4.4.8 SUBROUTINE ZTTPLA(P, V, ZPLA, FIRST, IPRP, IPZ, PHI0, PEND, VEND, DST, TRACK, ERROR) : Track intersect with PLAne

This routine tracks a particle with momentum p from v to the plane surface at z coordinate ZPLA. It returns the momentum (pend) and position (vend) at this point. It also returns the TKR parameters at the point.

ARGUMENTS:

INPUT :

    P : Momentum of track
    V  : Position where P is given
    ZPLA : z at which track parameters are requested.
           If ZPLA=0, the perigee parameters will be returned.
    FIRST : TRUE if first call for this track.
    IPRP : true IP in R-Phi (input if FIRST = FALSE)
    IPZ : true IP in Z (input if FIRST = FALSE)
    PHI0 : Phi angle to perigee point in R-phi plane
            (input if FIRST = FALSE)

OUTPUT :

    IPRP : true IP in R-Phi (output if FIRST = TRUE)
    IPZ : true IP in Z (output if FIRST = TRUE)
    PHI0 : Phi angle to perigee point in R-phi plane
            (output if FIRST = TRUE)
    PEND: Momentum of track (if ERROR <>0 then PEND=P)
    VEND  : Position where PEND is given (if ERROR <>0 then VEND=V)
    DST : Distance along track helix from V to VEND
    TRACK : TKR parameters for the track.
                 for the track
    ERROR : error flag :
             0 - no error
             1 - no intersection in barrel.
             2 - track turns back.
             3 - other error.

IMPLICIT INPUTS:

    From /PXCONS/ : BMAG, the magnetic field; CONSA, Speed of light.

IMPLICIT OUTPUTS:

    none

CALLED BY :

ZTCALO, Track to CALOrimeter (see 4.4.4). ZTTISP, TRacK InterSection with Plane (see 4.4.7).

CALLED ROUTINE(S):

ZTREFL (see 4.4.12)

(To REFLect track in x-y plane.)

ZTTRIP (see 4.4.10)

(To get TRue Impact Parameters.)

ZUI2PI (see 4.7.2)

(To bring angle In the range 0 to 2PI.)

ZUINPI (see 4.7.3)

(To bring angle IN the range 0 to PI.)

PXTPPX (see 4.7.5)

(To transform Track parameters on Plan to PXpypz)

ZTTCYL (see 4.4.6)

(To get Track intersection with CYLinder.)

SIDE EFFECTS:

none

AUTHORS:

M. Berggren, UFRJ

CREATION DATE:

10-dec-1995