Matter-Antimatter Asymmetry

Dr. Nicolas Garron, a Research Fellow in the Centre of Mathematical Sciences, and an international team of physicists have devised the first theoretical calculation of how the behaviour of subatomic particles called kaons differs when matter is replaced with antimatter. "Physicists have been waiting for more than 40 years for this kind of breakthrough,” says Garron.

The research stems from Nobel prize-winning work from 1964, work which first presented the concept of indirect CP violation (the idea that suggests that matter and antimatter are asymmetrical). Dr. Garron’s research is the first theoretical prediction on indirect CP violation.

To break this down a bit, in its most basic sense, antimatter is just matter with its electrical charge reversed. In this respect, antielectrons are like an electron but with a positive charge. Along the same lines, antiprotons are like protons but with a negative charge, and so on. According to our basic understanding of the universe - which postulates that the universe is essentially the same across large scale structures - the Big Bang should have created antimatter and matter in equal amounts.

However, when matter and antimatter meet, they annihilate one another. So if there were equal amounts of matter and antimatter, everything would have been destroyed. As far as scientists know, there must have been one extra matter particle for every billion matter-antimatter pairs.

Physicists are still trying to understand why the universe didn’t annihilate itself and why this asymmetry exists. In this respect, Garron and his team noted that the rate at which the kaons decay shows that, although they are virtually identical, there is an asymmetry between matter and antimatter. This research was published in Physical Review Letters.


The calculation used on the research of kaon decays was done on supercomputers housed in Plymouth University and various other institutions in the USA and the UK. This level of processing would taken a typical laptop over 200 million core processing hours to complete.

Dr. Garron stressed on the importance of these supercomputers in scientific research, saying that "High performance computing is now essential in research, even for the most fundamental sciences. We are very fortunate to have one such supercomputer here at Plymouth University.”

Subsequent research related to these calculations may allow us to better understand the true nature of matter-antimatter asymmetry.

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