What Exactly Is the Higgs Boson?

In order to truly understand what the Higgs boson is, however, we need to examine one of the most prominent theories describing the way the cosmos works: the Standard Model. The model comes to us by way of particle physics, a field filled with physicists dedicated to reducing our complicated universe to its most basic building blocks — subatomic particles.

It's a challenge we've been tackling for centuries, and we've made a lot of progress. First we discovered atoms, then protons, neutrons and electrons, and finally quarks and leptons (more on those later). But the universe doesn't only contain matter; it also contains forces that act upon that matter. The Standard Model has given us more insight into the types of matter and forces than perhaps any other theory we have.

Here's the gist of the Standard Model, which was formalized in the early 1970s: Our entire universe is made of 12 different matter particles and four forces [source: European Organization for Nuclear Research]. Among those 12 particles, you'll encounter six quarks and six leptons.

Quarks make up protons and neutrons, while members of the lepton family include the electron and the electron neutrino, its neutrally charged counterpart. Scientists think that leptons and quarks are indivisible; you can't break them apart into smaller particles.

Along with all those particles, the Standard Model also acknowledges four forces: gravity, electromagnetic, strong and weak.

As theories go, the Standard Model has been very effective. Armed with it, physicists have predicted the existence of certain particles years before they were verified empirically. Unfortunately, for decades, the model had a missing piece — the Higgs boson.

As it turns out, scientists think each one of those four fundamental forces has a corresponding carrier particle, or boson, that acts upon matter. That's a hard concept to grasp. We tend to think of forces as mysterious, ethereal things that straddle the line between existence and nothingness, but in reality, they're as real as matter itself.

Some physicists have described bosons as weights anchored by mysterious rubber bands to the matter particles that generate them. Using this analogy, we can think of the particles constantly snapping back out of existence in an instant and yet equally capable of getting entangled with other rubber bands attached to other bosons (and imparting force in the process).

Scientists think each of the four fundamental ones has its own specific bosons. Electromagnetic fields, for instance, depend on the photon to transit electromagnetic force to matter. Physicists think the Higgs boson might have a similar function — but transferring mass itself.

Can't matter just inherently have mass without the Higgs boson confusing things? Not according to the Standard Model. But physicists have found a solution. What if all particles have no inherent mass, but instead gain mass by passing through a field?

This field, known as a Higgs field, could affect different particles in different ways. Photons could slide through unaffected, while W and Z bosons would get bogged down with mass. In fact, all elementary particles that have mass get it by interacting with the all-powerful Higgs field, which occupies the entire universe.

Like the other Standard Model particles, the Higgs one would need a carrier particle to affect other particles, and that particle is known as the Higgs boson.

In 1964, Peter Higgs, François Englert and Robert Brout proposed the Higgs mechanism. Higgs, Englert and Brout hypothesized the existence of a fundamental particle that gave other particles their mass.

To test their hypothesis, scientists needed serious equipment; namely, the Large Hadron Collider at the European Organization for Nuclear Research. Only a high-energy particle collider could prove the existence of the Higgs particle.

On July 4, 2012, scientists working with CERN'S Large Hadron Collider (LHC) announced their discovery of a particle that behaves the way the Higgs boson should behave. The results were confirmed in March 2013 and Higgs and Englert were awarded the 2013 Nobel Prize in Physics.

Looking Forward

Now that the we've identified this elusive particle, what's next for the physics world? Scientists are using particle detectors at the LHC, ATLAS (A Toroidal LHC ApparatuS) and CMS (Compact Muon Solenoid) to learn more about the Higgs boson.

According to the U.S. Department of Energy, ATLAS and CMS experiments are gathering "precise measurements of the Higgs boson's properties" to determine if it confirms the Standard Model or points to new particles. Some theories suggest multiple Higgs bosons — at least five! Although the existence of the Higgs boson went a long way towards proving the Standard Model, we still have plenty more to learn about the fundamental particles that make up the universe.