Pile up question

[brade1994]

Suppose I run a file name sample.hepmc using the default FCC card and then run,
./DelphesHEPMC2 cards/FCC/FCChh.tcl sample.root sample.hepmc.

So I will have now an events store in sample.root.

Now suppose I create my own MinBias.Pile up file by using this tutorial,
https://cp3.irmp.ucl.ac.be/projects/delphes/wiki/WorkBook/PileUp

and then run,

./DelphesHEPMC2 cards/FCC/FCChh_PileUp.tcl sample_pileUp.root sample.hepmc.

Does the sample_pileUp.root contain already the events store in sample.root plus the pile-up events or only just the pile-up events?

Marlon

[Pavel Demin]

The sample_pileUp.root file will contain the events from the sample.hepmc file with the pile-up events added to those events. The number of events will be equal to the number of events in the sample.hepmc file but these events will contain additional particles from the pile-up events.

[brade1994]

Okay. But what confused me is that when I run my macro, i check the transverse momentum
for the sample.root and for sample_pileUp.root . I found out that in the sample.root there exist a single event where the transverse momentum of the muon is,

muon->PT: 482.757 GeV

But this event with the specified PT of the muon does not exist at all in the sample_pileUp.root because the highest transverse momentum event in the sample_pileUp.root is just about 15.6 GeV and in general there is no coincide between the values of transverse momentum in the two root file.

Now my follow-up question is, does the presence of pile-up changes the values of the transverse momentum of the non-pile-up events?

Marlon