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v3.3.5
Modification password: CWR
Put CADI number into meeting name
Organizer: QCD group (Katerina Lipka)
paper: http://cms.cern.ch/iCMS/analysisadmin/cadi?ancode=SMP-17-005
comments from Kelly Beernaert
General comment:
- for clarity please list numbers for 13 TeV and 8 TeV in the same order everywhere
- if you refer to a method from the previous analysis, please be consistent in its description, e.g.
This is done that way, explained or described or similar as in Ref.[REF].
- Fig 2-6: Labels are too small and are not readable; The data / MC in the 3 lower palens is repeated 3 times, instead make it just bigger.
- The R is different for 13 and 8 TeV analyses, but is not indicated in the plots.
- Systematic uncertainties: some systematic uncertainty sources are not explained (pileup) and some are not explained in the section "Systematic Uncertainties". Suggest itemizing.
- The summary should reflect the statements made in the introduction of omportance of this measurement to get insight into VBS and the measurement of couplings.
Abstract:
- move "in pp collisions at sqrt(s) = 8 TeV and sqrt(s) = 13 TeV." to the next sentence so that the "respectively" points to the same sentence.
- based on data samples collected -> based on data collected
- "The differential cross sections as a function of the jet multiplicity, the transverse momentum, and pseudorapidity of the pT-leading and subleading jets are presented. In addition, the differential cross sections are presented as a function of the invariant mass of the two pT-leading jets and their pseudorapidity separation." -> The differential cross sections are presented as a function of the jet multiplicity, the transverse momentum, and pseudorapidity of the pT-leading and subleading jets, in addition the cross sections are measured as a function of the invariant mass of the two pT-leading jets and their pseudorapidity separation."
Introduction:
- L4 symmetry breaking mechanism -> symmetry-breaking mechanism?
- L26: analyisis -> analysis
Signal and background simulation:
- L84: MCFM v7.0 for 13 TeV?
- L92: For 8 TeV dataset -> for the 8 TeV dataset
Event selection:
- L108: sub-leading lepton -> mention again "sub-leading electron (muon)" for clarity
- L109: dielectron and dimuon triggers require that the tracks corresponding to the leptons originate from within 2 mm of each other along the beam axis. -> is this also the case for the opposite flavour triggers? if so, replace "dielectron and dimuon triggers" with "dilepton triggers".
- L111: isolation request -> isolation requirement
- L112: 27 GeV and 22 GeV -> 27 GeV and 22 GeV respectively
- L112: help increasing -> help to increase
- L116: mention particle flow, or is that considered jargon? I assume the term is quite known by now?
- L121 and L123: primary vertex and primary pp interaction vertex -> pick one term and be consistent
- L139: "small energy deposits" sounds vaguely defined, rephrase as "taking into account the compatibility of the energy deposits in the calorimeter by a minimum-ionizing particle"?
- L140-141: these pT-threshold are below the trigger thresholds. Are there any tighter offline requirements on the leading pT leptons than the ones listed in the trigger description? -> perhaps move the lines to L178-182?
- L147: is the cone size the same for electrons and muons? is this the case in both 13 and 8 TeV?
- L153: same questions is the isolation cut-value the same for electrons and muons?
- L155: tag-and-probe
- L156: the correction happens with a scale factor? the formulation sounds as if the absolute efficiency from data is applied to MC, perhaps a better formulation is possible?
- L162: letpon -> lepton
- L161-162: perhaps should be moved to the description of the isolation in L145-154?
- L185-187: are here the invariant mass cuts not superfluous given the cuts in L192-193 which are tighter?
- L195: uncertainty on these numbers?
Background estimation:
- L213-214: uncertainties on these numbers?
Systematic uncertainties:
- L219-220: why is the full difference between the data and MC trigger efficiency used as systematic uncertainty? Is there no systematic uncertainty provided on the scale factor?
- L227: the contribution -> the uncertainty contribution
- L233: increases with the jet multiplicity as well?
- L236-237: the unfolding procedure hasn't been described up to this point
- L245-246: both directions, systematic uncertainty source
- L246: systematic uncertainty contribution
ZZ + jets differential cross section measurements:
- Figure 1: the hatched band indicate -> the hatched band indicates, with data driven method -> with a data driven method, legend: Syst. -> syst. unc.
- L282: The uncertainties include also -> The uncertainties also include
- L297-298: yielding a lower uncertainty with respect to the non-normalized case causing a lower uncertainty with respect to the non-normalized case -> yielding a lower uncertainty with respect to the non-normalized case
- L304-308: In the data, jets tend to have a lower pT-value than in the simulations and therefore, on average, they are less likely to pass the 30 GeV threshold, thus increasing the number of events with no jets. The observation of fewer events than expected with at least one jet can be ascribed to a softer distribution of the transverse momentum of the hadronic particles recoiling against the diboson system. -> Second sentence seems redundant.
Summary:
- L336: mesurements -> measurements
References:
- 8: doi: 10.1016/j.physletb.2017.10.020
comments from Patrick Connor
general
- put 8/13 TeV always in the same order (proposal: chronological order, since it is the less biased to any opinion/judgement)
- outline methods you only refer to; in contrast, when a method is given in details, mention at the end the references
- since there is a lot of repetitions with muon/electron and 8/13 TeV, it would be good to try to compile results into tables (inline enumeration are hard to read)
- be consistent throughout the whole text: either "Tab./Fig." or "Table/Figure"
section 1:
- L4: simulatneous -> associated?
- L5: measurament -> measurement
- L12-18: example of hereabove general comment about order of c.m.s. energies
section 3:
- L71: "unfolding response matrices" -> remove "unfolding" and replace "experimental" with detector (actually, a whole rephrasing would make sense, but more comments on unfolding are coming later)
- L78: 1 jets -> 1 jet
- L80: "at both 8 and 13 TeV datasets" -> rephrase
section 4:
- general: a few subsections would help the reader
- 2nd paragraph: related to general comments on reference... unclear whether you repeat here the method or not (which would be preferrable for readability)
- L123: mention anti-kt and cone size radii already here (and not later -- see comment below)
- L140-141: in relation to Tab. 2 (4 pages later!!), several inconsistencies (muon range, pt cuts, 8/13 TeV, ...)
- L143: where is "impact parameter significance" defined? add at least a reference, but could be better to define it properly
- L145-154: references to other analysis using the same isolation (indeed, it is quite standard at CMS, but as far as we know, there is no standard reference to it)
- L149-150: suggestion of rephraseing: "the contributions of neutral particles from pileup to the surrounding activity of the leptons is referred to as p_T^{PU}. It is obtained with different methods for electrons and for muons: for electrons ...; for muons..."
- L163-165: put the jet description at only one place (see L123)
- L160: "an" algorithm??
- L179-180: (second) highest? why not (sub)leading? is there a difference? other, better use standard phrasing
section 5
- first paragraph: the largest sourceS (and replace "or" by "and")
- L201: remove "However"
- L208-209: see generag comments about references (in the end, here it could be enough to say "this reference...")
section 6
- L216-218: unfolding was not even described yet (see more comments below)
- 2nd paragraph: use of \texttt{...} not consistent with previous paragraph (a priori, it is nice, but need to be consistent throughout the text)
section 7:
- general: a few subsections would help the reader
- general (L321): overall agreement? really? very few predictions are actually describing well the measurement... you say it yourself...
- Tab. 2: it should come in the event selection + muon coverage is likely wrong (muon chambers go only up to 2.4, or are you using tracker muons?)
- all figures: add "anti kt (R = 0.x)", especially relevant here where different cone size radii are presented simultaneously
- L271-275: many things to say
- should come before the uncertainties, maybe in a dedicated (sub)section
- a plot on migrations is missing (either a response matrix, or a plot on purities for instance)
- "unfolding method technique" -> redundant repetition: either method or technique
- what about fake and miss? how is the matching done?
- how did you define the number of iterations? which tests did you proceed to?
- did you cross check with other methods? (at least SVD in RooUnfold, or better: Tikhonov in TUnfold)
- did you check whether regularisation was actually needed? you seem to say that the statistics of the MC is much larger than the statistics of the data, so check the condition of the matrix: it could be that pure matrix inversion is enough (which is from far the preferrable option)
- did you proceed to all checks requested from statistics committee? check the TWiki on unfolding...
- L304: only parton shower? no MPI/fragmentation/etc.?
- L313-320: typical example of confusion between Fig. and Figure (see general example)
- Fig. 4-5 (potentially all figures): the gray bands seem sometimes smaller than the error bars... how can that be? can you check your code? we have strong doubts about the way it is implemented... JES are 17%, so a difference MUST be seen
section 8
- L334: "most recent version" -> give version number
comments from Katarzyna Wichmann
general: for MC/programs version be consistent, either with "v" or without, not mixed
line 20: ... and important test of the QCD corrections to ...
line 23: The study of the m_jj distribution ...
line 84: ... and with MCFM v7.0 [21] for 13 TeV.
line 119: Due to pileup the selected event can have several ...
line 123: strike "pp interaction"
lines 135-136: make clear how/when the tracks found outside-in and inside-out are used? which one is selected if both are found?
line 173: ... are extracted from the data ..
lines 201-210: give numbers for specific background contributions, maybe a table would be useful?
line 260: Due to the limited number of events ...
line 297-298: there is a repetition of the phrase: "causing a lower uncertainty ..."
line 313: ... at 8 and 13 TeV for NN_jets>=1 as functions of ...
line 328: a space between 3.59 and (19.7)
comments K. Lipka
l4-7 the sentence sounds a bit clumsy: “simultaneous production of VV and jets allows for measurement of jets associated with VV” which is kind of obvious but probably not what you want to say. Would a following change make sense? “Measurement of the associated production of jets and vector boson pairs gives insight into the vector boson scattering processes and probes the quadratic gauge couplings [1].”
-It would make the description in the first paragraph more clear, if some examples (feynman graphs) showing one VBS and a QCD process with the same final state could be included.
-l10: has been designed to provide -> provides (intend to test…) be more modest
-l19: no paragraph here.
-l19-20. In particular, the cross sections as a function of jet multiplicity are measured, providing important tests of QCD corrections to ZZ production. (repeating “as a function” twice (following sentence) is absolutely ok, you measure many distributions)
-l26-27: are any QCD+EWK predictions at fixed order you can compare to ? (natural way to understand QCD corrections)
-l71: could you please remove “to statistically remove experimental effects from the data distributions” or reformulate it? I assume you want to say you use unfolding to correct for detector effects and model bias (not for “experimental effects”).
-l78: you write explicitly ”NLO in QCD” because there is the LO EWK contribution?
-l79: you scale only POWHEG with a K-factor or the Madgraph is scaled up too?
l84: you probably mean that MCFM7.0 was used for 13 TeV? Did you check if the EWK constants are the same in different MCFM versions?
-l106 Suggest removing “loosely” since it is not specified what it means
-l107 (B-type) are tau decays also included (MC)?
-l116: “it is based on a complete event description” -> “event description algorithm”