The Higgs boson and the top quark

There were two developments in the news last week that were very important but at the same time didn’t get mainstream attention: Microsoft acquiring GitHub and the LHC collaboration’s measurement of the strength of the Higgs boson/top quark interaction.

Before either of these developments could pushed onto the front page (or equivalent), what the people could really have used was a “why does it matter” kinda piece. Paul Ford at Bloomberg had just such a piece explaining why it would be nice if more of us gave a damn about GitHub’s future. But I couldn’t fine the equivalent for the top quark announcement.

To me, the biggest reason to give a damn about the ATLAS and CMS detectors on the LHC measuring the strength of the interaction between the Higgs boson and the top quark is very simple. The Higgs boson, rather the Higgs mechanism in which it participates, is what gives a fundamental particle its mass. The stronger the boson couples with a particle, the higher the particle’s mass is.

The top quark is the heaviest known fundamental particle, which means the Higgs boson couples to it the strongest. It weighs ~172 GeV/c2, which is 1.3-times the mass of the Higgs boson itself, about 183-times the mass of a proton and almost the same as an entire atom of tungsten. If the fundamental particles were all the Angry Birds, the top quark would be Terence.

So by studying the strength and the nature of this coupling, physicists can learn more about both particles as well as the peculiarities of the Higgs mechanism. Additionally, of the six types of quarks, only the top quark has been known to never hadronise — i.e. come together with other particles to form a heavier particle. Protons and neutrons are each called a hadron because they’re made up of up and down quarks. The charm, strange and bottom quarks also hadronise.

In fact, all the other quarks can be (indirectly) observed only in the presence of other quarks, leaving the top quark to be the sole ‘bare’ quark in nature – further entrenching it as an object of interest among particle physicists.

Further refining what we know about the top quark and the Higgs boson also helps physicists decide what colliders of the future should be able to do, determine what questions they should be able to answer. And the sooner they know the better because particle accelerators/colliders are very hard to build and can take many years, so it pays to keep an eye on the ball at all times instead of regret not installing a feature later.