Questa è una vecchia versione del documento!
http://cms.cern.ch/cds/EXO-12-002
Ernesto
Type B comments
The paper is quite dense with a lot of details especially in the introduction (lines 1-33) and when discussing the assumptions used to extract limits on the stop mass (lines 163-172). This makes it an uneasy ready despite its limited length. I think that it would be much easier to describe the analysis as a (model independent?) search of an excess in final states with a particular topology (l tau_h bb) and then to interpret the results (no excess found) in terms of two different BSM hypoteses: LQ and stop. This would be even easier if a single value of the M(tau_h,b) cut (e.g. >170 GeV) were used for the search of the LQ in the whole mass range and for the stop search (l.89-90).
In that respect, is the gain in signal efficiency the high mass hypothesis really so large to justify this complication of the analysis? Also is the “450 GeV” mass threshold relevant in the LQ search or also in the stop search?
Table 1: tt background is largely dominant (~70%) in the muon channel while it is (only) 50% in the electron channel. Is this understood, e.g. do you control the tt background separately for the electron and for the muon channel? May this explain the excess in the electron channel observed in the data?
Type A comments
$\beta$ is used in the $\tan\beta$ definition as for the LQ branching ratio. To avoid ambiguities, define the latter differently (e.g. ${\cal B}$)
Some preference for using the full word “leptoquark” instead of the abbreviation “LQ” in the main text (l.6, 42, 61, 111, 159). Fine to keep “LQ” in the captions and in the table.
l.12: $\lambda$ appears only here. Everywhere else is $\lambda'$
l.21-22: do not break the sentence. Instead of “…M_t1<M_t2. Mt1 can be smaller…” write “…M_t1<M_t2 where Mt1 can be smaller…”
l.26: “a stop and an anti-stop pair” → “ a stop anti-stop pair”
l.28: “pair pair” → probably one of the two “pair” can be removed
l.34-35: add the centre of mass energy
l.42: is it common to use the “\equiv” instead of “=” for defining a variable?
l.43: “bjet” → “b jet”
l.47: “bjets” → “b jets”
l.49: mention the size of the analyzed sample for both D0 and CDF or for none of them
l.55: “and calorimetry” → “and a calorimetry”
l.57: remove “CMS also has an extensive forward calorimetry” as it is probably irrelevant for this analysis (and CMS has also many other things)
l.72: do not break the sentence “and photons. The PF candidates are used” → “and photons, and they are used” →
l.77: is it common to use the “\equiv” instead of “=” for defining a variable?
l.80: “Jets are reconstructed using PF candidates with the anti-$k_T$…”
l.85: isn't the requirement of the mu/ele-tau_h separation already embedded in what written at l.77-78?
l.87: which discriminant was used (TCHE,TCHP) and which working point?
l.88: “the mass” → “the invariant mass”
l.94: “pair production of top quarks” → “$t\bar{t}$ pair production”
l.95: “the jet” → “a jet”
l.98: “diboson processes.” → “diboson production processes.”
l.102-103: not clear why for the W is mentioned W+jets while for the Z is just Z/gamma*→ll. Probably better to call them “inclusive W production” and “inclusive Z/gamma* production” (similarly in Table 1)
l.110: “that” → “those”
l.114: specify if the “top background” is ttbar only or it includes single top
l.117-120: “Systematic uncertainties…compared” move this sentence closer to l.135 where the same numbers are repeated for the tt background
l.120+3: remove “loose”
l.120+5: are the identification and isolation criteria used for these leptons the same used in the main analysis? If not what is the effect of the difference?
l.120+12: what “fr” stands for? fake reco? Why not call this variable “P_{fr}”?
l.123: “bjets” → “b jets”
l.151: remove “criteria”
l.163: “stop production” → “stop anti-stop production”
l.171: RPV undefined; “bquark” → “b quark”
Table 1: use “e tau_h bb” and “mu tau_h bb” in the table headings consistently with the rest of the text
Figure 1: “distribution is compared” → “distribution compared”