D-branes as unstable lumps in bosonic open string field theory

We construct Dp-branes in bosonic string theory as unstable lumps in a trun cated string field theory of open strings on a D25-brane. We find that the lowest level truncation gives good quantitative agreement with the predicte d D-brane tension and low-lying spectrum of the D-brane for sufficiently la rge p and study the effect of the next level corrections for p = 24. We sho w that a U(1) gauge field zero mode on the D-brane arises through a mechani sm reminiscent of the Randall-Sundrum mechanism for gravity.