Higgs boson and metastable universe

[Einj]

Hi all. I have recently read an article that summarizes our knowledge about Higgs boson and the consequences of its existence and of the value of its mass. The author says that our universe could be stable, unstable or metastable and that the discrimination between this three options is give by the values of the higgs boson's and top quark's masses. He also says that, in the case that our universe would be metastable, in 13.5 billions year it will become (translate from Italian) "unstable with a potential that goes to -∞".
What does that mean? Of what kind of potential are we talking about??

Thanks to all

 

[Bill_K]

He's talking about the Higgs potential V(φ) which describes the interaction of the Higgs field with itself. This is input to the theory as a quartic polynomial. Its minimum determines the Higgs vacuum state, located at a value φ₀ = 246 GeV. Excitations from that minimum are Higgs bosons, and the second derivative of V(φ) at that point determines the the Higgs boson's mass.

But quantum modifications will modify the shape of the potential, depending on various parameters, including the top quark's mass. If there was no minimum the universe would be unstable. Of course that is not the case. But even if there is a minimum, V(φ) may go to -∞ at φ → ∞. In this case the universe could eventually tunnel through the barrier. Then the universe would be metastable.

 

[Einj]

Thank you very much.
Just let me check if I understood well. If the Higgs potential goes to -∞ what does that imply? I suppose that there is no stable state and so we could have something like a "falling" to states with energy always lower than the previous one right?

 

[Haelfix]

If the quartic coupling constant goes negative the generally agreed upon answer is that something known as vacuum decay occurs, which is a very traumatic event as it effectively ends the universe.

The dynamics of this type of physics was studied by Coleman and De Luccia back in the 1970s.

 

[Einj]

Ok, I'll search something about this. Thank you very much.

 

[Bill_K]

Thanks, Haelfix. The Coleman-De Luccia paper is available online here.

 

[Hoogah]

Its also Higgs is an elementary particle. I was stabbing at it.