Time evolution of the fission-decay width under the influence of   dissipation
  Different analytical approximations to the time-dependent fission-decay width used to extract the influence of dissipation on the fission process are critically examined. Calculations with a new, highly realistic analytical approximation to the exact solution of the Fokker-Planck equation sheds doubts on previous conclusions on the dissipation strength made on the basis of less realistic approximations. 
B. Jurado, K.-H. Schmidt, J. Benlliure