Harnett to speak on the strong nuclear force in UFV lecture

To study particle physics, you have a strong scientific and mathematical background. But you also need a good imagination, because you’ll be spending a lot of time studying things that you cannot see.

And that’s okay with Dr. Derek Harnett, a physicist who will be the second speaker in the 2011/12 University Lecture Series at UFV. Harnett will speak on Wed, Nov 16, at 4 pm in Room B121 on the Abbotsford campus.
Harnett will speak about Exotic Bound States of the Strong Nuclear Force.

The strong nuclear force is one of the four basic forces in nature (the others being gravity, the electromagnetic force, and the weak nuclear force). It is what scientists believe causes quarks to stick together to make protons and neutrons.

The science of physics includes a perpetual quest to further isolate the tiny subatomic building blocks of matter. Objects are made of molecules, which are comprised of atoms. Atoms can be broken down into protons, neutrons, and electrons.

Protons and neutrons are made of smaller ‘bits’ of matter called quarks.

Basic physics says that opposite electric charges attract and similar charges repel one another.
This is where the strong nuclear force comes in.

“Particle physics contends that there must be another force, stronger than the electric force, that provides a greater attraction than repulsion,” Harnett says. “They’ve labeled it, rather unimaginatively, the strong nuclear force.

“Ideally, we would isolate quarks in order to study them, but we can’t,” continues Harnett. “What we can do is study how quarks stick together in a bound state.

“We now know that forces are due to particle exchange. The particles interact by sending streams of mediating particles back and forth, exchanging energy. The bundles of energy that flow between quarks are called gluons.”

Harnett explains that protons and neutrons each contain three quarks. The “exotic” particles referred to in his presentation would be substituting one or more quarks with gluons.

“People are building machines now to try to see these particles,” Harnett notes. “Such exotic particles are predicted by theory but have yet to be conclusively identified in experiment. The big question is: do they exist and haven’t been found yet, or is the theory incomplete? My inclination is that the theory — formally called quantum chromodynamics — is fine.”

Harnett acknowledges that his research is strongly in the purely theoretical, as compared to applied, field.

“But when we ask why care about theoretical physics, we need to remember that before you can take a force and harness it for the purpose of engineering, you need a really deep understanding of it. Electromagnetism was pure scientific theory to begin with. Some guys just wanted to know why magnets stuck together. Now we have it powering wireless devices all over the world. We probably won’t reap the benefits of nuclear physics research in the foreseeable future, but it is still worthwhile and fascinating to study.”

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