Classical Solutions and Order of Zeros in Open String Field Theory
  Earlier an analytic approach is proposed for classical solutions describing tachyon vacuum in open string field theory. Based on the approach, we construct a certain class of classical solutions written in terms of holomorphic functions with higher order zeros. Taking the simplest among the new classical solutions, we study the cohomology of the new BRS charge and make a numerical analysis of the vacuum energy. The results indicate that the new non-trivial solution is another analytic candidate for the tachyon vacuum. 
Y. Igarashi, K. Itoh, F. Katsumata, T. Takahashi, S. Zeze