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= D*+- production in ATLAS =
Institute paper reading 'Measurement of D*± meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector' [http://cdsweb.cern.ch/record/1384502/ (cds link)].

[http://cdsweb.cern.ch/record/1340990/ ATLAS internal documentation]

== First draft, deadline for comments October 3rd 2011 ==
* [http://cdsweb.cern.ch/record/1384502/files/Dstar_jets_1.pdf| Link to cds first draft]
* Ad-hoc meeting to comment the paper on Monday (October 3rd) at 11:00

=== Lukas ===
Here are my comments (mainly consisting of things I do not understand):

23+ : Further experimental measurements on heavy flavor production will help in testing improved QCD-based models.
=> Does anybody know what those models are?

(not numbered line, first page lower left corner): The measured quantity reported here is R, the fraction of D∗± produced in jets, hereafter called D∗± jets...
=> this sentence is unreadable to me (its 10 lines long..).

90: where three different configurations: n = 5, n = 10 and n = 15, were used.
=> ":" should in my opinion not be used in the middle of sentences

104-109: another pretty long sentence

125: The NLO calculations predict partonic cross sections that are unmeasurable.
=> How can they be unmeasurable when the LO predictions seem to be?

140: Events are required to have >= 1 pp vertices
=> at least one? seems ugly written as it is now

165: Finally, a pT and η dependent jet energy scale (JES) [29] is applied
=> does one really apply a scale? or rather a correction or a factor?

207-209: The signs seem to be messed up.

FIG1: I don't understand those plots. What peek do I see when considering m(K,pi,pi)-m(K,pi)-m(pi)?

===additional comments (cborer):===

104ff: in addition to being long it consists of a lot of information compressed without explanation (or should that be standard knowledge?)

156ff: clusters are split or merged... might be just me, but this is not clear to me at the end of the sentence

397ff: standard procedure? (no reason given to why)

=== Lucian's comments ===

A: Unitary use of "experiment" and "detector" in title of paper and abstract (L2- of abstract)

B: parts of the paper seem to be written in present while other parts are in past

11: "showed results higher" - results cannot be higher - rephrasing needed

30: E(jet) is the D*\pm jet energy" - some might understand is the D*jet and not the jet with a D* in it (at least that is how I first read it)

70: => L2 and EF are software based

71: clearly stating that there is (not?) a L2/EF trigger selection

125: "The NLO calculations predict partonic cross sections that are unmeasurable" ???

171: jets between 25 and 70 GeV. Why this restriction ? Does not be explained anywhere!

174: first mentioning of D*jets while it was mentioned before i.e. L30

195: "MC simulation predicts..... consistent with what has been observed in data" - what is the degree of consistency?

203: "the momentum fraction of the D* is required" - was this defined anywhere?

Comments on Figures:

a) origin numbers are overlapping in all plots ... should be fixed

b) fig 3 might look better in log .... in the end on the bottom of it one cannot see any diff between all lines/points

text under figure 1 (unfolding)-last line: - "in order to obtain the measured quantities truth level " - should be particle/parton level- same comment after

=== Tobias's comments ===
no additional comments

=== Teresa's comments ===
As general comments:

- Many parts of the paper would benefit from some rephrasing to make it more precise and easier for the reader.

Examples:

380 "This is not a surprise."

125: "The NLO calculations predict partonic cross sections that are unmeasurable"

- "MC calculation/program" substitute for a more precise explanation or MC simulation, MC prediction

Introduction: first paragraphs: theory and data being dominant source of uncertainty, not clear.

27-28: give a few examples of the new physics searches use.

31 (and eq 5): clarify if only events that satisfy the selection D->D0pi D0->Kpi are used or if this number is corrected using the corresponding branching ratios.

51-53: Is this selection "typically used in ATLAS" or is it a selection required in this paper? If it is the first one, get rid of the sentence. If it is the later, get rid of "typically". Wouldn't it fit better in the "Event selection" section?

71: clarify that not HLT selection is used

72-73: "system of minimum bias trigger scintillators (MBTS)" -> "minimum bias trigger" [Explain below the use of scintillator and the acronym]

74: suppress "uses coarse detector information"

76: "A simplfied jet finding algorithm" in my opinion can be missleading regarding L1 jet trigger operations

79: Add reference to jet trigger description

84: suppress "above the threshold".

85: Add reference to MBTS description

95: Clarify MC treatment: since the jet trigger efficiency for these items is significantly different for jets ~50GeV (JES scale) it will affect pt distribution of low pt jets. Is the MC scaled to take the trigger prescales into account?

100: add a sentence summarizing the conclusion

101-132: Consider rephrasing. The simulation steps for each case are not cristal clear. Also in the "Conclusions" chapter seems to be an identification between pythia and leading order (as opposed to POWHEG and NLO) that seems to not be such when reading 129

144: suppress "region. Maybe add in line 143 "to the center" -> "to the nominal center"

156-157: would it be worth suppressing this sentence? if not, could it be rewritten or at least add some reference.

160-170: Review to rewrite more clearly/precisely

178-180: consider clarifying that only tracking info is used, no calo. How are the tracks chosen to be K and pi candidates? (out of all the possible combination... the ones closer invariant mass to D0 PDG value?

177,183 why pt>1GeV in one case and pt>0.5GeV in the other? Please motivate if possible

189-191: r definition is not clear.

195: "MC simulation predicts..... consistent with what has been observed in data" Quantify?

204-205: which reconstruction efficiency depend on z? (does it depend on z or pT?)

Caption figure 1: between the invariant mass of the wrong sign... (not clear)

Eq. 1, 2 and 3 seem to refer to the same quantity and have different definitions.

227: "after unfolding" rephrase

228-239: hard to read. Would it be possible to make it easier for non expert reader?

[Ex. "reweighting" in 233 it is not clear which weights are being used]

247:"where its" -> which

Systematics chapter: It is not clear why some cases <1% are discussed and taken into account and others said to be <1% (line ) are considered to be negligible

263: This sentence doesn't seem obvious to me. I need to check the support note, i am not sure trigger studies are correct. Wouldn't it be better to have it at the end as a conclusion after the studies?

293: migration matrix is being used without being defined.

295-296: sentence no clear, please rephrase

305: "approximately" -> "estimated to be"?

314: what does it mean "varied coherently". If they are varied the same amount 'in the same direction' doesn't seem clear to me....

327: "this full" refers to what?

336: rephrase or clarify. The connection between these numbers and the 14% in 331 doesn't seem so obvious.

343: "small (<1%)" -> below 1%

361: quote numbers (and references). Are uncertainties from PDG?

363: Start new paragraph before "Other

Results and Discussion chapter: Discussion regarding pythia, herwig and powheg is not easy to follow. Would benefit from some rewriting.

370: "Integrating" maybe a bit more clarification is needed.

406-407: The uncertainty values used are significantly higher than the mass errors in the PDG. Why?

421-422: "This is understandable..." Doesn't seem some obvious to me

== Comments to be added to CDS for draft 1 ==

* [http://cdsweb.cern.ch/record/1387035?ln=en/Link to our comments to draft 1 on CDS]
Based on above comments + extra input and discussion in the meeting (apologies for the 2h duration)

As general comments:

- Many parts of the paper would benefit from some rephrasing to make it more precise and easier for the reader.

Examples:

380 "This is not a surprise."

23+: "Further experimental measurements on heavy flavor production will help in testing improved QCD-based models."

125: "The NLO calculations predict partonic cross sections that are unmeasurable"

[Also: there are some very long sentences, might be worth to try to make them shorter. Ex.: line 28 "The measured quantity reported here is R..."]

- Use of ET or pT of the jet: either use coherent notation and naming or clarify the differences and the reason to choose one or the other.

Ex.: z definition in line 28, uses p in the numerator and E in the denominator

- "jet production rate" -> "jet production ratio" when referring to R (Ex. line 370)

- "MC calculation/program" substitute for a more precise explanation or MC simulation, MC prediction

- Parts of the paper seem to be written in present while other parts are in past

- Try to be coherent when using "experiment" or "detector" (Ex. tittle and line 2 in the abstract)

Comments on Figures:

a) origin numbers are overlapping in all plots

b) fig 3 might look better in log .... in the end on the bottom of it one cannot see any diff between all lines/points

----------------------------------------------------------------------------------

Notation used below: "->" means substitute the expression on the left for the one on the right. If editors have an expression that consider more suitable, please feel free to use it.

----------------------------------------------------------------------------------

Abstract

"carry a fraction of their jet's momentum" -> "carry a fraction z of their jet's momentum"

Clarify that this is an inclusive measurement (meaning for all D*+- and not only for the ones with the decay channel quoted in line 5)

----------------------------------------------------------------------------------

Introduction

If possible rewrite to clarify if more data is needed or more precise theory predictions, it doesn't seem clear to us.

11: "showed results higher" - results cannot be higher - rephrasing needed

27-28: give a few examples of the new physics searches use.

28: z definition, add it as a equation so it can be referenced later

28: "hereafter called D*+-jets" as said above this sentence would be easier to read if broken in several sentences. This part in particular is not clearly defined. The use of "D*-jets" from here on, could be better.

28: "in bins" introduction of the word bins here seems unneeded, postpone its use until later.

30: E(jet) is the D*\pm jet energy" - please try to rewrite more clear.

31 (and eq 5): clarify if only events that satisfy the selection D->D0pi D0->Kpi are used or if this number is corrected using the corresponding branching ratios.

----------------------------------------------------------------------------------

Detector

40-41: x,y and z are used without being defined. Use ATLAS standard paragraphs here.

47: 2 Tesla -> 2T or two Tesla

51-53: Is this selection "typically used in ATLAS" or is it a selection required in this paper? If it is the first one, get rid of the sentence. If it is the later, get rid of "typically". Wouldn't it fit better in the "Event selection" section?

57: "lead liquid argon calorimeter" reads strange.-> get rid of "lead" and add before the "," "with lead absorber" or something similar

Crosscheck calorimeter materials. Tungsten is missing in the forward calo description

70: => L2 and EF are software based

71: clearly stating that there is (not?) a L2/EF trigger selection

72-73: "system of minimum bias trigger scintillators (MBTS)" -> "minimum bias trigger" [Explain below the use of scintillator and the acronym]

74: suppress "uses coarse detector information"

76: "A simplfied jet finding algorithm is based on" -> "Jet finding is based on"

79: Add reference to jet trigger description

84: suppress "above the threshold".

85: Add reference to MBTS description

----------------------------------------------------------------------------------

Data and Monte Carlo Samples

89 (and in systematic section) L1_Jn: ATLAS jargon, suppress it. Rephrase explanation in 89-92

95: Clarify MC treatment: since the jet trigger efficiency for these items is significantly different for jets ~50GeV (JES scale) it will affect pt distribution of low pt jets. Is the MC scaled to take the trigger prescales into account?

100: add a sentence summarizing the conclusion

104-109: Long sentence, please rephrase.

101-132: Consider rephrasing. The simulation steps for each case are not cristal clear. Also in the "Conclusions" chapter seems to be an identification between pythia and leading order (as opposed to POWHEG and NLO) that seems to not be such when reading 129

----------------------------------------------------------------------------------

Event selection

140: "Events are required to have >= 1 pp vertices" => "Events are required to have at least one primary vertex"

144: suppress "region. Maybe add in line 143 "to the center" -> "to the nominal center"

156-157: would it be worth suppressing this sentence? if not, could it be rewritten or at least add some reference.

160-170: Review to rewrite more clearly/precisely: Ex.:165: Finally, a pT and η dependent jet energy scale (JES) [29] is applied => does one really apply a scale? or rather a correction or a factor?

171: jets between 25 and 70 GeV. Please motivate the kinematical constraints of the measurement

174: first mentioning of D*jets while it was mentioned before i.e. L30

178-180: consider clarifying that only tracking info is used, no calo. How are the tracks chosen to be K and pi candidates? (out of all the possible combination... the ones closer invariant mass to D0 PDG value?

177,183 why pt>1GeV in one case and pt>0.5GeV in the other? Please motivate if possible

189-191: r definition is not clear.

195: "MC simulation predicts..... consistent with what has been observed in data" - what is the degree of consistency?

203: "the momentum fraction of the D*" quote equation defining z

204-205: which reconstruction efficiency depend on z? (does it depend on z or pT?)

207-209: Typo in the signs

text under figure 1:

between the invariant mass of the wrong sign... (not clear)

(unfolding)-last line: - "in order to obtain the measured quantities truth level " - should be particle/parton level- same comment after

----------------------------------------------------------------------------------

Unfolding

Clarify when "true" "truth" is referred to parton or particle level.

[Ex. page 3 two last sentences]

225: Rephrase so the sentence doesn't start "If detector resolution effects were negligible"

Eq. 1, 2 and 3 seem to refer to the same quantity and have different definitions.

227: "after unfolding" rephrase

228-239: hard to read. Would it be possible to make it easier for non expert reader?

[Ex. "reweighting" in 233 it is not clear which weights are being used]

247:"where its" -> which

----------------------------------------------------------------------------------

Systematics

It is not clear why some cases <1% are discussed and taken into account and others said to be <1% (line ) are considered to be negligible

263: This sentence doesn't seem obvious to us, wouldn't it be better to have it at the end as a conclusion after the studies?

293: migration matrix is being used without being defined.

295-296: sentence no clear, please rephrase

305: "approximately" -> "estimated to be"?

314: what does it mean "varied coherently"

327: "this full" refers to what?

336: rephrase or clarify. The connection between these numbers and the 14% in 331 doesn't seem so obvious.

343: "small (<1%)" -> below 1%

361: quote numbers (and references). Are uncertainties from PDG?

363: Start new paragraph before "Other

----------------------------------------------------------------------------------

Results and Discussion

370: "Integrating" maybe a bit more clarification is needed. Connection between Table1 with numbers of the order of 0.00X with eq 5 result, is not obvious.

Discussion regarding pythia, herwig and powheg is not easy to follow. Would benefit from some rewriting.

397-400: Is this a standard procedure? Can some motivation on the values chosen be given?

406-407: Add the mass scale. Also the values used are significantly higher than the mass errors in the PDG. Please motivate the use of these numbers.

421-422: "This is understandable..." Doesn't seem some obvious to us, though we might be missing something. Could you clarify why?

----------------------------------------------------------------------------------

Conclusions:

442: reference to eq defining z

== Second draft 28 Oct 2011 ==
* [http://cdsweb.cern.ch/record/1394221 | Link to CDS second draft]

DStarPaper2011 - Revision history

Lhep: 1 revision imported

Lhep at 19:01, 5 November 2011