4.6.11 REAL FUNCTION ZAUSDI(I, J) : Shower DIstance

Calculate the distance (in terms of $\chi^2$) between showers I and J

ARGUMENTS:

INPUT :

    I,J   : Numbers of the two showers in ZATRS

IMPLICIT INPUTS:

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

IMPLICIT OUTPUTS:

    none.

FUNCTION VALUE:

$\chi^2$ of the distance between showers (ie. sum of (shoax$_i$-shoax$_j$)$^2$/( $\sigma^2_i + \sigma^2_j$) over the 4 components of shoax)

CALLED BY :

ZAUSHO, SHOWer merging (see 4.6.10).

CALLED ROUTINE(S):

ZUI2PI (see 4.7.2)

(To bring an angle withIn 2 PI)

ZUINPI (see 4.7.3)

(To bring an angle withIN PI)

ZTCRAD (see 4.4.17)

(To get a Cylinder RADius)

ZTPLAZ (see 4.4.20)

(To get a PLAne Z)

ZTCSDE (see 4.4.31)

(To get Calorimeter Shower Direction Errors)

VSUB,VDOT

(CERNLIB routines)

SIDE EFFECTS:

none.

AUTHORS:

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

CREATION DATE:

06-APR-1995