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This data was made by fitting a double gaussian to invariant mass histograms in various cases and pile up ranges. The trend shows as pile up and |h| increases, so does mass peak width. The first case is all events. The second is events in which both electrons go into the barrel. Then when one electron goes into the barrel and one into the endcap, and finally when both go into the endcap. The dielectron data showed that the resolution in the barrel fit a constant and did not significantly change due to pile up. This is consistant here as events with both electrons in the barrel do appear to reasonably fit a constant across different pile up simulations. When one electron is in the endcap then the pile up has a much larger effect because it appears that the endcap is effected by pile up to a much greater extent. Where as when both electrons are in the barrel the mass peak becomes difficult to fit. It is reasonable to say that peak width and thereby resolution is worse, however it is difficult to quantify.
