Cross Sections and Spin Asymmetries for Electron Collisions with Lead Atoms

We present integrated and angle-differential cross sections as well as spin asymmetries for elastic and inelastic electron collisions with lead atoms. The results were obtained using the fully relativistic convergent close-coupling (RCCC)~[1] and the Dirac B-spline R-matrix (DBSR)~[2] methods. They will be compared with experimental data and predictions from previous calculations. In particular, we find substantial discrepancies regarding the normalization of the experimental data at a number of energies for elastic and excitation cross sections. The spin asymmetries for the optically forbidden inelastic transitions from the (6p$^2$)$^3$P$_0$ ground state to other states of the 6$p^2$ manifold, measured by Geesmann {\it et al.}~[3], are known to be very challenging for theory~[4]. We analyze the sensitivity of the predictions to the quality of the target description as well as the number of channels included in the close-coupling expansion. [1] D.\ V.\ Fursa and I.\ Bray, Phys.\ Rev.\ Lett.~{\bf 100} (2008) 113201. [2] O.\ Zatsarinny and K.\ Bartschat, Phys.\ Rev.\ A~{\bf 77} (2008) 062701. [3] H.\ Geesmann, M.\ Bartsch, G.\ F.\ Hanne, and J.\ Kessler, J.\ Phys.\ B~{\bf 24} (1991) 2817. [4] O.\ Zatsarinny, Y.\ Wang, and K.\ Bartschat, J.\ Phys.\ B~{\bf 46} (2013) 035202.