First results from one of the new Large Hadron Collider experiments at CERN

CMS scientists running the world’s biggest scientific experiment have published their first collision data from the new particle accelerator.

Thursday 18 February 2010
By Natasha Martineau

Physicists are celebrating the publication of the first set of data from the Compact Muon Solenoid (CMS) particle detector, just two months after the Large Hadron Collider (LHC) was switched on late last year at CERN in Geneva.

The results are published in the Journal of High Energy Physics, and provide the first information about some of the particles produced from the collisions in the LHC, which has accelerated protons to the highest energies achieved in an accelerator so far (1.18TeV - Tera electron Volts).

The CMS experiment is one of the two general purpose experiments designed to collect data from the LHC. Many members of Imperial's High Energy Physics group are working on the mission to find new particles, detect the elusive Higgs boson particle (if it exists), and solve some of the mysteries of the universe, such as where mass comes from, how many dimensions there are, and what constitutes dark matter.

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"The new data show that the CMS is analysing and reconstructing particle energies in accordance with our expectations", says Imperial physicist Professor Tejinder Virdee, who for several years led the team of international scientists that designed and built the CMS experiment. "It is hugely reassuring after so much work that our equipment is now up and running, and that we're already publishing first results."

"The new collision events we're looking for are very rare, so we need a good understanding of the ordinary ones, so that we can recognise the unusual ones when they happen," says Professor Geoff Hall, who has also played a key role in the CMS experiment.

One of the first LHC collision events observed at the maximum energy of 2.36 TeV, with charged particles shown in yellow.

"The results from the initial collisions give us tremendous encouragement for the future. After the LHC's initial run from November to December 2009, we are now planning an 18-month run starting in February 2010, when we plan to accelerate protons to 3.5TeV which will give us enough data to explore several important areas of the new physics we are working on."

Professors Virdee and Hall talk about the aims of the CMS experiment, their first set of results and their future hopes for the research in the video (above).

CERN is the European Organization for Nuclear Research. Based in Geneva, it is one of the world's largest centres for scientific research. It uses two main kinds of equipment: particle accelerators, such as the LHC, which accelerates particle beams around a 27km circular tunnel underneath the French/Swiss countryside; and detectors such as the CMS detector that enables the scientists to observe, record and analyse the high-energy particle collisions.