Strong Nuclear Force & Particle Accelerators

[flintstones]

Homework Statement

Explain, in terms of the strong nuclear force, why high-energy particle accelerators are required to study subatomic particles.

Relevant Equations

None - conceptual

I am a teacher and the problem statement is part of our curriculum. I feel like I have a basic understanding of what particle accelerators are, but I only have a vague idea of what the strong nuclear force has to do with this.

Here's what I know:

• In a particle accelerator, you might smash protons together. You have a better chance of 'breaking' the protons apart the faster the protons move. This allows you to study the particles that make up a proton. (Is this even true? I watched a YouTube video that made it sound like this is one use for particle accelerators, but I am not sure how accurate the video was.)

• When you collide particles, the kinetic energy that the particles carry can be converted to mass. So in particle accelerators we can bring particles into existence and then study them. Let's say you want to make a Higgs boson. You will need ~125 GeV of energy, which is pretty big, so it makes sense that the particles need to carry a large kinetic energy before smashing.

Neither of my explanations used the strong nuclear force though. What am I missing?

Also can anyone recommend any good textbooks on the subject of particle physics that I can read over the summer?

 

[MikeeMiracle]

I am no expert but as I understand it...

The strong nuclear force is responsible for holding the different sub particles together that make up the protons and neutrons and I also believe holds the protons and neutrons together in the atomic neucleus. It is the strongest of the 4 fundamental forces of nature but it also works over the smallest range.

You smash the protons together in order to overcome the strong force and shatter the protons and neutrons into their component parts so you can study them. This all happens when you accelerate the particles to close to the speed of light. The energy of the collision determines how much you shatter the protons and neutrons and their sub-components, higher energies allows you to shatter the smaller sub-paricles and study them. I do not believe that you create particles, merely discover them from the shattered remains of the originals which you collided.

The matter creation you refer to I believe is something different. Going back to the strong force, this is only effective at the smallest scales. Protons are positively charged so they naturally repel each other. The challenge is to try and get the particles close enough for the strong force to kick in and join them. This would normally occur at a fraction of the speed of light as if you go too fast you will end up smashing them together and splitting them. I believe the last particle that humanity tried to create was done only using speed's of a tenth of the speed of light.

Again I am no expert and this is just my understanding of how it works, hopefully someone more knowledgeable will answer soon and clarify this.

 

[flintstones]

Thanks! I somehow missed that the strong force holds the sub-particles together that make up the protons and neutrons. That part makes a bit more sense now.

One thing I am still confused about is that if particle accelerators just broke protons and neutrons apart, we'd only see up quarks & down quarks after the collision. But don't we see many other types of particles as well? Where are those particles coming from?

 

[MikeeMiracle]

Another unqualified response from me, but I believe they are beign formed from the remains of the protons and neutrons. The protons and neutrons are actually quite big relatively speaking, its probably best not to consider them as one of the other sub-atomic particles that make up the standard model when trying to picture this in your mind. They are then split into these "standard model" particles and it is those which are made up of the quarks.

To be truthful i am not sure if they split into the other "standard model" particles or the other "standard model" particles form from the remains of the proton split. But it's not a straight "proton to quark" conversion as far as I am aware.

Again I hope someone more familiar with particle physics answers as I also curious to the exact process.