  The accretion-powered (non-X-ray burst) pulsations of XTE J1814-338 are
modeled to determine neutron star parameters and their uncertainties. The model
is a rotating circular hot spot and includes: (1) an isotropic blackbody
spectral component; (2) an anisotropic Comptonized spectral component; (3)
relativistic time-delays and light-bending; and (4) the oblate shape of the
star due to rotation. This model is the simplest possible model that is
consistent with the data. The resulting best-fit parameters of the model favor
stiff equations of state, as can be seen from the 3-sigma allowed regions in
the mass-radius diagram. We analyzed all data combined from a 23 day period of
the 2003 outburst, and separately analyzed data from 2 days of the outburst.
The allowed mass-radius regions for both cases only allow equations of state
(EOS) that are stiffer than EOS APR (Akmal et al. 1998), consistent with the
large mass that has been inferred for the pulsar NGC 6440B (Freire et al.
2008). The stiff EOS inferred by this analysis is not compatible with the soft
EOS inferred from a similar analysis of SAX J1808.
