Physicists say they have found a Higgs boson

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Lab > LANL scientist has done extensive research on the particle

By The Staff

The search is all but over for a subatomic particle that is a crucial building block of the universe.

Physicists announced Thursday they believe they have discovered the subatomic particle predicted nearly a half-century ago, which will go a long way toward explaining what gives electrons and all matter in the universe size and shape.

The elusive particle, called a Higgs boson, was predicted in 1964 to help fill in our understanding of the creation of the universe, which many theorize occurred in a massive explosion known as the Big Bang. The particle was named for Peter Higgs, one of the physicists who proposed its existence, but it later became popularly known as the “God particle.”

One Los Alamos National Laboratory scientist could not have been happier.

Michael Graesser has done extensive research on the Higgs boson particle and gave a series of lecture on the topic late last year.

Back in October, Graesser said, “A new particle was discovered last summer at the Large Hadron Collider at CERN in Switzerland. The Higgs boson gives mass to quarks and the electron but we don’t know yet if this new particle is the Higgs boson.”

But now, the rest of the science world knows the new particle is the Higgs boson.

“The confirmation yesterday that the Higgs-like particle discovered last July is indeed the Higgs boson of the Standard Model is indeed a big deal,” Graesser said Friday. “The latest measurements from the Large Hadron Collider suggest the new particle has spin 0, which what the Standard Model theory predicts. Before the latest data the new particle could have had instead spin 2, but now that hypothesis is becoming disfavored. The scientists at CERN should be congratulated on their achievements.

“These latest measurements suggest there is a new fundamental particle in nature, having spin 0. Because the Higgs boson has spin 0, the question of how fundamental particles such as quarks and the electron obtain mass in a way that is “natural” is brought sharply into focus.”

Graesser, who works on the lab’s theoretical division, said in the next two years the ATLAS and CMS collaborations will be coming their data, searching for additional new particles. To improve on their existing analysis, the collaborations will need new methods to better discriminate signatures of new particles from those produced by known backgrounds.

“This is where part of my recent research effort enters,” Graesser said. “Recently my collaborator Jessie Shelton (Harvard) and I have come with a new method to search for a class of new particles related to the top quark of the Standard Model, and we hope our new ideas will improve the sensitivity of the LHC experiments to such particles, if they exist.

“Right now, the LHC is shut down for the next two years to prepare the machine for an upgrade to higher energy and luminosity. Once the LHC restarts in 2015 we hope that by running at a higher energy more new particles will be discovered. The hope is that such new discoveries will give us a clearer picture into the physics occurring at such short distances.”

Graesser performs research in the areas of dark matter and theoretical subatomic physics. He has a doctoral degree in elementary particle theory from the University of California-Berkeley and had postdoctoral appointments at UC-Santa Cruz, Caltech and Rutgers University before joining Los Alamos. Graesser also did a graduate fellowship at the Natural Sciences and Engineering Research Council of Canada. He has been published in numerous journals.

Last July, scientists at CERN, the Geneva-based European Organization for Nuclear Research, announced finding a particle they described as Higgs-like, but they stopped short of saying conclusively that it was the same particle or some version of it.

Scientists have now finished going through the entire set of data year and announced the results in a statement and at a physics conference in the Italian Alps.

“To me it is clear that we are dealing with a Higgs boson, though we still have a long way to go to know what kind of Higgs boson it is,” said Joe Incandela, a physicist who heads one of the two main teams at CERN that each involve about 3,000 scientists.

Its existence helps confirm the theory that objects gain their size and shape when particles interact in an energy field with a key particle, the Higgs boson. The more they attract, the theory goes, the bigger their mass will be.

But, it remains an “open question,” CERN said in a statement, whether this is the Higgs boson that was expected in the original formulation, or possibly the lightest of several predicted in some theories that go beyond that model.

But for now, it said, there can be little doubt that a Higgs boson does exist, in some form.

Whether or not it is a Higgs boson is demonstrated by how it interacts with other particles and its quantum properties, CERN said in the statement. The data “strongly indicates that it is a Higgs boson,” it said.

The discovery would be a strong contender for the Nobel Prize, though it remains unclear whether that might go to Higgs and the others who first proposed the theory or to the thousands of scientists who found it, or to all of them.

The hunt for the Higgs entailed the use of CERN’s atom smasher, the Large Hadron Collider, which cost some $10 billion to build and run in a 17-mile (27-kilometer) tunnel beneath the Swiss-French border.

John Severance and the Associated Press contributed to this report.