# nucleon constituents

by mathman
Tags: constituents, nucleon
 Sci Advisor P: 5,892 I understand that nucleons (protons and neutrons) consist of 3 valence quarks and a sea of other stuff, virtual quark-antiquark pairs and gluons. Question: are the virtual quarks only up and down or may there be heavier quarks?
HW Helper
PF Gold
P: 2,606
 Quote by mathman I understand that nucleons (protons and neutrons) consist of 3 valence quarks and a sea of other stuff, virtual quark-antiquark pairs and gluons. Question: are the virtual quarks only up and down or may there be heavier quarks?
All flavors contribute because of $g\leftrightarrow q\bar{q}$ processes. A quick search didn't turn up any sort of canonical reference, but http://cerncourier.com/cws/article/cern/29441 explains some experimental measurements related to the strange component of the proton.
 Mentor P: 10,534 This pdg review has (predicted) parton distribution functions on page 12. Heavier quarks are suppressed, but they are present.
P: 5,892

## nucleon constituents

 Quote by fzero All flavors contribute because of $g\leftrightarrow q\bar{q}$ processes. A quick search didn't turn up any sort of canonical reference, but http://cerncourier.com/cws/article/cern/29441 explains some experimental measurements related to the strange component of the proton.
I would guess that it is possible that the other heavier quarks may be present, but the experiments might be difficult. Maybe LHC might find something?
 Sci Advisor P: 3,717 Naturally if you hit a proton hard enough, heavy quarks will be produced. I thought your question was, is there a significant percentage of heavy quarks already in the proton. And to answer this, as described in the ref, you want to do low energy experiments with high accuracy.