29 - Early Baryon and Meson Spectroscopy Culminating in the Discovery of the Omega-Minus and Charmed Baryons

Summary

The era of studying particle resonance production in the mesonic and baryonic domain was truly exciting and productive. As one looks back, the most important findings occurred in a relatively short time period – roughly 1958–1964, with the preliminaries in the 1950s and lots of details in the 1970s and 1980s. This period of intense activity had many characteristics among which are the following:

1. 1. Accelerators came into their own. Previous productive work occurred in cosmic rays, but now came the Cosmotron, Bevatron, AGS, and PS machines, all contributing important physics results.

2. 2. There was strong interplay between experiment and theory. Global symmetry, the Sakata model, Pais–Piccioni conjecture, Treiman–Yang angle, Jackson angle, Lee–Yang inequalities (and of course, the Gell-Mann–Nishijima, Gell-Mann–Okubo mass formulas), all attest to this close relationship.

3. 3. The early experimental results – even with low statistics – were usually correct. As you will see, the discovery of the ρ, K*, φ, and η just popped out. On the other hand, one had to use some caution, for some of the early indications could be misleading, a case in point being the τ spin-parity, where Robert Oppenheimer cautioned Jay Orear not to bet on horses.

4. 4. As data accumulated, a few incorrect results emerged – some of a major nature, which required large efforts in time and money to correct.

I begin by discussing the Barkas Table, the November 1957 version. It is worth noting that this earliest of compilations is very short – 16 entries.