Liquid hydrogen bubble chamber photograph showing the production of a baryon by the
interaction of a Kmeson (moving upward from the bottom) with a proton together with the
sebsequent decay of the into a ^0 baryon and a meson. The sketch shows the identities of
the charged particles that caused each track; the dashed lines indicate the paths of neutral particles
that leave no tracks. A magnetic field deflected the paths of the charged particles and enabled their
momenta to be determined. The baryon was predicted theoretically before its discovery in 1964.
(Courtesy Brookhaven National Laboratory)488 Chapter Thirteen
Figure 13.5Supermultiplet of spin ^12 baryons on a plot of strange- Figure 13.6Supermultiplet of spin 0 mesons.
ness Sversus charge Q(in units of e).Σ Σ+
−n pΣ^0
Λˆ^0Ξ Ξ^0−− 10s− 2
− 1 00Q + 1− 1π^0
π− π+K^0 Pη^0 ηK K^0
−0+ 1s− 1
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