parity همالی hamâli (#) Fr.: parité General: Equality, as in amount, status, or character;
equivalence; correspondence; similarity; analogy. Opposite of disparity.
Physics:
The principle of space-inversion invariance.
An operation that reverses the algebraic sign of the coordinate axes used to describe a system,
i.e. (x, y, z) → (-x, -y, -z).
The parity principle is important in quantum
mechanics because the wave functions which represent particles can
behave in different ways upon transformation of the coordinate system.
The parity is 1 (or even) if the wave function of the system is
unchanged by an inversion of the
coordinate system; it is -1 (or odd) if the wave function is changed
only in sign. Parity is conserved in strong interactions, but not in weak ones.
Math.:
The attribute, of an integer, of being even or odd. Thus, it can be said that 8 and 12
have the same parity, whereas 5 and 16 have opposite parity.
See also:
→ charge-parity symmetry,
→ even parity,
→ parity conservation,
→ parity symmetry,
→ parity violation. Etymology (EN): From M.Fr. parité, from L.L. paritas “equality,” from L. adj. par
“equal.” Etymology (PE): Hamâli, quality noun of hamâl, → pair (equivalent 2). |
