What is the Standard Model Higgs particle? It is the simplest form of Higgs particle that could be present in nature, a ripple in the simplest possible form of Higgs field that could be present in nature. And what is the Higgs field? It (or something very like it) is a crucial ingredient in our universe as we know it. (Read the Higgs FAQ for more details, or watch my video clips from my public talk at the Secret Science Club)
- The Higgs field (as with all fields) is something that has a value everywhere in space, but unlike most fields we come across it is not zero on average — it has a non-zero value everywhere in space.
- The Higgs field interacts with many of the particles of nature (and their own corresponding fields) including particles as diverse as the electron, the top quark, and the W and Z particles. (You can read about the known elementary particles of nature here.)
- All of the known apparently-elementary particles get their masses because the Higgs field has a non-zero value. The stronger is their interaction with the Higgs field, the larger is their mass.
- [Note: if you have read somewhere that the Higgs particle gives mass to the other particles, you should disregard it. That statement is simply wrong. The Higgs field does that job.]
- If the Higgs field was zero on average, then the universe would be a very different place; in particular, there would be no atoms, and thus no ordinary matter (and no earth and no humans.)
- We know very little about the Higgs field, except that it does what I’ve just described. We don’t actually know if it is one field, or several. We don’t know if it is an elementary field, or a field that is itself made from other fields. How are we going to find out?
- That’s where the Higgs particle (or particles) comes in. The Higgs particle is to the Higgs field as the vibration pattern of a violin string is to the violin string itself. If you want to know what a violin string is made of, and how tightly it is wound, pluck it. Study the vibrations of the string. If you want to know what the Higgs field is made of, give it a whack (with a proton-proton collision at the Large Hadron Collider [LHC]) and watch it ripple. Those ripples are Higgs particles; study them.
- Sometimes people say the LHC was built to find the Higgs particle. This is wrong. The LHC was built to understand the Higgs field. The particle is a means to an end, not an end in and of itself.
- Even with a Higgs field, there may not be an observable Higgs particle, though it will take us ten years to be sure of that. But this can only happen if there are other new phenomena for us to discover at the LHC. (Why? Long story…)
- The first step along the road toward understanding the Higgs field is to study the simplest possible version of that field, and the ripple that you can make when you disturb it: the simplest possible Higgs particle. These are called the Standard Model Higgs field and the Standard Model Higgs particle.
There are three articles nested below this webpage that will explain to you the program to search for the Standard Model Higgs particle (as of December 2011), and how and why, if we find a candidate, we’ll study it in such great detail.