Misalignment mechanism
Encyclopedia
The misalignment mechanism is a hypothesized effect in the Peccei-Quinn
proposed solution to the strong-CP problem in quantum mechanics
. The effect occurs when a particle's field
has an initial value that is not at or near a potential
minimum. This causes the particle's field to oscillate around the nearest minimum, eventually dissipating energy by decaying into other particles until the minimum is attained.
In the case of hypothesized axion
s created in the early universe
, the initial values are random because of the masslessness of axions in the high temperature plasma
. Near the critical temperature of quantum chromodynamics
, axions possess a temperature-dependent mass that enters a damped oscillation until the potential minimum is reached.
Peccei-Quinn theory
In particle physics, the Peccei–Quinn theory is the best known proposal for the resolution of the strong CP problem. The theory proposes that the QCD Lagrangian be extended with a CP-violating term known as the θ parameter...
proposed solution to the strong-CP problem in quantum mechanics
Quantum mechanics
Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...
. The effect occurs when a particle's field
Field (physics)
In physics, a field is a physical quantity associated with each point of spacetime. A field can be classified as a scalar field, a vector field, a spinor field, or a tensor field according to whether the value of the field at each point is a scalar, a vector, a spinor or, more generally, a tensor,...
has an initial value that is not at or near a potential
Potential
*In linguistics, the potential mood*The mathematical study of potentials is known as potential theory; it is the study of harmonic functions on manifolds...
minimum. This causes the particle's field to oscillate around the nearest minimum, eventually dissipating energy by decaying into other particles until the minimum is attained.
In the case of hypothesized axion
Axion
The axion is a hypothetical elementary particle postulated by the Peccei-Quinn theory in 1977 to resolve the strong CP problem in quantum chromodynamics...
s created in the early universe
Universe
The Universe is commonly defined as the totality of everything that exists, including all matter and energy, the planets, stars, galaxies, and the contents of intergalactic space. Definitions and usage vary and similar terms include the cosmos, the world and nature...
, the initial values are random because of the masslessness of axions in the high temperature plasma
Plasma (physics)
In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...
. Near the critical temperature of quantum chromodynamics
Quantum chromodynamics
In theoretical physics, quantum chromodynamics is a theory of the strong interaction , a fundamental force describing the interactions of the quarks and gluons making up hadrons . It is the study of the SU Yang–Mills theory of color-charged fermions...
, axions possess a temperature-dependent mass that enters a damped oscillation until the potential minimum is reached.