B. Hegner

Physics Analysis Tools for the CMS Experiment at LHC

The CMS experiment is expected to start data taking during 2008, and large data samples, of the peta-bytes scale, will be produced each year. The CMS Physics Tools package provides the CMS physicist with a powerful and flexible software layer for analysis of these huge datasets that is well integrated in the CMS experiment software. C++ generic programming is used to allow simple extensions of analysis tools. A core part of this package is the Candidate Model providing a coherent interface to different types of data. Standard tasks such as combinatorial analyses, generic cuts, MC truth matching and constrained fitting are supported. Advanced template techniques enable the user to add missing features easily. We explain the underlying model, certain details of the implementation and present some use cases showing how the tools are currently used in generator and full simulation studies as preparation for analysis of real data.

Planning and organization of an e-learning training program on the analysis software in CMS

Analyzing physics data at LHC experiments is a complicated task involving multiple steps, sharing of expertise, cross checks and comparing different analyses. To maximize physics productivity, the CMS experiment at LHC has developed a collection of analysis tools called the PAT (Physics Analysis Toolkit). A comprehensive training program was designed and setup on using PAT software as an integral key part of the analysis of data from the CMS experiment. This note summarizes the requirements and the considerations that led to establish the PAT training program, the approach taken, the main organizational issues and the experience on its implementation and maintenance. The training and the feedback has proved to be very successful both for participants and the PAT development team.

A Perspective of User Support for the CMS Experiment

The CMS (Compact Muon Solenoid) experiment is one of two large general-purpose particle physics detectors at the LHC (Large Hadron Collider). An international collaboration of nearly 3500 people operates this complex detector whose main goal is to answer the most fundamental questions about our universe. The size and globally diversified nature of the collaboration and the Petabytes/year of data being collected, presents a big challenging task in bringing users up to speed to contribute to the physics analysis. The CMS User Support performs this task by helping users quickly learn about the CMS computing and the needed physics analysis tools. In this presentation we give an overview of its goals, organization and usage of collaborative tools to maintain the software and computing documentation and conduct year around tutorials on several physics tools needed as a pre-requisite for physics. We also talk about the user feedback evaluating its work.

arXiv : HEP Software Foundation Community White Paper Working Group - Data Analysis and Interpretation

At the heart of experimental high energy physics (HEP) is the development of facilities and instrumentation that provide sensitivity to new phenomena. Our understanding of nature at its most fundamental level is advanced through the analysis and interpretation of data from sophisticated detectors in HEP experiments. The goal of data analysis systems is to realize the maximum possible scientific potential of the data within the constraints of computing and human resources in the least time. To achieve this goal, future analysis systems should empower physicists to access the data with a high level of interactivity, reproducibility and throughput capability. As part of the HEP Software Foundation Community White Paper process, a working group on Data Analysis and Interpretation was formed to assess the challenges and opportunities in HEP data analysis and develop a roadmap for activities in this area over the next decade. In this report, the key findings and recommendations of the Data Analysis and Interpretation Working Group are presented.

The CMS analysis model

We review the options for performing user analyses at CMS. In this text we put the CMS physics analysis software framework and other tools in the context of a bigger picture of performing data analysis. The flow of physics data through layers of skimming is briefly described, and the user options for analyzing objects on local computing resources or laptop discussed in turn. We present the first experiences with this model obtained after the recent start of the LHC physics programme.