OddParity
Odd parity is a property of functions or quantum states under spatial inversion, the transformation r -> -r. A function ψ is said to have odd parity if it changes sign under inversion: ψ(-r) = -ψ(r). If it remains the same, ψ has even parity: ψ(-r) = ψ(r). In quantum mechanics, states that have definite parity are eigenstates of the parity operator P, with eigenvalues ±1. The eigenvalue is called the parity, and values of -1 and +1 indicate odd and even parity, respectively.
Mathematically, the parity operator P acts on a wavefunction by Pψ(r) = ψ(-r). When a state is an
In atomic and nuclear physics, parity is closely related to orbital angular momentum. For a single-particle
Parity is a conserved quantity in strong and electromagnetic interactions but is violated by the weak interaction.
See also: parity operator, parity conservation, parity violation, spherical harmonics.