STAR AgML Alignment

Abstract:  The basic design of the STAR alignment framework for AgML is outlined.  Some additional notes related to alignment which will need to be taken into account are also discussed.


Application of the alignment parameters would be through the the StarDb mechanism... something like...

StarDb/Alignment/TPC/y2011.TIMESTAMP.C  (or something similar)


The ROOT documentation may leave out some important considerations.  For example:

  • According to the Alice webpage, alignment needs to be applied in a top-down manner.  i.e. going from the node closest to the TOP node down to the last leaves in the geometry tree.  This is not (clearly) indicated n the ROOT manual.

 So... in addition to the locking mechanism, we will need to implement either (1) a sanity check, to make certain that the nodes closest to the top of the tree are misaligned first, or (2) delay application of the alignment parameters and order them by the depth of the node being aligned.