In the following the documentation given for the different structures which are used to store hits and tracks during the tracking are repeated. They are a straight lift from the code- the reader is advised to check in the code that the version repeated here is up-to-date.
Access to the hits, tracks and results from the fits can be done either through a number of utility routines (see the TK package in the tracker part of the code for a complete list of these routines) or directly through statement functions, defined to map into the ZEBRA based storage of the hits and tracks. In the following the statement functions are documented.
**************************************************************************
* TRACKING SUBSYSTEM: PATTERN RECOGNITION AND TRACK MERGING
*
* TKBANK data structure
*
* Kristian Harder, 30 Sep, 1999
*
* many things taken from DELPHI TANAGRA manual by D. Bertrand, L.Pape
**************************************************************************
**************************************************************************
* a) MC track bank: true track parameters for all tracks in the detector
**************************************************************************
*
* This bank is filled by the TK package before calling the local patrec
* modules.
*
* --- total number of tracks that produced at least one hit
INTEGER TKNTRK
* --- track information (equivalent arrays for integer and real access)
* first index:
* 1 (real) px
* 2 (real) py
* 3 (real) pz
* 4 (real) E
* 5 (real) x of track origin
* 6 (real) y of track origin
* 7 (real) z of track origin
* 8 (integer) GEANT particle code
* 9 (integer) GEANT track number
* 10 (integer) number of hits left in detector
* 11 (integer) HEPEVT track number (if any, zero otherwise)
The information is accessible through two statement functions, called
**************************************************************************
* b) HIT bank: all hits collected in current event
**************************************************************************
*
* All hits recorded in the current event are saved here for use
* of the local pattern recognition modules. Filled by the TK package
* before the local patrec modules are called.
*
*
* --- total number of hits
INTEGER NTKHIT
* --- hit information (equivalent arrays for integer and real access)
* first index:
* 1 (real) x
* 2 (real) y
* 3 (real) z
* 4 (real) energy
* 5 (integer) subdetector ID
* 6 (integer) track ID, 0 for real data (sic!)
* 7 (integer) pointer to first exclusion (0 if none)
* 8 (integer) number of exclusions
* 9 (integer) resolution code (see below)
* 10 (real) resolution 1
* 11 (real) resolution 2
* position 7 and 8 are used for mutually exclusive hit candidates
* (mirror hits etc.). they point to entries in the exclusion list
* defined below.
*
* resolution code: two bits are set. The lower value bit describes which
* resolution is described by resolution 1 (pos. 10), the
* higher value bit describes resolution 2 (pos.11).
*
* bit 0 - error on r*phi
* bit 1 - error on z
* bit 2 - error on r
The hits are available as two statement functions:
*************************************************************************
*
* --- exclusion list (shared by all other banks)
INTEGER NEXCL,IEXCL(MXEXCL),EXCLERR
* --- pointer array: IHPOINT(ID_DET) points to position of first hit
* from subdetector ID_DET. IHNUMB(ID_DET) stores the number of hits
* found in this detector
INTEGER IHPOINT(3000),IHNUMB(3000)
**************************************************************************
* c) TE bank (subdetector output)
**************************************************************************
*
*
* Following DELPHI nomenclature, the information delivered by a subdetector
* is called track element (TE). A TE may contain fitted tracks (e.g. TPC),
* but may also contain single hits (e.g. Presampler hits).
* This bank must be filled by the local patrec modules.
*
* --- number of track elements (TEs).
INTEGER NTE
* --- DELPHI TANAGRA TE structure for track elements/hits (equivalant arrays)
* first index (m=length of packed covariance matrix):
* 1 (integer) subdetector ID
* 2 (integer) submodule: bit code for VTX/FTD layers used in TE
* 3 (integer) not used (yet) - MUST be set to zero
* 4 (integer) measurement code (see below)
* 5 (integer) pointer to end of TE (m+17)
* 6 (integer) charge (0=neutral, 1=positive, 2=negative, 3=unknown)
* 7 (integer) number of degrees of freedom
* 8 (real) chi^2 of the fit
* 9 (real) length of the track element
* 10 (real) coordinate 1 of reference point: x or R
* 11 (real) coordinate 2 of reference point: y or R*PHI
* 12 (real) coordinate 3 of reference point: z
* 13 (real) theta angle
* 14 (real) phi angle
* 15 (real) 1/p at the reference point (in 1/(GeV/c))
* (or 1/p_t - see measurement code)
* 16 (real) dE/dx (if measured - see measurement code)
* 17 (real) covariance matrix for measured quantities
* ... (see below)
* m+16 (real) error on dE/dx if dE/dx is measured
* m+17 (real) must be 0.0
*
* measurement code:
* bit 0 = 0 for x,y,z coordinates
* = 1 for R,R*PHI,z coordinates
* bit 1 = 0
* bit 2 = 1 if coordinate 1 is known (index 10), 0 otherwise
* bit 3 = 1 if coordinate 2 is known (index 11), 0 otherwise
* bit 4 = 1 if coordinate 3 is known (index 12), 0 otherwise
* ('known' means either defined by detector geometry or measured)
* bit 5 = 1 if R*PHI (x) is measured for bit 0 = 1 (0)
* bit 6 = 1 if z (y) is measured for bit 0 = 1 (0)
* bit 7 = 1 if theta is measured
* bit 8 = 1 if phi is measured
* bit 9 = 1 if 1/p is measured
* bit 10 = 1 if 1/p_t is measured
* ('measured' really means measured, i.e. this quantity contributes
* to the covariance matrix)
* bit 11 = 0
* bit 12 = 0
* bit 13 = 1 if dE/dx is measured
* bit 14-... = 0
*
* covariance matrix:
* every variable activated by a 1 in bit 5..10 is included
* in the covariance matrix. for a 3d tracking detector like
* a TPC, the measured quantities are in most cases
*
* R*PHI and z (coordinates of the reference point at a reference
* radius R which therefore has no error itself)
* theta,phi,1/p
*
* In this example, the order of elements in the covariance matrix
* is the following:
*
* D(R*PHI,R*PHI),
* C(R*PHI,z), D(z,z),
* C(R*PHI,theta), C(z,theta), D(theta,theta),
* C(R*PHI,phi), C(z,phi), C(theta,phi), D(phi,phi),
* C(R*PHI,1/p), C(z,1/p), C(theta,1/p), C(phi,1/p), D(1/p,1/p)
The TE are accessble through statement functions:
* --- additional information. first index: * 1 (integer) position of first associated hit in hit list (see below) * 2 (integer) number of hits * 3 (integer) pointer to first exclusion (0 if none) in exclusion list * 4 (integer) number of exclusions * 5 (integer) track no. (positive if 95% of the hits belong to * same track, negative if 75%, zero below.) * remark: the exclusion list is shared with the hit bank (see there).
This information is accessible through a statement function:
* --- hit list: pointers to entries in the hit bank.
INTEGER NHITTE,IHITTE(NHMAX)
**************************************************************************
* d) TS bank (ambiguous full track candidates)
**************************************************************************
*
* Merging result as created by the TK package and DELSEARCH.
* Ambiguous use of TEs is possible here; the unambiguous optimal
* track reconstruction will be entered into the TK bank (see below)
*
* --- number of tracks segments (TS) found by DELSEARCH
INTEGER NTS
* --- DELPHI TANAGRA TS structure
* first index (m=length of packed covariance matrix):
* 1 (integer) module identifier (internal use only)
* 2 (integer) bit code for used detectors
* 3 (integer) measurement code (see below)
* 4 (integer) track type (see below)
* 5 (integer) number of TEs used in this TS
* 6 (integer) charge (0=neutral, 1=positive, 2=negative, 3=unknown)
* 7 (integer) not used (must be zero, though)
* 8 (integer) number of degrees of freedom of the track fit
* 9 (real) chi^2 of the track fit
* 10 (real) track segment length
* 11 (real) x of TS start point
* 12 (real) y of TS start point
* 13 (real) z of TS start point
* 14 (real) x of TS end point
* 15 (real) y of TS end point
* 16 (real) z of TS end point
* 17 (real) coordinate 1 of reference point: x or R
* 18 (real) coordinate 2 of reference point: y or R*PHI
* 19 (real) coordinate 3 of reference point: z
* 20 (real) theta angle
* 21 (real) phi angle
* 22 (real) 1/p at the reference point (in 1/(GeV/c))
* (signed with geometric curvature of track
* measured from nside to outside of detector)
* 23 (real) covariance matrix for measured quantities
* ... (as above)
* 37 (real)
*
* measurement code:
* bit 0 = 0 no estimate at all for the track segment parameters
* = 1 track segment parameters are given
* bit 1 = 0 for x,y,z coordinates
* = 1 for R,R*PHI,z coordinates
* bit 2 = 0 crude estimation of errors (diagonal cov. matrix)
* = 1 full covariance matrix
* bit 3 = 0 all parameters are given if bit 0 is on
* = 1 no error matrix/starting point/end point
*
* track type:
* not yet documented. 1+8 (bits 0 and 3 set) means:
* crude estimation, plane reference surface (cartesian coordinates),
* no start/end points given
INTEGER ITS(MXTS,NTSMX)
REAL RTS(MXTS,NTSMX)
EQUIVALENCE (ITS,RTS)
* --- additional TS information. first index:
* 1 (integer) position of first associated TE in TE list (see below)
* 2 (integer) number of TEs
* 3 (integer) pointer to first exclusion (0 if none) in exclusion list
* 4 (integer) number of exclusions
* 5 (integer) track no. (positive if 95% of the hits belong to
* same track, negative if 75%, zero below.)
* remark: the exclusion list is shared with the hit bank (see there).
INTEGER ITSDAT(5,NTSMX)
* --- TE list. contains all TEs that are used by the TS. (referenced in ITSDAT)
INTEGER NTSTEL,ITSTEL(MXEVTE)
**************************************************************************
* e) TK bank (the real tracking result - unambiguous track candidates)
**************************************************************************
*
* Filled by TK package after resolving all TS ambiguities.
*
*
* --- number of tracks (TK)
INTEGER NTK
* --- DELPHI TANAGRA TK structure
* first index (m=length of packed covariance matrix):
* 1 (integer) module identifier (internal use only)
* 2 (integer) bit code for used detectors
* 3 (integer) measurement code (see below)
* 4 (integer) track type (as above)
* 5 (integer) number of TEs used in this TK
* 6 (integer) charge (0=neutral, 1=positive, 2=negative, 3=unknown)
* 7 (integer) not used (must be zero, though)
* 8 (integer) number of degrees of freedom of the track fit
* 9 (real) chi^2 of the track fit
* 10 (real) track length
* 11 (real) x of TS start point
* 12 (real) y of TS start point
* 13 (real) z of TS start point
* 14 (real) x of TS end point
* 15 (real) y of TS end point
* 16 (real) z of TS end point
* 17 (real) coordinate 1 of reference point: x or R
* 18 (real) coordinate 2 of reference point: y or R*PHI
* 19 (real) coordinate 3 of reference point: z
* 20 (real) theta angle
* 21 (real) phi angle
* 22 (real) 1/p at the reference point (in 1/(GeV/c))
* (signed with geometric curvature of track
* measured from inside to outside of detector)
* 23 (real) covariance matrix for measured quantities
* ... (as above)
* 37 (real)
*
* measurement code:
* bit 0 = 0 for x,y,z coordinates
* = 1 for R,R*PHI,z coordinates
INTEGER ITK(MXTK,NTKMX)
REAL RTK(MXTK,NTKMX)
EQUIVALENCE (ITK,RTK)
* --- additional TK information. first index:
* 1 (integer) position of first associated TE in TE list (see below)
* 2 (integer) number of TEs
* 3 (integer) track no. (positive if 95% of the hits belong to
* same track, negative if 75%, zero below.)
INTEGER ITKDAT(3,NTKMX)
* --- TE list. contains all TEs that are used by the TK. (referenced in ITKDAT)
INTEGER NTKTEL,ITKTEL(MXEVTE)
**************************************************************************
C --- the tracking common block
COMMON /TKBANK/ TKNTRK,
* & TKMCTR,
> NTKHIT,
* & ITKHIT,
> NEXCL,IEXCL,EXCLERR,
> IHPOINT,IHNUMB,
> NTE,
* ITE,ITEDAT,
> NHITTE,IHITTE,
> NTS,ITS,ITSDAT,NTSTEL,ITSTEL,
> NTK,ITK,ITKDAT,NTKTEL,ITKTEL
SAVE /TKBANK/
**************************************************************************
+KEEP,TKNOISEPAR.
***********************************************************
*
* background hits per bunch crossing for tracking detectors
*
***********************************************************
INTEGER TNVXL1,TNVXL2,TNVXL3,TNVXL4,TNVXL5
INTEGER TNVTX1,TNVTX2,TNVTX3,TNVF2A
INTEGER TNFTD1,TNFTD2,TNFTD3,TNFTD4,TNFTD5,TNFTD6,TNFTD7
INTEGER TNSIT1,TNSIT2
INTEGER TNFCH
INTEGER TNNBX,TNENERGY
COMMON /TKNOISEPAR/
> TNVXL1,TNVXL2,TNVXL3,TNVXL4,TNVXL5,
> TNVTX1,TNVTX2,TNVTX3,TNVF2A,
> TNFTD1,TNFTD2,TNFTD3,TNFTD4,TNFTD5,TNFTD6,TNFTD7,
> TNSIT1,TNSIT2,
> TNFCH,
> TNNBX,TNENERGY
SAVE /TKNOISEPAR/