Reconstruct hard process from LHEF or HEPMC data

[kilian]

This is necessary if we want to meaningfully reweight events provided by external programs. There was a routine in 2.1 which has to be revived and checked, whether it works and covers all cases.

[Juergen Reuter]

IMPOSSIBLE ...

[Juergen Reuter]

What is the status of this ticket? Which routine from 2.1.1 do you mean, WK?

[kilian]

Just looking into this, for LHEF.

[kilian]

r5940: Works now for LHEF with decayed events. Next, check showered events.

[kilian]

Reconstructing showered events: this runs into the problem that the particles are known only to SM_hadrons. There is some hack in the shower code, but ... we need a way to implicitly augment any model by hadrons, since all model particles may appear in the event record as resonances. Should somehow be built into the model module interface.

[Juergen Reuter]

Note that for HepMC there is a subroutine particle_set_init_from_hepmc.

[kilian]

Replying to jr_reuter:

Note that for HepMC there is a subroutine particle_set_init_from_hepmc.

Yes, and analogously for LHEF. The obstacles are elsewhere, mainly the handling of SM_hadrons.

[kilian]

For LHEF, the issue should be settled in r5955. Showered events are read in, and the squared matrix element value is recovered.

Let's see what to do with HepMC ...

[kilian]

LHEF done (except for #628), I created a separate ticket for HepMC, #647. Closing this one.