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

Neutron precession?

  1. May 11, 2008 #1
    We all know that the magnetic moment is (gq/2m)J, so then why does a neutron precess in a magnetic field if q=0? This should cause the Hamiltonian to be 0.
  2. jcsd
  3. May 11, 2008 #2
    neutrons precess in a magnetic field?
    neutrons aren't even stable alone... can you elaborate on the background?
  4. May 11, 2008 #3
    Hmm... ok, so I think I figured it out. Even though it is uncharged, it has charged quarks. Unlike the electron, neutrons aren't elementary so I can't think of them in that way. This explains why it does precess, as my paper indicates you can actually observe the interfence pattern caused by a 2pi rotation (which introduces the new wavefunction to be the negative of the original).
    Last edited: May 11, 2008
  5. May 13, 2008 #4


    User Avatar

    Your formula (gq/2m)J is a classical oversimplification. For neutral (or charged) particles,
    the magnetic moment is written as (mu)e/2m, where e is the magnitude of the electron charge, and e/2m (the nuclear magneton for hadrons) is just a convenient scale factor. In these units mu=+2.79 for the proton and -1.91 for the neutron.
  6. May 13, 2008 #5
    Quark charge has an appreciable effect on the motion of a neutron in a B-field?
    Thats cool... can you site the article?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook