Washington: Physicists have carried out the first full run of experiments that smash protons together at almost the speed of light, bringing them a step closer towards the discovery of dark matter.
Dark matter is an invisible substance that we cannot detect directly but whose presence is inferred from the rotation of galaxies.
Researchers said the experiment would help them either confirm or rule out one of the primary theories that could solve many of the outstanding questions of particle physics, known as Supersymmetry (SUSY).
"We have made an important step forward in the hunt for dark matter, although no discovery has yet been made,” said Professor Geoff Hall from the Department of Physics at Imperial College London, who works on the CMS experiment.
“These results have come faster than we expected because the LHC and CMS ran better last year than we dared hope and we are now very optimistic about the prospects of pinning down Supersymmetry in the next few years."
The lightest sparticle is a natural candidate for dark matter as it is stable and CMS would only ``see`` these objects through an absence of their signal in the detector, leading to an imbalance of energy and momentum.
In order to search for sparticles, CMS looks for collisions that produce two or more high-energy ``jets`` (bunches of particles travelling in approximately the same direction) and significant missing energy.
"We need a good understanding of the ordinary collisions so that we can recognise the unusual ones when they happen. Such collisions are rare but can be produced by known physics,” said "We need a good understanding of the ordinary collisions so that we can recognise the unusual ones when they happen. Such collisions are rare but can be produced by known physics.
“We examined some 3 trillion proton-proton collisions and found 13 ``SUSY-like`` ones, around the number that we expected. Although no evidence for sparticles was found, this measurement narrows down the area for the search for dark matter significantly."
The next step is the 2011 run of the LHC and CMS, which is expected to bring in data that could confirm Supersymmetry as an explanation for dark matter.
First Published: Tuesday, February 01, 2011, 11:50