Thank you for attending this meeting and providing suggestions to help me
in this analysis. Here is what I got out of today's meeting (please
update/append as required):
Things to do:
1) Once I get the proper timing calibration (units), look at ADC in the
TOF versus time of flight between TOF and NC bar for the positive tracks.
The TOF adc's should be on scale as opposed to the NC bars for protons.
Also pions should be minimum ionizing and have a TOF->NC flight time
difference on the order of 10 nsec (200 channels) compared to protons.
Protons: beta -> 0.5 or so
Pions: beta -> 0.8-0.9
1.5) Eventually we want to apply timing cuts for consistency.
2) Apply the gpn cuts to hydrogen data to find out whether or not we see
this peak near 100 deg opening angle as with the deuterium data (that
could be due to quasi-free delta production)
3) Determine what the lowest photon energy is that we can detect with
BLAST. I will talk to Adrian about this as he did some energy loss
studies with GEANT.
4) Find out how large are the differential cross sections of this and the
competing reactions.
5) Instead of overlaying Pn and Pn_calc plot Pn-Pn_calc -> it should be a
gaussian. Pn = neutron momentum directly from the ntuple. Pn_calc is
calculated neutron momentum from proton momentum, proton angle, and
neutron angle.
6) Also Chi later made the point that I should talk to Yuan as he is
looking for pions - maybe I could invert his cuts or some aspect of them?
What else was discussed:
What is the nature of this reaction?
Photodisintegration from
electron scattering has the following characteristics:
-related to internal bremsstrahlung
-large impact parameter
-occurs in the limit Q^{2} -> 0 ("quasi-real" photon)
-cross section dominated below 1 degree
*** PLEASE EMAIL ME WITH CORRECTIONS AND COMMENTS: THANKS!! ***
Pete
PS John has just imformed me that he is not convinced that we have the
proper start time. I am adding this to the above list!
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Pete Karpius
Graduate Research Assistant
Nuclear Physics Group
University of New Hampshire
phone: (603)862-1220
FAX: (603)862-2998
email: karpiusp@einstein.unh.edu
http://pubpages.unh.edu/~pkarpius/homepage.htm
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