Delta baryon magnetic moments from lattice QCD
Abstract
Theoretical predictions for the magnetic moments of the physical Δ baryons are extracted from lattice QCD calculations. We utilize finite-range regulated effective field theory that is constructed to have the correct Dirac moment mass dependence in the region where the u and d quark masses are heavy. Of particular interest is the chiral nonanalytic behaviour encountered as the Nπ decay channel opens. We find a Δ++ magnetic moment (at the Δ pole) of μΔ++=(4.99±0.56)μN. This result is within the Particle Data Group range of 3.7-7.5 μN and compares well with the experimental result of Bosshard et al. of μΔ++=(4.52±0.51±0.45)μN. The interplay between the different pion-loop contributions to the Δ+ magnetic moment leads to the surprising result that the proton moment may exceed that of the Δ+, contrary to conventional expectations.
- Publication:
-
Physics Letters B
- Pub Date:
- June 2003
- DOI:
- 10.1016/S0370-2693(03)00418-0
- arXiv:
- arXiv:hep-lat/0302008
- Bibcode:
- 2003PhLB..563..157C
- Keywords:
-
- Effective field theory;
- Lattice QCD;
- Magnetic moments;
- Delta baryons;
- High Energy Physics - Lattice;
- High Energy Physics - Experiment;
- Nuclear Experiment;
- Nuclear Theory
- E-Print:
- 7 pages, 7 figures, RevTex 4