[Rivet] Promptness of hadrons

[Holger Schulz]

Hi,

I am working with a student on the unvalidated LHCB_2012 analysis
which looks at prompt pions, kaons and protons. It seems as if
LHCB defines such objects using a cut on the distance from
the primary vertex.

I was wondering if there is a preferred way in Rivet (2.1.2) to
implement this without doing nasty things with the HepMC
event record.

Cheers,
Holger