Stanford Positron Electron Asymmetric Ring
Photo Date: 15 April 1976
Photo Number: 271 001 002
On April 28, 1972 - the Stanford Positron Electron Asymmetric Ring, first collided a beam of
high-energy electrons with a beam of positrons. The SPEAR facility began its career in high energy physics and found a second reincarnation as a national user facility for synchrotron radiation research. Research done at this colliding beam storage ring led scientists to discoveries of new particles resulting in two Nobel Prizes. The experimental evidence for the charmed quark or J/psi particle, indicated the existence of the charm quark. Often called
"the November Revolution" this discovery confirmed a prediction of the Standard Model Theory setting it, and the very idea of quarks, on a much firmer experimental basis. The discovery of the tau lepton showed the existence of a third family of leptons - hitherto unexpected by all but a few.
Sources and Methods
http://www.fas.org/irp/imint/doe_slac_spear_01.htm
Created by John Pike
Maintained by Webmaster
Updated Tuesday, December 30, 1997 10:19:25 AM