Abstract
Over the past few months press releases have announced a dazzling array of new particles: ψ (3.4 GeV), ψ (4.15), and ψ (4.45) from Stanford Linear Accelerator (SLAC) and ψ (2.8) and ψ (3.5) from DESY, the German laboratory – with reports from SLAC that there are two particles with masses near to 3.5 GeV/c2. These discoveries followed on from one of the most exciting developments in physics which took place just over a year ago (November 1974) with the discovery of a new strongly interacting particle (hadron) by independent teams of physicists working at the Brookhaven National Laboratory (BNL) and at SLAC.