The Eightfold Way

Improved treatment of loop diagrams in SU(3) baryon chiral perturbation theory

“…However, the non-analytic m 3/2 q terms come from loop diagrams, and the coefficients are not adjustable but are known in terms of the baryon-meson coupling constants. The leading SU(3) breaking terms involving b M go back to Gell-Mann and Okubo [14], the non-analytic corrections from one-loop diagrams, represented above by c M , were first calculated by Langacker and Pagels [15], and m 4 M corrections (including diagrams up to two loops) were calculated by Borasoy and Meissner [8]. The convergence difficulties in the expansion are demonstrated by the resulting fit for the nucleon mass where, in the same sequence, the different contributions are given, in GeV, by [8] M N = 0.711 + 0.202 − 0.272 + 0.298 + .…”

The co-discovery of conservation laws and particle families

“…The conservation of the quantities electric charge, baryon number, tau number, electron number and muon number that are shown in Table 1 is part of the Standard Model that takes the quarks as building blocks of particles and was elaborated by particle physicists in decades of research [10,2,41,22,3]. For brevity, I will sometimes abbreviate these quantities as C, B, T, E, M .…”

Polarisation observables for strangeness photoproduction on a frozen spin target with CLAS at Jefferson Lab

“…The introduction of the strangeness quantum number, and attempts to categorise the numerous hadronic states observed by experiment in terms of symmetries led to the grouping of hadrons according to the "eight-fold way" [3], developed independently by Gell-Mann and Ne'eman. This scheme arranged the hadrons into multiplets of nearly equal masses, along axes of strangeness and charge, as shown in figure 1.2.…”

“…3. Electrons are produced by a laser incident on a strained Gallium Arsenide (GaAs) photocathode, and initially accelerated by an anode.…”