What is the Experimental Evidence for the Spin of Bosons?

In summary: People can be so sure that a z-particle is spin 1 because the particle behaves the way classical mechanics predicts it would. Classical mechanics doesn't take into account the quantum behavior of particles, so the predictions are very accurate. There are other ways to measure spin, but they are more indirect.
  • #1
zincshow
104
0
The detection of spin in Hadrons and Leptons is done through magnetism, a spin 1/2 particle has two states in a magnetic field, an up particle goes up, a down particle goes down. A spin 1 particle has three states, an up/up goes up, a up/down stays straight and a down/down goes down. A spin 3/2 particle has 4 states, the up/up/up goes up a lot, the up/up/down goes up a bit, the up/down/down goes down a bit, a down/down/down particle goes down a lot.

What about the bosons? Wiki says the higgs is a 0 spin particle and the z/w/photon particles are spin 1.

Is this just theory or has it been experimentally shown?

Photons don't react to a magnetic field so what does it mean experimentally, what do people see?

How can people be so sure that a z-particle is spin 1? Are there specific effects that can be measured that show this?
 
Physics news on Phys.org
  • #2
The concept of spin is complicated. You should focus on that.
 
  • #3
You can look up the particles to see how their spins have been worked out.

Virtual particle spins are deduced from the interaction products.
Photon spin manifests, among other things, in polarization effects.
 
  • #4
zincshow said:
Wiki says the higgs is a 0 spin particle and the z/w/photon particles are spin 1.

Is this just theory or has it been experimentally shown?

http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.110.081803

Please take note that in physics, when something has been claimed to be verified or discovered, we very seldom base that on only one characteristic! We often have to verify several different properties. In this case, the Higgs was verified not just with a value for its mass, but also with many other properties that were predicted from the Standard Model. It is why had to build the LHC.

As has been mentioned, you CAN look up the experimental verification of other particles in the Standard Model so far.

Zz.
 
  • #5
zincshow said:
The detection of spin in Hadrons and Leptons is done through magnetism, a spin 1/2 particle has two states in a magnetic field, an up particle goes up, a down particle goes down. A spin 1 particle has three states, an up/up goes up, a up/down stays straight and a down/down goes down. A spin 3/2 particle has 4 states, the up/up/up goes up a lot, the up/up/down goes up a bit, the up/down/down goes down a bit, a down/down/down particle goes down a lot.

What about the bosons? Wiki says the higgs is a 0 spin particle and the z/w/photon particles are spin 1.

Is this just theory or has it been experimentally shown?

Photons don't react to a magnetic field so what does it mean experimentally, what do people see?

How can people be so sure that a z-particle is spin 1? Are there specific effects that can be measured that show this?

Your second example of a particle with spin 1 is a boson (all particles with integer spin are bosons) so I guess you have answered your own question there. The question you should have asked instead is how can we tell the spin of neutral particles. That includes bosons such as the photon and fermions such as the neutrino as well and excludes fermions such as the electron and bosons such as the W as well.

Yes, it's easier to figure out the spin of charged particles. It is also easier to see them at all. But there are indirect (and harder) ways to figure out the properties of neutral particles.
 
  • #6
zincshow said:
The detection of spin in Hadrons and Leptons is done through magnetism, a spin 1/2 particle has two states in a magnetic field, an up particle goes up, a down particle goes down. A spin 1 particle has three states, an up/up goes up, a up/down stays straight and a down/down goes down. A spin 3/2 particle has 4 states, the up/up/up goes up a lot, the up/up/down goes up a bit, the up/down/down goes down a bit, a down/down/down particle goes down a lot.
You can do this Stern-Gerlach experiment with a nuclei and electrons, but it is not useful for most unstable particles.

A common way to measure spin of unstable particles is an angular analysis of their decay products. Spin-0 particles will emit their decay products in all directions (in their rest frame) with the same probability, particles with non-zero spin show different patterns.

Another test is the production mechanism. If a particle is produced by a virtual photon, for example, it will have spin 1 (with the J/psi as the most prominent example), as the photon spin. For the photon, you can use classical electromagnetism to show it has to have spin 1.
 
  • Like
Likes 1 person
  • #7
Correct me if I am wrong, but doesn't the circular polarization of a single photon correspond to its spin?
 
  • #8
That is its spin orientation, not its particle property "spin 1". And that is the classical way to show the spin, right.
 

What are bosons?

Bosons are a type of elementary particle that have integer spin values, such as 0, 1, 2, etc. They are one of the two categories of particles in the Standard Model of particle physics, the other being fermions. Examples of bosons include photons, gluons, and the Higgs boson.

What is spin in bosons?

Spin is a fundamental property of particles that describes their intrinsic angular momentum. In bosons, spin is always an integer value and can take on values of 0, 1, 2, etc. It is a quantum mechanical property that cannot be directly observed, but its effects can be seen in experiments.

How does spin affect the behavior of bosons?

Bosons with different spin values behave differently, particularly in their interactions with other particles. For example, bosons with spin 0 (such as the Higgs boson) can mediate the interactions between particles, while bosons with spin 1 (such as photons) can carry electromagnetic forces.

Why is understanding spin important in bosons?

Understanding spin in bosons is important because it helps us understand how these particles interact with each other and with the forces in the universe. It is also crucial in the development of theories and models in particle physics, and in the design of experiments to study these particles.

How is spin in bosons measured?

Spin in bosons cannot be directly measured, but its effects can be observed through experiments. Scientists use various techniques, such as scattering experiments, to study the behavior of bosons and infer their spin values. The mathematics of quantum mechanics also plays a crucial role in understanding and calculating spin in bosons.

Similar threads

  • High Energy, Nuclear, Particle Physics
Replies
11
Views
1K
  • High Energy, Nuclear, Particle Physics
Replies
8
Views
1K
  • High Energy, Nuclear, Particle Physics
Replies
13
Views
2K
  • High Energy, Nuclear, Particle Physics
Replies
4
Views
2K
  • Quantum Physics
4
Replies
124
Views
3K
Replies
2
Views
945
Replies
6
Views
1K
  • High Energy, Nuclear, Particle Physics
Replies
4
Views
1K
Replies
4
Views
907
  • High Energy, Nuclear, Particle Physics
Replies
4
Views
2K
Back
Top