The thermal mass spectra of scalar and pseudo scalar mesons are studied in an
IR-improved soft-wall AdS/QCD model. The Reissner-Nordstrom AdS black hole
metric is introduced to describe both the finite temperature and density
effects. The thermal spectral function is computed, which shows that the
position of peak moves towards a smaller value and the width of peak also
broadens to a larger value as the temperature increases. The critical
temperature at which the peaks are completely dissolved has been found to be
around T_{c}\simeq 160\sim 200\MeV. The effect of chemical potential is shown
to be the same as the one caused by the temperature. It is found that when the
temperature approaches to zero T≈0, the melting down of mesons occurs
at the scaled critical chemical potential \mu_0/\kappa\approx 2.2\sim 2.4
\GeV.Comment: 13 pages, 4 figure