The New Collider

[Alex K]

Why does the weight of the higgs particle matter?

It basically fixes the last unknown parameter of the so called Standard Model which is the theory which correctly describes most known physics at the fundamental level, with few exceptions such as dark matter. The precise value is very interesting because it provides information about what kind of undiscovered physics can await at higher scales. The measured value of about 125 GeV for example excludes certain so called supersymmetric scenarios (though not all!) and points to new phenomena at very high energy scales. If the standard model is valid up to very high energy scales, the higgs mass can determine whether the universe is stable or might decay catastrophically. The measured value turns out to be exactly at the boundary where the universe is barely stable.