The Higgs boson
Fantasy turned reality
Those searching for the Higgs boson may at last have cornered their quarry
Dec 14th 2011 | from the print edition
WELL, they’ve found it. Possibly. Maybe. Pinning down physicists about whether they have actually discovered the Higgs boson is almost as hard as tracking down the elusive subatomic beast itself. Leon Lederman, a leading researcher in the field, once dubbed it the “goddamn” particle, because it has proved so hard to isolate. That name was changed by a sniffy editor to the “God” particle, and a legend was born. Headline writers loved it. Physicists loved the publicity. CERN, the world’s biggest particle-physics laboratory, and the centre of the hunt for the Higgs, used that publicity to help keep the money flowing.
And this week it may all have paid off. On December 13th two of the researchers at CERN’s headquarters in Geneva announced to a breathless world something that looks encouragingly Higgsy.
The Higgs boson, for those who have not been paying attention to the minutiae of particle physics over the past few years, is a theoretical construct dreamed up in 1964 by a British researcher, Peter Higgs (pictured above), and five other, less famous individuals. It is the last unobserved piece of the Standard Model, the most convincing explanation available for the way the universe works in all of its aspects except gravity (which is dealt with by the general theory of relativity).
The Standard Model (see table) includes familiar particles such as electrons and photons, and esoteric ones like the W and Z bosons, which carry something called the weak nuclear force. Most bosons are messenger particles that cement the others, known as fermions, together. They do so via electromagnetism and the weak and strong nuclear forces. The purpose of the Higgs boson, however, is different. It is to inculcate mass into those particles which weigh something. Without it, or something like it, some of the Standard Model’s particles that actually do have mass (particularly the W and Z bosons) would be predicted to be massless. Without it, in other words, the Standard Model would not work.
The announcement, by Fabiola Gianotti and Guido Tonelli—the heads, respectively, of two experiments at CERN known as ATLAS and CMS—was that both of their machines have seen phenomena which look like traces of the Higgs. They are traces, rather than actual bosons, because no Higgs will ever be seen directly. The best that can be hoped for are patterns of breakdown particles from Higgses that are, themselves, the results of head-on collisions between protons travelling in opposite directions around CERN’s giant accelerator, the Large Hadron Collider (LHC). Heavy objects like Higgs bosons can break down in several different ways, but each of these ways is predictable. Both ATLAS and CMS have seen a number of these predicted patterns often enough to pique interest, but not (yet) often enough to constitute proof that they came from Higgses, rather than being random fluctuations in the background of non-Higgs decays.
The crucial point, and the reason for the excitement, is that both ATLAS and CMS (which are located in different parts of the ring-shaped accelerator tunnel of the LHC) have come up with the same results. Both indicate that, if what they have seen really are Higgses, then the boson has a mass of about 125 giga-electron-volts (GeV), in the esoteric units which are used to measure how heavy subatomic particles are. That coincidence bolsters the suggestion that this is the real thing, rather than a few chance fluctuations.
Photo by Fabrice Coffrini/AFP/Getty Images.
Physicists haven't found the so-called "God particle" (known to the less sensational among us as the Higgs boson) just yet, but two teams have found "intriguing hints" pointing to the existence of the elusive particle that is thought to be a basic building block of the universe.
So what’s the big deal? And what’s with the haughty name?
The Washington Post explains: "[T]his particle—spotted—would all but complete the fundamental theory of particle physics, known as the Standard Model. Confirmation of the Higgs would solve the mystery of why matter has the property that physicists call mass—the resistance to being shoved around."
British physicist Peter Higgs and others theorized the particle’s existence over 40 years ago. Scientists haven’t had the tools or expertise to conclude whether or not it exists until now, and a pair of separate teams have sparked excitement among experts and laymen with early results—the latest of which were unveiled Tuesday—that show small but significant progress toward finally answering the question once and for all.
"The excitement is higher than anything I've seen in high-energy physics in the past 20 years," Joe Lykken, a physicist at the Energy Department’s Fermilab in Illinois, told the Post.
Two separate teams are using the European Organization for Nuclear Research's Large Hadron Collider—a 17-mile circular tunnel underneath the Swiss-French border that is so powerful that it can create conditions that mirror those that followed the theoretical Big Bang—to crash proton beams into each other at incredibly high speeds in hopes of finding the Higgs boson.
The Associated Press explains that scientists believe that only under these conditions can it be created, and only a fraction of the time. Both teams have concluded with some confidence the likely mass of the particle. They hope to reach an ultimate conclusion about whether or not the particle exists by next year.
"But be careful—it's intriguing hints," said Rolf Heuer, director of CERN. "We have not found it yet; we have not excluded it yet."
If scientists prove the Higgs boson exists, and at the mass they predict, it will support other physics theories related to the Big Bang Theory and the general makeup of the universe, says BBC. Those theories, in turn, would predict the existence of other particles that shape our universe.