Photoionization of the states in barium: measurements and<b><i>R</i></b>-matrix calculations

Abstract

We have completed both experimental and theoretical studies of the photoionization from the multiplet in barium, in the range 350 - 402 nm, by considering the , and states, after the state which we studied in Carré et al. We have measured differential cross sections from below to above the threshold, where a number of ; J and ; J resonances are excited, for different cases of laser polarizations. Angle-resolved partial cross sections critically depend on both modulus and phase of the dipole moments. The experimental results are compared with eigenchannel R-matrix calculations. The successful comparison performed over a large energy range strengthens the surmise that a good representation of states and final continua has been worked out in the frame of R-matrix formalism.