This post also at The Guardian.
This is a bit of a niche post but there was recently a review in Physics World of these videos I’m in about research at the Large Hadron Collider (LHC). While generally positive, the review pointed out that although the videos are partially based around a particular scientific paper about how one might find the Higgs boson (referred to in the films as the “Eurostar paper”), they don’t really explain the physics behind it, being focussed more on “how science works” than a specific result. Fair comment. So here is my attempt to explain the physics behind this paper to an intelligent but non-specialist audience.
I’ll concentrate on explaining the new ideas in the paper rather than giving a summary of why the Higgs is interesting or what the LHC is. I wrote something
about that at the end of this article for the BBC, and might try again at some point. But I’ll assume some familiarity with what the LHC is. For now, you need to know that if the Higgs boson exists, and if its mass (which we normally express in units of energy using E=mc2) is what seems to be the most likely value (around 120 GeV*) then lots of them will be produced at the LHC, and the realtrick is to be able to pick them out from all the other things going on when the LHC collides its protons.
Now you see it, now you don’t
If the Higgs is there, it is responsible for giving mass to all the other particles because of the way it “couples” or sticks to them. Because it couples to the mass of the particle, it is very likely to decay into the heaviest particle it can. These decays happen super-quickly so all we see is the things into which it has decayed. We have to work out from them that there was, briefly, a Higgs boson in our detector.
