Hi, Z dependent spin angle is added to DGen
It is implemented under the "white" mode, i.e. mode number 2. use
KINE 10 1 1 1 45 0 0 2 11
^^^
an aditional block to kine.init is added:
#TARGET_SPIN_ANGLE_PROFILE
-15 -10 0 10 15
47 45 47 45 47
Vitaliy, please put in correct spin angle profile from the survey. the
first line is the Z position, second is spin angle. each line can contain
arbitrary number of entries. DGen will SPLINE the profile and
interpolate/extrapolate this profile for arbitrary Z location.
In white mode, events are generated with uniform distribution. DGen will
pass spin 3 states of currnet event and two cross section values to
blastmc and then into lr ntuple through recon. in lr ntuple the MC spin
states appear in entries "pe:pz:pzz", the cross sections are in "xs:xs0".
xs is the polarized cross section with current spin state, "xs0" is the
unpol value.
spin angle is set per event, and cross sections are calculated per event.
Currently, function to calculate per event cross section Elastic and EEP
is only implemented for elastic and EEP channel. Mott/Maid/Epel will
follow.
MAKE SURE this line appears in your fort.99:
VERT -1
When reconstructing asymmetry from data generated this way, use the
following command in ROOT
lr->Draw("twl", "(pzz>0&&qwl==-1&&qwr==1&&ntl>-1&&ntr>-1)*xs");
note the "(...)*xs" in the cut.
MAKE SURE to generate enough many events. If one of your bins receives 100
events, the error will be 10%. At low Q2, this could be significant. It
took me a few days to realized this.
Chi
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