Electroweak Definition and 84 Threads

In general speaking,if the coupling constant is (mass) dimensionless then the quantum field theory is renormalizable.In electroweak theory the coupling constant g~e,so the coupling constant is dimensionless,then the electroweak theory(Weinberg-Salam theory) would be renormalizable.So I do not...

The electroweak theory describes the photon and vector bosons (Z0, W+, W-) as mixtures of bosons from the electroweak interactions (weak hypercharge and weak isospin). In addition, the vector bosons mix also with the Higgs bosons and thus gain mass. Photon does not mix with the Higgs, so it...

Hi there. I have a question. Different QFT books usually introduce de Simmetry Breaking mechanism something like this: 1) We have a local gauge theory. 2) The theory has a parameter which is usually positive but can be negative 3) If this parameter is, let's say, negative then the vacuum is...

A paper I am reading says My question is, "What does this mean?" The paper deals with WIMP annihilations into a photon and a Higgs which I suspect occurs via a fermion loop. I seem to recall that such triangle diagrams yield amplitudes proportional to the mass of the fermion in the loop (which...

Hello, I've been reading about the weak interaction. Basically, the weak interaction couples to particles that are left-handed, and we introduce the electron-electron neutrino as a (left-handed) SU(2) doublet. So, the gauge bosons (W+, W-, and Z) transform SU(2) triplet. Am I right...

Hi, quick question. "In electroweak theory, the neutrino belongs to an SU(2) doublet" So, does the neutrino belong to an SU(2)xU(1) (electroweak) doublet or just SU(2)? Thanks!

Before Higgs symmetry breaking of SU(2)xU(1) electroweak unified force or even before that, when strong and electroweak were unified as GUT theories propose, the vacuum was different from today's universe. What effects had these different vacua on the evolution of the universe? thanks

Hello, new member here. I've been fascinated reading some of the threads and decided I had to register to ask a question that's always been a bit confusing to me. From what I've learned The Big Bang theory seems the most likely explanation of the start of the universe but there's one thing in...

I can only assume it is, if a Higgs can be found anyway. I learned about hysteresis in certain physical processes. I don't have the math to guess nor Google skills to find a clear answer. If it were, would a sufficiently large and hot enough black hole be in danger of losing its mass terms...

What law of nature says that electroweak symmetry must be broken? Is it possible that in other parallel Superstrings (or others) universes.. electroweak symmetry were not broken and even after temperature of the Big Bang decreased to what is like ours, electroweak symmetry still existed in that...

The electroweak force is a unified force that combines both electromagnetism and the weak nuclear force. But since the electromagnetic force is mediated by photons and the weak nuclear force is mediated by W & Z bosons, which of these particles actually mediates the electroweak force? Is it the...

Hi there - does anyone know a good reference in which it is shown that we can derive QED from the Weinberg-Salam model? (Or if we can't, does anyone know why?) Thanks!

What if in the elettroweak theory we broke U(1) too? I read sometimes that electric charge would not be conserved anymore. Anyway, if the photon got a mass, even if U(1) gauge symmetry is broken, QED lagrangian would still be invariant under global U(1) transformation, and we should still have...

Can someone refer me to Feynman rules for electroweak interactions in the general case of SU(2) multiplets of weak isospin n and weak hypercharge Y interacting with EW gauge bosons? I can only find the standard rules for SU(2) doublet electron - neutrino. Thanks!

Can you clear something up for me? I see that the discovery of the W and Z boson in 1983 is described as confirming the electroweak unification theory. I was thinking that the W and Z were carriers of just the weak force. I don’t see how the experimental discovery of the W and Z show...

Now bear with me, I'm no expert when it comes to Electroweak Symmetry and Symmetry Breaking; I can only comprehend up to integrating, functions, derivatives, partial derivatives with a small hint of linear algebra and the basic, Hermitian, Hamiltonian, bras and kets. So my questions are the...

Hi all, I'm trying to calculate the Feynman Rules for the effective electroweak chiral Lagrangian. For example, this is the first term in the Lagrangian: \begin{eqnarray} \mathcal{L}=\frac{v^2}{4}\text{Tr}(D_{\mu}U D^{\mu}U^{\dagger}) \end{eqnarray} where \begin{eqnarray}...

In the GWS electroweak model, there are two fundamental charges: weak hypercharge and the third component of weak isospin (henceforth referred to as hypercharge and isospin respectively). The gauge boson of hypercharge is the B0, and those of isospin are the W+, W0, and W-. The B0 and W0 mix...

I've seen the value 129^{+74}_{-49} GeV/c^2 mentioned in some discussion and wikipedia as a prediction of the higgs mass from electroweak measurements. Are the largest contributions to the error bars statistical in nature, and is is likely that the LHC can greatly increase precision of this...

I saw this paper listed, http://arxiv.org/abs/1012.5529 Asymptotically safe weak interactions Xavier Calmet (Submitted on 26 Dec 2010) "We emphasize that the electroweak interactions without a Higgs boson are very similar to quantum general relativity. The Higgs field could just be a...

"Electroweak stars: how nature may capitalize on the standard model's ultimate fuel," De-Chang Dai, Arthur Lue, Glenn Starkman, Dejan Stojkovic, http://arxiv.org/abs/0912.0520 Pretty far out, and I'm not sure I believe it. One thing that surprises me is that they claim the standard model has...

I (moderately) understand the basics of the electromagnetic and weak nuclear forces, but I recently heard of a combined electro-weak theory. It apparently states that two forces are different manifestations of a single force at very high temperatures. Does this mean that the photon...

Anybody knows what is the physical meaning of hypercharge in electroweak theory?

I know that there are many reasons why SU(2) can't be the electroweak gauge group, but I want to have some clarifications about the following one, that disergads neutral currents: in this case the currents are (considering only the lepton sector of the first generation)...

If I understand the standard model correctly (a big assumption) you have electromagnetism - U(1) symmetry mediated by the photon weak interaction - SU(2) symmetry mediated by the W+- & Z bosons strong interaction - SU(3) symmetry mediated by gluons is there any reason to view...

Hi all, I would like to ask if anyone could recommend a good book in electroweak theory, possibly covering ew phase transition, ew baryogenesis as well? Thank you! Michela

the whole concept, I just don't get it. really its the unification I don't really understand. does flavor turn into charge? or is it some strange wave thing. does that mean that light takes on weak properties at high energy levels? or is there a new kind of light (like an electroweak wave?) and...

What's the Rb and Rc problems in electroweak theoy?

dear all, I am eager to read the "Gauge Theories of the Strong and Electroweak Interaction" wriiten by Manfred Böhm,Ansgar Denner,Hans Joos. But in my country, there's no the book. If you have the ebook or know the web sites to download it, please send it to my email(wuleihnu@yeah.net). Thank...

Interesting new paper from John Moffat: http://arxiv.org/abs/0709.4269 Introduces a non-local, finite QFT that dynamically generates boson and fermion masses as loop corrections. Experimental evidence for the theory will be visible in WW scattering at the LHC (coupling goes to zero, which...

One difference between GR and LQG is that LQG is chiral, whereas GR is not. In order to break the electroweak symmetry, a higgs field needs to be introduced by hand. Einstein's understanding of inertia implies a strong EP as gravitational mass and inertia are identical, while a higgs...

What does it mean to say to say that the electroweak interaction is described by a gauge field theory based on the SU(2)_{L}\timesU(1)_Y symmetry group? I know that SU(2) is a group of unitary matrices and U(1) is the circle group but I don't really see what the sentence means. I haven't taken...

How is the electroweak symmetry actually broken in the standard model ? Please could you explain the idea to me. Thanks Roger.

in particle accelerators, we've seen the electromagnetic force and the weak force unified. How? Do W+, W-, Z, and photons dissappear, to be replaced by another fermion, or what?