Samuel C. C. Ting | Biography

Samuel C. C. Ting is an American physicist who received the 1976 Nobel Prize for his discovery of the J/psi particle, which led to the detection of many new subatomic particles. Ting shared the prize with Burton Richter , who had made the same discovery almost simultaneously, using a different experimental technique. Ting is known as a confident, daring theorist, as well as a precise experimenter. He is a consummate practitioner of physics in the era of "big science," when research is conducted by large international teams using costly, complex experimental apparatus.

Ting was born in Ann Arbor, Michigan, on January 27, 1936, while his father, Kuan Hai Ting, was studying engineering at the University of Michigan. He completed his studies when Ting was two months old, and the family returned to mainland China, where his father became an engineering professor. His mother, Tsun-Ying Wang, was a psychology professor. As a child, Ting was cared for mostly by his maternal grandmother while both his parents worked. Although his grandmother emphasized the strong value of education, Ting was not able to begin school until he was twelve years old, because World War II intervened. After the war, the family moved to Taiwan, where Ting's father taught at the National Taiwan University.

In 1956, Ting enrolled at the University of Michigan, studying both mathematics and physics, and in 1959 he earned bachelor's degrees in both subjects. He married Kay Louise Kune, an architect, in 1960, with whom he would have two daughters. Ting received his Ph.D. in physics in 1962, and the next year he went to the European Center for Nuclear Research (CERN) in Geneva as a Ford Foundation fellow. He worked with Giuseppe Cocconi on the proton synchrotron, a device that accelerates protons (the nucleus of an atom) for analysis and measurement. In 1965 Ting joined the faculty of Columbia University, where he worked with Chien-Shiung Wu.

Ting became interested in the production of electron (negatively charged particles of an atom) and positron (positively charged particles of an atom) pairs by photon radiation after experiments conducted at Harvard raised questions regarding some of the predictions of quantum electrodynamic theory (the theory that deals with the interaction of matter with electromagnetic radiation). He took a leave of absence from Columbia and went to Hamburg, Germany, in 1966 to repeat the Harvard experiments at the German synchrotron facility. There his team built a double-arm spectrometer (an instrument used to analyze and measure particle emissions ), which enabled them to measure the momentum of two particles simultaneously. It also recorded the angles of their deflection from the radiation beam. The researchers were able to calculate the masses of the particles and their combined energy, making identification of the particles easier and clarifying their interrelationships. Results of these experiments confirmed the accuracy of the quantum electrodynamic description of pair production.

Ting's work at Hamburg led him to ponder the nature of heavy photons (particles of radiation). After his return from Germany, he moved to the Massachusetts Institute of Technology (MIT), where he became full professor in 1969. In 1971, while still at MIT, Ting began a project to determine the properties of heavy photons at Brookhaven National Laboratory in Long Island, New York. Rather than the usual method of bombarding a beryllium target with photon beams, he used a proton beam of ten trillion protons per second in hopes of creating a heavy particle that would decay into pairs of electrons and positrons.

Because the search for heavy particles requires such high energy levels, Ting's MIT team redesigned the double-arm spectrometer to detect electron-positron pairs between 1.5 and 5.5 giga-electron volts (a giga equals one billion). The spectrometer also had to be capable of adding precise but small amounts of energy incrementally, as well as detecting their effects on the particle pairs. After several months of searching, the Ting team was rewarded in August 1974 by the appearance of a sharp spike of high-energy electron-positron pairs at 3.1 billion electron volts. This was unexpected. Ting checked his measurements carefully and decided he was looking at evidence of a new particle that had not been predicted, the J/psi particle. It was heavier than known similar particles; it also occupied a very narrow range of energy states, and it lasted a relatively long time.

Ting reported his results to the Frascati Laboratory in Italy, where physicists were able to confirm his observations in only two days. Ting's paper and the results of the Frascati experiment were accepted for publication in Physical Review Letters. Just a few days after Ting discussed the paper with the review's editor, he attended a routine scheduling meeting at the Stanford Linear Accelerator Center; here he shared his results with Stanford's Burton Richter . Amazingly, Richter had made the same discovery at virtually the same time by creating collisions between positrons and electrons in an accelerator.

Ting and Richter shared the 1976 Nobel Prize physics. The two-year period between discovery and award was probably the shortest interval on record and caused considerable comment at the time, because some scientists feared the discovery would not stand the test of time. However, it has since been the basis for a virtual explosion in the detection of many other fundamental particles.

The J/psi particle's lifespan was a thousand times longer than expected for such a heavy particle (three times heavier than a proton). It was believed that most subatomic particles were made up of combinations of even more fundamental particles called quarks, of which only three types were thought to exist before the discovery of the J/psi particle. The peculiarities of the J/psi particle (especially its long life) suggested the existence of a fourth type of quark, called charm. The J/psi particle was interpreted to be composed of a charmed quark and an antiquark, creating a property called "charmonium." Charm had been predicted in 1970 and its addition to the family of quarks was thought to unify the electromagnetic and weak forces, further encouraging physicists to believe in the possibility of a grand unifying theory in which the fundamental forces of nature would be shown to be equivalent at very high energies.

There are several stories of how the Ting-Richter particle received its name of J/psi, which is a combination of Ting's name for it (J) and Richter's (psi). Classical particles were traditionally assigned Greek letters for names, while newly discovered particles are labeled with capital letters. One story says Ting called his particle J because he had been working with electromagnetic currents carrying a J label. Another story says the J derives from the physical symbol for angular momentum. A third claims Ting chose the Chinese symbol for his name. In any case, the particle has retained the double label. A similar particle, called the psi-prime, was found by Richter's team within ten days of the first discovery.

Ting is a fellow of the American, European, and Italian physical societies as well as several academies of science, including the Academia Sinica. In addition to the Nobel Prize, Ting received the 1976 E. O. Lawrence Award.