4.6 Patch SGVANAUTL : Utilities for event analysis

This patch contains utility code for event analysis. It is by no means a complete set of routines for such tasks. It has a slight emphasis on heavy flavour physics at LEP, and in particular in impact parameter determination. If contains a set of routines for vertex fitting, for calculation of impact parameters, and for event shape variables (jet-clustering (interface to the JETSET routine LUCLUS), sphericity, boosted sphericity, aplanarity, etc). It also contains code to find V0:s (optimized for rejecting them as background in b-tagging, rather than identifying them). Finally, a few routines from standard DELPHI libraries are included. They will not be written to the FORTRAN file if the patchy flag DELPHI is set.

All routines can act as entry points. However, for vertex fitting, the do-it-all routine ZAUVF1 is preferred, as is ZAUCIP for impact parameter calculation. Also, ZAUCLU calls the other routines needed for jet-clustering, and correctly fills the common blocks. It might, however, not be flexible enough for any application.

The code of this patch communicates with other patches as follows :

    ZAURST
      ZTTCYL in SGVTRKER

The communication with the caller (normally ZAUSER, possibly indirect) is through the common-blocks in ZACDE, or by arguments.