The creation of the Universe is one of the unknowns that has most intrigued researchers and scientists. Recently, the European Organization for Nuclear Research (CERN) tried to find a new particlethe axion, which could reveal, for the first time, what happened in the Universe one second after the Big Bang.
First proposed in the 1970s by physicist Roberto Peccei and his colleague Helen Quinn, The axion is an elementary particle resulting from a hypothesis to explain a problem in the theory of quantum chromodynamics (QCD), which is the theory that describes the interaction between quarks and gluons. The problem in question is the “parity conservation problem”, which suggests that certain properties should not be altered by nuclear interactions. The axion is introduced as a way to restore this symmetry.
Axions and dark matter
One of the most intriguing aspects of the axion is its possible role as a component of dark matterwhich represents approximately 27% of the mass of the universe. Dark matter does not emit light or radioactivity, making it invisible and detectable only through its gravitational effects. If axions exist, they could be abundant in the universe, which would explain dark matter because they are extremely light particles and difficult to detect.
The Big Bang and the Axions
The Big Bang, the primordial explosion that gave birth to the universe, is an event studied through various cosmological theories and models. We think that in the Immediately after the Big Bang, various particles and radiation were formeds. Axions, if they exist, could have been produced in large quantities during this initial phase, thus contributing to the evolution of the universe.
The study of axions not only has implications for dark matter, but also for our planet. understanding of the universe in its beginnings. Since the Big Bang generated a wide variety of particles, the existence of axions could offer clues to how matter and energy were organized over time.
What do we know about the past of the Universe?
Currently, observations of the electromagnetic spectrum of the cosmic microwave background (CMB) allowed scientists to go back nearly 14 billion years to when the Universe cooled long enough for protons and electrons to combine for the first time and form neutral hydrogen.
Photons shown by CMB observations were released 400,000 years after the Big Bangit is therefore almost impossible to know the history of the Universe before this time.
However, three British researchers have developed a theory that suggests the existence of a particle called axion which could be released in the first second of the history of the Universe. Although it is a hypothetical particle, there are many reasons to suspect that the axion could actually exist in the Universe.
What are axions?
Axions are fundamental particles which, although hypothetical, they could be linked to problematic aspects of current particle theories.
The existence of the axion would make it possible to resolve, for example, the problem of strong CP symmetry linked to the balance between matter and antimatter. Actually, could naturally explain why matter and antimatter have such similar properties and gives an idea of why the universe is full of matter and not antimatter.
Axions could also shed light on so-called “dark matter” which makes up 23% of the Universe. According to research, These particles are one of the promising candidates to be part of invisible matter or dark matter. which formed just after the Big Bang.
The axion and its presence in dark matter
Given the possibility that dark matter is composed of axions produced in enormous quantities after the Big Bang explosion, Researchers are trying to find the axion’s dark matter as quickly as possible.
According to an article published in Physical Review D, Developing new, more sensitive instruments to detect dark matter could also help uncover another sign of axions. in the form of CaB. That is to say an axion analogous to the CMB, called Cosmic Axion Fund. But because CaB has similar properties to dark matter axions, there is a risk that experiments will reject the CaB signal as noise.
For scientists, finding CaB would mean a double discovery. First, it would finally confirm the existence of the axion and, secondly, obtaining a new fossil from the early Universe for the scientific community. Depending on how CaB was produced, researchers were able to discover different aspects related to the creation and evolution of the Universe that were never known before.
CERN experiments to detect the axion
One of the experiments carried out to detect the axion particle is based on the use of resonant microwave cavities (at the mass of the axion) immersed in powerful magnetic fields. This technique is currently used by the ADMX experiment at the University of Washington and could detect the axion if, in fact, dark matter is composed entirely of axions.
Another technique used to detect axions is to use helioscopes, the purpose of which is to identify axions produced inside the Sun. To do this, a powerful magnet equipped with very low background X-ray detectors is used. The most powerful axion helioscope is the Solar Axion Telescope (CAST), in operation for a decade at CERN.
Although no evidence of axions has yet been obtained, CAST, in which researchers from the University of Zaragoza participate, It has exceeded astrophysical limits and provided access to a previously unexplored area. All new results and discoveries obtained are published in Physical Review Letters.
Recommended Reading
The axion as an explanation of the dark matter in the Universe
The origin of matter and energy in the Universe
