So, there’s a shiny new hadron collider in Geneva, and not only is it large, it works! The next step, of course, is for it to make all kinds of spectacular discoveries about the fundamental structure of matter. All across the blogosphere people are putting forth their predictions for what the Large Hadron Collider will find. The best prediction award goes to Jester, who calculated the probability of producing dragons. (The original possibility having been suggested by Nima Arkani-Hamed.)
And what part of nature is hiding around the corner, waiting to be discovered? You may have heard that the LHC was built to find something called the Higgs Boson, and that this has something to do with why things have mass. That’s correct, but the possibilities are even richer. It turns out that our current understanding of particle physics tells us that there are at least two things that exist, but haven’t been found. They are:
- The Higgs
- Something Else.
Point 1 is from the fact that if particles have mass (which they do) and if there wasn’t something like the Higgs around then the laws of physics would predict fun, exiting, and impossible things. Say, if you put strawberries and yogurt in a blender, they would tell you the probability that you get a smoothie is 235%. (OK, the actual calculation is that if you fired two W particles at each other, they would bounce off at an angle of, say, 35 degrees 235% of the time.) It not that the calculation is wrong, it’s that it doesn’t make sense. Put in the Higgs boson, and the probabilities suddenly become sensible.
On the other hand, if you do put in a Higgs boson, the theory also tells you that the mass of the W particle should be 10 million billion times larger than it’s measured mass. This is where point 2, Something Else, comes in. There has to be a Higgs to gives particles masses, and another ingredient to keep that mass light.
So, what are the options? The number of possibilities for new physics that could be found at the LHC is, frankly, enormous. Hitoshi Murayama once produced a slide to illustrate the dizzying array of ideas. Supersymmetry, extra dimensions, technicolor; the names are nearly as wild as the concepts, and yet there is a good chance that one of these ideas will turn out to be how reality works. Discovering any one of these would change our understanding of the world, which would be fantastic (in case there was any doubt).
But, being that I’m an incorrigible optimist, those aren’t the ideas I’m betting on. Murayama reserves several regions of his slide for “Not yet thought of”, although in light of Jester’s calculation we should perhaps rephrase that as: “Here be dragons”. It’s possible that the new physics looks nothing like the ideas that have already been put forward. Unlike Jester’s “real” dragons, which have essentially zero probability of being produced, these intellectual dragons are, in my view, the most likely result. I say I’m optimistic for betting on this because, as exciting as the other possibilities are, this would be by far the most spectacular. It’s been decades since there was a fundamentally new result in particle physics. Theorists have had all that time to speculate about what could be next. If the LHC finds something that hasn’t already been articulated, the reaction won’t be “Oh yeah, we should have thought of that.” Seeing a dragon would almost certainly mean the beginning of a wonderfully confusing and (therefore) exciting time in science.
So, for my prediction for what the LHC will find — out of blind optimism — I’m going with “dragons”.