570 10 Particle Physics – II
10.36
Fig. 10.6Y−I 3 plot for
baryon octet
10.37
Fig. 10.7Y−I 3 plot for
baryon decuplet
10.38 (a) The reaction channels for the pion reactionsπ−+p →π−+pand
π−+p→π^0 +nare charge symmetric to the reactions,π++n→π++n
andπ++n→π^0 +p. We can therefore expect the reaction cross sections
with pions to be nearly identical. On the other hand, the reactions with
kaons are not charge symmetric becauseK+andK−do not constitute an
iso spin doublet but are particle–antiparticle. Typical reactions with K+
areK++n→K++nandK++n→K^0 +p
However forK−many more channels are open.
K−+p→K−+p
→K^0 +n
→Σ++π−
→Σ^0 +π^0
→Σ−+π+So, there is no reason forσ(K−+p) to be equal toσ(K++n).
(b) Because of the CPT theorem,K^0 andK^0 which are particle and anti-
particle, cannot be distinguished by their decay modes, but can be identi-
fied through their distinct strong interaction process. Thus