What Will the Large Hadron Collider Find? And Bonus LHC Rap Video

Sean Carroll over at Cosmic Variance:

So here are my judgments for the likelihoods that we will discover various different things at the LHC — to be more precise, let’s say “the chance that, five years after the first physics data are taken, most particle physicists will agree that the LHC has discovered this particular thing.” (Percentages do not add up to 100%, as they are in no way exclusive; there’s nothing wrong with discovering both supersymmetry and the Higgs boson.) I’m pretty sure that I’ve never proposed a new theory that could be directly tested at the LHC, so I can be completely unbiased, as there’s no way that this experiment is winning any Nobels for me. On the other hand, honest particle phenomenologists might be aware of pro- or con- arguments for various of these scenarios that I’m not familiar with, so feel free to chime in in the comments. (Other predictions are easy enough to come by, but none with our trademark penchant for unrealistically precise quantification.)

• The Higgs Boson:  95%.  The Higgs is the only particle in the Standard Model of Particle Physics which hasn’t yet been detected, so it’s certainly a prime target for the LHC (if the Tevatron doesn’t sneak in and find it first). And it’s a boson, which improves CERN’s chances. There is almost a guarantee that the Higgs exists, or at least some sort of Higgs-like particle that plays that role; there is an electroweak symmetry, and it is broken by something, and that something should be associated with particle-like excitations. But there’s not really a guarantee that the LHC will find it. It should find it, at least in the simplest models; but the simplest models aren’t always right. If the LHC doesn’t find the Higgs in five years, it will place very strong constraints on model building, but I doubt that it will be too hard to come up with models that are still consistent. (The Superconducting Super Collider, on the other hand, almost certainly would have found the Higgs by now.)
• Supersymmetry:  60%. Of all the proposals for physics beyond the Standard Model, supersymmetry is the most popular, and the most likely to show up at the LHC. But that doesn’t make it really likely. We’ve been theorizing about SUSY for so long that a lot of people tend to act like it’s already been discovered — but it hasn’t.

And the rap:

Comments

[Dave Ranning]

We better find the Higgs Bosom, as the Standard Model is the last major accomplishment in Physics, in a very dismal period for advancement, historically.
Super Symmetry is a wish for the String Theorist, and their background dependent model, that seems to be mental masturbation with elegant math. It may be proven, but then what?

[jean-paul]

Great video, thanks. We could teach kids so much at school this way (and i say this as a grump who cannot take more than five seconds of rap without hitting the mute button! Foock, i'm old…).

[JTankers]

Nice RAP.

Have you read Dr. Rossler's take on the Large Hadron Collider project at LHCFacts.org?

[D]

The Higgs Bosom is an old idea that has by now lost most of its charm and all of its novelty value. Now SUSY's bosoms....

[Winfield J. Abbe]

Instead of looking to see what some experts say is or should be there, why not use this expensive machine to do some physics without prejudice for a change? Go exploring as one would in any unbiased experiment and simply record what is observed. Then, perhaps seek to explain the results in terms of existing knowledge. This kind of unbiased experimentation is also a lot more exciting and fun too. Who cares what the experts say should or must be there? Why bias the results by looking for what the experts claim is there?