Complete dipole response in 208Pb from high-resolution polarized proton scattering at 0 circle

In proton scattering at angles close to 0 circle one can selectively study dipole modes which, apart from the isovector giant dipole resonance, are poorly understood. Recent experimental progress at RCNP Osaka, Japan, allows measurements with intermediate-energy polarized beams at very forward angles including 0 circle combined with high energy resolution of the order ΔE/E∼8.10-5. This new experimental opportunity was applied to study soft electric dipole modes such as Pygmy Dipole Resonance (PDR) and the so-called toroidal mode. The preliminary data analysis indicates that at very forward angles 1- states are strongly excited via Coulomb interaction. The extracted B(E1) transition strengths are in a good agreement with data obtained from a nuclear resonance fluorescence experiment. E1/M1 contributions are separated based on multipole decomposition of a cross section angular distributions and utilizing spin-transfer observables.