What are the supposed characteristics of axions?

Thu, Nov 2023
Bard AI

Axions are hypothetical subatomic particles that are very light and weakly interacting with normal matter. They are predicted by extensions of quantum field theory, specifically extensions of the Standard Model of particle physics. Axions are proposed to explain the absence of the so-called strong CP problem, which is a theoretical inconsistency of the Standard Model.

Axions are predicted to have a mass of around 10^-5 eV/c^2, which is about 10 billion times smaller than the mass of an electron. They are also predicted to be very weakly interacting with normal matter, with a cross-section of around 10^-55 cm^2. This means that they are very difficult to detect, and only a few experiments have been able to set limits on their existence.

If axions do exist, they could have a number of important implications for physics and cosmology. For example, they could be a component of dark matter, the mysterious form of matter that makes up about 27% of the universe. Axions could also be used to explain the existence of pulsars, which are rapidly rotating neutron stars.

The search for axions is an ongoing effort, and a number of experiments are currently underway. If axions are ever detected, it would be a major breakthrough in physics, and would provide important insights into the nature of the universe.

ChatGPT 4
Axions are hypothetical particles that are postulated to solve the strong CP problem in quantum chromodynamics (QCD). They were first proposed by Roberto Peccei and Helen Quinn in 1977. Here are some of the supposed characteristics of axions: 1. Low Mass: Axions are expected to be very light, with a mass less than a billionth of an electron mass. This is because their mass is inversely proportional to the symmetry-breaking scale, which is expected to be much larger than the electroweak scale. 2. No Electric Charge: Axions do not carry an electric charge, which means they do not interact with electromagnetic fields and are therefore difficult to detect. 3. Spin Zero: Axions are predicted to be spin-zero particles, meaning they are bosons. 4. Weakly Interacting: Axions interact very weakly with other particles. They can pass through ordinary matter without any interaction, making them extremely difficult to detect. 5. Cold Dark Matter Candidate: Because of their properties, axions are considered a prime candidate for cold dark matter, the mysterious substance that makes up about 85% of the universe's matter but does not emit or absorb light. 6. Coupling with Photons: In the presence of a strong magnetic field, axions can couple with photons and convert into each other. This property forms the basis for many experimental searches for axion dark matter. 7. Non-thermal Production: Unlike most particles in the universe which were produced thermally in the Big Bang, axions would have been produced non-thermally through a process called "the misalignment mechanism". 8. Cosmological Implications: The existence of axions has implications for cosmology and astrophysics including stellar evolution and supernova explosions. 9. CP Conservation: The main motivation for introducing axions was to explain why QCD conserves CP (Charge Parity), a symmetry between matter and antimatter, even though it's not required to. 10. Very Long Lifetime: If they exist, axions are expected to have an extremely long lifetime, longer than the current age of the universe. This is due to their weak interactions with other particles. It's important to note that while axions are a compelling solution to several theoretical problems in particle physics and cosmology, their existence has not yet been confirmed experimentally.
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