anchor.diff:  ! =================================================================================================
   !  V.K. Berglyd Olsen, BE-ABP-HSS
   !  Created: 2019-07-22
  -!  Updated: 2019-07-22
  +!  Updated: 2019-11-20
  +!  Generate a particle to collide with.
  +!  Only used for Pythia REALBEAM scattering events, so we assume this is called from within the
  +!  PYTHIA compiler flag.
   ! =================================================================================================
   subroutine scatter_generateParticle(idPro, iElem, j, pVec)
   
  
positive.code:       orbXP = scatter_proList(idPro)%fParams(1)
        orbYP = scatter_proList(idPro)%fParams(2)
      end if
      pVec(1) = (orbXP*e0f)*c1m3
      pVec(2) = (orbYP*e0f)*c1m3
      pVec(3) = -sqrt(e0f**2 - pVec(1)**2 - pVec(2)**2)
  
    case(scatter_proBeamUnCorr)
  
  
negative.code:       isExact = .true.
  
      else
        ! We just let Pythia generate an event assuming both colliding particles
        ! are on-momentum, and collide head on.
  
        call pythia_getEvent(evStat, evType, t, theta, dEE, dPP)
  
  