Page 3 - Eureka 2012

the year of the

particle physicist Cover story

By Susan Hickman

his is the year of the particle his 80s, is credited with discovering unknown processes and particles that
Tphysicist – the year scientists who a mechanism some 50 years ago that might unveil such mysteries as extra
have been looking for the missing Higgs would give mass to particles. According dimensions of space, microscopic black
boson particle have been waiting for. to this model, elementary particles gain holes and string theory. Carleton’s team
They knew before the year was out they mass by interacting with an invisible, is the only Canadian group searching
would have either confirmed or refuted omnipresent field. The more they for the Higgs in the two channels
the existence of the hypothetical interact with the Higgs field, the more believed most likely to prove the
particle that is credited with providing mass they will have. existence of the elusive particle. They
the mechanism by which particles In fact, physicists in search of this are also responsible for developing,
acquire mass. And sure enough, on Higgs boson particle are not able to constructing and testing detector
July 4, the world learned that there actually “see” it. When high energy modules for the forward calorimeters of
was significant evidence of a new particle beams are smashed together, the LHC.
particle and that some of the particle’s what they see are the particles emitted Oakham, who is also a research
properties were consistent with the by the decaying Higgs. This summer’s scientist at TRIUMF (Canada’s National
Standard Model predictions of a Higgs discovery is still not “definite,” but Laboratory for Particle and Nuclear
boson particle. according to Oakham, the findings are Physics), has been developing detectors
The July 4 announcement has been consistent with the Higgs boson. for particle physics experiments since
decades in the making and there are Carleton’s physics department is a he was a PhD student at Carleton in
physicists, such as Carleton’s physics major contributor to this fascinating the early 1980s. He has been fascinated
professor Gerald Oakham, who have world of experimental physics and with the work at CERN since he was
been anticipating this year’s discovery its cutting-edge research in the in high school and began working in
their entire careers. What it means is a decades-long search for the Higgs the field of particle physics during his
revolution in physicists’ understanding puts a well-deserved feather in its cap. graduate studies.
of the smallest objects that make up Oakham leads a group of three other “The fundamental nature of the
matter, an extension of the Standard faculty members (Manuella Vincter, research is interesting,” says Oakham.
Model with something yet unknown Thomas Koffas and Alain Bellerive), “Since 1975, our understanding of the
that could explain mass, gravity and three research associates and seven constituents of matter have come very
other phenomena. graduate students in the ATLAS particle far. We didn’t know what made up
The Standard Model, a quantum physics experiment being conducted neutrons or protons and the idea of a
theory of all known elementary at one of four large detectors at the quark was a mathematical construct.
particles and interactions, is Large Hadron Collider (LHC) particle We couldn’t see the patterns and the
incomplete. We don’t know why accelerator in the underground relationships between the particles
particles have mass, and we’re European Organization for Nuclear then.”
not certain if quarks and leptons Research (CERN) laboratory in Geneva, Oakham and his team first considered
have further substructure, or what Switzerland. The Carleton team is joining the international collaborative
constitutes dark matter. among hundreds of teams of scientists ATLAS particle experiment in 2000, but
Peter Higgs, a British theoretical from more than three dozen countries it was “a complicated game” of decision-
physicist and emeritus professor at who are studying the basic forces making and searching for funds,
the University of Edinburgh, now in that shape our universe, and probing Oakham explains.

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