Promptness
From Particle Wiki
An object is prompt if it originates directly from something, usually a primary vertex of the event, as opposed to some subsequent decay of e.g. a hadron or tau lepton or other particle that is not a heavy resonance of interest. The exact meaning of promptness depends on the context.
Definitions in use
Rivet implementation
Rivet link to Rivet source Promptness is undone by being directly or indirectly color-connected to other parts of the event.
ATLAS recommendation
ATLAS http://cdsweb.cern.ch/record/2022743