High-resolution photoemission study of the ? states on Cu(111)

We report new photoemission results on the well-known d-like "Tamm" surface states at the (M) over bar-points in the surface Brillouin zone of Cu(111). For the first time these states can be resolved at all six M-points. The initial state energy at M is measured at E(i)=(-1.932+/-0.005) eV with respect to E(F). The surface bands disperse towards the upper d-band edge with an effective mass m*/m(0)=-2.86+/-0.20 with reference to the free-electron mass m(0).