Minutes 20 October 2009

Q=Question
A=Answer
C=Comment

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Sampling Fraction with New Geometry

Ilya C: Rechecked many things- including labels, re-ran cvs version.
Hal Q: Didn't you do this earlier? Where some parts where brighter?
(Link:

http://drupal.star.bnl.gov/STAR/pwg/spin/ilya-selyuzhenkov/photon-jets/2009/10-oct/20091012-jaso

n-eemc-geometry-position-correlations)
Ilya A: Was EEMC only and number of hits.
Scott Q: Is z-scale the same on all?
Ilya A: Yes
Jim Q: Which geometry year?
Ilya A: 2006.  Double checked all 2006 LOW_EM option.
Jim Q: Can you run with 2009 geometry?
Ilya A: Yes, how would it help?
Jim A: Something to check with a change.
Ilya C: Strange SMD is consistent, but not towers.
Jim Q: Why is 2nd preshower so different from 1st?
Ilya A: y-axis scale is different (see 10^-3) in left plot
Scott Q: Why any difference at all in preshower?  Wasn't all difference put in the SMD layer?
Jason A: Some minor changes: changes to steel structure, changed depth of polystyrene in

scintillator
Will Q: Any change in thickness of polystyrene on either side of tiles?
Jason A: No
Jason C: GPrint TMED.  Print tracking parameters at beginning of run and at end of run to see if

LOW_EM option is actually getting picked up.  Also check endcap materials - something strange

outside may be affecting something inside.  Will send in email.
Jim Q: Bright spots on borders and dark centers of tiles?
Ilya A: yes
Scott Q: What is threshold in "towers above threshold" plot?
Ilya A: 3 sigma
Jim Q: How to print out all volumes?
Jason A: Is a command, maybe not useful (TMI).
Jim C: Take stand-alone geometry and change front plate to lead.  Then we would know if material

in front increases sampling fraction or not.  (Should not increase)  Also like to see color

wheels for preshower.
Scott C: Try to figure out at what depth we see the effect.
Jason C: With my current code this is hard to do in Geant.
Hal C: 5 sections: 2 preshower, posthower and 2 towers.  2 tower sections are added together. In

EEmcUtil area.
Will C: Not shown, but postshower isn't crazy looking.
Hal C: When you calculate energy for sampling fraction how many towers do you use?
Ilya A: This is all towers above threshold.  Figure 5 is just the highest tower.
Jim Q: No chance full geometry has defined in it an active volume that shouldn't be there?
Jason A: No.
Jason C: Figure 5 seems to be telling us something opposite figure 2.  Maybe our intuition about

fig 2 is off.
Hal C: Yes, but difference between eemc stand-alone and full is not the same in figure 5 either.
Scott c: Maybe we need to look at MPV and not the mean
Jason Q: How do you determine thrown position?  NO cuts on SMD response?
Ilya A: Geant, no.
Hal Q: Are you losing event from TPC ribs?
Ilya A: Off-scale.
Scott c: Between thrown energy of 20 to 30 make a sampling fraction distribution so we can see

the shape.
Hal Q: Did you change the tower geometry at all?
Jason A: Just added a feature to allow wiggle, but not implemented.
Jim Q: Gap in towers?
Jason A: Isolation groove is there in eta.
Hal C: Figures in addition to s.f. for 1X1 tower - 2x2, etc.
Ilya C: 3x3 similar to figure 2, 2x1 different from both.
Will Q: What about Jan's comment about kONLY="MANY"
Jason A: Yes I use it, you must when volumes overlap.  GEANT says don't because computationally

expensive