A scientific theory which suggests that the universes of matter and anti-matter are not quite the mirror images they were once thought to be has been vindicated by an experiment in California which may provide an explanation for the existence of the universe. Or at least its mass.
Scientists at the Stanford Linear Accelerator Centre in Palo Alto, using a particle detector known as BaBar, have announced they found evidence of different rates of decay of B mesons and anti-B mesons, tiny sub-atomic particles which have a life of no more than one trillionth of a second.
The variations may explain why, at the beginning of the universe, 13 billion years ago, during the first fraction of a nanosecond after the Big Bang, all the matter which had been created was not obliterated by the equal quantity of anti-matter also generated.
Scientists had originally seen matter and anti-matter as completely symmetrical opposites, analogous to a hole and the material dug out of it, whose meeting resulted in nothingness. An asymmetry between matter and anti-matter would leave a residue when equal quantities met and would explain why the universe is not a vast emptiness.
Evidence of asymmetry in K mesons, ten times smaller than B mesons, had been discovered in 1964 by Dr James Cronin and Dr Val Fitch, for which they won Nobel prizes.
Another Nobel laureate, Russia's Prof Andrei Sakharov suggested three years later that the asymmetry, also known as "charge-parity violation", might explain the mass of the universe if it could be shown to affect substantially heavier particles.
"For 37 years people have looked and they haven't found anything beyond the original one," the Princeton University physicist, Dr Stewart Smith, a spokesman for the BaBar group said on Friday.
"Physicists now know that there are at least two types of subatomic particles that exhibit this puzzling phenomenon, thought to be responsible for the great preponderance of matter in the universe."
The BaBar team, an international consortium of more than 600 scientists from 75 institutions in Canada, China, France, Germany, Great Britain, Italy, Norway, Russia and the US, used a 1.3 mile particle accelerator and the 1,200 ton detector to track the effects of collisions of electrons and positrons.
The work tends to confirm the current view of the universe, the Standard Model, which accurately predicted that B mesons and anti-B mesons would be slightly asymmetrical.
"We don't have to invent new physics to explain our results," Dr Smith said.
But the Standard Model is missing something, even if it is correct as far as it goes. The amount of matter it predicts is only about one billionth as much as exists, Dr Smith said.
"Either there is some new set of ghostly particles, maybe they are just too massive to have been produced in accelerators . . . or there is some completely new phenomenon that we have not been able to see that is there to have catalysed the evolution of the universe."
