What would happen if an incredibly high energy photon passed through a human body?

What would happen if an incredibly high energy photon passed through a human body (or any other material)? When I say incredibly high energy photon, I mean higher than any known energy scales... higher than electronic energy scales, higher than nuclear transition energies, etc...

In my mind, I pictured the photon tearing apart whatever it passed through. However, browsing Wikipedia's article on the Photoelectric Effect, I noticed that the cross section went as $1/E^p$, where I think $E$ is energy and $p$ is some number. So, the probability of an atom being ionized by a high energy photon actually drops with the photon energy (although I don't know what approximations went into this calculation... first order perturbation theory?). If the other light-matter interaction processes also have cross sections of the form $1/E^p$, then an incredibly high energy photon would pass through us without harming us!

Or maybe this question is unanswerable because we don't yet understand physics at such high energy scales. What are your thoughts on this? What do you think would happen if an incredibly high energy photon passed through a human body?

• Please specify the energy of this "incredibly high" energy photon. Also, give the link from where you got $\frac{1}{E^P}$. And then use both of these to work out the effect. I'm just guessing, but it should be like a very very small hole through your body. – Hasan Jan 3 '14 at 11:44
• Related: physics.stackexchange.com/q/6435. – dmckee Jan 3 '14 at 17:05