[MRadtke]

OK, thanks. I didn’t realize that. So could it be that when that quark decays into an electron (about 200 times lighter than a muon), that electron is moving very fast as opposed to a muon it would change into? To “make up” for the missing mass, so to speak?

[who_would_fardels_bear]

Somewhere there is probably a list, or better yet diagram, that shows all of the ways that particles can change into other particles. I have a book called QED written by Feynman that has a few of the more simple ones. However, it is an introduction and doesn't detail how mass, spin, energy, charge, and momentum are conserved.

BTW, it turns out that due to the uncertainties of quantum mechanics that the number of possible particle transformations is infinite leading to infinities showing up in a lot of the equations. These pesky infinities have to be "normalized" out of the equations in order for them to be useful. This is still a somewhat controversial procedure to this day. So QM is still on somewhat shaky ground despite its seeming ability to be very accurate in certain situations.