1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Selection Rules (Electric Dipole)

  1. Nov 10, 2005 #1
    Hi, I have a question on selection rules for electric dipole transitions. It has to do with a GRE Physics exam question that's confusing a number of students at grephysics.net ... if any of the quantum guru's here would like to help, please check it out at http://grephysics.yosunism.com/disp.php?yload=prob&serial=1&prob=92

    thank you.
     
  2. jcsd
  3. Nov 10, 2005 #2

    CarlB

    User Avatar
    Science Advisor
    Homework Helper

    The problem has to do with an excited atom that emits a photon. Spin doesn't contribute to the energy and so cannot provide a reason for a photon to be emitted. Intuitively, spin just doesn't get you going in the direction you need to go.

    This wouldn't be the case if you were in a strong magnetic field, by the way.

    Carl
     
  4. Nov 23, 2005 #3
    what about delta j and delta n?

     
  5. Nov 27, 2005 #4

    CarlB

    User Avatar
    Science Advisor
    Homework Helper

    Since j and n do contribute to the energy (unlike spin).

    The reality is that there are always going to be some problems on the GRE that you're just not going to get right because the authors were too esoteric in their problem writing. There's probably some text out there that stresses this particular analysis.

    The sad fact is that there are many analyses of basic physics in standard textbooks that are completely wrong. This doesn't stop them from asking you questions about it. But in this case, I think the answer is correct, but the problem is unnaturally difficult.

    Carl
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Selection Rules (Electric Dipole)
  1. Selection rule (Replies: 3)

Loading...