http://cms.cern.ch/cds/FWD-11-002
Nicolo'
The paper presents clearly a nice and really important measurement. It provides details on the method and explanation on why the measurement is relevant.
The figures are relevant and clearly presented.
There are two main points we would like to see addressed
1) The English is not as fluent as we would like. Sentences are very long, with a lot of sub-structure. This makes the paper difficult to read. We suggest a revision.
2) In the last section, the paper presents the pt spectra for the fwd and central jets, and presents the fact that models do not reproduce them. It would be nice to go one step further and plot the 2D distribution of the pt of the two jets, to see what are the correlations in the data and in the model.
We congratulate with the authors for this nice work.
Michele
general comments
o) This is an interesting measurement. The combined study of forward and forward-central jets is very powerful.
o) The introduction appears to promise more (multiparton production, DGLAP, BFKL, CCFM, PDFs) than what we say in the conclusions. It might be appropriate to tone down the introduction a little bit, or perhaps make the conclusion sharper, if possible. As an example, based eg on Fig 8, one is tempted to conclude that Pythia 6 (D6T and Z2), Pythia 8 and Cascade are completely ruled out by the data. If this is so, then we could perhaps write it ?
o) Along a similar line of thought: it would be useful to know to what degree the current data are sensitive to unexplored regions in x and Q2. In other words, which of the measured bins probe regions where the PDFs were never measured ?
o) Do I understand well (sect 4) that PF objects were not used ? why ?
o) The text is sometimes difficult to read. Reading/checking by a native speaker of English might be useful.
o) Figures are very difficult to read in black and white. We should not assume that the reader has a colour printer – in fact text/captions should not refer to colours in the figured.
General cosmetic comments
o) please use the past tense for all events in the past, eg
data have been analysed –> data were analysed
events are required –> events were required
the vertex is reconstructed –> the vertex was reconstructed
Pythia is run –> Pythia was run
etc
o) please avoid dangling gerunds, eg
efficiencies are determined taking –> efficiencies are determined by taking
factors derived using data –> factors derived by using data
etc
o) please hyphen two-word combinations used as an adjective, eg minimum bias trigger –> minimum-bias trigger etc
o) please use abbreviation Fig. except when at beginning of sentence when Figure is ok.
line-by-line comments
o) Abstract – eta region is different from that in the main text
o) l 15 provideS
o) l 22 with –> by
o) l 24 for general vector-boson… –> for the measurement of vector-boson scattering cross sections
o) l 75 First, data –> Data
o) l 78 Secondly, data –> Data were also collected
o) l 84 beamS
o) l 85 centre of the detector –> nominal interaction point ?
o) l 92 ratio of the events –> ratio of the event yields
o) l 93 over the events –> over the yields of events
o) l 105 individual readouts of calorimeter channels –> individual calorimeter readout channels
o) l 109 forward and central –> central and forward
o) l 139 true centre – how was this determined ?
o) Fig. 1, If I understand well, these are not cross sections, but partially corrected yields. Please change caption and vertical label of plot accordingly.
o) l 160 diverse –> different ?
o) just below l 166 both methods –> the two methods
o) 4 lines below that –> which
o) l 168 comma before 'respectively'
o) l 169 obtained BY comparing
o) ll 167-175, including the paragraph without line numbering just above: I lose my way. Why is the correction factor now a function of sigma and not pT ? in fact I am not even too sure what f stands for here. Please clarify.
o) l 176 please consider rephrasing as Determination of the cross section and the systematic uncertainties
o) l 191 studied reconstructing –> studied BY reconstructing
o) l 191-193 what about the pileup without a vertex (which is probably important in the forward region) ?
o) l 206-208 shouldn't this be a bullet on its own ?
o) l 213 subdominant with respect to –> smaller than ?
o) Caption of Fig 3 uncertainty adding –> uncertainty obtained by adding
o) Table 1: please use fewer significant digits – uncertainties should have no more than two. Also please use the same number of significant digits in result and uncertainties.
o) l 217 Please consider rephrasing as Results and comparison to theory
o) l 229 Pythia 6 –> The Pythia6
o) l 239-243 Please consider splitting into 2-3 sentences – as it is it has two levels of incidental sentences built in and is difficult to read.
o) l 256 and added –> and the resulting variations of the PDFs added
o) l 262 subleading –> smaller
o) l 266 to 68% –> to the 68%
o) l 267 account –> accountS
o) l 269 and added –> and the resulting change in the results added
o) Fig 5, caption
error-bars –> error bars
show statistical uncertaintes and the systematic –> show THE statistical uncertainties; the systematic
o) l 292 please consider removing 'in comparison to data'
o) l 296 please consider removing 'with varying PDFs'
o) l 298 please consider removing 'at all pT bins'
o) l 299 the reader would probably be grateful for a one sentence 'bottom line' of this section.
o) l 309 the ratio…are –> the ratio…is
o) l 320 with THE Herwig parton shower
o) l 320 shape well –> shape of the data well
o) l 321 the normalisation –> their normalisation
o) l 323-324 It would be nice to say something for the uninitiated reader about the meaning of the comparison with a parton level prediction. WHat is the expected size of the correction ?
o) l 325-337 I wonder if one could be stronger and more explicit here: there seem to be a number of curves which are very far away from the data (Pythia 6 d6t and Z2, Pythia 8, Cascade). Aren't these MC simply ruled out by the data ?
o) l 337 here as well it would be nice to have a one- or two-sentence summary of this section. Which generators are ruled out ? what have we learned ?
o) l 341 please remove comma
o) l 341 by –> with
o) l 343 range of 35 –> range 35
o) l 345 scale –> scale uncertainty.
o) l 345-6 in parton –> in the parton
o) l 346 as well as accounting etc – something wrong with the structure of the sentence.
o) l 354-5 reproduces better the shape and absolute normalisation of the coincident central and forward jet spectra –> reproduces better the shape and absolute normalisation of the data with simultaneous production of central and forward jets
o) l 357 data-model disagreement –> disagreement
o) l 366-400 please replace with current file (notably remove line 400)
Marco
Trovo che il papero prometta piu di quello che puo realmente dimostrare
La misura e' motlo interessante e interpreto la generale discrepanza con i modelli come un “bene”, visto che la questione dei multijet e in particolare dell'adronizzazione e' tutta da capire
Non riesco a condividere come l347 si parli di globally well agreement per quanto ci sia il caveat del current uncertainties che sono dell'ordine del 20-30%
Credo che le conclusioni siano globalmente da rivedere in chiave piu' realistica: ad esempio
357 Calculations including resummation of low-x logarithms, as in the CAS- 358 C A D E Monte Carlo, do not reproduce well the central jet spectrum, but alternative approaches 359 that account for multijet BFKL-type topologies such as in the HEJ model reach a reasonable 360 agreement with the dijet data albeit at the parton-level.
e' vera per central jet ma falsa per il forward jet.
Per le questioni di forma mi allineo con quanto detto da Michele e Nicolo