Log entry time 03:09:56 on March 13, 2012

Entry number 366110

We were looking at Gep optics data (#22220, C12 foil, no LHe), and found
that they are probably from Aluminum.

In Figure 1, the up-left pad dp plot, if the highest peak is C12, then
the most right side peak should be Al, considering the momentum difference. 

Then according to the plot, the large negative VertexZ events mostly come
from the Al elastic peak. If including the central hole cut, Al peak cut,
and negative vz cut all together, vz distribution shows two peaks, which
look like two layers of Al.

Figure 1