What Is A Higgs Boson?

Early Tuesday morning, the Royal Swedish Academy of Science awarded this year's Nobel Prize in Physics to two theoretical physicists - Peter Higgs and François Englert - who each independently predicted the existence of the Higgs boson in 1964.

The Higgs boson is impossibly difficult to explain. But the fact of the matter is, if the Higgs boson did not exist, we would not be able to explain why fundamental particles, like electrons, have mass.

Without it, we could not exist. The universe could not exist.

Right now, we are all surrounded by something called the Higgs field. The Higgs field is always on. It is invisible to us, but within the field are little bosons that are popping up and vanishing all the time. Particles obtain their mass by plowing through the field.

"If the field wasn't around you, the electrons in your body would not have mass, and you would disintegrate," said Paul Padley, a physicist at Rice University who has been involved with experiments to discover the Higgs boson.

That's probably why the Higgs boson was nicknamed the "God particle," a term that the majority of physicists abhor, particularly Mr. Higgs who is an atheist.

There have been lots of alternative explanations to the Higgs boson. Ideas have come and gone in the 50 years that it took to actually find the particle bearing the name of today's Nobel Prize winner.

On July 4, 2012, physicists announced that they had discovered a Higgs boson using the Large Hadron Collider at CERN. Padley is one of thousands of scientists who contributed to the discovery, but a limit of three people can win the Nobel prize, so it went to the first people to theorize the process of how particles obtain mass - finding the particle is proof that this process is real.

Below you can find a lightly edited transcript of our interview with Padley, who describes the science behind the elusive particle and the significance of its discovery.

Business Insider: Can we say for certain that scientists found a Higgs boson?

Paul Padley: Initially there was hesitation - we knew we had found something. But at this point CERN and the Nobel Prize committee have basically declared that this is a Higgs boson.

BI: You were involved in the discovery of the Higgs boson - as were thousands of other physicists on the experimental side. Do you believe it was fair to recognize just two recipients and why do you think this decision was made?

PP: They [Englert and Higgs] published the first papers on this Higgs mechanism. There are other people who contributed theoretically, but they were a bit later. The Nobel Prize committee is very strict that it just goes by order of publication. I don't know how they could ever award a Nobel Prize for the experimental work. The experiments are worthy of the Nobel Prize, but the current rules of the Nobel Prize committee are that they only give it to up to three individuals, and we're a lot more than three individuals.

BI: What is the biggest misconception about the Higgs particle?

PP: Everybody has trouble understanding exactly what it is. It's really hard to explain it because it's quite intricate mathematically. Fundamentally, physics is a mathematical science. And when you try to explain it using English, or any language other than mathematics, you're going to come up short. In order to learn the mathematics behind the Higgs mechanism, you really have to go to graduate school in physics.

The underlying theoretical framework is something called relativistic quantum field theory. Take quantum mechanics, put special relativity on top of that, and then you have to apply that quantum mechanics and special relativity to the Higgs field. It's another level of abstraction mathematically from regular quantum mechanics. And that's actually the right framework to do things in.

BI: How did physicists know was properties they were looking for to confirm the existence of a Higgs particle?

PP: In the Large Hadron Collider, we take two protons and smash them together and scan through the debris looking to see what came flying out. When you create a Higgs particle, you don't measure it directly. It falls apart right away. We troll through the data looking for decay patterns that would correspond to something like a Higgs boson. For example, the theory predicts that the Higgs boson would decay to two photons some fraction of the time. So we look to see if we see these two photon decays, and we do see that.

BI: What role did you play in the discovery?

PP: I worked for a number of years on helping to construct and commission the CMS (Compact Muon Solenoid) experiment and participated in the analysis of the data. In particular, at Rice here we helped contribute some of the electronics that selects Muons - a type of fundamental particle that comes flying out of the detector. One of the ways in which the Higgs boson was discovered was by measuring it decay into two Z bosons. Those two Z bosons subsequently sometimes decay into muons. There was a large U.S. contribution - over a dozen universities and 100 people - that helped build the muon system.

BI: What's the practical benefit of this discovery?

PP: There's often a huge delay between when the theoretical idea is confirmed and when it turns into practical devices. We're at the forefront of knowledge. We're just trying to understand the basic laws of physics. Hopefully some day those will be put to good use. I think the immediate practical benefit is the technological advances that we have to make in order to do these experiments. These experiments are so technically challenging that sometimes we have to invent technology.