An sp type surface state has previously been reported at the YBAR point of the surface Brillouin zone of the Au(110) surface, and was associated with a gap in the calculated projected density of states of the unreconstructed surface occurring at the YBAR point of the (1x1) surface. More recent calculations, taking account of the true (1 x 2) structure of the surface, predict that there is no surface state at the YBAR point. We have carried out a detailed experimental investigation of the electronic structure of this system using angle-resolved photoemission excited by He I, Ne I and Ar I radiation and find no evidence for a surface state at the YBAR point, in accord with the calculations. A feature observed at the Fermi level with He I radiation is interpreted as photoemission from the d-band excited by He I beta-radiation. Features observed with Ne I and Ar I radiation in various parts of the Brillouin zone are interpreted as direct transitions in the bulk. This indicates that the reconstruction changes the electronic structure of the surface so that a surface state in the projection of the L gap does not occur.
