ScienceSunday: Finding the Higgs
The Higgs Boson. The “God particle”. This elementary particle is one of the most popular discussions of physics in the mainstream media, which is impressive, since the existence of the Higgs boson is still in question. But what exactly is the Higgs boson? Why is it called the God particle? Why is it some important that one of the major goals of the Large Hadron Collider, in Geneva, is trying to determine whether the boson exists or not? And what will it mean if we don’t find it?
Our current understanding of particle physics is represented by the Standard Model, which suggests that 12 elementary particles and 4 forces of nature make up the universe. So far, many experiments have tested and supported predictions made by the standard model. However, it’s not a watertight theory yet. Remember, in science, a theory is a hypothesis or model with so much support behind it and so much explanatory power to the real world, that it is taken as fact. Evolution is one such theory. The Standard Model, however, does not account for gravity, explain what dark matter is, and more. It also predicts the existence of the Higgs boson, a particle that gives the mechanism for the existence of mass.
How does a particle cause mass in other particles? Roger Cashmore, of the University of Oxford in the United Kingdom, explains this further:
It might be hard to understand the origin of one quantity, that quantity being the mass of the electron. Fortunately nature has given us more than one elementary particle and they come with a wide variety of masses. The lightest particle is the electron and the heaviest particle is believed to be the particle called the top quark, which weighs at least 200,000 times as much as an electron. With this variety of particles and masses we should have a clue to the individual masses of the particles.
Unfortunately if you try and write down a theory of particles and their interactions then the simplest version requires all the masses of the particles to be zero. So on one hand we have a whole variety of masses and on the other a theory in which all masses should be zero. Such conundrums provide the excitement and the challenges of science.
There is, however, one very clever and very elegant solution to this problem, a solution first proposed by Peter Higgs. He proposed that the whole of space is permeated by a field, similar in some ways to the electromagnetic field. As particles move through space they travel through this field, and if they interact with it they acquire what appears to be mass. This is similar to the action of viscous forces felt by particles moving through any thick liquid. the larger the interaction of the particles with the field, the more mass they appear to have. Thus the existence of this field is essential in Higg’s hypothesis for the production of the mass of particles.
We know from quantum theory that fields have particles associated with them, the particle for the electromagnetic field being the photon. So there must be a particle associated with the Higg’s field, and this is the Higgs boson. Finding the Higgs boson is thus the key to discovering whether the Higgs field does exist and whether our best hypothesis for the origin of mass is indeed correct.
Now, this article makes it sound like the Higgs has to exist for mass to exist. This isn’t quite true, as Mary and Ian Butterworth and Doris and Vigdor Teplitz explain:
If particles no get their masses from interacting with the empty space Higgs field, then the Higgs particle must exist; but we can’t be certain without finding the Higgs. We have other hints about the Higgs; for example, if it exists, it plays a role in “unifying” different forces. However, we believe that nature could contrive to get the results that would flow from the Higgs in other ways. In fact, proving the Higgs particle does not exist would be scientifically every bit as valuable as proving it does.
So, if scientists do find the Higgs boson, it helps strengthen and further supports the Standard Model. If we don’t, then the Standard Model need revision, at the very least, and new models and hypotheses may need to be developed. The next question, then, is how close are scientists to finding the Higgs? Hank Green, of Vlogbrothers and SciShow on YouTube, interviewed CERN physicists to find out.
There is a lot more to the Higgs, such as this recent article by Phil Plait of Bad Astromony, and several short explanations available on this page. It’s clearly an important piece to our understanding of the universe as it is. Whether or not we find it in the next year or so, the implications of this particle will change our understanding of the world we live in.