oevrall architecture -- Pythia addon?  Pythia version?

Other production processes -- read in?

stage 1 -- do the Z' production weight, decay rate, decay angles
  what particles to use in final state -- e+e-, t'b', Skands, vquarks?

SM:  
    to get angles, Z' needs to use [an existing particle] because it is 2 -> 2
    to add Z' -> vquarks, need to do 2 -> 1, but then no angles
    Z' couplings to 4th generation same as 3rd

stage 2 --
really want a v-hadronization routine using v-hadrons to avoid problems with expt QCD
  settings (GEANT)
good benchmark -- turn off strange quark in QCD-like showering/frag; set nf = 2
  SM: don't produce ssbar from gluons or string ends
      Peter's program: limitation all hadrons have to be scaled exactly from QCD?
      but higher hadrons can decay to Kaons -- an issue to be dealt with
change masses of QCD hadrons consistently? yes but need to redo decays
compute new v-hadron models internally [long way off]
do independent fragmentation or QCD-like showering/fragmentation
    [while avoiding resonances at various charm thresholds etc]

fragment a vquark-vsquark pair
catch the gluons in a shower and make them massive

remove the old LHA output version

work with vhadrons written out as QNUMBERS or PYUPDATE or as existing
 Pythia particles [but avoid h0]
   -- check with ATLAS  -- how does ATLAS plan to deal with new particles?
   -- ask Mrenna about plans for a standard?

various input modes

Stage 3a output: decay v-hadrons directly: 
  challenges : QNUMBERS needed? [event record]
               decays inside detector [GEANT]

Do we need to be able to write out all the vhadrons
  their numbers, masses, brnaching fractions ?  Yes


Stage 3b output: full Pythia output  in XDR storage with decays to a certain distance
  problem for input into Detector simulation -- even if we cut off the
   decays for QCD particles at beampipe, what about the undecayed v-hadrons?
   indeed what happens to other long-lived particles?


Peter to talk to Steve -- can/should there be the option to have a full
event record , stored at stage 2 or 3a ?  should general event record store
this info?

Can GEANT handle B mesons in detector material?!!

PETER: underlying event correctly? read in versus run through start to finish