First results from Large Hadron Collider

Liverpool scientists have presented some of the first results from the Large Hadron Collider (LHC) – the world’s largest scientific experiment – at the International Conference on High Energy Physics (ICHEP) opened in Paris this week by President Sarkozy.

Based 100 metres below ground at CERN, the European Particle Physics Laboratory in Geneva, the LHC is the most powerful particle accelerator ever built and is seeking answers to some of the most fundamental mysteries of the Universe, from anti-matter to dark matter and the existence of extra dimensions.

Operating at 3.5 TeV per beam – an energy three-and-a-half times higher than previously achieved by a particle accelerator – the LHC’s first measurements are rediscovering the particles that lie at the heart of the Standard Model. The Standard Model represents all the current understanding of the fundamental particles of matter and the forces that act between them.

CERN’s Director-General, Rolf Heuer, said: “Rediscovering our ‘old friends’ in the particle world shows that the LHC experiments are well prepared to enter new territory. It seems that the Standard Model is working as expected. Now it is down to nature to show us what is new.

“Particle physicists and engineers of University of Liverpool have made major contributions to the detectors and to first results presented at Paris by LHCb and ATLAS, two experiments of a new dimension at the LHC, which they have been preparing for nearly 20 years.”

Physicists from the University worked on the construction of LHCb and ATLAS – two of the four detectors in the LHC – working closely with engineers and scientists from around the world. One of the central sub-detectors of ATLAS – the EndCap-C silicon micro-strip tracker – was assembled entirely at the Semiconductor Detector Centre.

Post-doctoral Fellow Jan Kretzschmar, from the Department of Physics, presented the first results surrounding production of W and Z particles at the conference using ATLAS data. W and Z particles are the force-carrying particles of the ‘weak’ force, responsible for aspects of radioactivity and the processes which power the Sun and all stars. Liverpool PhD student Peter Waller made a presentation on detector and software performance.

Senior Physics Lecturer Uta Klein, who co-chairs an analysis team working on data from ATLAS, said: “The Liverpool team made strong contributions to the analysis on one of the hottest topics at the conference – the first results at this energy on production of the W and Z bosons.

“To have two of the 32 ATLAS presentations given by Liverpool scientists at the conference when there are 174 institutions involved in the ATLAS collaboration is clearly a great tribute to our research team.”

Professor Phil Allport, Head of Particle Physics, added: “This is a tribute to those presenting, to many colleagues like Uta, Dr Andy Mehta, Dr Monica D’Onofrio and others on editorial boards or preparing conference notes, and also to Professor Max Klein who has taken over leadership of the Liverpool ATLAS Group from Dr Neil Jackson, who in turn oversaw much of the UK hardware contributions to the experiment that made all this possible.”

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