What is the Higgs Boson Particle? Part 1

Find out what all the hubbub is over the Higgs boson particle discovery and why you should care about it.

Jason Marshall, PhD,
July 6, 2012
Episode #112

If you’ve watched or read any news this past week, you’ve probably noticed that physicists around the world are very excited over something called the Higgs boson. And in all likelihood, you were told that you should get excited about it, too. But why exactly should you care? What does this discovery mean?

If you’re looking for a Quick and Dirty primer on all things Higgs to help you answer these questions, look no further. Today we’re going to talk about the background behind the Higgs hubbub, and then next week we’ll follow that up with a look at what the term “statistical significance” means, and we’ll see why this idea has led physicists to confidently state that they’ve finally found what they’ve been looking for.

What Is a Higgs Boson?

Since this is The Math Dude, it should come as no surprise that our discussion of the Higgs boson over the next few weeks will be geared towards understanding the math—and in particular the statistics—that physicists used to discover it. But before diving into that math, we’d first better figure out what exactly this thing is that has been discovered. So without further ado, it’s time to introduce the main character in our drama: the Higgs boson.

What exactly is a Higgs boson? The short answer is that it’s a kind of clustering in something called the Higgs field. But unless you’re a particle physicist, that really doesn’t make much sense. So let’s just say that a Higgs boson is the until-now hypothetical particle that in a roundabout way causes all of the other fundamental particles—including things that we know and love like electrons, protons, and neutrons—to have the property that we call mass. And since we and most things we interact with in the world are made from bazillions of these electrons, protons, and neutrons, the discovery of the Higgs boson means that we now potentially understand why stuff like panda bears, people, and planets have mass. In other words, the discovery of the Higgs boson opens the doors to a better understanding of the universe.

The discovery of the Higgs boson opens the doors to a better understanding of the universe.

Why Is the Higgs Such a Big Deal?

Despite how impressive this all sounds, you still might very rightly be wondering why there has been so much hype? I mean, lots of amazing discoveries are made every year, but few receive this kind of fanfare. What’s the deal? Well, one reason for the hoopla is that physicists have been searching for this particle (and its associated Higgs field) for decades. Thousands and thousands of people’s careers have been spent looking for it, and all of those folks are quite understandably excited to have found it.

More importantly though, this discovery of a Higgs-like particle (so called because we can’t yet say with certainty if this is a “normal” Higgs or something more exotic), means that the puzzle slowly being assembled to understand the universe has jumped leaps and bounds closer towards completion. Don’t get me wrong, there’s still a lot to be discovered. For example, physicists know that the so called Standard Model which predicted the existence of a Higgs particle can’t actually be the final answer. Instead, there must be a yet deeper underlying theory (of which the much publicized string theory is one possibility) that encompasses the Standard Model, gravity, and more. The discovery of the Higgs particle is undeniably exciting because it’s the first step in putting the rest of this puzzle together. And in my mind at least, that means that its discovery is very deserving of this party.

How Was the Higgs Discovered?

Speaking of its discovery, how exactly did it happen? And, getting back to our main topic, what math was behind it all? To understand the math, we need to understand the method. And to understand the method, we need to understand how a particle accelerator like the LHC where the Higgs was discovered works. Particle accelerators are amazingly complex machines designed to carry out an extremely simple task: get two particles moving incredibly fast and smash them head-on into each other. Although this might just sound destructive, it’s actually surprisingly useful because what comes out of these collisions is usually different than what goes into them. And sometimes what comes out is a Higgs boson.

So we just have to take some pictures of these Higgs bosons, collect our Nobel prizes, and be done, right? Sadly, no—we can’t simply photograph a Higgs particle. Instead, we have to wait for it to break up into other particles that we can detect. When that happens, we see a certain “signature” that lets us know that a Higgs boson was recently there. So we just have to take a picture at this point and then we’re done, right? Again, sadly, no—there are many other things that can happen inside a particle accelerator that have very similar signatures. Which means that it’s difficult to figure out whether or not a detected Higgs boson signature is actually from a Higgs or something else far less interesting.

How Statistics Found the Higgs

This problem of untangling authentic Higgs boson signatures from all the other noise is precisely the point at which math enters the story. And while this is a difficult problem, when we combine a nearly uncountable number of collisions with a bit of statistics and some heroic work by scientists, it’s a problem that can be solved. How exactly? Unfortunately we’re out of time for today, so the conclusion to the story of how statistics helped find the Higgs boson will have to wait until next time. In the meantime, keep an eye out for more details about the Higgs discovery in the coming weeks from Everyday Einstein.

Wrap Up

