07.06.12

After the Higgs Boson: What Scientists Will Do With the Discovery

The Higgs boson discovery revolutionizes the world of physics. Cosmologist Sean Carroll on the doors it opens—and the challenges ahead.

A decades-long quest reached a successful conclusion when scientists announced on July 4 that they had finally discovered the Higgs boson, a crucial missing piece in the Standard Model of particle physics. Research carried out at the Large Hadron Collider outside Geneva, Switzerland, were able to produce the new elementary particle by colliding protons together at extraordinarily high energies. The question on everybody’s mind, naturally, is: When I am getting my Higgs-boson-powered smartphone and/or jet pack?

Don’t get your hopes up too high. Particle physicists have long obsessed over the search for the Higgs because the boson was clearly predicted by our best theories of fundamental interactions. Without the Higgs, we wouldn’t understand how other elementary particles like quarks and electrons acquire their mass. In a Higgs-less universe, the known particles would be massless and zip around at the speed of light, just like the photons that make up light itself. In the real universe, there is a Higgs “field” that pervades all of space, turning massless particles moving through it into the massive ones we know and love. The Higgs boson is a propagating ripple in the Higgs field, much like sound is a propagating ripple in the air.

The boson, while providing crucial clues about how Nature works, doesn’t lend itself to technological applications. Most importantly, if you produce a Higgs, it will decay in about a zeptosecond–a thousandth of a billionth of a billionth of a second. Simply put, Higgs bosons don’t hang around long enough to be put to much good use.

We might imagine “turning off” the effect of the Higgs field, leaving particles with no mass, just because that sounds kind of interesting. But again, not practical. To turn off the Higgs field in a region the size of a small marble would require as much energy as we would get by letting the Moon collide with an anti-matter Moon and releasing pure energy. Not a realistic prospect.

But the quest for the Higgs isn’t supposed to be about improved technology, it’s about improved knowledge. We can now lay claim to having a working understanding of all the particles that make up ordinary matter around us, fulfilling a dream that human beings have had since at least the ancient Greeks. That counts for a lot, even without jet packs.

We have reason to believe that there are many particles waiting to be discovered, and the Higgs could be the portal that connects us to this invisible world.

The physicists are nowhere near done. Astronomers have shown that the large majority of matter in the universe is not the ordinary matter around us, but a mysterious “dark matter” that isn’t explained by the Standard Model. We have plenty of ideas, but need experiments to decide between them. The good news is that in many theoretical models, dark matter interacts with ordinary matter via the Higgs boson, and we will use that interaction while searching for it.

We have reason to believe that there are many particles waiting to be discovered, and the Higgs could be the portal that connects us to this invisible world. Physicists bandy around concepts like supersymmetry, technicolor, and extra dimensions. By studying how the Higgs behaves, what it interacts with and which particles it decays into, we are opening up a new window on the hidden universe.

The Higgs, in other words, represents the end of one era, but also the beginning of the next. We’re not just putting the Higgs on our mantelpiece; we’re going to use it to search for particles and forces beyond those we know. With this new tool at our disposal, we’re ready to take the next steps to understand the fundamental architecture of reality.