1976 Nobel Prize in Physics
The prize was awarded jointly to:
- Richter, Burton, U.S.A., Stanford Linear Accelerator Center, Stanford University, Stanford, CA, and
- Ting, Samuel C. C., U.S.A., Massachusetts Institute of Technology, Cambridge, MA, and CERN, Geneva, Switzerland
"for their pioneering work in the discovery of a heavy elementary particle of a new kind".
Charm: The 4th Quark
Burton Richter (SLAC) led the group that designed and built the Stanford Positron Electron Asymmetric Ring (SPEAR). Experiments at SPEAR in 1973 - 1974 looked at the rate of occurrence of events in which a colliding electron and positron annihilate, disappearing and producing other particles in the process. At certain energies, the rate seemed inexplicably large.
Gerson Goldhaber, Martin Perl,
and Burton Richter
view an event display in the SPEAR (Mark I) counting room.
On November 10, 1974, remeasurements in the problematic energy range confirmed a dramatic rate increase. Many further checks found that this peak is due to the production of particles containing a new kind of quark-- the charm quark.
The charm and the tau discoveries occurred in the same experiment. Subsequent work at SPEAR by the Goldhaber-Trilling group of Lawrence Berkeley National Lab identified D mesons, thereby confirming the charm discovery.
The Nobel Prize was shared by Richter and Samuel Ting (Brookhaven), who led a group that independently discovered the same particles.
The SPEAR colliding electron-positron storage ring in 1974.
