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2: these runs were simulated with both std and LE physics. we observe no big effect below 10GeV, as expected, but we find a surprising increase in number if hits which gets closer to the data as energy increases. I have put all reports here http://www.pi.infn.it/~sgro/reports_EleLowEnergy_16_4_08.zip^{Image Removed}

3: left is tower not hit by the beam, right is tower hit by the beam; top is cluster, bottom is hits. interesting to notice that red curve for cluster matches better data (black)

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Philippe (PB): we know, at least for energy discrepancy, that we will need to add some material in front of the CU, I showed some time ago that if you add 10%X0 the cluster nb gets into agreement with data, so at least for 50GeV, where you have a perfect matching, you will loose agreement with extra material - so we need to keep this in mind (see https://confluence.slac.stanford.edu/download/attachments/13893/beamtestmeeting_20071107.pdf?version=1^{Image Removed})

Johan (JB): i do not remember that, but at some point there was some plot suggesting that at SPS we might have too much mnaterial in the beam line, which was provoking some spread of the beam with wrong divergence, so we do not know yet if and how much material we have to add for the SPS simualtion. For cuts, we use 10um, as usual, and showed many times that going below this does not make any change; i am currently in touch wiht Vladimir Ivantchenko at CERN, and he is suggegsting some test with configurable parameters to understand where these changes come from. I plan to make these test in the CU standalone tower simulation, at that point it will make sense to test different geometries as Leon suggest

David (DP): I had found no difference when changing production cuts, although I did not check with LE phsyics (see here https://confluence.slac.stanford.edu/download/attachments/4096462/Check_ProdTh_Geant4_2008_02_06.pdf?version=1^{Image Removed}). Did you check what happens with runs with energy>50GeV?
CS: yes, you can find plots for all those runs in the link I pasted in the chat window, I just selected two representative runs
DP: is the agreement that you find good at high energy? is there a different behaviour?
CS: agreement is good at any energy>20GeV; there is something strange in the sim at the highest energy, slightly worse than 50GeV, but anyway better than std physics