Undergrad Is the top quark stable in the absence of the Higgs field?

[kodama]

Yes, but you would likely have to give a very good argument as to why these fields would not couple to all fermions as allowed by the quantum numbers.

are there any proposals to extend the SM with additional degree of freedom and quantum numbers, to allow for a "higgs charge" so that second and third generation fermions have more higgs-charge than first generation via yukawa coupling?

 

[Orodruin]

are there any proposals to extend the SM with additional degree of freedom and quantum numbers, to allow for a "higgs charge" so that second and third generation fermions have more higgs-charge than first generation via yukawa coupling?

What do you think the Yukawa couplings are? They describe how strongly the different fermions couple to the Higgs field.

Edit: Note that they are not a charge in the sense of a charge related to a gauge symmetry.

 

[kodama]

What do you think the Yukawa couplings are? They describe how strongly the different fermions couple to the Higgs field.

Edit: Note that they are not a charge in the sense of a charge related to a gauge symmetry.

that's what i am wondering about

a hypothesis that the reason second and third generation fermions are heavier than first and interact more strongly with the higgs field there is a higgs-charge that is a charge in the sense of a charge related to a gauge symmetry

 

[mfb]

The coupling constants are these charges you are looking for. It doesn't matter if you call them coupling constants or charges. Same thing.

If there is no Higgs the Z is massless and does not decay (well, truth with modification). This is why I said cross sections instead of decays. A closer analogue would be the QCD color factors.

There would also be no physicists to perform experiments ;).

 

[kodama]

The coupling constants are these charges you are looking for. It doesn't matter if you call them coupling constants or charges. Same thing.There would also be no physicists to perform experiments ;).

isn't that another degree of freedom that all fermions and w and z bosons posses? a higgs-charge that determine yukawa interaction.

in a higgless universe, all particles then would be massless and travel at the speed of c is that correct? but they still have their charges so they could form something

 

[nikkkom]

that's what i am wondering about

a hypothesis that the reason second and third generation fermions are heavier than first and interact more strongly with the higgs field there is a higgs-charge that is a charge in the sense of a charge related to a gauge symmetry

Yukava couplings are partially analogous to charges. The difference is that charges related to a gauge symmetry manifest themselves as a constant in the gauge covariant derivative's formula, and this constant is the same for all particles. For QED, the constant is the electron's charge.

Yukava couplings are constants too, but they are _different_ for every higgs-to-fermion coupling. No evidence so far exists that they are multiples of some fundamental, minimal "charge".

The reason for this difference is that coupling terms in Lagrangian for fermion-to-spin1-boson coupling and fermion-to-spin0-boson coupling have different forms.

 

[ChrisVer]

If there is no Higgs the Z is massless and does not decay (well, truth with modification).

I don't get that part, why wouldn't Z decay?

 

[Orodruin]

I don't get that part, why wouldn't Z decay?

How many massless particles do you know that decay?

 

[ChrisVer]

How many massless particles do you know that decay?

I know 1 massless particle out of the 1 massless particles there which can decay (well not alone)...

 

[Orodruin]

(well not alone)...

So, not a decay.

 

[e.chaniotakis]

This means that in a Higgsless universe you would not have 3 neutrino flavors also?

 

[mfb]

You would still have three flavors. If you can distinguish between different neutrino types depends on the mechanism that leads to neutrino masses, but the different masses (if applicable) would be the only difference you could see.

 

[Orodruin]

You would still have three flavors. If you can distinguish between different neutrino types depends on the mechanism that leads to neutrino masses, but the different masses (if applicable) would be the only difference you could see.

Many (not all, but I would say a majority of) neutrino mass models give rise to neutrino masses through the appearance of a Weinberg operator after integrating out some heavy states. Without the Higgs, such operators do not exist.

 

[kodama]

in a higgless universe, what would happen if a tau interacts with a positron?

 

[ChrisVer]

in a higgless universe, what would happen if a tau interacts with a positron?

What happens in this universe (Higgsfull) when a tau interacts with a positron?
I don't know, is the Lepton number also associated with the existence of the Higgs?

 

[kodama]

What happens in this universe (Higgsfull) when a tau interacts with a positron?
I don't know, is the Lepton number also associated with the existence of the Higgs?

i was going to ask that to