http://news.bbc.co.uk/2/hi/science/nature/8593780.stm
http://news.bbc.co.uk/2/hi/science/nature/7567926.stm
The Alice detector will investigate the moments after the Big Bang.
The Standard Model comprises 16 particles – 12 matter particles and four force-carrier particles. The Standard Model has worked remarkably well so far. But it cannot explain the best known of the so-called four fundamental forces: gravity; and it describes only ordinary matter, which makes up but a small part of the total Universe. There is an essential ingredient missing from the Standard Model. Without it, none of the 16 particles in the scheme would have any mass.
All the matter that we can see in the Universe – planets, stars and galaxies – makes up a minuscule 4% of what is actually out there. The rest is dark energy (which accounts for 73% of the cosmos) and dark matter (23%).
According to one idea, dark matter could be made up of "supersymmetric particles" - massive particles that are partners to those already known in the Standard Model. Each basic particle of "ordinary" matter has its own anti-particle. Matter and antimatter have the same mass, but opposite electric charge.
When a particle of ordinary matter meets its anti-particle, the two disappear in a flash, as their mass is transformed into energy.
They are said to "annihilate" one another. But equal amounts of matter and anti-matter must have been produced in the Big Bang. So why did matter and anti-matter not completely annihilate each another after the birth of the Universe? Today, we live in a Universe almost entirely composed of ordinary matter. Scientists will use the LHC to investigate why this is, and what happened to all the anti-matter.
Attempts to unify gravity with the other fundamental forces have come to a startling prediction: that every known particle has a massive "shadow" partner particle. All particles are classified as either fermions or bosons. A particle in one class has superpartner in the other class, "balancing the books" and doubling the number of particles in the Standard Model.
