One of the all-time famous mysteries in physics is why our universe holds more matter than antimatter, which is the equal of matter but with the reverse charge. In order to tackle this question, a worldwide group of scientists have accomplished to produce a plasma of equal amounts of matter and antimatter – a state that we think made up the initial universe. Ordinary matter appears in four different states: solid, liquid, gas, and plasma, Plasma is actually very hot gas where the atoms have been exposed of their electrons. Though, there is also a fifth, unusual state: a matter-antimatter plasma, matter-antimatter plasma is whole regularity between negative particles (electrons) and positive particles (positrons). This strange state of matter is supposed to be present in the atmosphere of exciting astrophysical objects, such as black holes and pulsars. It is also believed to have been the essential component of the universe in its beginning, in particular during the Leptonic era, starting roughly one second after the Big Bang.
|The atmosphere of black holes contain a matter-antimatter plasma. Image Credit: NASA Goddard Spaceflight Center|
A fraction of a second of life
One of the difficulties with generating matter and antimatter particles together is that they intensely dislike each other – vanishing in a burst of light when they meet. Though, this doesn’t take place straight away, and it is probable to study the behavior of the plasma for the fraction of a second in which it is alive. Comprehending how matter acts in this unusual state is fundamental if we want to understand how our universe has developed and, especially, why the universe as we currently know it is made up mostly of matter. This is a confusing feature, as the theory of relativistic quantum mechanics proposes we should have equal amounts of the two. Actually, no present model of physics can clarify the inconsistency. In spite of its necessary importance for our understanding of the universe, an electron-positron plasma had never been formed before in the laboratory, not even in gigantic particle accelerators such as Large Hadron Collidor. A worldwide group of researchers, including physicists from the UK, Germany, Portugal, and Italy, finally accomplished to crack the nut by entirely altering the way we look at these objects.
Instead of concentrating on huge particle accelerators, researchers turned to the ultra-powerful lasers accessible at the Central Laser Facility at the Rutherford Appleton Laboratory in Oxfordshire, UK. They used an ultra-high vacuum chamber with an air pressure equivalent to a hundredth of a millionth of our atmosphere to fire an ultra-short and powerful laser pulse (hundred billions of billions more powerful that sunlight on the Earth surface) onto a nitrogen gas. This exposed off the gas’ electrons and accelerated them to a speed tremendously close to that of light.
The ray then hit a block of lead, which decelerated them down again. As they slowed down they discharged particles of light, photons, which produced pairs of electrons and their anti-particle, the positron, when they bumped into the nuclei of the lead sample. A chain-reaction of this procedure provided growth to the plasma. Though, this experimental success was not without effort. The laser beam had to be directed and controlled with micrometer exactness, and the sensors had to be exceptionally adjusted and shielded – resulting in frequent long nights in the laboratory.
But it was well worth it as the progress means a thrilling branch of physics is opening up. Apart from examining the important matter-antimatter asymmetry, by observing how these plasmas relate with ultra-powerful laser beams, we can also find out how this plasma spreads in vacuum and in a low-density medium. This would be efficiently reconstructing circumstances alike to the generation of gamma-ray bursts, some of the utmost luminous happenings ever noted in our universe.