  We investigate models in which inflation is driven by a single geometrical
tachyon. We assume that the D-brane as a probe brane in the background of
NS5-branes has non-zero angular momentum which is shown to play similar role as
the number of the scalar fields of the assisted inflation. We demonstrate that
the angular momentum corrected effective potential allows to account for the
observational constraint on COBE normalization, spectral index $n_S$ and the
tensor to scalar ratio of perturbations consistent with WMAP seven years data.
