| 释义 |
hypercharge Nuclear Physics.|ˈhaɪpətʃɑːdʒ|
[f. hyper(onic) charge: see quot. 1956.]
A property of hadrons that is conserved in strong interactions and is represented by a quantum number Y that is the same for all the particles of a charge multiplet (isospin multiplet), being equal to twice their average charge quantum number.
The hypercharge Y of a particle is related to its charge Q and the third component, I3, of isospin by Y = 2(Q - I3); and to its strangeness S and baryon number B by Y = S + B.
1956J. Schwinger in Physical Rev. CIV. 1164/2 It is now natural to suppose that the K meson, with isotopic spin ½, possesses a similar physical property [to the nucleonic charge] in the nature of a charge, which is also dynamically realized by a coupling with the π field. We shall term this new property hyper(onic) charge Y, with Y = +1 characterizing the K+K0 multiplet, and Y = -1 describing the antiparticles K0K- . As the agent for the dynamical exhibition of nucleonic and hypercharge, the π field does not itself bear these charges. 1964New Scientist 20 Feb. 460/3 According to the conservation of baryons and hypercharge, the omega-minus should be produced in collisions between K-minus mesons and protons and should decay (weakly, with a change of hypercharge) to a xi-particle and pion, or to a lambda-particle and K-minus. 1972G. L. Wick Elem. Particles v. 92 All of the strongly interacting particles fall into families which are specified by three quantum numbers—hypercharge, isotopic spin and baryon number. Ibid., In the final analysis, either strangeness or hypercharge will suffice as a quantum number. In practice experimenters prefer to use strangeness—largely for historical reasons... On the other hand, some theoreticians have adopted the new terminology as it is easier to manipulate in the equations. |