So, as promised here’s my follow up to my brief piece earlier.
The first point is that this is a boson. Not necessarily “the” Higgs boson. So there’s a lot more data to be taken over the next few years, firstly to verify things like the spin of the particle (if I remember there was some data pointing at it being spin 0 and therefore hinting at a scalar Higgs field from the CMS data first thing this morning), but also we need to find out about the nature of it and work exactly what this data is saying.
Now, just in case you didn’t quite understand all of that, I’d better do a little explaining.
In physics there is a system of rules governing the particles which make up our universe which we call the standard model. It classifies all the different particles according to their properties and how they interact, and it tells you some amazing stuff. For example, earlier I mentioned this thing called spin, which is a property of tiny particles, and electrons (which I’m going to assume you have heard of if you’ve read this far..) are what’s called spin 1/2. This tells us (through certain theories of quantum mechanics) that all the electrons in the universe are linked in certain ways which make things like chemical bonds, and therefore the structure of our universe, possible.
The Standard Model as is helps us predict the properties of particles, much like the famed Higgs boson. This thing was predicted as a consequence of a theory on by theoretical physicist Peter Higgs (as well as others working on electroweak symmetry breaking) back in the 60′s. The methods used allowed physicists to predict all the forms that the particle might exist in, the particular one being related to more fundamental properties of matter. I would just like to take this opportunity to sat that Prof Higgs is a man to live up to and has my greatest respect.
One of the big consequences of Higgs’ theory is something called the Higgs field, which is a field theory of how things have mass (mass is a scalar value, hence you will hear it called a scalar field). Probably the most common analogy used to describe it is that it’s a bit like being in a vat of molasses, and the more the molasses slows you down the more mass you have (unfortunately particle physics doesn’t lend itself too well to analogies, but it gives you an idea…). What it technically tells us is that particles don’t really have mass, they just interact at different levels with the Higgs field. Which any way you think about it is quite a revelation!
The Higgs boson (or bosons) gives much more weight to this theory, it exists in this model because the Higgs field does, and tells us about theories that go even deeper than the standard model (for example, the mass of the particle discovered is low enough to tell us that it might be a supersymmetric Higgs particle, so if it’s tested that’ll be an avenue down which to venture further..). Thus finding it would be a huge leap forward in particle physics, it would tell us where we are, where we might go, where we should go, and just generally tells us how much we really do about the nature of the universe. That makes this a really big thing for people involved/interested in physics around the World.
It also tells about a time just after the big bang, when some theories suggest all the particles and forces in the Universe had enough energy to act in the same way. Eventually this energy spread out across space and this things separated out into the constituents of the modern universe (this is symmetry breaking). A lot of the mechanisms (as mentioned earlier) in this require the Higgs field.
So that’s a little bit about why it’s being done, and it’s probably worth looking briefly at how as well. The two collaborations announcing results today were ATLAS and CMS (to give them their full titles: A Toroidal LHC ApparatuS, and the Compact Muon Solenoid respectively), which are the names of two of the particle detectors used to gather data from the Large Hadron Collider at CERN. The LHC is 17km long ring which accelerates protons up to nearly the speed of light and smashes them together, detectors like ATLAS and CMS then use various methods to look at what comes out in debris of these collision. At higher energies particles that can’t be seen on a day to day basis can be spotted using the detectors. This is what has been going on for the last few years at CERN. Hence we have the data which has been analysed to give today’s results. It’s also important to note that this the heaviest boson seen in a particle detector, which is a true testament to the magnitude of the LHC.
As is clear from most of the things you can say about the particle, this mornings news is pretty massive (excuse the pun…). As I said before, it is important to remember that a new boson has been discovered, the physicists involved are as yet unable to say much more than that, but it is also true that it is at a mass concurrent with what is expected by some theories and unless there are large gaps in our knowledge there isn’t a lot more it could be (it is also most likely that it is one of a few different Higgs bosons), so while there’s a long way to go before the claim is verified, as is usual in particle physics, it’s at least very closely related to what they were looking for.
To summarize, we don’t know what they’ve found yet, it needs more work at CERN and other colliders around the world, but we do know that whatever it is it’s very important. There’s a lot of “probably” in all of this, but it’s pretty clear that we’ve found something very Higgs like (though don’t hold me to it) and the next few years will hopefully answer a lot of questions about the universe.
Watch this space!
Also, if any readers would like to see the slides used at this mornings seminars they can be found here
Pete Baker over at Slugger ‘o’ Toole has a great piece on the physics community’s reaction here