American physicist Burton Richter (born 1931) was instrumental in the development of an innovative particle collider, the Stanford Positron–Electron Accelerating Ring (SPEAR), that resulted in the discovery of an entirely new particle, now called the Psi/J particle. Coincidentally, the same subatomic particle was almost simultaneously found by scientist Samuel C. C. Ting in an entirely different experiment. The two men shared the Nobel Prize in physics in 1976.
Richter was born the eldest child and only son of Abraham and Fannie (Pollack) Richter on March 22, 1931 in Brooklyn, New York. His father was a textile worker. Richter's early education was at Far Rockaway High School in Queens, New York, and the Mercersburg Academy in Mercersburg, Pennsylvania. Already keen on the study of science when he started college at the Massachusetts Institute of Technology (MIT) in 1948, he was nonetheless unsure whether he wanted to pursue physics or chemistry. Physics got the nod in his freshman year, and Richter always gave credit to the influence of undergraduate professor Francis Friedman for having set him on his life's course.
Between Richter's junior and senior year at MIT, he became exposed to the electron–positron system in the school's magnet laboratory. There, he worked under professors Francis Bitter and Martin Deutsch, the latter of whom was conducting his noted positronium experiments in the former's lab. Drawing from this experience and under Bitter's direction, Richter's senior thesis was on the quadratic Zeeman effect (splitting of single spectral line when substance is subjected to a magnetic field) in hydrogen.
Richter received his B.S. in 1952 and remained at MIT for his graduate studies. He continued to work with Bitter during his first year of graduate school, but soon suspected that his interests lay elsewhere. So, he arranged with physicist David Frisch to spend six months in 1953 at the famed Brookhaven National Laboratory on New York's Long Island. At Brookhaven, Richter was able to work with one of the world's most powerful proton accelerators in order to find out if particle physics was his true passion. He found that it was, and went back to MIT's synchrotron (accelerator) laboratory. Richter obtained his Ph.D. from MIT in September of 1956.
After gaining his doctorate, Richter cast about for a place to research his new interest in quantum thermodynamics (QED). At the time, Stanford University's High Energy Physics Laboratory had a 700 million electron volt linear accelerator that Richter judged perfect for exploring the short–distance behavior of QED. So, he got a position as a research assistant at the facility in 1956, and ended up remaining at Stanford for the rest of his impressive career.
Richter pursued his QED experiments for nearly ten years, finally demonstrating QED's efficacy down to at least the diameter (less than 10–14 centimeters) of an atomic nucleus in 1965. Meanwhile, he was quickly moving up the ladder of his academic career, becoming assistant professor of physics in 1960 and associate professor in 1963, the same year he joined the Stanford Linear Accelerator Center (SLAC). (He was also married in 1960, to Laurose Becker). Richter became a full professor in 1967 (a position he still held in 2005) and moved into administration in 1982 with a post as technical director of the SLAC. In 1984, he became the Paul Pigott Professor in the Physical Sciences, along with director of SLAC. He stepped down as SLAC director on August 31, 1999, and remained the facility's emeritus director in 2005. His many contributions to the university community included his service on the Academic Senate, the Graduate Study Committee, and the University Cabinet. Although Richter had an unquestionably stellar career, it was his research that made him a public figure.
The Psi/J Particle
Richter first began to involve himself in the design and building of high–energy physics tools in the 1950s, when he teamed up with Gerard O'Neill, W.C. Barber, and Bernard Gittelman to make the first colliding beam device. The result, on which he conducted his successful QED experiments, became the forerunner of all such mechanisms to follow. But even before the pioneering device was operating, Richter had begun to think of ways to take the concept further. Specifically, he wanted to design a colliding beam machine that would extract electrons and positrons (their antiparticles) and store them as counter–rotating currents (electrons traveling in one direction, positrons in the other) in a ring. Within the ring, the particles would be allowed to collide, producing new particles with minimal background radiation. When Richter initially began to ponder this idea in the early 1960s, he had just become part of the SLAC. The then–director of the center, W.K.H. Panofsky, encouraged his plan, and a preliminary design was completed in 1964. The project then languished on the back burner for the next six years because of budget constraints. Finally in 1970, the funding came through, and the groundbreaking new machine, SPEAR, was ready for action.
One of the many puzzles of particle physics in the 1960s was the behavior and/or existence of quarks, the subatomic particles thought to make up hadrons. Once offered as a theoretical concept by Murray Gell-Mann of the California Institute of Technology, the reality of the existence of such particles began to appear more likely by the end of that decade. As evidence started to appear that quarks did indeed exist, Gell-Mann's early postulation that there were three to a hadron was brought into question, and many found physicist Sheldon Lee Glashow's 1964 suggestion that there were in fact four—one "up," one "down," one "strange," (the three original ones) and a fourth, that he dubbed "charm"—began to appeal as a way to explain the inexplicable behavior of the original three. It was against this backdrop that SPEAR experiments were begun.
Richter had no specific agenda in mind, outside of an interest in the structure of strongly interacting particles, when he started his new research. Theories were rife at the time, but he did not carry a torch for any particular one. What he found in November of 1974, however, was a new particle that was about three times the size of a proton and with an approximately 5,000 times greater lifespan than naturally expected. He named the particle "psi." Coincidentally, Samuel C.C. Ting of MIT had made the identical discovery at nearly the same time on the East Coast, and named the particle "J." The two made a joint announcement of their historic finds on November 11, 1974, at Stanford, and the breakthrough came to be known as the Psi/J particle.
What the two scientists had discovered was the elusive charm quark, and what they had set in motion was the "November Revolution," which ushered in a whole new era of particle physics. The ramifications of the find were myriad, not the least of which was that quarks had become a scientific reality. The revolution also lent a measure of stability to the volatile world of physics that was unprecedented. Indeed, so momentous was the discovery that Richter and Ting were jointly awarded the Nobel Prize in Physics just two years after they announced their findings.
After the Nobel
After becoming a Nobel Laureate, Richter went back to his thriving academic career. As noted above, he eventually got out of research and went into administration as technical director (1982–1984), then director of the SLAC (1984–1999). When he retired from his duties as director, the Stanford News quoted some of Stanford President Gerhard Casper's remarks: "All the world knows Burt Richter's qualities as a physicist because they were recognized by the Nobel Prize. Stanford and I know his qualities as an extraordinarily able, dedicated, and tenacious director of the Stanford Linear Accelerator Center and as a good citizen of the university." Along the way, of course, Richter had also received many other testaments to his eminence. Among these honors were the E.O. Lawrence Medal from the U.S. Department of Energy (1976), membership in the National Academy of Sciences (1977), and induction as a fellow to the American Academy of Arts and Sciences (1989). Not incidentally, he was a Loeb Lecturer at Harvard University in 1974 and a DeShalit Lecturer at the Weizmann Institute (Israel) in 1975 as well.
But Richter was not all business and science. He was noted for his somewhat eccentric dressing habits, donning sneakers and a golf hat for almost any occasion. Candor and charisma were also hallmarks. Martha Krebs, director of the Office of Science at the U.S. Department of Energy was quoted by the Stanford News as having said, "I can always depend on Burt to speak the truth. When he's not charming, he's winning." He had a disarming sense of humor as well, as evidenced by his spin on Shakespeare's seven stages of man, given at a dinner in his honor, cited by P.A. Moore of the CERN Courier. "Monomaniacal physicist—that lasts up until about age 40," he said. "Then in the 50s one becomes mature. I got a little concerned about turning 60, then I decided that was the age of wisdom. But in a few years I'll turn 70, and I am looking forward to the next stage, whatever that may be."
Richter did turn 70 in 2001, but there were no signs of his intellectual curiosity slowing down. He had begun to cultivate an interest in climate conditions and global warming, along with energy needs for the developing world. As all Americans were, he was also deeply affected by the terrorist attacks of September 11, 2001, and was devoting time to the problems of protecting the populace without imperiling its civil liberties. Richter remained a professor at Stanford as of 2005, and continued to serve as emeritus director of the SLAC as well. As to the astounding discovery that changed the face of physics and earned Richter a place in history, the scientist was certain that change would come again. "Of course," he told David Perlman of the San Francisco Chronicle, "as accelerators reach higher and higher energies, we may need a new Standard Model (what his discovery had validated for the physics' view of the universe), or at least today's may need to be modified, but that's the way science operates." And despite the wider range of important interests his later years embraced, the words Richter wrote in his autobiography for the Nobel Prize in 1976 still resonated years afterward. Quoted from the Nobel website, those words were: "Writing this brief biography had made me realize what a long love [affair] I have had with the electron. Like most love affairs, it has had its ups and downs, but for me the joys have far outweighed the frustrations."
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RICHTER, BURTON (1931– ), U.S. physicist and Nobel prize winner. Born in New York, Richter received his doctorate from the Massachusetts Institute of Technology in 1956. In the same year he joined Stanford University as a research associate, becoming assistant professor (1960). He moved to the Stanford Linear Accelerator Center as an associate professor (1963) and full professor (1967). In 1979 he was appointed the Paul Pigott Professor of Physical Science. He was director of the Center from 1984 to 1999. He served as president of the American Physical Society (1994), and the International Union of Pure and Applied Physics (1999–2002). He was a member of the National Academy of Sciences, the American Academy of Arts and Sciences, and the American Philosophical Society. Richter shared the 1976 Nobel Prize in physics with Samuel Ting of mit for their discovery in 1974 – each working independently – of a new subatomic particle, called "psi" by Richter and "J" by Ting, three times heavier than the proton and with a life-span some 10,000 times longer than anticipated by theory at that time. This significant contribution in the field of elementary particles provided evidence for a fourth quark.
Science, 194 (1976), 825; Current Biography (1977), 359–62.
[Bracha Rager (2nd ed.)]