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Introduction

Timestamp:: Oct 1, 2013, 10:23:27 AM (11 years ago)
Author:: Michele Selvaggi
Comment:: --

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Private/RefereeComments/Introduction

-              v4
+              v5
 >> Please let me know if you think that these are too many citations.
+>>>(Michele) thanks for the references, I think we can include them all (see below in the suggested intro)
 Third paragraph:
 …
 the expression ”along the beam direction” could be used to the sake of clarity.
+>>> addressed
 L5: The energy smearing applies also to all other particles, not only to
 photons and electrons. Why are these two particles singled out here ?
+>>> addressed: photons and electrons have been replaced by
+long-lived visible particles"
 L6-7: ”Jets and missing energy can be computed with the particle-flow al-
 …
 comments that follow are related to this aspect.
+>>> addressed
 >> We agree that the particle-flow algorithm should be defined.
 >> We now call our approach a "particle-flow-like emulation" in the new draft: we don't aim at re-implementing the PF algorithm itself, but at emulating its effects.
 >> This would make more clear why we only apply it to jets and MET: there is no PF-like approach that we can follow for muons, electrons, etc., as those are already perfectly identified objects in our simulation.
+>>> We'd rather call this particle-flow emulation later, but not mentioning the word particle-flow here (otherwise we have to cite).
+>>> We believe it is better to have a smooth introduction of Eflow (aleph,atlas) and pflow (cms) in the dedicated section.
 The suggestion regarding the last two comments is to explain that all
 …
 for the next paragraph.
+>>>addressed
 Paragraph 4:
 …
 or anything closer to the truth, after ”predecessor”.
+>>> it was actually bugged, and creating photons out of nowhere, but how can we say this to ref.?
 L3: Add ”to deliver a list of reconstructed and identified particles as close
 as possible to the true (generated) list.” after ”sub-detectors”
+>>> see prior comment, not mentioning particle-flow at this stage, but just saying that we.
 L6: ”fully modular” would need some more explanation for the reader to
 understand it. But is it so important for a JHEP article ?
+>>>It is important to mention the modularity since it is crucial improvement
+>>>with respect to the prior version. The modular aspects of Delphes are explained
+>>>in the technical description part, which was moved in the appendix section.
 Paragraph 5:
 L2/L3: Propose to drop. The software implementation is out of context.
+>>> Dropped the software description since it will be in the Appendix, but the use cases should be mentioned.
 PAGE 3
 …
 A mention of the fact that this efficiency can be user-defined should appear
 at the beginning of the paragraph, and replace ”(good)”.
+>>(Michele suggested introduction)
+High energy particle collisions can produce a large variety of final states. Highly sophisticated detectors are designed in order to detect and precisely measure particles originating from such collisions. Experimental collaborations often rely on Monte-Carlo event generation for designing and optimizing specific analysis strategies. Whenever such studies require a high level of accuracy, the interactions of long-lived particles with the detector matter content are fully simulated with the \GEANT package~\cite{bib:geant4}, electronics response is emulated by dedicated routines, and final observables are reconstructed by means of complex algorithms. For preliminary studies, where such a high level of accuracy is not needed, LHC collaborations have developed their own fast-simulation techniques~\cite{bib:atlfast1,bib:atlfast2,bib:cmsfast1,bib:cmsfast2,bib:cmsfast3} which are 2 to 3 orders of magnitude faster than fully GEANT based simulation.
+This procedure requires expertise and the deployment of large scale computing resources that can be handled only by large collaborations.
+For most phenomenological studies, such a level of complexity is not needed and a simplified approach based on the parametrisation of the detector response is in general good enough. In 2009, the \DELPHES framework~\cite{bib:delphes} was designed to achieve such goal.
+\DELPHES takes as input the most common event generator output data-formats and performs a fast and realistic simulation of a general purpose collider detector.
+To do so, long-lived particles emerging from the hard scattering are propagated to the calorimeters within a uniform magnetic field along the beam direction. The particle energies are computed by smearing the initial long-lived visible particles momenta according to the resolution of the relevant sub-detectors. As a result, high-level physics objects such as jets, missing energy, isolated leptons and photons, and taus can be computed.
+With respect to its predecessor~\cite{bib:delphes}, the present \DELPHES version now includes a technique allowing to combine and optimally use the information of all the sub-detectors. This approach is particularly suitable to the treatment of pile-up, which has also been included in \DELPHES 3.0. Other features such as $b$ and $\tau$-tagging have been revisited, and it is now possible to apply an energy scale correction on jets. From a technical perspective, the code structure is now fully modular, providing a greater flexibility to the user.
+The modeling of the detector, as well as the reconstruction and validation of the physical observables will be described. A couple of illustrative use cases of Delphes in the context of LHC studies are presented.