Simple question about Fourier transform

Question

Let $f (x)=e^{-2\pi x}\mathcal X_{(0,\infty)}(x)$, where $\mathcal X_\Omega (x)$ is the characteristic function of $\Omega$. What is the Fourier transform of $f $? I searched in my notes and in internet too, but I only found results about the Fourier transform of a periodic function; however $f $ is not periodic and it cannot be extended to a periodic function on $\mathbb R$. Can you give me some information? Thank you very much