http://cms.cern.ch/cds/B2G-12-015
Per ora solo nel link: https://cds.cern.ch/record/1603150
Stefano C.
TYPE B:
The paper is well written even though the analysis is quite complicated. Nevertheless the readability can be improved with a better description of the event samples and the channels involved in the analysis.
- For instance, it is not always clear which event sample is targeting which final state of the TT decay. One way of making it more clear would be to add a table with all the samples considered, the summary of the cuts applied to target specific final states etc.
- Another point is the following: how is the Higgs decay treated? In lines 65-66 the authors say that the decay of the Higgs is incusive assuming SM BRs: this is a clear statement about the MC samples used, but there is no mention on the strategy for “tagging” the Higgs in the data samples. How is the sample enriched in T→tH is not really explained, while it is clear how you are tagging W (leptons+MET, W-jets) or b-quark (CSV).
TYPE A:
Abstract
- “accumulated” → “collected”
Main Body
- L 14-28: consider putting a figure with a Feynman diagram of the processes involved
- L 20: what does “democratic” mean in this context?
- L 107-108: not sure that the reader wants to know efficiency and purity of b-tagging algorithm with such a precision
- L 110-112: it is not 100% clear the way you apply this additional jet-analysis and the interplay with the standard jet-recobstruction using the anti-kt algorithm. Please rephrase or add a statement to clarify
- L 145-148: the procedure is not clear to me. Furthermore: “initially” refers to what? If “initially” then also “finally” or “in a second step” should appear somewhere… Please rephrase this part
Figure 1
- consider using a different color for the pulls in the bottom, since it's exactly the same as the top background above
- where does the uncertainty come from? Statistics + systematics on the normalization? Add a line in the caption
- L 155-159: rephrase to avoid repetition
Table 2
- remove the arrow after lepton flavor
- L 175: consider removing “four”, since in the following lines (until L 183) the reader can find only 3 categories
- L 237-240: it would be good to have some more details on the shapes. Are they binnned shapes? How are they obtained? For example, I see in figure 2 that the signal sample seems to suffer from low statistics at low value of the BDT: how did you deal with this?
- L 245-259: what about listing the systematics? this paraghraph can be re-organized and make it clearer
Figure 6:
- slightly bigger?
Table 5:
- is it really necessary to have this table? consider dropping it, since the figure 7 standalone is already very explicative
- if it is essential, remove the “Scenario” column, since it is useless and there is no other mention on “scenarios” through the text
Giacomo
Type B
The article presents some new stringent limits on the existence of T, and for the first time this includes all the final states. This is of clear interest for all B2G searches. The physics message is clear and well presented. The article is well written and it's of easy understanding even to people not expert of the argument, and I think it just need some minor improvements.
I would put some more emphasis on the fact that this is the first such measurement performed that does not depend on assumptions on the final states branching fractions. A sentence underlying this fact can be easily added to both the abstract and the introduction without altering too much the paper flow.
I would also consider to expand a bit the conclusions, as they are now they are very short. Maybe you can add a sentence about the fact that no excess is visible in the data.
Type A
Abstract:
The last sentence “Limits between […] states” can be easily misunderstood. As it is written now it seems that the exclusion region goes from 687 to 782 GeV. Please rephrase it into something like “A lower limit of 687 is set for all the possible final states branching fractions. Depending on the branching fraction, more stringent lower limits can be set up to 782 GeV” (or just re-use the sentence in the conclusion, which is clearer)
Introduction:
Lines 3-7 Some theoretical references are needed
Line 7: remove “, for example,”
Lines 10-13: Are there consequences from these assumptions? Is there any reference you can quote that can justify them and proves they do not severely affect the analysis?
Line 16: Add “of the cross-section” after “ … order calculation”
Line 20: Please consider rephrasing this sentence, and possibly avoid the “democratic” adjective
Line 23: “signal independentLY”
Event Samples:
Line 69: CTEQ6ML does not have any reference
Event Reconstruction:
Line 98: “differ only by a few percent from 1”, please put the actual numbers
Lines 115-117: You can consider to drop the part “it can also […] has smaller pt” to make the text smoother
Multilepton channel:
This section needs some re-organization of the text. As it is now it is a bit confusing, you start saying there are 4 categories, then say that there are 2 di-l (OS, SS) and tri-l and then after a while you say that there are actually 2 OS.I would list all the categories first (OS1, OS2, SS, tri-lepton) and then discuss them separately.
Limit computation and systematic uncertainties:
Are you using the CLs method for the limit? If so please specify this somewhere and put a reference.
Figure 6: Why did you decide to quote sigma instead of sigma/sigma_95%, that is a more common way to present limits? (If it is a standard way to present B2G results please ignore this comment)
Figure 6: Can you make this figure bigger?