4.6.15 SUBROUTINE ZAUCSH(DELTA) : Charged part to SHower assoc.

Associate showers in calorimeters to charged tracks if they are close both in position and direction.

ARGUMENTS:

INPUT :

      DELTA : maximal distance between track extrapolation and shower
              start-point to merge showers.

IMPLICIT INPUTS:

    From /ZASTE/ : IGEOM, the number of the present detector;
                   MSTCA,  Lowest distance between shower start-point
                   and track extrapolation to calorimeter at which the
                   shower will not be attached to the track;
    From /ZAEVT/ : MTRK, the total number of seen particles; NSHOW, Number of
                   showers;
    From /ZACLU/ : NCLUST, number of clusters in the calorimeters;
                   CTYPCL, Number of the calorimeter seeing the cluster;
                   CLUAX, cluster axis position and direction;
    From /ZATRS/ : PAR, Seen track parameters at perigee; PVEC,True and
                   seen momentum of track;

CLUAX, cluster axis position and direction; NSHICL,

IMPLICIT OUTPUTS:

    To /ZAEVT/ : NSHOW, Number of showers;
    To /ZATRS/ : CLUNBN, cluster number of particles.
    To /ZACLU/ : TRMAIN, main (most energetic) track pointing to cluster;
                 CHACLU, Charge assignment of cluster;
                 CDCLU, Particle Id code of cluster;
                 CLUORIN, list of showers in cluster;
                 NSHICL, Number of showers in cluster

CALLED BY :

ZAUSHO, SHOWer merging (see 4.6.10).

CALLED ROUTINE(S):

ZTCBNL (see 4.4.28)

(To get Calo (Barrel) Number of Layers)

ZTCRAD (see 4.4.17)

(To get Cylinder RADius.)

ZTCZED (see 4.4.19)

(To get Cylinder ZED limits)

ZTTCYL (see 4.4.6)

(To get Track intersection with CYLinder.)

ZTCFNL (see 4.4.29)

(To get Calo (Fwd) Number of Layers)

ZTPLAZ (see 4.4.20)

(To get PLAne Z.)

ZTPRAD (see 4.4.21)

(To get Plane RADius.)

ZTTPLA (see 4.4.8)

(To get Track intersection with PLAne.)

SIDE EFFECTS:

none.

AUTHORS:

M. Berggren, LPNHE, Paris K. Hultquist, Fysikum, Stockholm

CREATION DATE:

26-NOV-2002