[Frost] Vertex shift

[Michael Dugger]

Hi,

I think I messed up when writing about the effect of a shifted vertex on 
the eloss calculation. For forward going protons, a z-vertex shifted 
upstream would result in ALL of these protons getting over corrected. This 
of course assumes that all of the z-vertex are being systematically 
shifted. The case I described in the previous email would make sense if 
only the z-vertex near the upstream end cap where being shifted.

Lately, I can not just write a single email. First I write an email, then 
I write a correction :(

I have to slow down before hitting the enter key!

Take care,
Michael