  We present an Angle-Resolved PhotoElectron Spectroscopy study of the changes
in the electronic structure of electron doped Ba(Fe(1-x)Co(x))2As2 across the
superconducting phase transition. By changing the polarization of the incoming
light, we were able to observe the opening of the gap for the inner hole pocket
alpha, and to compare its behavior with the outer hole-like band beta.
Measurements along high symmetry directions show that the behavior of beta is
consistent with an isotropic gap opening, while slight anisotropies are
detected for the inner band alpha. The implications of these results for the
s+/- symmetry of the superconducting order parameter are discussed, in relation
to the nature of the different iron orbitals contributing to the electronic
structure of this multiband system.
