Abstract
The outcome of the SAMPLE experiment suggests that the strange-quark contribution to the nucleon magnetic moment, may be greater than zero. This result is very difficult to reconcile with expectations based on the successful baryon magnetic-moment phenomenology of the constituent quark model. We show that careful consideration of chiral symmetry reveals some rather unexpected properties of QCD. In particular, it is found that the valence u-quark contribution to the magnetic moment of the neutron can differ by more than 50% from its contribution to the magnetic moment. This hitherto unforeseen result leads to the value with a systematic error, arising from the relatively large strange quark mass used in existing lattice calculations, that would tend to shift towards small positive values.
- Received 30 December 1999
DOI:https://doi.org/10.1103/PhysRevD.62.074505
©2000 American Physical Society