  In the preceding paper (arXiv:1103.0329 [math-ph]) we treated the
Jaynes-Cummings model with dissipation and gave an approximate solution to the
master equation for the density operator under the general setting by making
use of the Zassenhaus expansion.
  However, to obtain a compact form of the approximate solution (which is in
general complicated infinite series) is very hard when an initial condition is
given. To overcome this difficulty we develop another approach and obtain a
compact approximate solution when some initial condition is given.
