STOCKHOLM — The entire physics community anticipated Tuesday that Swedish Royal Academy of Sciences would bestow a Nobel Prize in physics for the discovery of the Higgs boson, the elusive subatomic particle that plays a crucial role in the fabric of the universe. But who, exactly, would get the honor? The aging theorists who dreamed it up back in 1964? Or the mostly younger experimentalists who last year said they’d found it?
The academy went with the theorists — two of them, at least. The new Nobel laureates are 84-year-old Englishman Peter Higgs, after whom the particle is named, and Francois Englert, 80, of Belgium. That left out in the cold several other theorists who could plausibly claim to have deserved the honor as well.
Englert materialized by voice Tuesday morning in a teleconference after the announcement in Stockholm and did not sound particularly surprised as he answered a few questions about enduring unknowns in physics (dark energy, dark matter, quantum gravity). But a Nobel committee official said no one had been able to reach Higgs, despite multiple phone calls. The committee had also emailed him the news.
“I am overwhelmed to receive this award,” Higgs said in a statement released by the University of Edinburgh. “I hope this recognition of fundamental science will help raise awareness of the value of blue-sky research.”
The Higgs boson, once dubbed by scientist Leon Lederman as “the God particle,” is associated with an invisible field that is part of the basic infrastructure of the cosmos. The mass of particles is determined by how they interact with this field.
The Nobel committee said it gave the prize to Englert and Higgs “for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN’s Large Hadron Collider.”
Rarely has a Nobel Prize announcement arrived with so much hype and anticipation. Everyone in the physics community knew that the prize could go to someone involved with the Higgs particle. It was as if the prize would be the final validation of the discovery, which was announced on July 4, 2012.
“This is great for physics. It’s great for science. The story is fantastic,” said Michael Turner, president of the American Physical Society. “They answered a question that’s so simple and so basic that few people asked it — why do things have mass?”
“These gentlemen did this work in 1964, and they had to wait half a century to see it come to fruition,” said Fred Dylla, executive director of the American Institute of Physics. “The Nobel committee has done a very fair job on a very difficult decision.”
Lisa Randall, a Harvard physicist and author of the book “Higgs Discovery,” said the prize was well-deserved and noted the “heroic efforts” of the experimentalists who found the particle.
More questions about the Higgs remain to be answered, she said: “Looking forward, we want to know the resolution to the so-called hierarchy problem, the question of why the Higgs boson isn’t 16 orders of magnitude heavier, as our theory of quantum mechanics and special relativity would predict.”
Although the physics community expected that the prize would recognize, in some fashion, the discovery of the Higgs particle, no one knew how the Nobel committee would apportion the credit. Without the experimental work, no one today would likely be talking about the theories of the 1960s. But the efforts at the Large Hadron Collider at CERN involved thousands of scientists and engineers, including many from the United States.
Turner, the APS president, said Tuesday, “Discoveries more and more involve a village. It took 10,000 people and $10 billion and 20 years to build the instrument that made this discovery, and you’d be hard pressed to narrow that group down even to 100, let alone to three.”
There were six theorists, including Englert and Higgs, who have been widely credited with the theoretical framework that led to the discovery of the new particle. Of the six, five are still alive (the Nobel cannot be awarded posthumously). The Nobels by tradition are awarded to no more than three people.
Englert published first in 1964, co-authoring a paper with Robert Brout, and was followed soon thereafter by Higgs. Brout died in 2011. The American physicist Gerald Guralnik has written an account of his own work in 1964, in collaboration with Carl Hagen and Tom Kibble.
“It stings a little,” Guralnik, a professor at Brown University, said Tuesday morning, but he did not belabor the fact that he and his two collaborators had been bypassed by the royal academy.
“I’m not surprised. It was pretty clear how this was shaping up. I would be lying if I didn’t say I’m a bit disappointed. All in all, it’s a great day for science. I’m really proud to have been associated with this work that has turned out to be so important,” Guralnik said.
Guralnik said they had arrived at their theory independently in 1964 but had been overly cautious in submitting their work for publication. With their paper already sealed in an envelope and ready to be mailed to a scientific journal, they saw pre-prints of the two papers by Englert/Brout and Higgs, and briefly added to their own paper an acknowledgment of the other theoretical work without considering it to be terribly significant or accurate.
“Frankly we didn’t even take them very seriously at the time. We thought they missed the main point,” Guralnik said.
Hagen on Tuesday did not attempt to hide his disappointment at being bypassed, and alluded to the academy’s tradition of granting a prize to no more than three people.
“Faced with a choice between their rulebook and an evenhanded judgment, the Swedes chose the rulebook,” Hagen, of the University of Rochester, said in an email. “Not a graceful concession by any means, but that department has never been my strong suit.”
“There is no question that Higgs and Englert deserve this. The only question would be how exactly they made the decision to exclude the other three,” said Mario Livio, an astrophysicist at the Space Telescope Science Institute in Baltimore.
On Tuesday, the world tuned in to the Nobel Internet feed at 11:45 a.m. Stockholm time — 5:45 a.m. Eastern time — only to see an enigmatic announcement on the screen: The announcement is a few minutes delayed.
This went on for an hour. It was unclear if the delay was due to the committee’s inability to reach Higgs and tell him the news. He has previously said he would not be available for interviews in association with the prize announcement.