Burton Richter
Nobel Prize-winning American physicist who found a new building block of matter
Burton Richter, physicist. Born: 22 March 1931 in Brooklyn New York City, United States. Died: 18 July 2018, in Stanford, California, aged 87.
Burton Richter, whose discovery of an unexpected particle revealed a new building block of matter and brought him a share of the 1976 Nobel Prize in physics, has died at 87. The cause was heart failure.
Richter was the rare particle physicist who possessed a broad expertise both in the engineering of how accelerators slam together subatomic particles at near-light speeds and in understanding what comes out of those collisions.
“Burt was very different,” said Samuel CC Ting, the Massachusetts Institute of Technology physicist who shared the Nobel with Richter. “I know of no one else” like him.
Richter’s versatility proved to be a boon in the early 1970s, when he designed the Stanford Positron Electron Accelerating Ring, or SPEAR, and cajoled the US Energy Department into providing $6 million to build it. The machine accelerated electrons and positrons – the antimatter version of electrons – in opposite directions around a circular ring. The physicists hoped that the high-energy collisions would reveal new particles.
“He was the force behind building SPEAR,” Martin Breidenbach, a professor at SLAC and Stanford University who began working with Richter as a postdoctoral researcher in 1972, said.
Experiments began in 1973. Richter was eager to push on to higher energies, where discoveries seemed more likely, but Breidenbach and others wanted first to sort out some inconsistent readings that they had observed at one particular energy level, 3.1 billion electron volts.
“We were given a weekend to waste,” Breidenbach said. “What happened that weekend became all consuming.”
On that Saturday, 9 November 1974, the physicists figured out that the readings were inconsistent, because the energy of the earlier runs had not been set precisely. No one had thought that was a crucial parameter. By Sunday, Richter and his colleagues had homed in on a sharp peak in the number of particles coming out of the accelerator at a particular energy – the hallmark of a new particle. They started writing a draft of a paper to describe the discovery, naming the new particle psi, the 23rd character of the Greek alphabet.
The next day, by coincidence, Ting was at SLAC attending a programme advisory meeting. “When I met Sam early that morning, he said to me, ‘Burt, I have some interesting physics to tell you about’,” Richter recalled in an article published in the laboratory newsletter in 1976. “My response was, ‘Sam, I have some interesting physics to tell you about!’ ”
Ting was surprised to learn of the discovery of psi, and Richter was surprised to learn that Ting’s team had a few weeks earlier observed the same particle in experiments at Brookhaven National Laboratory on Long Island in New York. The team had not yet announced the finding. Ting had named it the J particle.
Later that day, the two teams jointly revealed the discovery andgaveitthecombinedname J/psi. That set off what physicists called the “November revolution” – a wave of ensuing excitement in exploring a bounty of new particles that required revising the foundations of physics.
“The new particle is something separate and new, and it has formed the beginning of a new family of its own,” the Nobel committee said in announcing the physics prize for Richter and Ting less than two years later. Both men were in their 40s, among the youngest to win the physics Nobel.
Theorists figured out that explaining the existence of the J/psi required a new type of quark. (Quarks are the building blocks of particles like protons and neutrons.) At the time, physicists knew of three types of quarks – up, down and strange. The new quark became known as charm. The J/psi consists of two quarks: a charm quark paired with a charm antiquark, each circling the other like twirling square dancers.
Burton Richter was born on 22 March 1931 in Brooklyn, the oldest child of Abraham Richter, a textile worker, and Fanny. After graduating from high school, he enrolled at the Massachusetts Institute of Technology at 17. He obtained his undergraduate degree in physics there in 1952, and a doctorate four years later.
Richter then joined Stanford’s High-energy Physics Lab as a research associate and became an assistant professor of physics in 1960. In 1963 he also took a position at the Stanford Linear Accelerator Centre, one of the leading particle physics laboratories in the world. As laboratory director from 1984 to 1999, Richter oversaw the construction of the Stanford Linear Collider, a new type of machine that, instead of guiding positrons and electrons along a circular ring, fired them at each other along straight paths. Construction ran into many difficulties and delays, but ultimately the machine lived up to its promise.
Richter was the author of Beyond Smoke and Mirrors: Climate Change and Energy in the 21st Century (2010). In 2014, he received the National Medal of Science from US President Barack Obama in a White House ceremony.
He was a member of the National Academy of Sciences and a fellow of the American Academy of Arts and Sciences and the American Association for the Advancement of Science. He was also a member of Jason, an independent group of scientists that advises the federal government.
Breidenbach fondly remembered the arguments he and Richter would have every week or so. “We usually argued about the management of SLAC, what’s important in science, why the place can’t be better and stuff like that,” he said. “It was something we both enjoyed.”
He went to visit Richter the day before he died.
“He was sitting in a chair with oxygen,” Breidenbach said. “He was as acute as ever. He was a little down, not surprisingly, and I asked his wife, Laurose, if it was OK to argue with him. And she laughed and said, ‘Of course.’ And so we set off doing it.”
He is survived by his wife, Laurose; a daughter, Elizabeth Richter; a son, Matthew; and two grandchildren. KENNETH CHANG The Scotsman welcomes obituaries and appreciations from contributors as well as suggestions of possible obituary subjects.
Please contact: Gazette Editor
n The Scotsman, Level 7, Orchard Brae House, 30 Queensferry Road, Edinburgh EH4 2HS;
n gazette@scotsman.com
“We were given a weekend to waste. What happened that weekend became all consuming”