Scientists set to simulate creation of the universe

Artist's impression of the underground experimental hall, complete with 15m long main detector (the central cylinder), of the proposed linear electron- positron collider

Scientists at Oxford are among an international group of physicists devoted to recreating the immediate aftermath of the big bang, as part of a major project to study the infinitesimal world of elementary particles. The project, which aims to explain how the universe was created, will involve building two 10km long particle accelerators capable of shooting beams of electrons head-on at positrons. The electrons and positrons, travelling at almost the speed of light, would annihilate one another on impact. Their collision would produce an energy equivalent to 1,000 billion volts. This contrasts with, say, the electrons that light up a television set which have an energy equivalent to about 10,000 volts. By producing such an enormous amount of energy in a tiny region of space, particle physicists hope to recreate the conditions which were present just a fraction of a second after the universe was created in the big bang. The energy will condense into new subatomic particles, including, potentially, the `Higgs boson', a particle which has been said to exist, but as yet undiscovered. It is the last undiscovered component in the periodic table of subatomic particles that is described by the Standard Model. Dr Philip Burrows, Particle Physics and Astronomy Research Council Advanced Fellow in the Sub-department of Particle and Nuclear Physics, organised an international workshop at the University in April, which brought together 170 delegates from Europe, the US, and Japan, to address key issues such as the technologies needed to detect the hoped-for new subatomic particles. The world's largest particle accelerator is currently the 27km long circular collider at CERN, the European particle physics research centre. However, the planned linear collider would allow the electrons and positrons to be accelerated about five times the energy. In order to maximise the chance that the electrons and positrons will collide, about 10 billion of each will be put into beams—each measuring around one-thousandth the width of a human hair. Dr Burrows said: `Making these beams hit one another head-on after accelerating over 20km will push large-scale engineering technology to the limits. The process will be much harder than firing two machine guns at one another and making the bullets collide. `The new instrument would, for particle physicists, be a tool comparable to that provided by the Hubble Space Telescope for astronomers,' said Dr Burrows. `Hopefully we will be able to uncover a new level of structure and beauty at the smallest distances yet probed.' Following the Oxford workshop, it is hoped that the world physics community will join in a single endeavour to open up a new window on the quantum universe.