A common man’s guide to the God Particle


What is the God Particle? The “God Particle” is the name physicist and author Leon Lederman gave to the Higgs boson in his book The God Particle: If the Universe Is the Answer, What Is the Question? It’s meant to communicate the importance of the particle to our understanding of physics; Lederman has also said that he settled for “the God Particle” because his intended title, “the Goddamn Particle,” was rejected by the publisher.
What is the Higgs boson? At its simplest, it’s a hypothetical particle that physicists believe gives all other particles mass.”Higgs boson” isn’t the name of a particle that scientists have seen and observed and recorded with their enormous magic science binoculars; it is the name of a particle whose existence has been predicted by physicist Peter Higgs (among others: Robert Brout, François Englert, Gerald Guralnik, C.R. Hagen, and Tom Kibble). Over the course of the last five or six decades, particle physicists have been developing a mathematical model for their field that explains, more or less, what the fundamental particles of the universe are and how they interact. The Standard Model started as a reverse engineering of the universe, based on what we could say was true with a reasonable degree of certainty thanks to experiments and what theorists could extrapolate from that — a series of sort of educated guesses, or predictions, about what the particles are and how they act at parties. It’s a bit like being in a room, blindfolded, and having to draw a picture of its layout: you know one wall is here, and you bumped into another wall there, so you can figure out with varying degrees of certainty the location and size of the other walls, and where the corners are as well. As scientists are able confirm the existence of certain particles through experimentation — in other words, find the other walls — and observe the ways those particles (or walls) deviate from what the Standard Model predicts, physicists are able to modify and refine their theory. In 1983, for example, physicists at CERN (the European Organization for Nuclear Research) found evidence of two bosons — the W and the Z — that had been predicted by Steven Weinberg, Sheldon Glashow and Abdus Salam when they laid out the Standard Model in the 1960s. It was a big deal.
And so the Standard Model predicts the existence of the Higgs boson? Yes. In this sense, “predicts” means something like “requires in order to exist.” It’s the last particle left to be “seen” by scientists, and without it, the Standard Model doesn’t really work. Physicists are hoping to observe (as best they can) the Higgs experimentally — or even better, something similar to, but slightly different from, the Higgs — to help confirm that they’re on the Right Track.
Why would it be better if it
wasn’t the Higgs? The hunt for evidence of the Higgs boson has been the major focus of particle physics for years now. If physicists find the Higgs exactly as it’s predicted to exist in the Standard Model, it’s kind of boring. They know that the model, being partially theoretical, is unlikely to be a completely accurate picture of the universe at the atomic level. If they can find a particle that does the same work and fulfills the same function as the (theoretical) Higgs, but has certain differences, it helps them modify and refine the Standard Model — which in turn helps point the way toward new work.
The Higgs boson is a quantum — the minimum possible amount — of this thing called the Higgs field. To paraphrase a famous scientist: the Higgs Field is what gives a particle its mass. It surrounds us and penetrates us. It binds the galaxy together. (Hypothetically, of course! Remember: we assume the Higgs Field exists because math that describes the universe very well wouldn’t work if we didn’t include the Higgs Field in it.) Without the Higgs Field, all elementary particles — the six kinds of quarks, electrons and the other five leptons, photons, gluons and the Z and W bosons — would be massless and move at the speed of light. This would not be a very fun universe; or, it might be fun, but fun would be a meaningless concept because nothing would exist. With the Higgs Field, however, some particles slow down: in interacting with the field, they gain mass, and move through the field with more difficulty. (At this level, we should be aware, mass and size don’t correlate; mass is a characteristic like electric charge and particles with different masses are the same size.)