C and P parity of gauge bosons - what are the values?

[heinz]

Can somebody explain the parities of photons, W, Z and gluons?

QFT says that bosons and antibosons have the same P parity.
But the P parity of the gauge bosons is rarely given.
Sometimes photons are said to have negative parity, while other say this
is only the case for electric dipole transitions.
For W and Z, it is sometimes written that they have no P
parity because of the P violation of the weak interaction.
Is that correct?
In short, I am confused: what are the P parties of the
gauge bosons?

C parity exists only for neutral particles. Thus it can be
defined at most for the photon, the Z and the gluons.
Do they have a C parity? Does it make sense for them at all?

Thanks for any help!

Heinz

 

[LightHero]

The parity (P) of a particle is related to its mirror reflection. A particle with positive P parity would remain the same after a reflection, while one with negative P parity would be reversed. The parity of photons is usually given as positive, meaning they will remain the same after a reflection. W and Z bosons are believed to have no P parity as they are associated with the weak force which violates parity. Gluons, the particles responsible for the strong force, also have no known P parity.

 

[sir-pinski]

The C and P parities of gauge bosons are important concepts in quantum field theory that can help us understand the properties and behavior of these particles. The C parity, or charge conjugation parity, refers to the transformation of a particle into its antiparticle. In other words, particles and their antiparticles have opposite C parities. On the other hand, the P parity, or parity, refers to the transformation of a particle's spatial coordinates into their mirror image. This means that particles and their mirror images have the same P parity.

In terms of the specific gauge bosons mentioned, the photon, W, Z, and gluons all have different C and P parities. The photon, being a neutral particle, has a C parity of +1 and a P parity of -1. This means that the photon is its own antiparticle and its spatial coordinates are inverted in its mirror image. The W and Z bosons, which are responsible for the weak interaction, have a C parity of -1 and a P parity of +1. This is because the weak interaction violates the conservation of parity, meaning that the W and Z bosons and their antiparticles have opposite P parities. Finally, the gluons, which mediate the strong interaction, have a C parity of +1 and a P parity of -1. This is similar to the photon, as the gluon is its own antiparticle, but its spatial coordinates are inverted in its mirror image.

It is important to note that the P parity of the gauge bosons is not always specified because it is not a conserved quantity in all interactions. As you mentioned, the weak interaction violates parity, so it is not meaningful to assign a P parity to the W and Z bosons. However, in some cases, the P parity may still be used to describe specific processes or transitions involving these particles.

In terms of the C parity, it is only applicable to neutral particles, so it does not make sense to assign a C parity to the W and Z bosons, which are charged. The photon and gluons, being neutral particles, do have a C parity of +1.

I hope this helps clarify the C and P parities of gauge bosons for you. It can be a confusing concept, but understanding these properties can greatly enhance our understanding of the fundamental interactions in the universe.