Introduction To Elementary — Particles Solutions Manual Griffiths

2.1 The first particle accelerator was built in 1930 by Cockcroft and Walton.

9.1 The gauge group of QED is $U(1)$.

1.3 The antiparticle of the electron $e^{-}$ is the positron $e^{+}$.

6.2 The quark model explains the hadronic spectrum.