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skydivephil
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As i understand it, at some point in the early unvierse, the Higgs field was off, then it swtiched on. Is this correct? I can't find when this is supposed to have happened, does anyone know?
The electroweak symmetry is restored in the Standard Model above the temerature of the order of 100 GeV. As the universe cooled down below this point the Higgs would have obtained a non-zero vacuum expectation value (VEV) giving weak gauge bosons and fermions (other than neutrinos) their masses.skydivephil said:As i understand it, at some point in the early unvierse, the Higgs field was off, then it swtiched on. Is this correct? I can't find when this is supposed to have happened, does anyone know?
Mordred said:Thinking about it I don't recall any of my cosmology textbooks covering SUSY. they usually describe GUT without including super symmetry. I have 6 cosmology textbooks and I don't recall any of them even mentioning the Higg's
Mind you I haven't finished reading Linde's yet but he mentioned he made it free for distribution as its outdated
http://arxiv.org/pdf/hep-th/0503203.pdf "Particle Physics and Inflationary Cosmology" by Andrei Linde
Mordred said:Fair enough like I stated earlier it depends on the model. My understanding is that neither the Gut SM nor the MSSM models work completely. Best hope being on the SO(10)
In regards to SO(10) my understanding (still studying it) the higgs turns on earlier. As well as in the MSSM minimal super symmetric model.
I guess the only correct answer is that it is anyones guess lol
skydivephil said:As i understand it, at some point in the early unvierse, the Higgs field was off, then it swtiched on. Is this correct? I can't find when this is supposed to have happened, does anyone know?
I think you are quoting the MSSM GUT scale there (supposing your units are GeV). What does SUSY have to do with electroweak symmetry breaking?Mordred said:answer 246 GeV Minimal standard model, as I stated the electroweak scale depends on the model used
in the MSSM models the electroweak scale is roughly 1015
edit however the SUSY scale may be too high in the MSSM model so I wouldn't place any faith in MSSM. Least from what I've been reading
Mordred said:How many Higg's fields.Bosons are there lol? I certainly don't know.
see alternate models, Higgs
The Minimal Standard Model as described above is the simplest known model for the Higgs mechanism with just one Higgs field. However, an extended Higgs sector with additional Higgs particle doublets or triplets is also possible, and many extensions of the Standard Model have this feature. The non-minimal Higgs sector favoured by theory are the two-Higgs-doublet models (2HDM), which predict the existence of a quintet of scalar particles: two CP-even neutral Higgs bosons h0 and H0, a CP-odd neutral Higgs boson A0, and two charged Higgs particles H±. Supersymmetry ("SUSY") also predicts relations between the Higgs-boson masses and the masses of the gauge bosons, and could accommodate a 125 GeV/c2 neutral Higgs boson.
http://en.wikipedia.org/wiki/Higgs_boson
The standard model is U(1)*SU(2)*SU(3) this portion has 4 Higg's particles including its anti particle
The SU(5)*SU(3)*SU(2)*U(1) MSSM needs 12 Higg's goldstone bosons forthe lie algebra if memory serves right. However I'm still learning lie algebra so I could be wrong.
So in that sense your correct in that its a different Higg's in a way lol Not sure how the SO(10) works yet but some of the numbers I've seen on it involve 72 higgs
Mordred said:by the way wiki has the electroweak scale at 246 GeV, makes me wonder where the difference is (not that we can trust wiki 100%)
http://en.wikipedia.org/wiki/Electroweak_scale
could this be why?
"Physically, it describes the moment in our universe evolution when electric and
weak forces differentiate. At temperature scales above 100 GeV, MSM Lagrangian exhibits the gauge symmetry:"
SU(3)c*SU(2)L*U(1)Y
SU(3)c
refers to the color symmetry and plays no role in our rendition of the electroweak phase transition."
that was why I questioned the 100GeV value in post 6
Chronos said:Lawrence Krauss suggests SU(10) is favored by BICEP2 data - http://arxiv.org/abs/1404.0634.
bapowell said:I think you are quoting the MSSM GUT scale there (supposing your units are GeV). What does SUSY have to do with electroweak symmetry breaking?
.phsopher said:What I'm getting at is that when you say that in some models the Higgs turns on earlier do you mean that other higgses turn on earlier or that the SM one does? I don't see why it would be that latter. We've probed the energies up to 10 TeV in accelerators, if new physics pushed the symmetry breaking scale to higher energies wouldn't we have seen it in accelerators? Since SM works at energies up to 10 TeV and there is a symmetry breaking phase transition at ##T\sim \mathcal O(\text{100 GeV})## in the SM then it must have happened in the early universe.
246 GeV is the vacuum expectation value of the Higgs in the broken phase. The temperature at which the transition happens depends on the masses of the Higgs, weak gauge bosons and the top quark; see Mukhanov, equation (4.137).
Slow down Mordred. Nobody is saying that the SM is complete, and that there isn't important unknown physics happening at and above the GUT scale. All I'm saying is that above the electroweak scale, the Higgs field responsible for breaking electroweak symmetry is *by definition* off, in the sense that the symmetry is restored. This is absolutely true at the GUT scale, as evidenced by the fact that GUT symmetry breaking occurs many orders of magnitude above the electroweak scale. Phsopher is saying the same thing: the Higgs is turned "on" when it acquires a VEV -- are you saying that the electroweak Higgs has a nonzero VEV above the electroweak scale?Mordred said:but according to you the Higgs field is and I quote "off" above the electroweak scale. If that's the case then explain these articles. How can one define OFF when it obviously has influences above 246 GeV? A different Higg's that is a poor argument.
or its off, but its not off when your talking the GUT scale, that doesn't make one iota of sense. Considering the purpose of any particle physics model is to define and explain all the particles and their interactions at any temperature scale, GUT just happens to be one of the goals in that. Their are countless papers that discuss the limitations of the standard model. I've been posting numerous papers throughout this post that all mention the standard model limitations. Why do you think the standard model has extensions?
Mordred said:.
The standard model only uses one Higg's field, The calculation of 246 Gev is only with one Higg's field. The research papers I posted in the previous threads, show the relations with the other potential Higg's fields and possibly the seesaw mechanism. (mexican hat).
keep in mind I was very clear that it depends on which model. The choice of models favored is up to the individual. My take is the Higg's sector has a lot of open questions, and more research is needed to truly make any statements one way or the other.
The Higgs field is a theoretical concept in physics that is believed to permeate throughout the universe. It is responsible for giving particles their mass and is an essential component of the Standard Model of particle physics.
The Higgs field works by interacting with particles as they move through it. This interaction slows down the particles and gives them mass. The more the particle interacts with the Higgs field, the more massive it becomes.
In the early universe, the Higgs field played a crucial role in the process of symmetry breaking. This process allowed for the formation of the Higgs boson, which is responsible for giving particles their mass and is a fundamental building block of the universe.
The Higgs field was first theorized in the 1960s by Peter Higgs and other physicists. It was later confirmed in 2012 by the Large Hadron Collider (LHC) at CERN, through the detection of the Higgs boson. This discovery provided evidence for the existence of the Higgs field.
Scientists are currently conducting further research on the Higgs field in the early universe to gain a better understanding of the fundamental forces and particles that govern our universe. This includes studying the behavior of the Higgs field during the period of inflation in the early universe and its potential role in the formation of dark matter.