  The finite temperature spectrum of pseudo-scalar glueballs in a plasma is
studied using a holographic model. The $ 0^{-+}$ glueball is represented by a
pseudo-scalar (axion) field living in a five dimensional geometry that comes
from a solution of Einstein equations for gravity coupled with a dilaton scalar
field. The spectral function obtained from the model shows a clear peak
corresponding to the quasi-particle ground state. Analysing the variation of
the position of the peak with temperature, we describe the thermal behavior of
the Debye screening mass of the plasma. As a check of consistency, the zero
temperature limit of the model is also investigated. The glueball masses
obtained are consistent with previous lattice results.
