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Lecture explores impact of Higgs boson

Christopher Barnes | Thursday, August 23, 2012

Professor Colin Jessop, an experimental particle physicist, delivered a lecture Wednesday on the landmark discovery of the Higgs boson, better known as the “God particle,” which surfaced last month at the Large Hadron Collider (LHC), an underground facility located in Geneva, Switzerland.

Jessop said the standard model of particle physics describes the particles that exist in the universe and how they decay, and this model provided the foundation for the Higgs’s discovery.

“The standard model of particle physics includes two types of particles: hadrons, those that are composed of quarks, and leptons, elementary particles with no constituent parts,” Jessop said.  “The Higgs field is the means by which these types of particles acquire mass.”

Jessop said the effect of the Higgs’s field upon hadrons and leptons can be likened to a boat floating in a lake.

“When a boat floats within a lake, the water particles interact with the boat’s particles to provide a drag force, slowing the boat down,” he said.  “The lake represents the Higgs field, which provides fundamental particles with mass as they move within it.  Just as the bottom of the boat is surrounded by the lake, so are all particles immersed within the Higgs field.”

Jessop compared a ripple on the surface of a lake to the boson’s effects.

“When an object moves on the surface of a lake, the event causes a ripple that disturbs the water’s surface,” he said.  “In the same manner, the Higgs particle travels outward from the source of the disturbance in the Higgs field.”

Jessop said understanding the historical background of the search for the Higgs boson reveals the importance of its discovery.    

“The Higgs mechanism was first proposed by Peter Higgs, a theoretical physicist working at the University of Edinburgh in Scotland,” he said. “The scientific community realized the significance of his ideas in the 1970s, and we have been searching for the particle responsible for the phenomena ever since.”

The United States was in the process of building a facility to house experiments for the search in the early 1980s, but the project was never completed, he said.

“The Superconducting Super Collider was approved by President Reagan to find the Higgs boson, but President Clinton cancelled the construction of the collider in 1993,” Jessop said. “Politicians overlooked the fact that it would have cost less to finish the construction of the collider rather than eliminating it entirely, so it was done away with.”

The LHC opened in 2008 in the hopes that it would quicken the path to the Higgs’ discovery, Jessop said.

“The LHC has a circumference of sixteen miles and collides protons together at an energy of 14 TeV, which is still only a fraction of a Joule of energy,” he said.  “The project cost about $6 billion, $2 billion of which was donated by the United States in funding construction.”

The Higgs discovery is only the beginning of the work at the LHC, which will undergo improvements in the future, Jessop said.

“An intensive series of upgrades to the accelerator and detector to enhance data taking is planned through 2021,” he said.  “The question that we will hope to ultimately achieve with these upgrades is the following:  Is this exactly the Standard Higgs model we think it is?”

Jessop said he looks forward to pursuing the new questionsethat will arise now that the existence of a Higgs-like particle has been confirmed.

“The Higgs particle could be either fundamental or composite, which means that it could be composed of smaller particles or be entirely uniform,” he said.  “In addition, there could be more Higgs according to the Standard Model. One theory, known as supersymmetry, includes three neutral Higgs and two charged Higgs.”