Lancaster, PA: The American Physical Society, 1947. Wraps. First Edition. 145-214, 281-326, 439-539 pp. 4to. Green paper wraps that are quite clean inside and out, very minor age toning to spines. Very Good.
The first meson was discovered in 1936. For many years physicists believed this to be the pi meson (now pion) predicted by Yukawa in 1935. Then in 1947, a series of four papers led to the realization that there are in fact two mesons (the pion and the muon) and the one that had been discovered in 1936 is the muon. In the first paper in early 1947, three Italian physicists, Conversi, Pancini and Piccioni, noted unusual results in the decay of cosmic ray mesons. A few months later, Fermi, Teller, Weisskopf, and John Wheeler concluded from these results that the interaction of mesons was much weaker than predicted by theory. Shortly thereafter, Marshak and Bethe built on these findings to propose the two-meson hypothesis. Note: Three of the authors (Fermi, Wheeler and Bethe) became Nobel Laureates.