Version of note with results blessed by ARC

* TOP-11-028_blessed_by_ARC.pdf: This version includes the new plots requested by the ARC for Fig. 1.

Introduction

The flavor-changing neutral-current (FCNC) processes play important roles in vari- ous b decay studies, especially on the CP violation related topics. It is also checked in the hadron machines with a rather modest limits. Here a 4.6/fb data collected with CMS is used to search for this decay channel.

Event lists for comparison

Event selected for no b-tagging approach with Z+W MET > 30, and at least 2 jets > 30 (most difference comes from exact 3 lepton requirement)

Z->ee

Run ID Event ID
163760 165347126
166380 765067202
166841 42157067
167102 113554882
172033 47460671
172033 5579311723
172620 9835934
172822 1718374837
172865 328047902
176308 254672254
176309 1801917819
176933 282591029
177139 72564756
177718 1698729345
178421 776451603
179563 1826760372
180076 332256743

Z->mumu

Run ID Event ID
165467 398015722
166950 43141279
172033 5579311723
172822 1238207696
172992 802001354
175866 236532940
176201 368050803
176286 303205297
176309 1801917819
176933 694468950
177718 196584207
177790 495880738
178151 24631532
178479 52217115
179434 1087579331
179563 163370697

Events with a Z candidate (60-120), 3 leptons, MET > 30, two jets > 30 GeV, HT_s > 250

Z->ee     Z->mm    
163760 239 165347126 165467 316 398015722
166380 682 765067202 172163 531 755767436
166841 41 42157067 172822 904 1238207696
167102 109 113554882 172992 571 802001354
167102 256 267075445 175866 266 236532940
172033 37 47460671 176201 241 368050803
172620 13 9835934 176286 223 303205297
172822 2024 -1718375837 176309 1230 1801917819
172865 211 328047902 176933 297 519980845
176308 190 254672254 176933 394 694468950
176309 1230 1801917819 177718 153 196584207
176933 170 282591029 177790 388 495880738
177139 45 72564756 178151 53 24631532
177718 1080 1698729345 178151 107 115010966
177878 320 485447908 178840 161 228848831
178421 547 776451603 179434 650 1087579331
178479 67 52217115 179563 101 163370697
178708 204 340559601      
179563 1164 1826760372      
180076 186 332256743    

Events with a Z candidate, 3 lepton, MET > 30, and at least 2 jets > 30, HT_s > 250 (Yuan)

Z->ee     Z->mm    
Run ID LS Evt. ID Run ID LS Evt. ID
163760 239 165347126 165467 316 398015722
166380 682 765067202 166950 44 43141279
166841 41 42157067 172033 436 579311723
172033 37 47460671 172822 904 1238207696
172620 13 9835934 172992 571 802001354
172822 2024 -1718375837 175866 266 236532940
172865 211 328047902 176201 241 368050803
176308 190 254672254 176286 223 303205297
176309 1230 1801917819 176309 1230 1801917819
176933 170 282591029 176933 394 694468950
177139 45 72564756 177718 153 196584207
177718 1080 1698729345 177790 388 495880738
178421 547 776451603 178151 53 24631532
178479 67 52217115 179434 650 1087579331
179563 1164 1826760372 179563 101 163370697
180076 186 332256743      

Events with a Z candidate, 3 lepton, MET > 30, and at least 2 jets > 30 (Steven)

Z->ee Z->mumu
172033 37 47460671 172033 436 579311723
163760 239 165347126 166950 44 43141279
166380 682 765067202 165467 316 398015722
166841 41 42157067 172992 571 802001354
167102 109 113554882 176309 1230 1801917819
172620 13 9835934 176933 297 519980845
172865 211 328047902 176933 394 694468950
176547 73 120044930 177718 153 196584207
176933 170 282591029 177790 388 495880738
177139 45 72564756 177791 195 195934467
177718 1080 1698729345 176201 241 368050803
177878 320 485447908 176286 223 303205297
176308 190 254672254 175866 266 236532940
178421 547 776451603 179434 650 1087579331

Additionally with the requirement that exactly one of the jets has TCHE > 1.7 (TCHEL working point)

Z->ee Z->mumu
172033 37 47460671 172033 436 579311723
176547 73 120044930 166950 44 43141279
176308 190 254672254 172992 571 802001354
176309 1230 1801917819
176933 297 519980845
177790 388 495880738
175866 266 236532940
179563 101 163370697

MC sample used

Sample name cross-section calculation order
TTJets_TuneZ2_7TeV-madgraph-tauola_Summer11 157.5 NLO
WJetsToLNu_TuneZ2_7TeV-madgraph-tauola_Summer11 31314 NNLO
DYJetsToLL_TuneZ2_M-50_7TeV-madgraph-tauola_Summer11 3048 NNLO
WW_TuneZ2_7TeV_pythia6_tauola_Summer11 42.9 NLO
WZ_TuneZ2_7TeV_pythia6_tauola_Summer11 18.3 NLO
ZZ_TuneZ2_7TeV_pythia6_tauola_Summer11 7.67 NLO
WWTo2L_TuneZ2_7TeV_Madgraph_tauola_Summer11 --- NLO
WZTo3Lnu_TuneZ2_7TeV_Madgraph_tauola_Summer11 0.7192 NLO
WZTo2L2Q_TuneZ2_7TeV_Madgraph_tauola_Summer11 1.44 NLO
ZZTo4L_TuneZ2_7TeV_Madgraph_tauola_Summer11 0.03906 NLO
ZZTo2L2Q_TuneZ2_7TeV_Madgraph_tauola_Summer11 --- NLO
T_TuneZ2_s-channel_7TeV-powheg-tauola 3.19 NNLO
Tbar_TuneZ2_s-channel_7TeV-powheg-tauola 1.44 NNLO
T_TuneZ2_t-channel_7TeV-powheg-tauola 41.92 NNLO
Tbar_TuneZ2_t-channel_7TeV-powheg-tauola 22.65 NNLO
T_TuneZ2_tW-channel-{DR,DS}_7TeV-powheg-tauola 7.87 NNLO
Tbar_TuneZ2_tW-channel-{DR,DS}_7TeV-powheg-tauola 7.87 NNLO

Comparison on two approcahes:

https://twiki.cern.ch/twiki/bin/view/Main/FCNCTopCrossCheck

Comments and responses to Analysis note:

AN-2011-358

AN-2011-482

Dear John,

I'm read the updated AN-11-482 and I still have some questions and comments. There are some nice updates in there, thank you very much for so much efforts in such small time scale. However, there might be another round of comments (and some additional cross-checks) needed. Please let me know after you looked at the questions I had.

For next iterations, please use the TOP-11-028 HN : https://hypernews.cern.ch/HyperNews/CMS/get/TOP-11-028.html

Cheers, Jeremy

Table1 : The signal is actually part of inclusive ttbar. Then, if you use theoretical calculation of ttbar cross section, you need to remove from the ttbar cross section the fraction of top decaying into ZWbb, to stay consistent.

*The point is, if you use the theoretical cross section to rescale ALL standard model ttbar events, then you are searching for some extra ttbar events, not "contained" in the SM ttbar cross section, which are decaying into ZWbb. But I think this is not what you are willing to do. I think you want to estimate the Br(t->Zb) within the ttbar events produced by SM processes. I hope I was clear enough, please let me know.*

... Yes, the "measured" ttbar (bWbW) x-s. should be used here. Then the "extra" comes from t->Zb. Since the contribution is estimated to be 0 and we are not using MC expected number, this should not affect the final results.

For description of low invariant mass DY events, you have to use the MadGraph Fall11 DYToLL_10-50. This sample gives a much better description of the DY after the jet cuts.

... Originally I would expect no need as a Z mass window 60-120 is used. But this reminds me about the Fig. 1 & 2 which have no cuts on any object except for the HLT and VTX selections. I'll check again on this.

Sorry if I already asked the question but, could you remind me why you don't use the MuEG datasets ? For this dataset, triggers might have lower threshold or looser isolation criteria. You should then get few more events.

... Since we have Z requirement, it's easier to separate our events with just di-elec and di-muon trigger. With MuEG datasets, I need to filter out (more) duplicated events.

Line 56 : do you apply trigger selection on MC as well ?

... Yes.

Figure 1, 2 : I don't understand why you show plot with such bad data/MC comparisons. I still don't understand why you have so much less MC events. I'm not sure also what you would conclude from them, given that : - data is one order of magnitude higher compared to MC, - you have log scale ... So things are hardly comparable.

... Our DY MC is have pre-cuts. There would be some QCD contributions too. (checked with Z cuts and confirmed to have matched results)

Line 99 : if I get it right, you remove the events if you find 2 Z candidates in the Z mass window 80-120 ? You do not exclude the events if it has 4 isolated leptons , regarding less of the corresponding invariant masses ?

... An event with 4 isolated leptons is not rejected unless they can form 2 Z candidates with mass 80-100. After change the selection the difference on signal is ~3%

Line 132 : did you actually checked that the tops are back to back in the transverse plan ? I think his is perfectly true for LO diagrams. For the production of ttbar+Njets (which contributes significantly to the LHC cross section), or with the presence of ISR/FSR, this could not be completely true anymore.

... Will prepare a plot on the dPhi later.

Line 132 : could you please give more details of the method you used to reconstruct the tops ? For t->Zb, this is quite obvious. But how do you solved the t->Wb branch ? I think more explanations are needed in the text.

... An updated version this afternoon on this. (sorry) Basically I have (possibly) multiple W, multiple Z (sharing daughters), multiple jets and using dPhi to sort out the best one. After this, a very loose mass window 10-250 GeV is applied.

Table 3 : the cuts "2t(HT_S)" and top mass are not explained in the text. Could you please precise which variables are used and what are the cut values ?

... This means I have top pair candidate and the H_T of the event is greater than 250 GeV/c. (will put this in next updated AN)

In Table 4 : I would use the lepton and trigger scale factors as well as the data driven estimate in this table. Or at least, I would suggest to reproduce a new table later in the text with the event yields corrected for data driven estimate.

... Ok.

Section 6 : that's very nice to see some results of a data driven estimate of backgrounds. Here you estimate the backgrounds from fake isolated leptons assumed to come from W candidate. But, as the selection of leptons from the Z is different, are you planning to use the same method to estimate the fakes from fake Z candidates ?

... The "one W" selection is simple a tight, isolated lepton + MET cut. The lepton can be shared with the Z. So you see "W+Z" cut gives zero entry in MC study. To have two fake lepton and one of it pairing to pass the Z mass window (80-100) is expected to be very difficult. Not even mention about the jet selection That's why I didn't consider "one lepton" case in data-driven method.

Section 6.2 : you use Jet dataset to estimate the fake rate. But as some jet triggers are highly prescaled, and since the prescales are changing with the run number, the pT spectra of jets change with he run number. While the fake rate is function of the jets pT in your sample, you have probably a different pT spectra than in you signal sample. These effects have to be accounted, eventually as systematic uncertainties.

... Ok.

Table 7 : I don't understand the numbers. How the fake rates could be so large ? Did you remove the default lepton isolation cut in PAT when producing PATTuples ? What MC samples did you use for this studies ? Which systematics uncertainties are you considering ?

... The large error mainly comes from the statistics and the fitted ratio of pT spectra. The ratio is on (Iso<0.1 / Iso<0.2) as a pre-cut 0.2 is applied when making PATuples.

Line 164 : you normalized the WZ+ZZ yield from the number of observed event in the 0 jet bin. I think much more details should be given : - what is the contamination of ttbar, single top, signal in the 0 jet bin ?

... ttbar is of 2.7 events and others are under permill order to WZ/ZZ.

- the jet multiplicity from WZ+ZZ *pythia might not be well described. Then, the extrapolation from the 0 jet bin to the 2 jets bin is probably wrong. Could you cross check with the WZ+ZZ+WW MadGraph samples ?*

... We are updating with this sample.

- in any case, uncertainties related to the jet multiplicity extrapolation (JES, JER, Q2, matching in case of MG, PDF) should be studied.

... Ok.

WZ/ZZ are your main backgrounds. It deserves more detailed studies. Even if the presented results are very encouraging.

Section 7 : when using b-tagging, you have to account for the true b-tagging and mistag rate efficiencies in data. You then have to use the b-tagg and mistag Scaling Factor provided by the BTV POG.

... b-tagging is used only for cross-check.

Table 13 and 14 : I'm not sure to understand everything there. But I have a couple of comments. - For signal, the systematics related to Q2 and matching have to be estimated. This is affecting the signal events selection efficiency. Usually, for TTbar event, there are centrally produced ttbar MG events with different matching threshold and max Q2 scale. In your case, you would have to reproduce the samples by yourselves.

... Ok.

- why to take MC estimate for background events ? Since you have data driven estimates of them, why not to use them ? Could you justify ? You are not considering ttbar for the systematic uncertainties ?

... Here ttbar is considered with data-driven method. For WZ/ZZ some systematics such as luminosity uncertainty can be canceled so not all items in the table are considered in the upper limit calculation.

- why the MC stat uncertainty so large for signal ? How many signal events did you produced ?

... Shown in table 3. Yes, it's due to low statistics as W decays inclusively in this sample.

- extrapolate the background estimation with data from the loose selection into the tight selection and check with the MC prediction (if this takes time can be done during the ARC review).

... loose tight top mass window b-tag WZ+ZZ: 13.6+1.1=14.7+-3.8 * 0.22 * 0.13 (TCHEL) = 0.42+-0.11 ttbar+DY: 1.5+-0.6 * 0.20 (tt only) * 0.76 = 0.23+-0.09

So in total: 0.65+-0.14 which is quite consistent with the current tight background estimation from MC: 0.8+-0.9 (statistical errors only)

WZ+ZZ: 0.42+-0.11+-0.08 tt+DY: 0.23+-0.09+-0.09

adding b-tag syst.: WZ+ZZ: 0.42+-0.11+-0.97 tt+DY: 0.23+-0.09+-0.09 ==> 0.65+-0.14+-0.97 (so the benefit lost due to miss-tag)

tight selection: 0.80+-0.90+-0.18

Comments and responses from ARCs on the PAS:

See https://twiki.cern.ch/twiki/bin/view/Main/FCNCTopARCComments2

(Summarizing the responses by Mayda)


Paolo -------------- 1) Line 47: One number is given for each of the ee and mumu double lepton trigger efficiencies (97% and 90%). However, for the selections where the 3rd lepton is of the same type of the first two, the trigger efficiency should be higher, shouldn't it?

===> Correct, see Table 5 in AN-2011/358 where the selection efficiency is broken out more completely, this is explicitly shown as HLT iffy. The effect is fairly small, of order 3% more efficiency.

2) lines 57-58 and lines 60-61: the description of the requirement of muons and electrons to be associated with the primary vertex could be made once for both. Actually, this is already done later on lines 73-75, so the first 2 sentences should simply be removed.

==> done

3) Was any optimization of the final event selections performed? The cuts on MET, HTs and the windows around the top mass value would be good candidates to be optimized to see if the potential of the 2 selections could improve.

==> This was done before looking at the data. However, after the "box" was open, the two analysis were asked to converge in some basic aspects and some of the optimization was lost. Since the impact is not dramatic, we rather not change the cuts.

4) line 134: Naively I would not have expected that the correct p_z solution could be found 100% of the times by choosing the less energetic of the 2 solutions (or by any other method). Could you please point me to the study or plots that show this?

==> We did a study on the generated signal MC, and checked the reconstructed solutions against the MC truth, the lower energy solution was the correct one for 100% of ~3k events.

5) Also, in the AN-11-358 dated 2012/01/20, lines 252-253 state something else: "the two solutions for p_z are examined to determine which one (in combination with the lepton) gives the closest value to the W mass". Don't the 2 solutions give the exact W mass by definition? What am I missing?

===> Yes, this is an error that will be corrected in the next version of the AN in a few days.

6) Sections 4.1 and 4.2: I would suggest to swap the order of presenting the 2 sections. The description of the loose selection should go first and the tight after. Various things would become clearer and easier to describe I believe, or at least clearer to me. For example, since you introduce the request on one b-jet in Section 4.1, it was not clear to me (without saying it explicitely in Sec. 4.2) that this is not asked in the loose selection. I would swap the tight/loose order everywhere else too, Tables, figures etc.

===> will do in the next round�

7) Section 5: The Z+jets bkg, where a jet could fake a lepton (an electron more than a muon), is mentioned in the AN lines 221-222, but not in the PAS. Could a sentence be added?

==> done

8) Section 5: The multijet background is presumably very small with 3 leptons, however even the background level is very low in this analysis. Was the multijet bkg checked in any way?

===> it was done early on and there was no enough statistics do do anything, but it not a surprise given that with the requirement that 3 leptons pass stringent quality cuts, the multijet requirement is considered to be negligible. (It'd have to be a 5-6 jet event, and 3 of those jets would have to fake electrons (one at WP80/supertight), and the other 2 would have to accidentally reconstruct a mass in the Z window.)

9) Line 182: Table 3 is pointed to for the systematic on the bkg, but only stat. errors are reported on the table.

==> made more clear in caption

10) Lines 196 and 200: what are the 1-sigma boundaries of the expected limits?

===> Will be provided soon�

Minor or style comments:


11) line 37-38: the sentence "These events are generated .... event generator" could be removed and the citations of the generator programs simply moved to the next sentences.

==> done

12) line 42: "They are then simulated ..." --> "The CMS detector response is simulated using ..."

==> done

13) line 54 and line 60: for the muon case "strip and pixel detector" is used while for the electron case "silicon tracker" is used. The same wording could be used for both.

==> done

14) line 65: "to maintaining" -> "to maintain"

==> done

15) line 81-2: "articles" -> "particles"

==> done

16) line 86: "after correcting for multiple proton-proton interaction" could be expanded a bit, e.g. "after correcting for additional underlying activity due to multiple proton-proton interactions" or similar (and placed between commas).

==> done


Francisco --------------- In the introduction, it looks a bit odd you mention BR of O(10^-14) and then search in the O(10^-3). Are there models that make predictions in this range or close?

===> Added a sentence about the models with predictions at the level of 10-4

lines 67-66, is the 4th lepton veto done with loose or tight lepton ID?

===> tight, added info to text

line 72-77, do you really need this cut? Is there any cosmic left after all other cuts, including vertex? Does it kill any signal?

===> it does help according to EWK group and it does not harm our signal. That is, the cut on opening angle (to reject cosmics) rejects 0/17959 signal events in the MC sample we have, ie, it has no effect on signal efficiency.

lines 99-100, it's not clear to me what you intend to say here

===> added text, this also more relevant in the discussion of the signal efficiencies given in table 2.

Table 1, I agree that there are too many significant digits. Then the agreement is not always that good. Since you say that you use data-driven methods to obtain background, can this table be improved? BTW , second line of mumue, "total" column, the error seems to be wrong +-123, looks rather +-12.3

==> Table improved. Data-driven only done once the 2-jet condition is applied and not available for this stage of the preselection.

Figure 1, related to above, the agreement is not perfect. a) shows some excess in the high njets (where only signal is expected) (c) shows some excess in the Mw region. Again, if you use data-driven methods, can this be improved?

Table 2, is it really simulation only? doesn't it include the usual scale factors for trigger, lepton ID, btagging, etc?

===> yes it does, that is what the lines 99-100 are supposed to say.

Figure 2, not obvious what you mean by "basic selection"

==> Improved caption.

Section 5, are the WZ and ZZ backgrounds taken purely from data? Can't they be estimated or at least cross-checked with data? you mention DY is data driven, but don't explain at all how. Please explain or refer to other analyses. The last sentence on b-jets is rather cryptic...

==> added some clarification. It is based on MC, but scaled according to the difference between the data and MC observed in the zero jet bin in the MC/Data comparison.

Systematics, I think that more detail (or a reference) is needed of each of the systematic errors

==> will add references.

Line 193-194, again you mention "on simulated" events, while I think is more than purely simulation (or should be)

==> added clarification.

Line 201, I think this kind of statement has to come from the beginning. It is included in the harmonization I asked. From the intro say that you propose two methods and you take one that gives slightly better performance. Then I would only quote limits for the chosen one.

===> As soon as I convinced that the final answer is in I will update and make the relevant changes.

Browsing the references, I see that most refer to PAS of year 2010, aren't there newer ones?

===> You are right. They need to be updated.

----- Luca -----

line 6: why not simply: "where q is a u or c quark"

==> done

line 14: "This allow us" -> "This allows us"

==> done

line 15: "the boson" -> "the Z boson"

==> we also have a W for the 2nd top decay

Section 2: for a PAS the detector section can be omitted, leaving just "the CMS detector is described elsewhere [5]"

===> we are using the short version recommended for PAS

line 41: "Drell-Yan (DY)" -> "Drell--Yan (DY) events", with double-dash

==> done

line 42: "single top events" -> "single-top events"

==> done

lines 52-66: do we need such level of details for a PAS? Those paragraphs could be probably shortened, leaving references to the PASes.

==> reduced

line 76: "cosmic ray background" -> "cosmic-ray background"

==> done

line 86: "interaction" -> "interactions"; add comma before "after" and after "interactions"

==> done

line 89: please, use a different notation for MET: either the default E^{\mathrm{miss}}_{\mathrm{T}}, or:

\newcommand{\met}{\ensuremath{{E\!\!\!/}_{\mathrm{T}}}\xspace}

===> Need to see how to do it for the plot as well before changing

line 103: "the dibosons includes" -> "Dibosons include"

==> done

line 104: "the single top is dominated by" -> "Single-top production is dominated by"

==> done

line 105: "data and the simulation" -> "data and simulation"

==> done

line 107: "the simulated events" -> "simulated events"

==> done

line 107: "Figure 1 shows the comparison in data and simulation of the distributions of ...."

==> done

line 110: "but it also includes..." -> "where the requirement of two or more jets is also applied"

==> done

line 123: "heavy flavor quark" -> "heavy-flavor quark". Please anticipate here the b-tagging requirement and reference from line 139

==> done

line 124: "heavy quark not checked": jargon. Please use something like: "no requirement on the identification as a b-jet..."

==> done

line 124: "require a minimum value on the scalar sum of..." -> "require a minimum value of HTs" ==> done

line 126 Add "The" at the beginning of the sentence; "backgrounds" -> "background"

==> done

line 129+3: "calculated from" -> "calculated as"

==> done

line 131: "under..." -> "imposing the constraint that the invariant mass of the lepton and the neutrino is equal to the W mass"

==> done

line 139: The b-jet requirement and reference should be anticipated to line 123, where it's used for the first time. ===> we would like to keep this reference here as it is referring to the algorithms

line 150: remove "the" before M_Wb

==> done

line 151: remove "value". Remove "The" before "M_Zj"

==> done

line 154: "Figure 2 shows the comparison of the distributions of M_Zj and M_Wb in data and simulation"

==> done

line 156: "shown" -> "are shown"

==> done

line 160: "unlikely" -> "is unlikely"

==> done

line 165: for 0.23 \pm 0.54 \pm 0.04 specify stat. and syst. contributions

==> added a line about stat vs sys.

line 165: as commented by Nick, how do you deal with negative background events? It's important in the background determination: do you use a log-normal for the corresponding nuisance parameter in the CLs determination? In this case, you could quote an asymmetric uncertainty (if the uncertainty on the logarithm of the background yield is normal -> the yield has asymmetric uncertainties)

===> the 0.97 was a typo. Now corrected. It was current on the text, but not in the table.

line 165: does the estimate of 0.001 background events has an uncertainty? Please, quite it. Or just say it is negligible.

==> it was 0 +/- 0.001. That is why we are saying that is smaller than 0.001

line 167, 168: please quote uncertainties on background estimates

==> same thing� 0+/-0.004 and 0+/-0.39

line 169: "data driven estimation" -> "estimate from data"

==> done

line 172: "backgrounds" -> "background"; "error" -> "uncertainty"

==> done

line 190: "Cls method" -> "modified frequentist approach (CLs method)"

==> done

line 193,194: "This fraction is ...": not clear, pleaser rephrase and define more clearly what you mean.

==> done

line 195: "The calculated limit ..." -> "The 95\% CL upper limits are shown..."

==> done

line 206: "of the existence" -> "of the existence of the decay"

==> done

line 208: "The branching fraction of ..." -> "A branching fraction B(t->Zq) larger than..."

==> done

Fig 1: add in the caption a description of the different contributions (data are points with the error bars, the solid white histogram is the signal assuming B(t->Zq)=1\%, etc.)

==> done

Tab 1: please, reduce the number of significant digits

==> done

Tab 1: specify what are the four different blocks with appropriate labels

==> done

Tab 1: can you explain the difference between 126 \pm 11 and 194 (6 sigma) in data, and consequently 68 \pm 8 and 85 (3.4 sigma)? Is it a hint of new physics smile ? Is this reflected somewhere in Fig. 2? It's not clear to me which block corresponds to which selection...

===> added systematics, the differences are not significant.

Tab 4: maybe the b-tagging uncertainty could be presented as "8 (0)", and then the total uncertainty as "23 (21) for tight (loose)".

==> done


Nick -----------------

> 1) Abstract. the limit is given as 0.39% here, but 0.4% in the Conclusions.
> I would probably choose to use 0.39% in both places.
>

==> done

> 2) Table 1: I think we quote far too many significant figures in many numbers here.
> For example, "161226.12 +/-1269.73" I would change to "161666+/-1270"
> similarly "425.66 +/- 20.63" change to "425+/-21" and many others.
>

==> done

> 3) Table 2: I would put the percent sign in the table itself.
> Also in "0.375+/-0.13" the number of significant figures doesn't match.
> Change to "0.37+/-0.13%"
> Same for other numbers under "Tight selection".

==> done

>
> 4) general comment: somewhere (first time) when saying xxx+/-yyy+/-zzz
> we should say which is statistical and which systematic.
> Is it CMS style to say this everywhere?
>

===> not sure what CMS standard is. Added general comment "The uncertainties in the background estimation include the statistical and systematic components (in that order)."

> 5) Table 3: There are many of these, but this one jumps out.
> "0.65+/-0.14+/-0.97" This would seem to imply that negative numbers
> of events are OK. We should decide how best to deal with these cases
> and use that style everywhere.
>

===> this was a typo : the correct value is 0.65 +/- 0.14 +/- 0.011 Individual background estimates were correct in the text in Sec. 5. Section 7 has the same mistake as in Table 2.

> 6) Table 3
> Also, is 0 events background in the tight selection really allowed at one standard deviation?
> This would seem to be in conflict with the quoted WW background
> of "0.38 +/- 0.10 +/- 0.06". I don't think adding the uncertainties in quadrature is
> appropriate here.
>

===> Part of the discussion given above.

> 7) p.2
> Somewhere we should say that all three leptons are required to come
> from the same vertex explicitly.
>

==> done

> 8) p.3 Section 4.
> In the second sentence we say "We also expect BR(t->Zq) to be small..."
> I would move this to Section 1 Introduction to right before the sentence
> "We present a search for t-> Zq...." This explains why we chose to search in
> this channel.

==> moved to introduction

>
> 9) p.5 Section 7 - Results
> We should say explicitly how the limit is calculated for the loose selection,
> particularly since this is the result we end up quoting as our final result.
>

===> changed

> Editorial Suggestions.
> 1) p. 1
> "properties within the standard model (SM) and as a probe of new physics."
> -> "properties both as a test of the standard model (SM) and as a probe of new physics."

==> done

>
> 2) p.1
> "large enhancement, hence a model-independent..."
> -> "large enhancement, and provides a model-indepedent..."
>

==> done

> 3) p.1
> "for a cleaner measurement at the expense..." ->
> "for a measurement with less background at the expense..."

==> done

>
> 4) p.2
> "which associates with the most transverse activities." ->
> "associated with the most transverse energy."
>

==> changed

> 5) p.3
> "the Particle Flow Technique" -> "a Particle Flow Technique"
> "The anti-k_T clustering..." -> An anti-k_T clustering..."

==> done

>
> 6) matter of taste but I would spell out Drell-Yan everywhere and not use "DY".
>

==> Done

  • Number of Jets after common basic selection without re-normalizing:
    hist_njets.png

  • Number of Jets after common basic selection after re-normalizing:
    hist_njets_sc.png

Topic attachments
I Attachment History Action Size Date Who Comment
PDFpdf TOP-11-028_blessed_by_ARC.pdf r1 manage 480.5 K 2012-02-22 - 16:42 MaydaVelasco  
PNGpng hist_njets.png r1 manage 16.0 K 2012-02-20 - 14:27 YuanChao Number of Jets after common basic selection without re-normalizing
PNGpng hist_njets_sc.png r1 manage 13.8 K 2012-02-20 - 14:28 YuanChao Number of Jets after common basic selection after re-normalizing
PNGpng hist_top_dphi.png r1 manage 11.6 K 2012-06-12 - 11:30 YuanChao  
Edit | Attach | Watch | Print version | History: r12 < r11 < r10 < r9 < r8 | Backlinks | Raw View | WYSIWYG | More topic actions
Topic revision: r12 - 2012-06-12 - YuanChao
 
    • Cern Search Icon Cern Search
    • TWiki Search Icon TWiki Search
    • Google Search Icon Google Search

    Main All webs login

This site is powered by the TWiki collaboration platform Powered by PerlCopyright & 2008-2019 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback