Instead, he enrolled in the Polytechnic Institute of Brooklyn with the aim of becoming a chemical engineer. With the onset of World War II, he left to attend the United States Merchant Marine Academy and was then drafted into the Army. He spent a year doing desk work in Washington.

After the war, he resumed his studies and graduated in 1948. Hired by General Electric, he became interested in a new technology, television, particularly in how television tubes worked.

“At the age of 23,” he wrote, “I finally decided to begin the study of physics.”

He earned a Ph.D. at Columbia, studying the nuclei of sodium atoms under the Nobel laureate Isidor Isaac Rabi. After a stint at the University of Michigan, he was offered at job at the new Stanford Linear Accelerator Center (now known as SLAC).

Dr. Perl saw the new lab as a place where he could dig into a longstanding puzzle. In the 1930s, physicists had discovered a new particle they called the mu meson (it is now called the muon), which was identical to an electron but 200 times more massive. Where this particle fit in the scheme of things was a mystery. “Who ordered that?” Dr. Rabi is said to have asked.

Burton Richter, a former director of SLAC, said in an interview that when he first met him, “Martin was already fascinated by the quest for the brotherhood of the mu mesons: Why there was only one mu meson? Why weren’t there more? Could there be more?”

Dr. Perl thought that finding an even heavier electron might answer some of these questions and help explain the muon’s role in the scheme of things. He and his group figured out that such particles might be detected in a new collider being planned called Spear, for Stanford Positron Electron Accelerating Ring. The particles would decay radioactively immediately but would leave behind a distinctive trail of subatomic debris.

In the official proposal for the Spear collider, the heavy lepton search was left for last, and allotted just three pages. As Dr. Perl wrote, “to most others it seemed a remote dream.”