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Thursday, 5 July 2012


The Higgs boson may have been found: CERN [1] researchers have found a new subatomic particle, that is in the mass range, expected for the Higgs.

What's the Higgs?

They didn't teach you advanced particle physics in school?

Well, it's like this: 'Naturally' all particles should whizz about at the speed of light. But that doesn't make for a very interesting universe, so there's a thing called the 'Higgs field [2]' or 'Higgs mechanism'. This is like a sea of gloop, that fills the universe and slows most particles down - although some, like photons, can just ignore it.

So, in short: The Higgs field slows particles down by giving them mass. For a bit more, I'll leave it to Brian Cox:

Video above: The BBC asks Professor Brian Cox to explain what the Higgs boson is, and why all us scientists are wetting ourselves like a four year old getting a holiday to the north pole at Christmas. Video courtesy of the BBC.

This field needs a particle to carry it about, like any kind of gloop needs to be made of some kind of particles if you look at it hard enough: That's the Higgs particle. The particle can be made by high speed collisions between protons, but it decays so fast that it can only be spotted by watching for a very specific pattern of other particles, produced as it decays.

In order to find it CERN have built a 38,000 ton, 27 kilometre circumference, machine called the 'Large Hadron Collider [3]' that smashes particles into each other at nearly lightspeed. These collisions make, amongst lots of other things, possibly-Higgs-particles, which decay into other particles that can be detected. By working backwards from these particles scientist can work out how much mass the Higgs particle itself has.

Image above: One very large part of the large hadron collider. Please don't ask me which part, or exactly what it does.Image courtesy of the Telegraph newspaper.

The Standard Model theory [4] predicts that the Higgs should have a mass in a certain range, and what the CERN team have found is very, very, strong evidence for a previously unseen particle, that has a mass in the right range for a Higgs. They still need to do more tests to see if the particle they've found behaves the way that the theory predicts a Higgs should.

If it looks like a dog.... then it probably is. But we're not quite there yet. What CERN have found looks like a dog. It remains to be seen if it barks like one, and widdles up against lampposts...

The Higgs particle is the key to understanding how the things in the universe have mass, and why some things don't. Imagine what we could do if we could crack that mystery...and imagine the responsibility having that knowledge might entail.

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