Tachyon Solution in Cubic Neveu-Schwarz String Field Theory
  A class of exact analytic solutions in the modified cubic fermionic string field theory with the GSO(-) sector is presented. This class contains the GSO(-) tachyon field and reproduces the correct value for the nonBPS D-brane tension. 
Irina Ya. Aref'eva, Roman V. Gorbachev and Peter B. Medvedev