Physicists Make Strides in Finding Higgs Boson

Finding the undiscovered Higgs boson and the origin of mass is like finding a needle in a very large haystack. Measurements by University of Mississippi physicist Breese Quinn and the team he belongs to recently made that haystack smaller than ever before.

Dr. Breese Quinn

Quinn, his graduate student, Sudeep Bhatia, and postdoctoral assistant, Alex Melnitchouk, are among 600 researchers worldwide involved in the D0 (pronounced “DEE-zero”) experiment at Fermilab’s Tevatron, a proton-antiproton collider in Batavia, Ill. For 40 years, the Tevatron has been the world’s most powerful accelerator, colliding particles at two trillion electron volts (TeV) of energy since 2001. The Tevatron brings particles up to their maximum energy and steers them around a 4-mile ring into collision, and experiments (such as D0) use massive particle detectors to record and analyze the collision debris. While Quinn commutes to the lab, his student and postdoc have spent years in residence helping to conduct the experiment, collect and analyze data.

“At Fermilab we produce teeny, tiny amounts of antimatter all the time,” Quinn said. “When these particles of antimatter collide with matter, an explosive energy is generated for a few split seconds.”

By splitting protons, researchers create conditions like those that existed earlier than the first billionth of a second of the universe. Theoretically, such experiments may lead to an understanding of what are the basic building blocks of creation and how they fit together.

“For years, particle physicists have been trying to answer fundamental questions, such as ‘Where does mass come from?’, ‘Are there extra dimensions of space?’, ‘What is dark matter?’” Quinn said.

His work addresses the origin of mass. Physicists think everything gets its mass from the Higgs boson. But the Higgs is closely related to a known particle, the W boson. Precisely measuring the mass of the W narrows the Higgs search, sort of like reducing the size of the haystack you have to search to find the needle. Quinn’s group is leading this measurement on D0, where they recently published the world’s most precise W mass measurement. Basically, they closed in on the Higgs and the origin of mass more than ever before.

The European lab CERN recorded the first proton collisions at a record 7 TeV at the 16-mile Large Hadron Collider in Geneva, Switzerland, March 30, making it the new highest energy accelerator.

Fermilab's Tevatron, a proton-antiproton collider in Batavia. Illinois.

“Fermilab will run the Tevatron for another year or so before the LHC really takes the lead and I join my colleagues on the CMS [Compact Muon Solenoid] experiment there,” Quinn said.

UM physicists join more than 1,700 scientists, engineers, students and technicians from 89 American universities, seven U.S. Department of Energy national laboratories and one supercomputing center, which helped design, build and operate the LHC accelerator and its four massive particle detectors. American particle physics is supported by DOE’s Office of Science and the National Science Foundation.

“The LHC will run for another year and a half at half energy, and CMS will publish papers on that data,” Quinn said. “Then it will shut down for a year and restart with energy at full capacity.”

Quinn conceded that “big” discoveries [such as the Higgs boson] are probably years away but celebrates the success of D0 and the start of CMS.

“A lot of people have waited a long time for this moment, but their patience and dedication are starting to pay dividends,” he said.