So, the bosons are good predictors of degrees of attraction or repulsion. But apparently, they don't hold the clue to how mass is introduced at a subatomic level. Enter the elusive Higgs boson.
In the ideal world of the Standard Model, the bosons would be massless. They would simply be the carriers of forces-electromagnetism, strong nuclear interactions, weak nuclear interactions, etc. But they are not massless. Two of the bosons (Z and W) are hefty. What's the deal? Also, the Standard Model fails to explain primary forces affecting atoms. The model does not include gravity, for starters. And why the variations in masses of particles-and the masses of the force carriers, the bosons? In addition, calculations derived from our assumptions about the Standard Model don't accurately predict events occurring at very high energies. For instance, the Model reports that some events will happen more than 100% of the time.
The Higgs boson is the factor that will make all things right with the Standard Model. Right? Well, presumably. The Higgs factor would explain why "massless" forces might not be massless and why particles' masses vary widely, apparently without logic. If there were a Higgs particle, for instance, it might pair up with other particles or accompany particular kinds of forces. Like lint, it would be potentially ubiquitous but selective. Trouble is, the Higgs factor might not be a particle at all.
Physicists tend to explain the Higgs as either (a) a "field" or "mechanism" or (b) a particle. Remember that in quantum eletrodynamics, the same entity can be a wave (or as a series of waves, a "field") or a particle. The Higgs, too, might have options.
Visualizing the Higgs as a particle has problems. How would a Higgs add mass to another particle? Is mass an added property, like a wad of bubble gum stuck to the side of a tennis ball? That hardly seems likely, but it is hard to imagine a Higgs particle adding mass to other particles without imagining some sort of aggregation. Furthermore, if the Higgs is the contributor of mass, it presumably must have enormous mass itself. If it has such mass, why hasn't it been observed already? Even nimbler, lighter, and shorter-lived particles might be elusive but they have been observed. Why not the densest thing in the universe?
As a field, perhaps the Higgs makes more sense. The Higgs needs to provide a theoretical mass value when it is factored into other equations/reactions. Whereas a Higgs particle doesn't contribute anything to calculations requiring mass, a Higgs field does. Imagine that a particle gained its mass, not by aggregation with another particle, but by interacting with a force field. David Miller, of University College, London, explains the field/interaction idea this way: "In order to give particles mass, a background field is invented which becomes locally distorted whenever a particle moves through it. The distortion-the clustering of the field around the particle-generates the particle's mass." The idea comes from the physics of solids. Imagine a solid, say, our tennis ball, contains a lattice of positively charged crystal atoms. When an electron moves through the lattice, its atoms are attracted to it, causing the electron's effective mass to be as much as 40 times bigger than the mass of the electron when it is free of the field. Crystal lattices carry waves without needing electrons to move through them, and these waves even behave as though they are particles. "The postulated Higgs field in the vacuum," Miller conjectures, "is a sort of hypothetical lattice which fills our Universe."
Simon Hands at CERN provides an alternative analogy. The Higgs field is like the grain in a plank of wood. "The direction of the grain is undetectable, and only becomes important once the Higgs' interactions with other particles are taken into account. For instance, all particles called vector bosons can travel with the grain...." In this case, the same particle travelling one direction (say, "with the grain") would have one identity-a photon, perhaps-and travelling in the other direction ("against the grain") another identity-perhaps a Z or W boson. The Higgs field, then, could actually simplify the Standard Model by making mass an outcome of the activity of particles rather than one of their unchanging characteristics.
Physicists' energetic defense of their informed beliefs might remind us of the story of the blind men and the elephant. For lack of proper instruments (eyes), the blind men guessed about the elephant's appearance based on the information available to them. So it is with physicists and the Higgs factor. "Take a poll in, say, the Fermilab cafeteria on what exactly the Higgs is," writes David Kestenbaum, "and you could very well start a food fight." Is it a field? Is it a split-second pairing of particles? Is it a major flaw in the Standard Model, requiring many more particles to be named? The instrumentation is vital for discovering the links and finding experimental evidence of the mass-factor, whatever it is. A new generation of colliders may well provide the answers in the next few years. CERN's LEP collider, limited by the energies it deals in, could identify a "light" Higgs factor. The facilities at Fermilab could detect a somewhat "heavier" Higgs, and CERN's Large Hadron Collider, which will replace Fermilab's Tevatron as the highest-energy accelerator in the world, would probably be able to identify an even "heavier" Higgs.
I myself would not steer people to that article. I wish I had time to critique it in detail.