  One of the goals of the XMM-Newton survey of the Small Magellanic Cloud is
the study of the Be/X-ray binary population. During one of our first survey
observations a bright new transient - XMMUJ004814.0-732204 - was discovered. We
present the analysis of the EPIC X-ray data together with optical observations,
to investigate the spectral and temporal characteristics of
XMMUJ004814.0-732204. We found coherent X-ray pulsations in the EPIC data with
a period of (11.86642 +/- 0.00017) s. The X-ray spectrum can be modelled by an
absorbed power-law with indication for a soft excess. Depending on the
modelling of the soft X-ray spectrum, the photon index ranges between 0.53 and
0.66. We identify the optical counterpart as a B = 14.9mag star which was
monitored during the MACHO and OGLE-III projects. The optical light curves show
regular outbursts by ~0.5 mag in B and R and up to 0.9 mag in I which repeat
with a time scale of about 1000 days. The OGLE-III optical colours of the star
are consistent with an early B spectral type. An optical spectrum obtained at
the 1.9 m telescope of the South African Astronomical Observatory in December
2009 shows H_alpha emission with an equivalent width of 3.5 +/- 0.6 A. The
X-ray spectrum and the detection of pulsations suggest that
XMMUJ004814.0-732204 is a new high mass X-ray binary pulsar in the SMC. The
long term variability and the H_alpha emission line in the spectrum of the
optical counterpart identify it as a Be/X-ray binary system.
