Talk:Neutron electric dipole moment

This article should list the current neutron EDM limit listed by the particle data group http://pdg.lbl.gov/ in their "baryons" listings:

Electric dipole moment d < 0.29 × 10−25 e cm, CL = 90%

Kaplan1958 (talk) 19:18, 20 September 2008 (UTC)[reply]

There is an apparent inconsistency between the section entitled "Strong CP Problem" and the previous two. The strong interactions are part of the Standard Model, and the section on it states that the "natural" value of CP violation in it is of order 1, so wouldn't it be more accurate to state that there is no Standard Model prediction for the EDM? The axion, introduced as a possible solution to the strong CP problem, has never been observed and is not normally considered to be part of the Standard Model.

Dusty14 (talk) 14:19, 14 February 2011 (UTC)[reply]

If I have read the article correctly, one is for the electroweak interaction, the other is for the strong interaction. So, the different values are for different interactions.-LaoChen (talk) 04:40, 15 February 2011 (UTC)[reply]

T violation

The discussion of why a nonzero EDM for the neutron violates P and T (and thus CP) is not strictly true: for a spin-1/2 particle the only axis of quantisation -- and thus the only well defined direction -- is proportional to its spin. Hence, we have to define the EDM d to be along that axis; the term entering the Hamiltonian is -d.E, which is T-odd and P-odd. Acting with T reverses the neutron's spin and thus d; acting with P reverses the direction of E -- hence giving rise to the CP violation. (http://arxiv.org/pdf/0709.3100v3) I'm not convinced by the magnetic moment picture painted, and I may well update the page after consulting with my more learned colleagues. 129.67.119.242 (talk) 19:18, 20 June 2011 (UTC)[reply]

Internet meme

sigh* NEDM,The internet meme, the Cat,the heavy metal song...Sandbag for smash bros 4 16:49, 27 November 2012 (UTC) — Preceding unsigned comment added by Jowee the Raposa (talk • contribs)