By William Yardley

New York Times News Service

Gerald Guralnik, one of six pioneering physicists who in the 1960s came up with a theory that nearly 50 years later would lead to the discovery of a subatomic particle that helped explain a perennial mystery about the universe — why it contains life and diversity — died April 26 in Providence, R.I. He was 77.

His son, Zachary, said the cause was a heart attack.

The discovery of the particle — it is known as the Higgs boson, though some call it “the God particle” — in 2012 confirmed a longstanding belief about why some elements have matter and some do not, and it earned a Nobel Prize for some of the physicists who first asserted that it existed.

Guralnik did not win the Nobel, but his crucial role in one of the most ambitious pursuits of modern physics is not in dispute.

On July 4, 2012, he and other surviving founders of the theory received a raucous ovation when they entered an auditorium at CERN, a multinational research center headquartered in Geneva. They had been invited to hear the announcement that a younger generation of scientists had used an immense multibillion-dollar machine called the Large Hadron Collider to confirm a theory many of the older men had drafted when they were starting their careers.

Guralnik, reveling in a spectacle rare for physics, said the applause was “like a football game.”

In 1964, he and the five other physicists, working in three independent groups, published papers describing a field of energy that is everywhere all the time but nowhere to be seen. This force, they theorized, provides mass to the elemental ingredients that make up everything else: people, places, things, the living, the inanimate, the aromatic.

Decades later — after refinements by others, after major government investments around the world and after thousands of scientists sifted through the results of trillions of collisions of protons inside the Large Hadron Collider — they were told how right they were.

“The finding affirms a grand view of a universe described by simple and elegant and symmetrical laws — but one in which everything interesting, like ourselves, results from flaws or breaks in that symmetry,” Dennis Overbye wrote of the CERN announcement in a front-page article in The New York Times in 2012 under the headline “Physicists Find Elusive Particle Seen as Key to Universe.”

“According to the Standard Model,” he continued, “the Higgs boson is the only manifestation of an invisible force field, a cosmic molasses that permeates space and imbues elementary particles with mass. Particles wading through the field gain heft the way a bill going through Congress attracts riders and amendments, becoming ever more ponderous.

“Without the Higgs field, as it is known, or something like it, all elementary forms of matter would zoom around at the speed of light, flowing through our hands like moonlight. There would be neither atoms nor life.”

In addition to his son, survivors include his wife, the former Susan Ellovich, whom he married in 1963; his sister, Judith Ingis; and two grandchildren.