There was someone who once got hit by a particle beam in the USSR, albeit of much lower energy. It seems to have made a high-aspect ratio, extremely deep but localized radiation burn. I.E. Burning a hole in him. He did live, but had permanent injuries and... weirdness happen to that side of his face and I think even seizures.
Of course, with just 1 singular particle, the energy would be on the order of like a microjoule or so, so it wouldn't do much damage, probably heat up your hand or kill a few cells or something. It also depends on whether, after going through your hand and depositing a small fraction of it's kinetic energy, it got to go back around the loop multiple times and continue repeatedly being slowed in your hand.If it weren't moving so fast, you'd normally imagine that it would just stop dead in it's tracks after getting nanometers into you and making an explosion, but I think at that speed, the cross section of an atom that could actually have much of an effect on it's trajectory is much smaller. It probably would have to hit the nucleus, and even then, I'm not sure if that would be "solid" enough to stop them from passing straight through each other and just heating up or being blown to smithereens, but nonetheless, not fully "colliding."
Basically, Newton's penetration depth calculation is utterly worthless here because the particles aren't colliding, they are going through each other, so it'd probably go through you, depositing a few GeV.
