In this paper, we study the properties of baryons by using a holographic dual of QCD on the basis of the D4/D8-brane configuration, where baryons are described by a soliton. We first determine the asymptotic behavior of the soliton solution, which allows us to evaluate well-defined currents associated with the U(N_f)_L × U(N_f)_R chiral symmetry. Using the currents, we compute the static quantities of baryons such as charge radii and magnetic moments, and perform a quantitative comparison with experiments. It is emphasized that not only the nucleon but also excited baryons, such as Δ, N(1440), N(1535), etc., can be analyzed systematically in this model. We also investigate the form factors and find that our form factors agree well with the results that have been well established empirically. Using the form factors, the effective baryon-baryon-meson cubic coupling constants among their infinite towers in the model can be determined. Some physical implications following from these results are discussed.
Progress of Theoretical Physics
- Pub Date:
- December 2008
- High Energy Physics - Theory;
- High Energy Physics - Phenomenology;
- Nuclear Theory
- Latex 2e, 45 pages, v2: a figure is added to compare electromagnetic form factors with a dipole profile, v3: version published in PTP, v4: magnetic moments of Delta corrected