Finding the Higgs boson: Why does it matter?

KENNESAW, Ga. (March 21, 2013) Nikolaos Kidonakis is a theoretical physicist at Kennesaw State University  whose research involves the elementary particles in physics, including quarks and the Higgs boson, which the media often refers to as the “God particle.” His calculations have been used by scientists running experiments at the Large Hadron Collider at CERN, the European Laboratory for Particle Physics. Recently, scientists at CERN made news around the world when, after analyzing data from a series of experiments, they announced they were certain that the Higgs boson had been discovered.

Kidonakis, an associate professor, explained the significance of this.

What is the Higgs boson?

The Higgs boson was predicted in the 1960s by Peter Ware Higgs, a theoretical physicist and professor emeritus at the University of Edinburgh, and a few other physicists. It is the missing piece in the Standard Model of Particle Physics. We know of four fundamental forces in nature: gravity, electromagnetism, strong interaction and weak interaction. People are more familiar with gravity and electromagnetism. Strong and weak interactions are nuclear forces. That is, they occur at the nuclear and subnuclear level. In the very, very early universe, the electromagnetic and weak interactions were unified. As the universe expanded and cooled, these two forces separated and appeared as we know them now.

The Higgs particle appeared in this process of separation. We think of the Higgs field as existing everywhere throughout the universe. Quarks are subatomic particles that make up protons and neutrons, and  hence matter. There are six types of quarks. The top quark is the heaviest particle we know. The Higgs gives mass to these particles. The Higgs coupling to the top quark is large because the top quark is very heavy. The Higgs gives mass to the elementary particles but it is not responsible for all the mass in the universe.

What happened at the Large Hadron Collider?

Scientists collided protons at a very high speed to see the products of these collisions. In December 2011, they had some tantalizing evidence that they had found the Higgs. Then, on July 4, 2012 they presented more conclusive evidence, enough to claim discovery. But they kept on collecting data. The new data strengthens the announcement that they made in July that they had discovered the Higgs.

Why does this matter?

There is a fundamental human desire to understand how the universe works. It is our innate desire to understand. First we seek to understand the universe. Then we seek to apply our understanding. Applications may take a while. But GPS, electronics, all of our modern technology is based on asking fundamental questions about how nature works. Basic research often has no practical use at the time, but it leads to many discoveries and applications. The Large Hadron Collider needed very powerful magnets. This pushed the technology. Today we have mini colliders, very small versions of this, in many hospitals in the form of Proton Emission Tomography, or PET scans. The World Wide Web was created as a platform for theoretical physicists to share their data. Now the next thing is the Grid, which can handle more data.

How does this affect the work you do?

I have worked on the Higgs as part of both Standard Model calculations and beyond the standard model physics. My calculations make predictions about how these particles, the Higgs and the top quark, will behave. They are used worldwide by experimental collaborations. They have been used at the Large Hadron Collider.  Experimenters compare their results with my theoretical calculations. So far my predictions agree very well with experimental results, most notably for the top quark. There are theories that there are more kinds of Higgs particles. The next question is whether the Higgs boson that we found is the Standard Model Higgs or a more exotic kind of Higgs particle.

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Image: Scientists at CERN collided protons at a very high speed and observed the products of these collisions. Image source: CERN