Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Protons, neutrons mass

  1. Sep 19, 2012 #1
    I was checking and I couldn't find a similar thread so I am going to ask it here.
    I read a paper from Franz Wilczek and I do see that Protons mass comes from the masses of quarks and gluons but they account for only part of the protons mass , so where does the other part comes from , I guess from the kinetic or whatever kind of energy they exert being part of the proton?
    Is this true or not, I just got a little lost while reading maybe you could clear up some things .
  2. jcsd
  3. Sep 19, 2012 #2


    User Avatar
    Science Advisor


    (From the article)

    Quarks and the mass of the proton

    In quantum chromodynamics, the modern theory of the nuclear force, most of the mass of the proton and the neutron is explained by special relativity. The mass of the proton is about eighty times greater than the sum of the rest masses of the quarks that make it up, while the gluons have zero rest mass. The extra energy of the quarks and gluons in a region within a proton, as compared to the rest energy of the quarks alone in the QCD vacuum, accounts for almost 99% of the mass. The rest mass of the proton is, thus, the invariant mass of the system of moving quarks and gluons that make up the particle, and, in such systems, even the energy of massless particles is still measured as part of the rest mass of the system.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook