ECCE production: are the cross sections correct for each Q2 range?

[c-dilks]

The latest ECCE stack production has the following directories:

                10x100-q2-high
                10x100-q2-low
                10x100
                18x275-Lambda
                18x275-q2-high
                18x275-q2-low
                18x275
                5x41-q2-low
                5x41

We need to be able to combine data from differing Q2 ranges together. For ATHENA, this was straightforward since the directories specified the Q2 minimum in the name. For ECCE, however, there are three ranges:

1. q2-low: 1 < Q2 < 100
2. q2-high: 100 < Q2
3. general Q2 -- what is the minimum Q2? Assuming 1 for now, but is that right?

We need the correct cross sections for each of these. In #180 we added the following to datarec/xsec/xsec.dat, being careful to note the FIXME comment:

# Pythia 6, from ECCE production files:
# S3/eictest/ECCE/ProductionInputFiles/SIDIS/pythia6
# FIXME: there are no HEPMC files here, just ROOT files; since the generation
#        of this table requires HEPMC files (`s3tools/get-cross-section-ALL.sh`), for
#        now we just guess the cross section from the corresponding ATHENA Pythia 8
#        production above. These ECCE production files have Q2 maxima, unlike the
#        ATHENA HEPMC files; therefore, the cross sections may be a bit wrong here.
#label                     cross_section_[pb]  relative_uncertainty
pythia6:ep-5x41            4.0012e+05          0.00266   # general Q2
pythia6:ep-5x41-q2-low     4.0012e+05          0.00266   # 1 < Q2 < 100
pythia6:ep-10x100          5.5566e+05          0.00276   # general Q2
pythia6:ep-10x100-q2-low   5.5566e+05          0.00276   # 1 < Q2 < 100
pythia6:ep-10x100-q2-high  1343                0.0023    # 100 < Q2
pythia6:ep-18x275          7.4167e+05          0.00277   # general Q2
pythia6:ep-18x275-q2-low   7.4167e+05          0.00277   # 1 < Q2 < 100
pythia6:ep-18x275-q2-high  3370.2              0.00245   # 100 < Q2

Note that any changes to the Q2 minima values should also be updated in s3tools/make-ecce-config.sh in the following function:

# function to get the Q2 minimum, given subdir $1
function getQ2min {
  if   [[ "$1" =~ "q2-low"  ]]; then echo 1;
  elif [[ "$1" =~ "q2-high" ]]; then echo 100;
  else echo 1  # general Q2 # FIXME: is Q2min=1 correct?
  fi
}

[rseidl-rcf]

sorry, I did not want to close it, just comment.

I will check the cross sections and update the table (they are different - eg 18x275 high 3097, low 8.796e+5). The files without Q2 cut are indeed from 1 GeV upward. We probably also need a similar table for the radcor files that exist at least on the generator level (and eventually also in produced form). In principle all of the originally eic-smear generated files have a TObjectString crossSection, nEvents and nTrials in them but that did not get picked up in the full simulations.