In search of the Higgs Boson at the Large Hadron Collider

On Tuesday 13 December 2011 scientists from the European Organisation for Nuclear Research (CERN) held a press conference where researchers working at the Large Hadron Collider (LHC) announced that they might have glimpsed the elusive Higgs boson.

Tom Whyntie is a member of Imperial College London‘s High Energy Physics group. Tom currently works on the Compact Muon Solenoid experiment, one of the giant “digital cameras” photographing activity inside the LHC.

At school you are taught that atoms are made up of protons, neutrons and electrons; so what is the Higgs boson and where is it proposed to be?

Protons and neutrons are made up of even smaller particles called quarks. Together with electrons (and their ghostly "neutrino" cousins), these are what we think makes up matter – the stuff we're all made of.

Three fundamental forces – electromagnetism, the weak nuclear force and the strong nuclear force – hold it all together. But permeating everything is a sort of strange, quantum mud that sticks to some particles – giving them mass – but not to others. This is made up of Higgs bosons, and it's what we've been trying to find at CERN.

Who proposed that the Higgs boson existed?

Peter Higgs is popularly credited with suggesting that such a particle could explain how some particles get mass, but a few others had the same idea at around the same time –including Guralnik, Hagen and Kibble from Imperial College London.

Why is the Higgs boson so important?

Without it, nothing in our theories about how the Universe works at the smallest scale imaginable makes sense: we know particles have mass, and the best way of making sure that they do in equations is with the Higgs boson.

If it's not there, we have to go right back to the drawing board.

How have scientists been trying to find out whether the Higgs boson exists?

We smash protons together in our 27km-circumference underground tunnel at nearly the speed of light with the hope of creating Higgs bosons from high-energy collisions. If it exists, it would then disappear almost instantly, so we use cathedral-sized digital cameras to take "pictures" of the collisions and look for things that the Higgs boson might have left behind.

How long has it taken them to look for the Higgs so far?

The two experiments looking for the Higgs boson – CMS and ATLAS – took around twenty years to design, build and get running.

What do the latest results show? Have they found the Higgs Boson?

Both experiments have had a tantalising glimpse of something that might be a Higgs boson – and importantly, it looks like the same thing – but we can't be sure.

What will the researchers do next to prove whether they have seen the Higgs boson or not?

Collect more data! The really important finding from [the recent] announcement is that we know the accelerator and the experiments are performing fantastically well. And with the same level of hard work from the thousands of scientists and engineers involved (and a bit of luck!) we should have an answer either way by the end of next year.

We can't wait!