Extended AA Processed Data

Extended AA Processing

Data from all run 2 data epochs (run 2a and run 2b pre- and post- 2007 shutdown) have been reprocessed using the fixer release p20.13.02. This fixer release contains several improvements compared to previous (unofficial) extended AA processing passes, including the following.

More robust -- fewer crashes.
Minimum track radius 20 cm.
Better muon matching/reconstruction.
Merging tracks from extended and standard reconstruction.

In this case, fixing consists of basically full reconstruction starting from track reconstruction onward (vertex finding, particle id., etc.).

Input Data for Extended AA Processing

Event Selection

Input data for extended AA processing is the MUinclusive physical skim, the AA_JPSI logical skim (SKIM_AA_JPSI event flag), plus the additional requirement of having a dimuon mass in the range 2.5 to 4.0 GeV. The net effect of these requirements corresponds to the following dimuon mass requirement.

2.5 to 3.6 GeV for run 2a.
2.5 to 4.0 GeV for run 2b.

The difference between run 2a and run 2b is due to the fact that the definition of the SKIM_AA_JPSI event flag changed between run 2a and run 2b. The dimuon mass selection did not impose any muon quality requirment (over and above d0reco) or any vertex requirement. This filtering selects around 2% of the all stream.

Input Datasets

A single input dataset has been defined for each of the three major epochs, as follows.

Run 2a - CSskim-MUinclusive-PASS3-p17.09.xx
Run 2b preshutdown 2007 - CSskim-MUinclusive-PASS2-p21.03.00-allfix2007
Run 2b postshutdown 2007 - CSskim-MUinclusive-PASS4-p20.12.xx

The run 2a and run 2b preshutdown datasets are standard, previously defined, datasets for the MUinclusive skim. The run 2b postshutdown is the union of five previously defined MUinclusive datasets for the run 2b postshutdown period, up to the 2009 shutdown.