How can a single Gluon, spontaneously form itself into a Anti-DownQuark/DownQuark pair Pion?

Question

https://youtu.be/xG_YtASz7gY

In this video made by David Butter, he explains where particles get their energy and mass from.
At 11:30, he mentions the process of a Gluon leaving the Proton and forming a down-quark/anti-down-quark pair. Basically a Pion. Then the Pion drifts into the other Proton.

So how can one particle spontaneously creat another set of particles from itself. Where does the particle get the ingredients to create other particles completely different from itself.

It’s like if I get a Golf Ball, then spontaneously the Golf Ball creates two Basketballs out of nowhere. Where did the Gold Ball get the ingredients to create two entire Basketballs?

In: Physics

Answer 1

>Where does the particle get the ingredients to create other particles completely different from itself.

This is answered by Quantum Field Theory (QFT). It states that particles are just excitation states of those fields, so they can be created simply by interaction with that field. Some additional restrictions apply to keep conservative variables constant in a system.

Imagine those fields like the surface of the ocean, and particles like individual waves on it. Just adding energy causes water to rise in one place, but it must go down in another.

That means particle/antiparticle pairs can spontanously appear all the time, this is called quantum fluctuation. In most cases they quickly annihilate each other again, but there are some cases were one half gets lost to some other process leaving the partner alone.