Experimental High Energy Physics
In the late 1960s, Professors Friedman, Kendall and Taylor executed at the accelerator a famous series of experiments on the scattering of electrons by protons, deuterons (a proton bound to a neutron), and heavier nuclei. Firing a beam of high-energy electrons at targets made of hydrogen or deuterium, the researchers were able to unravel mysteries in the data that characterized how the electrons were scattered.
In 1968, these investigations gave the first clear evidence of a charged, point-like substructure -- quarks -- inside these massive particles. The revelation went completely against the conventional model of the interiors of protons and neutrons as "mushy" regions. It was believed that no point-like substructure would be found within the nucleons -- protons and neutrons.
1990 Nobel Laureate with Richard E. Taylor and Henry W. Kendall for a series of experiments (1967-73) that showed that protons and neutrons are not fundamental particles of matter but are composed of smaller particles known as quarks.