We all know what it's like – the frustration of tearing the house upside down looking for something, the longer it takes the more doubt sets in, but then you find it – woo-hoo!
Well this is one of those moments – on a grand scale. Physicists have found a new particle, possibly one that they have been hunting for almost 50 years. It is called the Higgs boson.
The particle was suggested to exist back in 1964. Professor Higgs (and others) came up with the idea as they pieced together the different types of subatomic particles and forces known to fill our Universe. It's called the Standard Model and it describes how things work on a fundamental level.
But there was something missing. Those tiny subatomic particles need a way to obtain mass – it turns out it's not an inbuilt process. Higgs put forward that mass could be transferred through a kind of field that's all around us.
It sounds strange, but think of other fields that you know. There's the magnetic field – most of us have seen the trick of putting iron filings on a sheet of paper and watching them all align when a magnetic is placed nearby. Earth's gravitational field is another one, we don't see it but we feel its effects all the time.
The idea is that subatomic particles could obtain mass by interacting with the Higgs field and the Higgs boson is the particle connected to that field. But it is incredibly elusive; it can only exist for a tiny fraction of a second before breaking down.
How do you find such a thing? It's done by smashing protons together at very high speeds.
The Large Hadron Collider, underneath the Franco-Swiss border, accelerates the protons and then they collide in detectors like ATLAS that measure the fall out. What I find amazing about these collisions is that the protons don't just shatter. There is so much energy in the collision that new particles are created. It's just like Einstein said, energy can turn into matter.
A LEGO model of the ATLAS detector, currently on display at Scienceworks.
Image: B. Healley
Source: Museum Victoria
A Higgs boson is expected to appear once every trillion collisions, so they're incredibly hard to find. What's more, physicists weren't quite sure where to look – it wasn't known how energetic the collisions had to be for the chance to create a Higgs boson.
But now a new particle has been found and much follow up will be done to confirm that it has all the characteristics expected for the Higgs boson.
It's a huge leap forward, and like most scientific leaps, when first discovered it's hard to get our heads around it. I'm sure a hundred years ago, when British physicist J. J. Thompson first announced the discovery of the electron, people were left scratching their heads. I'm just excited to know that I was around for such a discovery. That's pretty cool.
ARC Centre of Excellence for Particle Physics at the Terascale