Normal State Spin Dynamics of Five-band Model for Iron-pnictides

Normal state (assuming absence of SC or AF order) spin dynamics of iron-pnictide superconductors is discussed by calculating spin structure factor $S(q,\omega)$ in an itinerant five-band model within RPA approximation. Due to the characteristic Fermi surface structure of iron-pnictide, column like response is found at $(\pi,0)$ in extended Brillouin zone. This is consistent with recent neutron experiments. Furthermore, we show that the temperature dependence of inelastic neutron scattering intensity is reproduced if we set interaction parameters appropriately.