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Saturday, June 5, 2010

Why is there something rather than nothing

The Big Bang theory predicts that equal amounts of matter and anti-matter were created in the early universe. Since these two materials annihilate each other, a question that has puzzled physicists is: why is there something rather than nothing? In other words, why does matter exist? Physicists at Fermi National Accelerator Laboratory have taken an important step in answering that question.

The research team, known as the DZero collaboration, used Fermilab’s Tevatron Particle Collider (the second largest particle collider in the world, now that the Large Hadron Collider is back on line) to analyze neutral B-meson decay. B-mesons are subatomic particles that spontaneously switch between anti-matter and matter trillions of times per second in ‘flavor oscillations’. When the B-mesons decay, they can form either muons (another type of subatomic particle) or anti-muons, depending on what state the B-meson was in at the moment of decay. To the scientists’ surprise, they found that fully 1% more muons than anti-muons were formed during the B-meson decay. For some as yet unknown reason, B-mesons spend fractionally more time as matter than as anti-matter.

The asymmetry between the amounts of matter and anti-matter is what allows our universe to be full of ‘stuff’. This set of experiments is the first time that asymmetry has been directly observed. If confirmed by further experiments, it could lead to whole new ideas in physics.

The Tevatron Particle Collider at Fermilab.