The Higgs role in the universe

[Breo]

What are the lines of investigation right now? I'd have listened that it could be more than one kind of Higgs particle, which ones?

What if them are found?

Could an arbitrary universe exist without the Higgs field? or it would exist as a it must exist? (maybe this is very philosofical)

What our universe would be like if the Higgs did not exist?

 

[mfb]

What are the lines of investigation right now?

- measure the strength of all production modes
- find more decay modes (split up by production mode where possible), measure them more precisely
- measure cross-section as function of the transverse momentum and direction (pseudorapidity) of the Higgs.
- measure angular distributions of decay products to further confirm its spin and parity
- measure the decay width of the Higgs
- search for events with more than one Higgs boson to find the Higgs self-coupling (needs 10-20 years more data-taking if it is as frequent as predicted by the standard model).

I'd have listened that it could be more than one kind of Higgs particle, which ones?

Supersymmetry is the most interesting model for more than one Higgs boson.

What if them are found?

That would be amazing! It would allow to study completely new physics.

Could an arbitrary universe exist without the Higgs field?

Why not? It is no problem to write down laws of physics without it. This just does not happen to be our universe. Without the Higgs mechanism and without anything else doing something similar, all our particles would be massless, unable to form atoms, stars, planets and so on.

 

[Breo]

Without the Higgs mechanism and without anything else doing something similar, all our particles would be massless, unable to form atoms, stars, planets and so on.

What about confinement? And there are other ways to obtain masses (very light masses), right?

 

[mfb]

Hadrons would be trickier (especially with 6 degenerate quarks), that's why I limited my post to atoms. As far as I know, the electron would still have something to get an effective mass as well (it has an electric charge), but not enough to form atoms.

 

[ChrisVer]

Without the Higgs mechanism and without anything else doing something similar, all our particles would be massless, unable to form atoms, stars, planets and so on.

Hahaha... I felt the emotion in that!
Well, if there was no Higgs mechanism, then we would have to abandon the model of quarks & leptons that contained the symmetry breaking through the Higgs field (since we know that those particles have mass).
Probably look for a Higgs alternative.

 

[ChrisVer]

I'd have listened that it could be more than one kind of Higgs particle, which ones?

What if them are found?

Yes as already mentioned Supersymmetry introduces 5 Higgs bosons... The 2 Higgs doublet models can as well be motivated by Supersymmetry, by axion models and by the baryon asymmetry we observe (that the SM cannot explain).

Could an arbitrary universe exist without the Higgs field?

It wouldn't be ours... yet neither of this questions make physical sense... If for example there was not a higgs field in some weird alternative universe, what could that tell you for our higgs?
I mean if you change the whole background, you can't expect to find a reasonable answer.

What our universe would be like if the Higgs did not exist?

Nothing. As I already mentioned if there was no Higgs particle, we would go with some Higgs alternative... The known thing was that particles had mass and that's why we introduced the Higgs particle. It didn't go the other way around...so to say that without the Higgs there would be no mass. It just happened to exist and so be it...
http://en.wikipedia.org/wiki/Alternatives_to_the_Standard_Model_Higgs

 

[Breo]

As far as I know, the electron would still have something to get an effective mass as well (it has an electric charge), but not enough to form atoms.

So all the particles with electric charge would still get an effective mass? Can you explain me, roughly, this?

 

[mfb]

Ask our theory experts. @vanhees71, @Orodruin, @Vanadium 50, @fzero, @Hepth, ... (certainly not a complete list!)

 

[Breo]

Ask our theory experts. @vanhees71, @Orodruin, @Vanadium 50, @fzero, @Hepth, ... (certainly not a complete list!)

they were summoned? Or I need to pm them?

 

[Vanadium 50]

I am hardly a theory expert.

Chris Quigg has written an article on a Higgsless universe. We disagree on some aspects of this, but the disagreements all revolve around what properties you think such a model will have. The problem with a massless electron is that the vacuum becomes unstable against pair production. This is an area where the theory is discontinuous: any non-zero mass, no matter how small, prevents this (although it has cosmological implications).

 

[Breo]

Could you link here the article?