| 16 | | >>> The authors disagree with this comment. The reasons are: |
| 17 | | |
| 18 | | >>>- the resolutions in the Delphes CMS and ATLAS cards are taken directly from the cited papers, and it would be redundant to quote them here. |
| 19 | | >>>- the only possible difference is in the calorimeters granularity. Both the CMS and ATLAS configurations in Delphes use the granularity of the HCAL detector. As said in the calorimeter section, the ECAL granularity is exactly the same as the HCAL >>> granularity in Delphes. This comment has now been added. A table with the actual HCAL granularity of the LHC experiments (already public in the relevant technical design reports of CMS and ATLAS) >>> would be of poor interest to the reader and redundant. |
| | 16 | > The authors disagree with this comment. The reasons are: |
| | 17 | >>(CD) We disagree... |
| | 18 | >- the resolutions in the Delphes CMS and ATLAS cards are taken directly from the cited papers, and it would be redundant to quote them here. |
| | 19 | >- the only possible difference is in the calorimeters granularity. Both the CMS and ATLAS configurations in Delphes use the granularity of the HCAL detector. As said in the calorimeter section, the ECAL granularity is exactly the same as the HCAL granularity in Delphes. This comment has now been added. A table with the actual HCAL granularity of the LHC experiments (already public in the relevant technical design reports of CMS and ATLAS) would be of poor interest to the reader and redundant. |
| | 20 | >(CD) I think that the text should state the unique version number used for the paper. ATLAS and CMS cards may evolve in the future, and it should be clear to what minor version we refer in the paper. |
| 62 | | >>> addressed. However, the referee, as well as the LHC experiments, should be aware that any study performed with Delphes should be understood as preliminary. A Delphes based study should be perfomed after a pure parton-level and before |
| 63 | | >>> a geant based fast or full-simulation study. As a result, the authors are perfectly happy with an agreement with a few percents discrepancy in the physics object resolutions. |
| | 65 | > addressed. However, the referee, as well as the LHC experiments, should be aware that any study performed with Delphes should be understood as preliminary. A Delphes based study should be perfomed after a pure parton-level and before |
| | 66 | > a geant based fast or full-simulation study. As a result, the authors are perfectly happy with an agreement with a few percents discrepancy in the physics object resolutions. |
| | 67 | >>(CD) I would add that "we made this point clear when consulted by the LHC collaborations. Delphes is designed as a |
| | 68 | >> pheno tool, not as a replacement of fast simulation tools from the collaborations. |
| 100 | | >>> We totally disagree with the referee here. The examples given here a purely illustrative and it is out of scope |
| 101 | | >>> to fine-tune them. The purpose was precisely to show the opposite: without particular fine-tuning |
| 102 | | >>> Delphes gives very reasonable agreement with the CMS analysis. We insist that a 20% difference |
| 103 | | >>> is an acceptable difference since very often results (rates, efficiencies) obtained with full geant based simulation give larger discrepancies than 20% with respect to data. |
| 104 | | >>> As a side comment, the efficiency was re-computed after the change in the energy-flow algorithm and the result was found to be the same. |
| | 104 | > We totally disagree with the referee here. The examples given here a purely illustrative and it is out of scope |
| | 105 | > to fine-tune them. The purpose was precisely to show the opposite: without particular fine-tuning |
| | 106 | > Delphes gives very reasonable agreement with the CMS analysis. We insist that a 20% difference |
| | 107 | > is an acceptable difference since very often results (rates, efficiencies) obtained with full geant based simulation give larger discrepancies than 20% with respect to data. |
| | 108 | >>(CD) Add: Most LHC analysis nowadays make use of signal-free regions to normalize backgrounds, and scale factors in excess of 1.2 are not unusual. |
| | 109 | > As a side comment, the efficiency was re-computed after the change in the energy-flow algorithm and the result was found to be the same. |
| | 110 | >>(CD) More generally, private communications from CMS collaborations recently confirmed that an excellent agreement is observed when comparing Delphes to internal studies made with full simulation. Unfortunately, these are not results that we are allowed to show. |
| 202 | | >>> "high pile-up scenarios" has been replaced by "extreme pile-up scenarios", which is we actually meant. |
| 203 | | >>> To our knowledge there is no evidence that fast-simulation can cope to >100 simultaneous interactions environments, simply since these did not occur in any hadron collider yet. |
| | 208 | > "high pile-up scenarios" has been replaced by "extreme pile-up scenarios", which is we actually meant. |
| | 209 | > To our knowledge there is no evidence that fast-simulation can cope to >100 simultaneous interactions environments, simply since these did not occur in any hadron collider yet. |
| | 210 | >>(CD) I would reformulate further the sentence in the paper, saying that Delphes has not yet been compared to fullsim at extreme PU. Indeed, once done, it may become more quantitative in that region too. Still, by the time we reach such pileup conditions, experimental collaborations may find ways to cope with pileup that are not foreseen in Delphes. |
