Hi, recently we found that the beam-target vector asymmetry produced by
blast monte carlo bears the wrong sign.
This problem is checked out and fixed today. Interestingly, it was
corrected, and at a certain point, "HEL1 -= ..." was "corrected" to
"HEL1 += ..."
With this fix, we are able to reproduce the figures in
Arenhovel's paper: Z.Phys.A - Atomic Nuclei 331, 123(1988) see also the
Erratum: Z.Phys.A - Atomic Nuclei 334, 363-364(1989)
A script PlotEEPAsym.C is added into DGen to produce those two figures and
it could be modified to plot asymmetries against other kinematic
variables.
The script generates 8 figures, they are:
AdT vs. theta_cms calculated by DGen, in parallel and perpendicular kinematics.
AedV vs. theta_cms calculated by DGen, in parallel and perpendicular kinematics.
AdT generated by DGen (i.e. histogramming the generated theta_cms, and use
Jason's GetAsymmetry() to get asymmetry, the way one would do to get
asymmetry from data). in both kinematics
AedV generated by DGen in both kinematics.
The tensor generated asymmetry is not done properly since GetAsymmetry()
does not handle spin states other than 1. but it gives a general check
that the asymmetry is generated with correct sign, and evolution against
kinematic variables. I invite people to correct it.
In order to reproduce Arenhovel's plots, I have to change the kinematics
range set in kine.init:
#EEP_KINE # max values
6 0 -3 3 # 6, number of points in phi_e is 6*2
10 0 -180 180 # 10
20 0 0 180 # 20
20 1 0.0 0.25 # 20
20 1 24.5 60 # 20
because the kinematics in those plots are not at the most significant
region for BLAST.
The eep Monte Carlo for blast common use will be regenerated some time
later today.
Chi
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