# Photon as force carrier particle

• Almeisan
In summary, virtual photons are a factor in the perturbation expansion for the EM force. They are similar to the real photons we know, only they can be in or out of a field's state. Force carrier particles are at some point virtual, but quanta are photons.
Almeisan
To my embarrassment I realized I do not understand this.

How does a photon mediate the EM force? If I put two magnets close to each other then there is no EM radiation jumping from the one to the other. So how does the photon carry the particle?

I know that very magnet has a Magnetic field and that a photon is a little moving quanta of EM energy. Or a EM disruption in the EM field.

But I fail to understand this. A EM field has nothing to do with photons right? Or do photons only jump over if there is an actual force on a charged object?

Then, is it possible to observe a EM field through photons?

Or lies my problem in the difference between an electric field, a magnetic field and an electromagnetic field?

Last edited:
Daevren said:
How does a photon mediate the EM force? If I put two magnets close to each other then there is no EM radiation jumping from the one to the other. So how does the photon carry the particle?

Those are virtual photons, not real ones. A virtual photon is basically a mathematical device. It's a name we assign to a factor that repeatedly occurs in the terms of a perturbation expansion in quantum field theory.

Richard Feynman noticed that one could easily construct or remember the perturbation expansion for a particular process by drawing a series of diagrams which represent the various terms in the expansion. The various lines in the diagram correspond to factors within those terms. A certain kind of line/factor has properties which are similar to some of the properties of a real photon, so for convenience in labeling, we call it a "virtual photon".

I think most of the conceptual problems that people have with virtual photons are caused by trying to make them more "real" than "virtual."

In order to have "real" electromagnetic radiation, you need real photons.

So all force carrier particles are virtual particles?

So one could say all fields are made by virtual photons? These aren't there unless they interact and then they appear real just before their energy is used?

Daevren said:
So all force carrier particles are virtual particles?

Nope,not necessarily.They can be in/out states.

Daevren said:
So one could say all fields are made by virtual photons?

Nope,all fields,at quantum level,are made up of particles we call "quanta".

Daevren said:
These aren't there unless they interact and then they appear real just before their energy is used?

Nah,it's more to it.A particle is real iff is on its mass shell,which,in the case of Feynman diagrams means in/out states.

Daniel.

Let me rephrase, all force carrier particles are at some point virtual?

But quanta are photons?

The last bit doesn't make sense to me.

This isn't helping. Are these questions good to ask or am I missing some point? Could someone explain this in some detail? Or is it really all abstract math that cannot be translated into words or concepts?

Daevren said:
Let me rephrase, all force carrier particles are at some point virtual?

Yes,in some diagrams,they are.

Daevren said:
But quanta are photons?

More like the other way around.Photons are light quanta.

Daevren said:
This isn't helping. Are these questions good to ask or am I missing some point? Could someone explain this in some detail? Or is it really all abstract math that cannot be translated into words or concepts?

It is abstract math.As for explaining,what level of mathematics & physics education do you have...?

Daniel.

I am not a physics student.

More like the other way around.Photons are light quanta.

So quanta are packets of energy and photons are packets of energy in EM form?

I am not looking for a explanation of the in-detail QM effects. I just want an answer to the original question. That seemed pretty basic.

Daevren said:
I am not a physics student.

Okay.

Daevren said:
So quanta are packets of energy and photons are packets of energy in EM form?

That's right.

Daevren said:
I am not looking for a explanation of the in-detail QM effects. I just want an answer to the original question. That seemed pretty basic.

Daniel.

So energy is stored in a field in the forms of quanta and these can become virtual or real photons in some situations?

Also, how similar are the photons we know as EM radiation and the virtual photons that are EM force carriers? The one is a mathematical construction and the other is visible depending on its frequency. So the last one must be real, right?

Hmm it seems I really want to know this stuff but my math might not allow it. Could someone give me a page that goes into some of this stuff? I looked at wikipedia and I didn't find anything I was looking for.

Then I can see how far I can understand this. I don't want to ask someone to type out all kinds of stuff for nothing.

## 1. What is a photon as a force carrier particle?

A photon is a type of elementary particle that is known to be the force carrier for the electromagnetic force. It is the smallest unit of light and has zero mass and charge.

## 2. How does a photon act as a force carrier particle?

As a force carrier particle, a photon mediates the electromagnetic force by transmitting energy and momentum between charged particles. This allows for the interaction and attraction/repulsion between charged particles.

## 3. What are the properties of a photon as a force carrier particle?

In addition to having zero mass and charge, a photon also has a spin of 1 and travels at the speed of light. It also has wave-particle duality, meaning it can behave as both a particle and a wave.

## 4. What is the role of a photon in the Standard Model of Particle Physics?

The Standard Model of Particle Physics is a theory that describes the fundamental particles and forces that make up the universe. In this model, the photon is one of the four fundamental force carriers, along with the W and Z bosons (for the weak nuclear force) and the gluon (for the strong nuclear force).

## 5. Can a photon interact with other particles besides charged particles?

While the primary role of a photon is to mediate the electromagnetic force between charged particles, it can also interact with other particles such as neutrinos and other photons through processes like scattering. However, these interactions are typically much weaker than those involving charged particles.

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