Meson Resonances

Bubble chambers have played an immensely important role in developing our understanding of meson resonances. As a matter of fact, if we look at the four lowest lying meson nonets: 0 +, 1-, 2 ++, and 1 ++, all the 27 states in the last three nonets were discovered via the bubble chamber technique. In addi t ion , their spins and par i t ies were also determined in bubble chamber experiments. Bubble chambers were also impor tan t in ob ta in ing information about the members of the first nonet which contains states stable against decays via strong interactions. Both I] and q ' were discovered and i den t i f i ed as 0 "÷ s ta tes in bubble chamber experiments; the same technique also provided spin and/or parity information about K mesons and r~ °. It is natural to ask why bubble chambers were such a dominant technique in this area of particle physics. I bel ieve that there was a for tunate confluence of several factors which contributed to this success. I will enumerate them briefly: