Properties of Baryons from D-Branes and Instantons

We give a brief summary of our recent works [H. Hata, T. Sakai, S. Sugimoto and S. Yamato, Prog. Theor. Phys. 117 (2007), 1157; hep-th/0701280. K. Hashimoto, T. Sakai and S. Sugimoto, arXiv:0806.3122] on the baryons in holographic QCD [T. Sakai and S. Sugimoto, Prog. Theor. Phys. 113 (2005), 843; hep-th/0412141; Prog. Theor. Phys. 114 (2005), 1083; hep-th/0507073]. In the holographic description, meson effective action is given by the five dimensional Yang-Mills - Chern-Simons theory in a certain curved background. The baryon is described as a soliton carrying an instanton number on the four dimensional space. By quantizing the soliton, we obtain various baryon states and calculate static quantities such as charge radii, magnetic moments, axial coupling, etc.