Does Renormalisability Depend on Spin in Quantum Field Theory?

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In summary, the conversation discussed the concept of renormalisability in quantum field theory, specifically in relation to particles with different spin values. It was mentioned that spin 0 or 1/2 particles have renormalisable field theories, while spin 1 particles are originally unrenormalisable but can be cured by gauge theory. Spin 2 particles, like those in quantum gravity, are unrenormalisable. The conversation also referenced the renormalisation sections in books by Ryder and Peskin and asked for clarification on the topic. It was suggested to refer to section 12.1 of Weinberg's "Quantum Theory of Fields, Volume 1" or section 10.1 of Peskin and Schroeder for a more
  • #1
ismaili
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Dear all,

I heard that renormalisability has something to do with the spin. A quantum field theory of particles with spin 0 or 1/2 is renormalisable; where with spin 1 is originally unrenormalisable, however, since we have gauge theory for the spin 1 particles, the symmetry cures the problem, and the field theory becomes renormalisable in the case of spin = 1.
In this perspective, a field theory of spin 2 particles is unrenormalizable, like the quantum gravity.

But I haven't read about this from the renormalisation sections of some books, like Ryder or Peskin.
Is this related to the proof provided by 't Hooft?
Or anyone can provide a correct and clear picture or explanation?
Many thanks!
 
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  • #2
See section 12.1 of Weinberg's "Quantum Theory of Fields, Volume 1".

Although it's basically just Section 10.1 of Peskin and Schroeder. There they obtain formulas for Bosons and Fermions and you can see the vertex terms, i.e. ##V## contains a term depending on the dimensionality of the coupling. It's simply that for the higher spin cases the simplest interacting terms have couplings with negative dimension.
 

Related to Does Renormalisability Depend on Spin in Quantum Field Theory?

1. What is renormalisability?

Renormalisability is a property of a quantum field theory that ensures that the theory can be made mathematically consistent by appropriately adjusting the parameters in the theory. This is important because it allows us to make predictions that are both finite and meaningful.

2. What is spin in quantum mechanics?

In quantum mechanics, spin is a fundamental property of particles that describes their intrinsic angular momentum. It is a quantum mechanical version of the classical concept of angular momentum, but unlike classical angular momentum, spin is quantized and can only take on certain discrete values.

3. How does spin relate to renormalisability?

Spin plays a crucial role in renormalisability because it determines the behavior of particles in a quantum field theory. The spin of a particle dictates how it interacts with other particles and fields, which in turn affects the renormalisability of the theory. In general, theories with higher spin particles are more difficult to renormalize.

4. What is a renormalisable theory?

A renormalisable theory is one in which the parameters of the theory can be adjusted in a way that ensures that all calculations and predictions are finite and meaningful. This means that the theory can be used to make accurate predictions about the behavior of particles and their interactions, and it is considered to be a successful and reliable theory.

5. What is the significance of renormalisability in physics?

Renormalisability is a crucial concept in physics because it allows us to make meaningful and accurate predictions about the behavior of particles and their interactions. It also helps us to understand the fundamental forces and particles of the universe, and it has been a key factor in the development of the Standard Model of particle physics.

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