BCAL hadronic efficiencies

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Description of Method

This procedure determines a (biased) efficiency for each cell using charged tracks that are tracked with the drift chambers and point at the BCAL. The sample of tracks consists of charged particles with a reconstructed track and a matched shower in the BCAL. While the absolute value of the efficiency does not reflect the true efficiency of a cell, it is used to monitor the uniformity from run to run and can effectively identify issues with the data and the software reconstruction process. In checking the efficiency for a given layer, the algorithm requires a pointing track and a hit in at least one layer past the layer of interest, except for layer 4 since this is the last layer. The code then checks whether here is a hit close to the extrapolated track in the layer of interest (currently +/- 3 sectors). An inefficiency is tagged if no hit is found in this range. Efficiencies are computed as a function of position along the calorimeter z, track momentum pmom, and

Analysis Procedure

The code is located on Github. The user will be mainly interested in the scripts contained in the folder ROOT_macros.

Steps to extract the BCAL Hadronic Efficiencies (see README file on Github):

  1. Generate the root trees using the BCAL_Hadronic_Eff plugin. This is usually completed as part of the routine GlueX monitoring launches.
    • The output trees are located in files such as /cache/halld/offline_monitoring/RunPeriod-2019-11/ver12/tree_bcal_hadronic_eff/merged/tree_*.root
  2. Run python script Read_bcal_hadronic_eff2.py. Edit the file as needed to point to the correct directories.
    • Create directories with the names of 'root', 'dat' and 'pdf'
    • Execute the python script Read_bcal_hadronic_eff2.py.
    • This script iteratively executes the Read_bcal_hadronic_eff2.C script on each of the root trees.
    • The ROOT output files will be placed in the 'root/' subdirectory.
    • Summaries of the efficiencies are stored in the 'dat/' subdirectory. These will be used later for plotting summaries.
    • Output plots with details of the efficiency systematics are placed in the 'pdf/' subdirectory. These can be checked for problems.
  3. Run python script plot_bcal_hadronic_eff.py. Edit the file as needed to point to the correct directories.
    • The output of this script is just a file called plot_bcal_hadronic_eff.list, which contains the list of run numbers obtained from the 'dat' subdirectory.
  4. Run the ROOT script plot_bcal_hadronic_eff.C, Edit as needed to produce useful output.
    • The output of this script is the file bcal_hadronic_eff.pdf file with various plots of efficiency vs run number.

Data Studies

  • Log book entry for Spring 2020 data Log Entry 3812382
  • Log book entry for 2018 Log Entry 3642018
  • Log book entry for 2017 tracking improvements (comparison between versions 19 and 21) Log Entry 3486656
  • Log book entry for 2016 and 2017 efficiency studies Log Entry 3478578. Shows comparison of data and MC and including inefficient channels into the CCDB database.