Since the last look at the simulation set (http://drupal.star.bnl.gov/STAR/blog/ncolmena/2011/jul/06/2nd-attempt-run-6-simulation & http://drupal.star.bnl.gov/STAR/blog/ncolmena/2011/jun/27/run-6-simulation-fit-curious-pion-centroid), it was determined that in the pi0 macro, the vertex was fixed to 0 when the code was run over the set. This time the code was run over the set with it using the pythia vertex distribution instead of fixing it at 0. Although the centroids are not spot-on with the actual pi0 mass, they are much closer and do not exhibit the drastic drift that was seen in the past two looks at the simulation set. Also, a quick look at the efficiencies from the Run 6 simulation yielded a very low value of 5%. This is being investigated and results should be posted in the next blog.

4-5 pT:

5-6 pT:

6-7 pT:

7-9 pT:

9-35 pT: