2

I just read that the mass of a proton is one hundred times more than the sum of the masses of the quarks composing it. Now, I know that these numbers (the mass of the proton and the sum of the masses of the quarks) don't need to agree due to E=mc2, but why isn't the mass of the proton less than the sum of the quark masses? I mean, the quarks are obviously bound together to form a proton, and from QM I know that bound states require the total energies to be negative (assuming the potential energy at infinite separation is zero, but I guess that's fair if the strong force goes to 0 as the distance between two interacting particles, two quarks in this case, goes to infinity). In other words, the sum of the kinetic and potential energies of the quarks should be negative, causing the mass of a proton to be less than the masses of the quarks. This is similar to how the mass of an atomic nucleus is less than the sum of the masses of the protons and neutrons, or that the mass of an atom is less than the sum of the masses of the electrons, protons and neutrons. Why is this totally wrong, and how is it that a proton is as much as a hundred times heavier?

Qmechanic
  • 201,751
Physics2718
  • 115
  • 2
    Related: https://physics.stackexchange.com/q/207644 and links therein (and links therein) – Nihar Karve Feb 08 '21 at 16:25
  • @NiharKarve Actually, the answer you linked to answered my question. Not sure if my question should be closed, or if I should delete it all together. – Physics2718 Feb 08 '21 at 16:39
  • @NiharKarve Oh wait, now it did :) – Physics2718 Feb 08 '21 at 16:39
  • 2
    No need to delete your question (the system would count that as a "negative" entry in your question record), closing as duplicate is the preferred procedure. – ACuriousMind Feb 08 '21 at 16:40
  • @ACuriousMind Okay, thank you. Seems like somebody closed it though, so it's fine now :) – Physics2718 Feb 08 '21 at 16:41
  • Frank Wilczek has some free articles on mass & QCD: http://www.frankwilczek.com/core.html In particular, see The Origin of Mass. Frank's an excellent writer (IMHO), and it's great to read about this stuff from the guy who won a Nobel Prize for it. ;) – PM 2Ring Feb 08 '21 at 16:50
  • this link might interest you https://profmattstrassler.com/articles-and-posts/largehadroncolliderfaq/whats-a-proton-anyway/ – anna v Feb 10 '21 at 05:34

0 Answers0