The thickness of material (defined as the sum of the density times step size) for volumes within the inner region of STAR is plotted.  We compare the y2014 geometry to the y2013 geometry with and without the pixel detector.  Figure 1 shows the thickness encountered in passing through the IDSM.  The plots show the material distribution vs eta on the left, averaged over all phi.  On the right, the plot shows the material vs phi, averaged over the eta range [-1, 1].  The solid black and dashed red histograms correspond to the y2014a geometry.  Figure 2, 3 and 4 show the pixel, ist and ssd detectors respectively.

Black: y2014a ROOT geometry (input to reco)
Red: y2014a GEANT geometry (input to simu)
Blue: y2013_1c ROOT geometry (pixel in)
Green: y2013_2c ROOT geometry (pixel out)

Figure 1 -- Left (right) panel shows the material thickness vs eta (phi) for all volumes within the IDSM.  The black histogram corresponds to the y2014a ROOT geometry.  The red dashed histogram is the y2014a GEANT geometry.  The blue histogram is the y2013_1c geometry (pixel in).  The green histogram is the y2013_2c geometry (pixel out).



Figure 2 -- Left (right) panel shows the material thickness vs eta (phi) for all volumes within the PXMO (pixel mother).  The black histogram corresponds to the y2014a ROOT geometry.  The red dashed histogram is the y2014a GEANT geometry.  The blue histogram is the y2013_1c geometry (pixel in).



Figure 3 -- Left (right) panel shows the material thickness vs eta (phi) for all volumes within the IBMO (ist mother).



Figure 4 -- Left (right) panel shows the material thickness vs eta (phi) for all volumes within the SFMO (ssd mother).



Conclusions:

1) There is no difference between the ROOT and GEANT geometries.  We have no evidence of a problem with AgML source translation.
2) There is approximately 2x as much material in the central region for the y2014 geometry as compared to y2013 w/ pixel in.  This is consistent with adding support cone and pixel plus 1 g/cm^2 of additional material in the ist and ssd.