Related Experiment Video
Updated: Jan 18, 2026
06:37
Quantifying Cytoskeleton Dynamics Using Differential Dynamic Microscopy
Published on: June 15, 2022
4.1K
Searching for the QCD dark-matter axion.
Masha Baryakhtar1, Leslie J Rosenberg2, Gray Rybka2
1Physics Department, University of Washington, Seattle, WA 98195-1560, United States of America.
Reports on Progress in Physics. Physical Society (Great Britain)
|September 10, 2025
Summary
The quantum chromodynamics (QCD) axion, proposed 50 years ago, may solve strong interaction puzzles and is a dark matter candidate. Recent experiments and theoretical work are reviewed, focusing on dark matter axion searches and future techniques.
Area of Science:
- Particle Physics
- Cosmology
- Astrophysics
Background:
- The quantum chromodynamics (QCD) axion was proposed to resolve the strong CP problem.
- It is a leading candidate for cold dark matter.
- Recent years have seen significant advancements in axion detection experiments and theoretical understanding.
Purpose of the Study:
- To review astrophysical searches for the QCD axion.
- To summarize theoretical progress on axion dark matter.
- To provide an overview of current and future dark matter axion experiments.
Main Methods:
- Review of astrophysical search strategies.
- Analysis of theoretical developments in axion physics.
- Survey of experimental techniques for axion detection.
Main Results:
- The QCD axion remains a compelling candidate for dark matter.
- Experimental sensitivity and mass range for axion searches have rapidly improved.
- Theoretical frameworks for axion dark matter have been further developed.
Conclusions:
- The search for the QCD axion is an active and evolving field.
- Future experiments aim to improve sensitivity and explore new detection techniques.
- Continued theoretical and experimental efforts are crucial for understanding the axion's role in the universe.
Related Concept Videos
01:10Detection of Black Holes
2.5K
Although black holes were theoretically postulated in the 1920s, they remained outside the domain of observational astronomy until the 1970s.
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
2.5K
02:45The Quantum-Mechanical Model of an Atom
56.6K
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra.
56.6K
01:09Electron Behavior
11.7K
Electrons are negatively charged subatomic particles attracted to and orbit around the positively-charged nucleus of an atom. They reside in spaces associated with energy levels called shells and are further organized into subshells and orbitals within each shell.
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus have less energy,...
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus have less energy,...
11.7K
00:54Electron Behavior
107.3K
Overview
Electrons are negatively charged subatomic particles that are attracted to an orbit around the positively-charged nucleus of an atom. They reside in locations that are associated with energy levels called shells and are further organized into sub-shells and orbitals within each shell.
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the...
Electrons are negatively charged subatomic particles that are attracted to an orbit around the positively-charged nucleus of an atom. They reside in locations that are associated with energy levels called shells and are further organized into sub-shells and orbitals within each shell.
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the...
107.3K
01:21Schwarzschild Radius and Event Horizon
2.6K
No object with a finite mass can travel faster than the speed of light in a vacuum. This fact has an interesting consequence in the domain of extremely high gravitational fields.
The minimum speed required to launch a projectile from the surface of an object to which it is gravitationally bound so that it eventually escapes the object’s gravitational field is called the escape velocity. The escape velocity is independent of the mass of the object. Merging the idea of escape...
The minimum speed required to launch a projectile from the surface of an object to which it is gravitationally bound so that it eventually escapes the object’s gravitational field is called the escape velocity. The escape velocity is independent of the mass of the object. Merging the idea of escape...
2.6K
01:21Energy Associated With a Charge Distribution
1.9K
The work done to bring a charge through a distance r is given by the potential difference between the initial and the final position. To assemble a collection of point charges, the total work done can be expressed in terms of the product of each pair of charges divided by their separation distance, defined with respect to a suitable origin. Solving this expression gives the energy stored in a point charge distribution.
1.9K