Do we need to refer all interactions to symmetries?

In summary, your question is related to the renormalization of quantum field theory. There are two reasons why this is less obvious in the case of the electroweak theory than in the case of the quantum chromodynamics (QCD) theory. First, massive gauge bosons play a significant role, and second, the left-right handedness of the fermions is important for the renormalization.
  • #1
ndung200790
519
0
Do we innevitably need to attach each interaction with a symmetry?Could we contruct a theory of an interaction without using any symmetry theory(example gravity interaction)?

Why do we not need to demonstate QCD being renormalized,but we must demonstrate electroweak theory is renormalized(I hear t'Hooft did that)?Is that because we separate left handed from righ handed representation,then appearing the chiral anomalies,so we must demonstrate the renormalization?If the left-righ handedness were reserved in electroweak theory,then we would not to have demonstrate the renormalization as QCD?
 
Physics news on Phys.org
  • #2
Not every possible interaction is related to an underlying symmetry.
In QFT, many interactions are attached to gauge symmetries (any interaction with spin 1 particle).
However, interactions invloving scalars and fermions (like yukawa interactions) are not nescesaraly related to any symmetry. For examples, ineratctions of the higgs with fermions
in the SM are not related/dictated by any underlying symmetry.

For the question about renormalization, there are two reasons why renormalizability in Electro-Weak theory is less obvious than in qcd.
1) Massive gauge bosons

-It has been shown that if the masses are due to the higgs mechanism the theory is still renormalizable.

2) left are right handed fermions have different gauge interactions (transform differently under the gauge symmetry) - chiral theory

-It has been shown that the SM is still renormalizable due to intricate cancelation between the gauge quantum numbers of the SM fermions. The gauge anomalies vanish
 
  • #3
The gravity interaction is a real(existing) interaction despite the gravity theory is nonrenormalizable theory.But in elimination (infinite) impossible interactions they consider nonrenormalizable interactions being impossible interactions(for example Phi-5,Phi-6...interactions,but only accepted Phi-4theory).Why do they not accept all those nonrenormalizable interactions and manage to bypass the nonrenormalizability by ''nonperturbative'' theories or finding some ''symmetries'' that reduce infinite counterterms to finite counterterms?
 
  • #4
How can we deduce the gauge bosons have spin 1 from Standard Model?Why must carrying force particles be bosons,but they can not be fermions?
 
  • #5
I hear in Supersymmetry theory there is a ''symmetry'' between bosons and fermions(?).But I would like to know the problem in Standard Model
 
  • #6
I see you didn't follow my advice in the previous thread; two-thirds of it is reproduced below.

  • https://www.physicsforums.com/blog.php?b=3588
  • It is customary to say "thank you" when you ask a question and have it answered.
 
Last edited by a moderator:

1. What are symmetries and why are they important in science?

Symmetries are patterns or properties that remain unchanged under certain transformations. In science, symmetries can reveal underlying laws and principles, and can help us better understand the natural world.

2. Do all interactions need to be referred to symmetries?

No, not all interactions need to be referred to symmetries. Symmetries are often used to simplify and explain complex interactions, but they may not apply to all situations.

3. How do symmetries play a role in particle physics?

In particle physics, symmetries are essential for understanding the fundamental interactions between particles. The Standard Model of particle physics is based on the idea of symmetries and their breaking.

4. Can symmetries be broken?

Yes, symmetries can be broken. In fact, the breaking of symmetries is crucial for understanding the different states and phases of matter, such as solid, liquid, and gas.

5. Is the concept of symmetries relevant in other scientific fields?

Yes, symmetries are important in many scientific fields, including mathematics, chemistry, and biology. In mathematics, symmetries are used to study patterns and structures. In chemistry, symmetries help predict the properties of molecules. In biology, symmetries can reveal underlying principles in the structure and function of living organisms.

Similar threads

I Are SM B & L conservation violations through sphalerons possible?
    • High Energy, Nuclear, Particle Physics
Replies
1
Views
921
A Learn SU Groups in QCD: Chiral Symmetry, 8 Goldstone Bosons & More
    • High Energy, Nuclear, Particle Physics
Replies
8
Views
2K
Puzzling Chiral Symmetry Breaking
    • High Energy, Nuclear, Particle Physics
Replies
16
Views
3K
A Why do we write that there are no right-handed neutrinos?
    • High Energy, Nuclear, Particle Physics
Replies
8
Views
3K
A Why do we need to renormalize in QFT, really?
    • High Energy, Nuclear, Particle Physics
Replies
5
Views
2K
Yang-Mills theory, confinement and chiral symmetry breaking
    • High Energy, Nuclear, Particle Physics
Replies
2
Views
2K
I How do the collider experiments measure the mass of the W boson?
    • High Energy, Nuclear, Particle Physics
Replies
4
Views
2K
What is the origin of C,P and CP violations?
    • High Energy, Nuclear, Particle Physics
Replies
8
Views
2K
A Spinor indices on Yukawa coupling terms in electroweak sector
    • High Energy, Nuclear, Particle Physics
Replies
1
Views
1K
I Graviweak Unification and Coleman-Mandula theorem
    • Beyond the Standard Models
Replies
7
Views
2K

Hot Threads

Recent Insights

Back
Top