing a restructuring and reorganization to optimise its functionality and to make it suitable for handling the forthcoming data taking. In particular, the functionality which allows users to search for datasets has been replaced with a new client The Bookkeeping (Bkk) is a crucial component in the LHCb software infrastructure, both for the production, as it registers and uploads to the database all newly produced files, as well as for the data analysis, since it is the tool which allows physicists to retrieve datasets and their metadata. The motivation for this activity on the Bkk arises from requirements of the physicists, who outlined a lack of efficiency of the service. Issues raised include the current user interface, implemented as a web page, is not flexible enough and has broken functionality. Furthermore, the service does not provide exhaustive information on the metadata and returns the output to the user in a rather cumbersome way. The objective now is to provide a new client to allow physicists to search for data and relative metadata in the most flexible and efficient way possible. The new client is implemented in Python, for consistency with the rest of the LHCb software infrastructure The impact of a restructuring of the Bkk is immediate for the physics community of the LHCb experiment since physicists are direct users of this service. The new client of the Bkk will be also implemented in the Ganga framework, easing the way LHCb physicists can construct their analysis jobs and improving the functionality to search for replicated data at different sites A new client for the BKK is being developed. The client is implemented as a python module, and includes all the functionality required by the LHCb physicists. The implementation of the module inside Ganga is still ongoin

Human Behavior Understanding with Wide Area Sensing Floors

The research on innovative and natural interfaces aims at developing devices able to capture and understand the human behavior without the need of a direct interaction. In this paper we propose and describe a framework based on a sensing floor device. The pressure field generated by people or objects standing on the floor is captured and analyzed. Local and global features are computed by a low level processing unit and sent to high level interfaces. The framework can be used in different applications, such as entertainment, education or surveillance. A detailed description of the sensing element and the processing architectures is provided, together with some sample applications developed to test the device capabilities