An international team of over 2,000 scientists, led by Professor Tejinder Virdee from Imperial College London’s Department of Physics is stepping up preparations for the world’s largest ever physics experiment next year at CERN near Geneva, Switzerland.
Professor Virdee is the lead scientist on the Compact Muon Solenoid (CMS) particle detector experiment, which will aim to find new particles, detect mini black holes 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. Particles are the building blocks of matter and are even smaller than atoms. Scientists hope the CMS experiment may also help them progress towards a unified theory to explain all physical phenomena – a theory that has eluded scientists up until now.
The CMS experiment has so far involved thousands of scientists and engineers working for 15 years to design and build the massive particle detector, which is currently being lowered – huge bit by huge bit – into a chamber 100 metres below the French town of Cessy, near the Swiss border. Next year, CERN’s Large Hadron Collider particle accelerator will be switched on for the first time, accelerating beams of particles around a 27km circular tunnel underneath the Swiss/French countryside. These particles then collide with each other – with higher energies than in any experiment ever before – at the precise location where the particles are passing through the CMS detector.
Professor Virdee explains: “When the particles smash into each other inside the CMS detector the high energy conditions created in these collisions will be similar to those that occurred in the first instants of the universe, immediately after the Big Bang. The unique conditions created by these collisions will create many new particles that would also have existed in those early instants. Resultant particles will fly away from the site of the collision in all directions. The different layers of our complex detector will measure the properties of these particles, track their paths, and measure their energies. An extremely powerful magnet built into the detector will bend the paths of electrically charged particles, which will help us identify the different types of particles produced in the collisions.”
One of the particles that Professor Virdee and his colleagues are hoping to detect is the Higgs-Boson, a particle which has been theorised but never actually recorded. “It would be a real coup if we recorded, for the first time ever, the existence of the Higgs-Boson particle,” says Professor Virdee. “Scientists believe the Higgs-Boson is the particle that gives the property of mass to other particles such as electrons and so on. If we can prove that it exists and that this is the case, we will have taken a big step towards a much fuller understanding of how the universe works, and indeed, what happened in the instants immediately after it was formed.”
The CMS detector is one of four experiments sited at different locations on the 27km ring of CERN’s Large Hadron Collider. The construction of CMS is an international effort, with different parts of the various layers of the detector being made by scientific collaborators from 37 different countries.
Constituent parts of CMS, weighing up to 2000 tonnes, are currently being lowered, by a specially-adapted shipbuilding crane, down 100 metres into the cavern where they will be re-assembled and prepared for data taking over the course of the next year. It is anticipated that the particle accelerator will be switched on just before Christmas 2007, at which time data will begin to be recorded. Imperial College London / Science Daily