Recent content by Physiana

Good link :) I was stuck with Kochs "Introduction to chiral symmetry" and could hardly believe that I couldn't find sth more comprehensive...

Thank you :) I have read everything, so far my knowledge was solely on SSB in the elctroweak sector of the SM. But the gauge symmetry is preserved even with Higgs field and it is only the ground state that is broken, that is why we use SSB, isn't it? And gauge symmetry is also preserved on...

I don't know if it is the correct sub-forum, if I choose wrong then feel free to move the thread. I was listening to a talk today using DCSB. I think I could get a glimpse on some other parts of the talk and found some ideas intriguing. I would like to understand them better, but I cannot...

Then I don't understand why Newton's third law would be violated.

I struggled with exactly the same question many many times. And I agree that the most stupid people are those who are unable to admit that the know next to nothing ;) They have come to believe that geniuses would know everything and have forgotten that even geniuses are humans and thus very...

:) Thank you.

why would the forces be of different strength? I can't see it.

To specify; For space time transformations I get a \delta L , while for all the symmetries of the Standard model (QCD, GWS and chiral) the Lagrangian remains invariant. Space time symmetries are external symmetries, while QCD, GWS and chiral symmetries are internal symmetries. So can I...

So there is a difference between a Lagrangian being invariant and it "transforming as". Does it say anything about the underlying symmetry, if a Lagrangian is invariant or "only" transforming as? (e.g. space-time, external, internal) In field theories one generally speaks of invariance...

I am not sure if I understood your question correctly but if by electroweak symmetry you mean SU(2)xU(1), then yes. It is generally called Weinberg-Salam or Glashow-Weinberg-Salam model of electroweak interaction.

"invariant" Lagrangian or action Hello everyone, I tried to describe my question but it seems getting too complicated and confusing to write down my thoughts in detail, so I am trying to start with the following question... Are invariance of the Lagrangian under a transformation and...

Is there really no one who has an idea?

Pion Nucleon Scattering and a bit about group theory/ representations Hello everybody, I am going through Ryder's book about Quantum Field Theory right now. In the chapter about Pion Nucleon scattering he writes the interaction term like L_{int}=ig \bar{\psi} \gamma_5 \tau_a \psi \phi^a...

After reading some threads I decided to post my question, since I couldn't find an sufficient answer. In general the generators of a lie group combined with the compostion [A,B]=ifB build a Lie-Algebra. Where the Generators build the base of the vectorspace. In a common vectorspace you can find...