ˈpseudoscalar, n. and a. Math. and Physics.
[f. pseudo- + scalar a. and n.]
A. n. a. A quantity that transforms as a scalar under rotation but changes sign under reflection. b. A sub-atomic particle whose wave function is such a quantity, the particle having zero spin and odd parity.
| 1938 N. Kemmer in Proc. R. Soc. CLXVI. 137 The quantities occurring in our possible fundamental equations are one scalar (ϕ), two 4-vectors (χα and ϕα), two antisymmetrical tensors of the second order (χαβ and ϕαβ), two ‘pseudovectors’, that is, totally antisymmetrical tensors of the third order (χαβγ and ϕαβγ), and finally one ‘pseudoscalar’ (χ0123). 1950 Physical Rev. LXXVIII. 805/2 It then follows..that the π-meson is a pseudo⁓scalar. 1966 McGraw-Hill Encycl. Sci. & Technol. IX. 566/2 Thus S·p is a pseudoscalar, and so such a term cannot occur in the angular distribution of a parity conserving process. |
B. adj. Involving or being a pseudoscalar.
| 1941 Physical Rev. LX. 151/2 Pseudo-scalar theories can give a scattering small enough to agree with that observed. 1947 Rev. Mod. Physics XIX. 5/1 The initial vector meson is decomposed into a pseudoscalar meson and a photon. 1949 [see coupling constant s.v. coupling vbl. n. 8]. 1974 Physics Bull. Dec. 579/2 Pions are pseudoscalar objects and cannot condense out in states of zero momentum (in infinite nuclear matter) because they do not have the quantum numbers of the vacuum. |