A feature article in Symmetry Magazine discusses the contribution of Cornell’s Department of Physics to a breakthrough in particle physics concerning the possible existence of a fourth quark.
On November 11, 1974, the members of Cornell’s high-energy physics group came together in a lunch meeting to chat about the discovery of a new particle, now known as J/psi, by researchers from two different labs on opposite sides of the country. It would be Ken Wilson, a physics professor, who would make the connection between the discovery of J/psi, and a seminar by Tom Appelquist, a physicist at Harvard University, on “charmonium,” a bound state of a quark and an antiquark.
“Only a few of us were thinking about the idea of a fourth quark,” Appelquist said. “Ken called me right after the discovery and urged me to get our paper out ASAP.”
The possibility of a fourth quark pointed to cracks in the three-quark model and would contribute to the Standard Model of particle physics as we know it today.