When the universe was born, there was symmetry. This symmetry came in the form of matter and antimatter. Matter is what we’re familiar with – like an electron that constitutes the material existence we have come to know. But all matter particles are theoretically accompanied by their antimatter particles. In the case of an electron, that particle would be a positron; antimatter particles have the same mass as their counterparts, but qualities like electric charge are opposite.
Most of what we know – like planets – is composed of matter. This makes our universe highly asymmetrical, for antimatter particles hardly make up anything around us. To understand why there are such asymmetrical proportions of particles in our universe, recent research has focused on the events following following the big bang, which should have given rise to an equal amount of matter and antimatter. (1) With this aim, the latest research at the University of California, Los Angeles has concluded that the early laws of physics governing the moments after the Big Bang seemed to favor matter over antimatter. Published in Physical Review Letters, their idea begins with the Higgs boson.
Found in 2012 by Switzerland’s Large Hadron Collider, the Higgs boson is a particle that is responsible for creating the Higgs field: the field that all particles pass through to obtain mass. (2) Alexander Kusenko and his colleagues at UCLA recently proposed that the Higgs field originally had a larger value than that measured today. This could have allowed for antimatter and matter asymmetry during the cosmic inflation that occurred after the big bang; (3) specifically, their research indicates that the post-big bang Higgs field created a difference between the total masses of matter and antimatter. (4)
As a result, there could have existed a small fraction – something like one particle per 10 billion – more matter particles than antimatter particles. The significance of this is that when matter and antimatter particles meet, they annihilate one another, leaving only energy behind. If the proportions of matter and antimatter were even, then all of the particles would annihilate each other and there would be none remaining to give rise to the world around us. Only the energy created during the particles’ interaction and subsequent annihilation would have been left. But due to the small fraction of increased matter particles that had no counterpart (because of the increased primordial Higgs field), a few matter particles “survived” to give rise to the entire universe that’s in existence today. (3, 4)
…the latest research at the University of California, Los Angeles has concluded that the early laws of physics governing the moments after the Big Bang seemed to favor matter over antimatter.
In this way, the researchers have provided a mechanism to help explain how the initial symmetry between matter and antimatter particles in the early universe was replaced by the asymmetry we observe today. A small change in the early laws of physics allowed for asymmetry to triumph over symmetry.
- “Matter/antimatter asymmetry.” Cern Press Office. CERN. Web. 12 June 2015.
- Lincoln, Don. “The Higgs Boson…or a Higgs Boson?” Understand Space and Time. PBS, 15 Mar. 2013. Web. 13 June 2015.
- Kusenko, Alexander, Lauren Pearce, and Louis Yang. “Postinflationary Higgs Relaxation and the Origin of Matter-Antimatter Asymmetry.” Phys. Rev. Lett. Physical Review Letters 114.6 (2015). PubMed. Web. 13 June 2015.
- Wolpert, Stuart. “UCLA Physicists Offer a Solution to the Puzzle of the Origin of Matter in the Universe.” UCLA Newsroom. The Regents of the University of California, 24 Feb. 2015. Web. 13 June 2015.
Atrin Toussi is the Primary Research Editor for Brevia. She can be reached at firstname.lastname@example.org.