ACADEMIA

Thirty one UK and Ireland members of the LHCb collaboration braved uncertain weather to attend the third LHCb-UK Software Course, held at the National e-Science Centre (NeSC), Edinburgh, on 7th-10th January. Like previous years' events, the course introduced participants to the software and computing environment of LHCb, and was supported by GridPP. The course particularly focused on the software for physics analysis and on the tools for running an analysis on the Grid, but applications for event simulation and reconstruction were also covered. In contrast with Edinburgh's cancelled Hogmanay celebrations, the LHCb-UK Software Course was again an outstanding success. Familiarity with the experiment's software applications and Grid-based computing model is of vital importance for anyone who wants to be involved in the LHCb physics exploitation. Jonas Rademacker, LHCb-UK physics coordinator and one of the tutors at the software course, explains: "In about a year from now, LHCb will start recording vast amounts of data for 14TeV proton-proton collisions at the LHC. LHCb is designed for precision measurements of CP violation and the structure of the quark sector, with high sensitivity to new physics. The LHCb-UK community aims to be at the forefront of LHCb data analyses, with high quality and highly relevant results already in the first year of data taking. To achieve this, LHCb-UK physicists need to be in a position to make best use of the available resources, analysis software and the Grid. The annual LHCb Software course is therefore an essential part of the training of LHCb-UK postgraduate students and all others preparing for LHCb data analysis." Each half-day of the course consisted of two or three relatively short presentations, followed by an extended hands-on session, where students gained experience with the software they'd just heard about. The hands-on sessions took place in the NeSC training room, which was equipped with 20 desktop machines and additionally allowed up to 20 laptop users to connect to a wireless network. Participants worked on their accounts on the CERN lxplus machines, so that everyone had the same work environment and had access after the course to files created during the exercises, but the LHCb software was also installed on the NeSC desktop machines as a backup in case of network problems. A special characteristic of the LHCb-UK Software Courses is that a tutor from one session can be a student in another session, which might deal with a topic where he or she has less expertise. In this way, all participants are brought up-to-date with a wide range of LHCb software developments. Participants were welcomed by NeSC director Peter Clarke, and over the course's two-and-a-half days had talks from 11 speakers. The first day's morning session provided an overview of the LHCb computing environment, the experiment's C++ software framework, named Gaudi after the Catalan architect, and the data-processing applications. The afternoon session then covered Grid-based computing in LHCb, the Ganga (Gaudi and Grid Alliance) job-managment framework developed to simplify access to Grid resources, and the basics of the LHCb analysis application. Detailed use of this application was explored during the second day, where participants developed their own algorithm for selecting a particular b-hadron decay, many obtaining impressive signal peaks by the end of the afternoon. The course finished with the third day's morning session, which dealt with the LHCb applications for simulation, digitisation and reconstruction. Previous LHCb-UK Software Courses have been instrumental in introducing participants to distributed computing and Grid tools, last year's course leading directly to the first significant use of the Grid for LHCb physics analysis (http://www.gridpp.ac.uk/news/-1149863627.881156.wlg). With the EGEE Grid offering an increasingly large number of resources, the LHCb Grid tools, and in particular Ganga, had even more importance at this year's course. Having learnt to work with it on the first day, participants used Ganga in all subsequent sessions for building and running their code. NeSC technical support staff were greatly impressed by the high levels of activity during the software course, commenting that they had "never seen the training room so busy". Andres Osorio, who took care of the local organisation, expands on this: "This was not only because most of the desktop computers were used by the participants, but also because of the number of laptops being used by students and tutors, and the dynamic atmosphere that characterised these sessions. Despite the heavy load on the network, all training sessions went smoothly. The students didn't encounter any technical difficulties, meaning that they were free to concentrate on the course content. An indicator of the success of these sessions was the difficulty of bringing them to an end: everyone was well motivated to keep working on the exercises. There was no time to be bored!" Andres echoed the sentiments of all participants in his appreciation of the work done by the NeSC staff in helping make the course a success: "I really want to thank the conference organisation team at NeSC, and in particular Lee Callaghan, for their excellent work. I similarly want to thank the technical support staff, who helped install the LHCb software on the NeSC computers, and provided us with a venue of very high standard for our training." Presentations and exercises from the 3rd LHCb-UK Software Course are attached to the course agenda at: its Web site If you're interested in attending, or hosting, a future LHCb-UK Software Course, please contact: Karl Harrison. Source: GridPP