  We apply the coherent state approach to study the noncommutative scalar field
theory with $\phi^4$ self-interaction and Yukawa coupling to the spinor field.
We verify that, contrarily to the commutative result, the scattering amplitude
is ultraviolet finite. However, the $\frac{1}{\theta}$ singularities arise as
the noncommutative parameter $\theta$ tends to zero. For a special relation
between two couplings, these singularities are shown to be cancelled, partially
in the massive case and totally in the massless case.

High Energy Physics - Theory