Rigorous Study of the Higgs Boson - Question

[Sunnyocean]

There is. It's called an undergraduate education in physics followed by a graduate education in physics, and it takes a decade or so of full-time study. Unfortunately, if there were a shortcut, everybody would be taking it.

Vanadium 50, I have already been through that (except for the PhD) and sadly I cannot agree with you. Basically now I have to revise even the basics or even replace the "basics" (i.e. the course materials I studied) with proper books / proper materials, because the programme I went through was focused on "getting the grades" rather than on conveying a real understanding of physics to students.

 

[Dragon27]

An article by Sergei Winitzki explores somewhat the issue of teaching theoretical physics and the difficulties students encounter in trying to understand it:
Why is theoretical physics hard to learn no matter how much you already know?

This essay is an outgrowth of my ruminations on the problem of learning and teaching theoretical physics. I try to explain why it seems to be very hard to learn a recently discovered branch of physics, while it is comparatively easy to learn and to teach a long-established branch. Another issue is that, among students, even well-known areas of physics have a reputation of being mysterious and incomprehensible. It seems that one source of the problem is the widespread attitude that performing calculations and obtaining specific results is more important than achieving a logical and conceptual understanding of the material. I explore the interdependence of mathematics and physics which is inevitably involved in a learning process and show that this “principle of delayed understanding” has detrimental consequences. Another problem is the mixing of mathematical methods and their application in physics, which frequently confuses students. To illustrate these problems, I quote some examples from widely used physics textbooks (the reader who is not familiar with theoretical physics may skip the examples). I also comment on the basic differences between the contemporary practices of teaching mathematics and physics, in an attempt to propose a better way of presenting physics to students.

 

[PeroK]

Vanadium 50, I have already been through that (except for the PhD) and sadly I cannot agree with you. Basically now I have to revise even the basics or even replace the "basics" (i.e. the course materials I studied) with proper books / proper materials, because the programme I went through was focused on "getting the grades" rather than on conveying a real understanding of physics to students.

Here you go. This is a quotation from Tobias Osborne from this lecture on QFT. About 12 minutes into the video he says:

"What characterises a physicist, I think, is someone who is willing to step outside the comfort zone of rigorous maths."

 

[Vanadium 50]

because the programme I went through was focused on "getting the grades" rather than on conveying a real understanding of physics to students.

The fact that your education was unsatisfactory - and I am sure you bear no portion of the responsibility for that - doesn't change the fact that learning physics at this level takes about a decade, and if there were a shortcut, everyone would take it.

 

[Sunnyocean]

I see the discussion has deviated so I am re-posting these questions:
Can anyone please answer the following two questions regarding books / materials:

Another question: "Why is the (mass)^2 term of the Higgs Boson negative in the Standard
Model Lagrangian to start with?"
(From https://www.physicsforums.com/threads/why-is-the-higgs-boson-tachyonic.115864/).
In which book can I read about the Standard Model Lagrangian (and also, very importantly, what exactly a Lagrangian is). I have seen it used before, including in my own undergraduate courses, but I need a book (probably also mathematics) that presents in detail, rigorously, what a Lagrangian is and so on. And, of course, following that, another book about the mathematical form of the Standard Model, how the Lagrangian is used in it and so on.Also, the questions below:

Here is a fragment that I read in a paper presented in a related post:
"There is a well-defined Hilbert space, a well-defined
Hamiltonian constructed without any use of perturbation theory,
a well-defined unitary dynamics, well-defined bound states that
are eigenstates of the Hamiltonian, and everything is invariant under
the 2D Poincare group ISO(1,1)"
(taken from https://arnold-neumaier.at/physfaq/topics/different )

I do not know what exactly a Poincare group is, much less a 2D Poincare group, and what group classification is (e.g. "ISO(1,1)").
Could anyone recommend some good / rigorous mathematics books where I can study these?

 

[vanhees71]

Here you go. This is a quotation from Tobias Osborne from this lecture on QFT. About 12 minutes into the video he says:

"What characterises a physicist, I think, is someone who is willing to step outside the comfort zone of rigorous maths."

This is a great quote. Take it together with Sadri Hassani's motto in the preface of his "Mathematical Physics" textbook: "If math is the language of Nature then physics is its poetry."

 

[shjacks45]

So a Higgs boson walks into a church. The priest said,"We don't want your kind in here." The Higgs boson replied,"But you can't have Mass without me."

 

[Demystifier]

So a Higgs boson walks into a church. The priest said,"We don't want your kind in here." The Higgs boson replied,"But you can't have Mass without me."

I don't get it, why do they not want the God's particle in the church?

 

[vanhees71]

Because in reality it's the "god-damn particle". It got its "title" "god particle" only due to the hippocracy of the popular-science-book publishers who feared it might provoke an outcry, if they'd use Lederman's suggestion of this title for the book .

 

[Vanadium 50]

hippocracy

Rule by hippos?

Getting back to the question at hand, I doubt there is any book that answers both the question "what is a Lagrangian", "what is the SM Lagrangian" and "why is this particular term negative". Especially given all the constraints.

 

[vanhees71]

It's negative to get a non-zero vacuum-expectation value for the Higgs field, which "Higgses" the local gauge symmetry from $\mathrm{SU}(2)_{\text{wiso}} \times \mathrm{U}(1)_{\text{Y}}$ to $\mathrm{U}(1)_{\text{em}}$, such that you end up with only one massive Higgs boson and three massive W and Z bosons and one massless photon, which is exactly what's needed to describe the weak and em. interaction right.

 

[Tendex]

Talking about "understand in a really, really rigorous manner the Higgs field", what happened to the issues with quantum triviality of the Higgs field. I remember proofs about the triviality(in the mathematical sense) of the scalar field $\phi⁴$ in any dimension, how was this circunvented?