Yamamoto, who was born and raised in Hawaii, came to MIT as a freshman in 1953 and spent his entire career at the Institute. He was known for his love of working with his hands as well as his contributions to understanding elementary particles, according to colleagues.
"He loved to work with students, making things," says Peter Fisher, division head of particle and nuclear experimental physics, who began working with Yamamoto in 1994. "He was happiest when he had his hands on some knob, adjusting a mirror, and looking at an oscilloscope."
Yamamoto worked for many years on experiments at Fermilab and the Stanford Linear Accelerator Center, where his team showed that a type of particular interaction called a weak interaction appeared differently if viewed in a mirror - a phenomenon known as a parity violation, not seen in any other particle interactions. As part of that work, he devised a way to use a laser to accurately count the number of left-handed and right-handed electrons in a beam of electrons. They used this method to measure the interaction strength of a particle called the Z boson, a heavy elementary particle first discovered in 1983.
Fisher recalled that Yamamoto's team at Stanford had some difficulty figuring out why two different electron-counting methods were producing different results, but the director of the accelerator center was pressuring the team to publish their results. Yamamoto insisted on waiting until they figured out why their numbers were off, which they eventually did.
"Dick was a mild-mannered guy, but when push came to shove, he stood up to the system," Fisher says.
Yamamoto's research team also carried out very precise studies of how particles containing heavy quarks would decay if time flowed backward.
Yamamoto earned his bachelor's degree and PhD, both in physics, from MIT in 1957 and 1963, respectively. He joined MIT's Laboratory for Nuclear Science in 1963 and became an instructor of physics in 1964. He joined the faculty as an assistant professor in 1965 and became a full professor in 1972.
"Dick was a wonderful colleague, teacher, and friend to many faculty, staff and students," says Edmund Bertschinger, head of the physics department. "His kindness and gentle enthusiasm helped make the department an exciting and supportive place for everyone in physics. Although he will be greatly missed, his values and spirit persist in the culture of our community."
Yamamoto is survived by his wife, Kathleen Yamamoto; his former wife, Lily Yamamoto; three daughters, Cara-Jean Donaghey, Lani Yamamoto and Sharon Yamamoto; and eight grandchildren.
A memorial service will be held at the MIT Chapel at 1:30 p.m. on Thursday, Oct. 29, with a reception in the Pappalardo Room (4-349), from approximately 2:30 to 4 p.m. Burial will be in Hawaii Memorial Park on Oahu, Hawaii.
Donations may be made to the Cancer Center at Massachusetts General Hospital.