| 释义 |
isospin Physics.|ˈaɪsəʊspɪn|
[Contraction of isotopic spin, isobaric spin.]
A vector quantity associated with elementary particles and atomic nuclei which is used to give mathematical expression to the fact that the strong interaction is independent of electric charge; its quantum number (symbol T or I, T = 0, {pm}½, {pm}1, {pm}3/2, etc.) is assigned on the basis of there being 2T + 1 particles in a charge multiplet, each with the same value of the quantum number T but differing in the value of the third component of isospin T3 (or Tz) according to the charge of each particle, with the result that these can be treated as different states of a single particle.
1963S. Tolansky Introd. Atomic Physics (ed. 5) xxiii. 395 The decay of a particle is controlled by a quantity T which has been called the isotopic spin vector or more simply, the isospin. 1965H. Muirhead Physics Elem. Particles i. 14 The isospin of a system is formally similar to angular momentum but is linked to the charge states of the system. 1970Physics Bull. Jan. 22/1 These hadrons and their compounds (the atomic nuclei) appeared as charge multiplets, the members of which had essentially the same mass and the same strong interactions, but different charge values, these being the (2I + 1) values (½B - I)e, (½B - I + 1)e,..(½B + I)e where B is the baryon number..and I (called the isospin) is characteristic of the multiplet. 1971P. E. Hodgson Nucl. Reactions xix. 575 The isospin T of a nucleus is the sum of the isospins ti of its constituent nucleons... The isospins t of the nucleons have the same mathematical properties as the spin vectors σ, that is t2x = t(t + 1)x, tzx = {pm}½x, where tz = + ½ refers to neutrons and tz = -½ to protons. Here the z component refers to isospin space and not to ordinary space. |
