Hi!
Following Richard's suggestion at the last Collaboration Meeting, I did
the inverted B case for e-p elastic again (I was not sure then about the
results with the final geometry for that case).
Plots can be seen at:
http://einstein.unh.edu/~adrian/eloss/EPEL/maxBinvfield/
Comparing the event number with the normal B case, and noticing that some
protons barely make it to the TOFs (as it was the case for the deuteron),
I conclude that this does not help us at all, it is worse: due to the
different angle of incidence, now we get to see the energy loss effect for
the protons too (please remember Chi's argument for the deuteron inverted
B case).
Also, one issue John wanted addressed was: for the normal B case, what are
we losing due to the field (electrons or protons)? That issue comes from
the fact that in either case we lose the coincidence trigger - no e-p
events.
I added a couple of fictitious TOFs:
- TOF # 17 in the forward direction;
- TOF # 18 in the backward direction;
Numbering them like this (instead of a normal sequence) turned out to make
it easier for me to see what was going on.
Results can be seen at:
http://einstein.unh.edu/~adrian/eloss/EPEL/eORp/
>From the plots we can see that adding a TOF in the backward position did
not make much of a difference. Adding a TOF in the forward position did
help - please notice the huge electron peak in TOF #17.
So my conclusion is that, in the normal B case, we lose the electrons that
get bent too much inward - thus losing the corresponding e-p trigger for
slow protons (low q2).
As John mentioned before, we will get that region back when we run 440 MeV
beam...
Adrian
PS: I was planning on mentioning these results at Bates on Wednesday.
Unfortunately, I cannot make it due to a car problem I discovered a short
time ago (big coolant leak under my car - which explains why it was
overheating two days ago :-( while driving to Portsmouth)...
-------------------------------
Adrian Sindile
Research Assistant
Nuclear Physics Group
University of New Hampshire
phone: (603)862-1691
FAX: (603)862-2998
email: asindile@alberti.unh.edu
http://einstein.unh.edu/~adrian/
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