C... parameters for this program are 
C...  Zprime mass ZPMASS [not used in STAGE 3]
C...  V-Pion mass PIMASS in GeV
C...  V-Pi-Zero lifetime PIZLIF in picoseconds (should be nonzero)
C...  V-Pi-Plus/Minus lifetime PIPLIF 
C...                          (should be negative if V-PiPlus stable,
                               should be positive if V-Pi-Plus unstable  )


C - arrange for proper v-pion masses, decays and lifetimes
C - (currently using h0 25 and H0 35 as v-pi-zero and v-pi-plus/minus)
C - will need to change this using QNUMBERS if possible

      PMAS(25,1)=PIMASS
      PMAS(25,4)=PIZLIF

C - turn off all but fermion decays for h0
      DO I=222,226
         MDME(I,1)=0
      ENDDO

C - turn off decay (if PIPLIF<0) or turn off all but fermion decays for H0
      PMAS(35,1)=PIMASS*0.1396D0/0.135D0
      IF (PIPLIF.GT.0.D0) THEN
      PMAS(35,4)=PIPLIF
      ELSE
      MDCY(35,1)=0    ! if piplif < 0 don't let H0 decay
      ENDIF
      DO I=346,357    ! otherwise allow decays to fermions only
         MDME(I,1)=0
      ENDDO

C - Thus the v-pions inherit the fermionic branching fractions of h0, H0.
C - At some point the decay branching fractions will be set more carefully
C - The above may slightly overestimate the number of tau's produced
C - but this requires more study.

C - When we reset the particle number for h0, H0 to something new, 
C - probably needed to get ATLAS software to use it, then we will need to set
C - up all the decay modes and the branching fractions at this point as well.