Restriction on relaxation times derived from the Lindblad-type master   equations for 2-level systems
  We discuss a restriction on relaxation times derived from the Lindblad-type master equations for 2-level systems and show that none of the inverse relaxation times can be greater than the sum of the others. The relation is experimentally proved or disproved and can be considered to be a measure for or against the applicability of the Lindblad-type master equations and therefore of the so-called completely positive condition. 
Gen Kimura (Waseda Univ., Tokyo, JAPAN)