Section 4

PAGE 9

”Charged pile-up subtraction”

There are several problems in this paragraph.

• It is not stated if this paragraph is specific to PF or not. If it’s not, the procedure to remove charged particles from the event in which purely calorimetric jets are reconstructed needs to be spelt out clearly.

Two sentences have been added at the end of the paragraph to clarify this point.

• Even if the paragraph is PF specific, it is not clear what ”subtracted from the event: means. For example, are the pile-up charged hadrons removed from the event before computing the missing transverse en- ergy ? To the best of my knowledge, it is not what is done in LHC experiments.

charged particles are not removed for calculating the missing energy as this would degrade the overall missing Et resolution. The last sentence should now clarify what we mean by "subtracted from the event".

• The criterion ”a distance |z| > Zvtx” is obscure. What if the hard interaction is produced with |z| > Zvtx ? and what is the definition of this ”distance” ? If is is the distance between the vertex of a PU interaction with respect to the vertex of the hard interaction, the use of ”z” instead of ”z” (with the proper definition in the text) is in order.

A sentence was added at the beginning of the paragraph to clarify that in Delphes, every hard scattering occurs at (0,0,0) coordinates. The notation of "Zvtx"has been changed as suggested.

”Residual pile-up subtraction”

• It is not clear how ”rho” is obtained in DELPHES

addressed, a sentence stating that we use FastJet to estimate "rho" has been added.

• ”mainly the jet energies and the isolation” : is ”rho” used for anything else ? if yes, it should be stated. If not, ”mainly” should be removed.

addressed

PAGE 10

Par 2:

L4: It would be useful to mention one of the advantages of the PF recon- struction in the context of PU mitigation, namely the fact that the calorime- ter energy deposits associated to PU charged hadrons are ”automatically” removed. In DELPHES, however, this does not happen when a charged hadron and a neutral deposit fall in the same calorimeter tower, because the charged hadron is then ignored by DELPHES.

Thanks to the new implementation of the energy-flow algorithm, every charged particle originating from pile-up, as well as its corresponding calorimeter deposit can now be removed prior to the jet clustering. The sentence has been changed in order to account for this comment.