Evidence of Quarks Published

Date: October 20, 1969 • Location: West Menlo Park, United States

Experimental results from the Stanford Linear Accelerator Center were published showing that protons were composed of smaller particles, the first evidence of quarks.

SLAC National Accelerator Laboratory, originally named the Stanford Linear Accelerator Center, is a federally funded research and development center in Menlo Park, California, United States. Founded in 1962, the laboratory is now sponsored by the United States Department of Energy and administered by Stanford University. It is the site of the Stanford Linear Accelerator, a 3.2 km (2 mi) linear accelerator constructed in 1966 that could accelerate electrons to energies of 20 GeV, and later up to 50 GeV.