When mass disappears during fission, that mass is replaced by energy (according to E=Mc2). What happens to the quarks that make up the mass/particles that disappear?
The “mass” is actually binding energy. What happens in fission is a separation of a single proton/neutron cluster into two. Once this separation is large enough electrostatic repulsion from the the new new proto-nuclei will overcome the strong nuclear binding force. The difference is basically what gets released as energy.
Quarks make up hadrons like protons and neutron and don’t really play a role in fission. They tend to be paired and interestingly enough, if you pull them apart, so they normally would be considered independent, the energy you put into the system is enough to cause new quarks to appear and and pair up with your original two.
Nothing. The majority of the mass is the energy in the binding of the quarks together (embodied as the colour force) in either a meson or a baryon. The actual mass of the quarks is the minority of the mass. The energy that is released in fission is some of this energy.
The number of quarks doesn’t change - three per baryon - and since the number of protons and neutrons hasn’t changed, the quarks are undiminished. But the geometry of the nuclei they find themselves in has changed, and the amount of energy holding the mess together is less than before. So overall there is less mass. The energy change is in the bit of the colour force that is holding the protons and neutrons together - which can be called the residual strong force .
I should clarify, quarks make up hadrons which include mesons (made up of 2 quarks) and baryons (made up of 3 quarks). There have been 4-quark and 5-quark particles created in labs but those are fairly exotic.
The important aspect is that in relativity, (rest) mass is not additive. I.e. a compound object composed of two sub-objects of mass M1 and M2 does not necessarily have mass M1 + M2.
For most objects we have day-to-day experience with, the difference in mass is very, very slight. But nuclei aren’t like most objects so the difference between the mass of nucleus and the mass of its individual quarks is noticeable. Protons and Neutrons are even more extreme, and their mass is hugely greater than the mass of the constituent quarks.
Given that, breaking apart a nucleus and finding out that the mass of the components is not as much as the mass of the original nucleus doesn’t mean that some discrete piece has been lost.
So, are the quarks immortal? If you accelerate them, do they gain mass?
Only if there is some profit potential for them.
The only way to be rid of quarks is to react them with the corresponding antiquarks, and the only way to produce new ones is likewise to create them in quark-antiquark pairs.
And like any other form of matter, if you accelerate them, they gain energy, but not mass. That’s a common misconception, unfortunately common enough that it makes it into many textbooks. Well, it can be true, if you define “mass” in a particular way, but that definition is completely unhelpful for any other purpose.
Do quarks also have Buddha-nature?
Mu.
EDIT:
Although, they do follow the Eightfold Way.
I believe the way this goes that its relativistic momentum increases, and if you use the non-relativistic equation relating velocity, mass, and momentum, it looks like an increase in mass.
A question on this comment from an uneducated - specifically on this line:
Despite the mass of the quarks being very very small, it still ‘is’. How does the process of inputting energy manufacture new quarks - essentially turning energy into matter? Is this a physical reality? What are the losses and gains associated with it, do they relove around e=mc2 like the opposite conversion?
Yup, it works exactly the same way going in either direction.