4.6.10 SUBROUTINE ZAUSHO(LIMPRO) : SHOWer merging

Merge showers in calorimeters that are close both in position and direction.

ARGUMENTS:

INPUT :

      LIMPRO : Limiting probability to merge showers. If the separartion
         of the two showers is such that the probability >= LIMPRO that
         two meassuerments of the SAME shower would give that same
         observed separartion (or less), the showers are merged.
         Hence, big LIMPRO -> many showers merged, and v.v.

IMPLICIT INPUTS:

    From /ZASTE/ : IGEOM, the number of the present detector.
    From /ZAEVT/ : MTRK, the total number of seen particles;
    From /ZAEVT/ : CTYPN, calorimeter types; SHOAXN, shower axis.

IMPLICIT OUTPUTS:

    To /ZAEVT/ : NCLUST, the total number of calorimeter clusters.
    To /ZATRS/ : CLUNBN, cluster number of particles.
    To /ZACLU/ : CLUAX, cluster axis position and direction; NSHICL,
                 number of showers in each cluster; CLUORIN, list of
                 showers in each cluster.

CALLED BY :

ZAUSER, user routine (see 4.5.10).

CALLED ROUTINE(S):

ZAUSDI (see 4.6.11)

(To find the Shower DIstance )

ZAUCSS (see 4.6.12)

(To Collect Shower Statistics-counters)

ZUI2PI (see 4.7.2)

(To bring an angle withIn 2 PI)

ZTCRAD (see 4.4.17)

(To get a Cylinder RADius)

ZUINTS (see 4.7.6)

(To put element INto Set)

ZUSOR (see 4.7.12)

(To do Set OR)

ZUCINS (see 4.7.8)

(To Check if element IN Set)

ZAUSHS (see 4.6.13)

(To do SHOwer Sorting)

ZAUSIC (see 4.6.14)

(To do Shower particle Id and Charge assignment.)

ZAUCSH (see 4.6.15)

(To do Charged part to SHower association)

CHISIN,VZERO,VMUL,UCOPY

(CERNLIB routines)

SIDE EFFECTS:

none.

AUTHORS:

M. Berggren, UFRJ, M. A. Do Vale, UFRJ

CREATION DATE:

06-APR-1995