Dear Wouter,
On 03/28/2013 11:07 AM, Wouter Hulsbergen wrote:
I have been volunteered to send in our institutional review of the B0s->phiK* paper. For details see below. If you would like me to include your comments, please send them to me by April 4th. (There is no reason to be bored in your Easter holidays!)
Here are my comments for the phi K* paper. About being bored, I must say it's one of the worst LHCb papers I have seen in collaboration wide review for quite a while. I couldn't read more than 3 pages at once without getting too angry to continue. This is a surprise to me with Steve and Steven on the committee. Anyway, Here's what I have:
General: ------------ We are not convinced by your 6.06 significance. It's the significance for observing KKKpi in a 14x300 MeV^2 window. You determine that only 89% of that is phiK*. The significance of Bs->phiK* should be determined from the probability of all backgrounds to fluctuate to the yield you see. These backgrounds include the non-resonant component (as this is nto part of what you report). How does your significance change if you take that into account?
Line 131: Your training explicitly removes phi. Does that mean real phi are not your typical background? I would have expected the opposite. If you had trained on real phi's maybe the Bs->phiphi background (L.139) wouldn't be a problem?
282: why would a set of rectangular cuts tell you anything about systematics? If you have used rectangular cuts, would you have checked for biases with a GL? We don't think this needs to be included in the systematics.
Wording: ----------------- abstract: of 6.06 sigma -> in excess of 6 sigma 2: use template \cp 3: B mesons 4: do you really need NP? In line 8 "would indicate NP" doesn't read very well. 7: SM CP violation -> the SM prediction for CP violation 9: given by -> by a factor. "consequently... scale" is too vague. What scale? 13: $B$-factories. Here and in many places you use a long dash -- when you should be using a hyphen -. q is undefined. 14: K_S : Here and in many other places use the LHCb template for particles. 15: Do Time and Violation really need to be capitalised? 16: Ref.~[4] 17: "more valuable" wrt what? 20: highly -> dominantly (?) 22-23 and many other places. You use rho, omega, K*, phi without stating that you mean rho(780), K*(892), phi(1020)... 25: comparable with, and -> of similar size, or 27-28: We am not sure how I should understand this sentence. Is the comma at the right place? 29, 32: ~ -> about 31: There seems to be a large space in front of [17 32: "quite large" is vague 33: Ref.~[20]. 34: There must be more other B->VV modes if you count higher excitations of phi and K*. 37: No error on 1.3? Without that info we cannot judge if the statement "not compatible" is correct or not. What's the level of incompatibility? 39: "some evidence" is vague 43: into light vector. This sentence is long. Maybe cut after the parenthesis. 49: which polarization puzzle? The one mentioned in lines 23-26? 73: 3 kHz 81: \bquark-hadron 95 and many other places: It seems to be assumed that kaons and pions are always charged. Please say so. It would make the paper clearer if you always put the charge. 96: the KK -> a KK footnote 2: {miss} -> {\rm miss}. Same for corr. 110: remove baryonic. Lambda_b is not the one from the template. 116: opening -> momentum 118: physics -> natural (?) 119: No dash in Geometrical Likelihood 120: No dash before meson 125: "reconstructed from... tracks" what does that mean? 136: Boosted Decision Trees should be singular and we have a standard sentence for that. See recent publications. 142: simulation -> simulated 145: Ds: use template 150: DLL_pk -> DLL_pK 151: use \L from template. Also Lambda_c 158: small sample of two combinations -> small contribution from the decays 165: Reference missing for mass difference. 166: "plus a Gaussian" means what? 167: You don't need to define the CB. 170-171: Do you have evidence from simulation for this claim? Our experience is that the tails come from events that have a large mass error due to long extrapolation distances and small opening angles. If your explanation is correct then a Gaussian model is not the best description. You can easily kill these candidates using the mass error. 176: the parameter you fit for is that ratio of the factors of Gaussian and CB (not the ratio of the functions). Table 1 and 191-192: You use Events and Candidates interchangeably. Are they? 195: why parentheses? Lines 202-206: is the formula really needed? Fig2: what's the point of the top plot? There's a parenthesis too much in the label. M and c should be italics. 216: form -> from 223: The p_T of the daughters could also come from a different p_T of the B mesons, which could be a much larger effect. We have measured f_d/f_s in bins of P_T. You can refer to that. Eq.1 : f_\dquark, {\rm Acc} (also elsewhere) 240: are discussed in section 8. No comma after 10^-6 242-246: This comment is meaningless here as you have not yet included a systematic error. Please move this to the conclusion. Table 2: to -> used in. with -> in 255: "The angle convention is shown..." also add it is described in the caption. 257: That optimizes... what optimizes? And why? 259: period missing. 263: calculation ... depends on -> determination ... is affected by. 265: was -> is. Generally stick to present tense except for the data taking description. simulation -> simulated. 265: weighted : how? 270: accounted -> accounts 275: to Monte-Carlo -> peudo-experiments. 280: "official" ? 289: Table.. Figure (also elsewhere) Table 3: S-wave Fig 4: There are 2 dotted lines but no dashed line. Please change the figure to match the caption. green line -> green dotted 295: effects -> uncertainties 298: give 1.7 additional... does not really mean anything. 304: remove "with an uncertainty of" Table 4: BR is undefined (and should be roman) 320: why do you suddenly allow for K+pi- combinations? It's Bs->phi(KK)K*bar(K-pi+) you measure. 326 and 330: result -> central value. But we presume the central value of the theoretical expectation and Vtd/Vts are actually the same thing. 334: of -> for 335: "disagrees" is too strong for 2 different channels. Refs: use the LHCb refs from the template. [1] and many others: Collaboration -> collaboration [6] and many others: BABAR -> BaBar. BELLE->Belle [15] No title for Ali? [18] and many others: Remove capitals in title. [24] should be replaced by the trigger paper. [30] why CASCADE? It's just the word "cascade" [32] is that the correct title? [33] Remove paper numbers.
Cheers, Wouter
Title : First observation of the decay $B_s^0 \to\phi\bar{K}^{*0}$
Journal : JHEP Contact authors : Antonio Romero, Cibran Santamarina Rios Reviewers : Alvaro Neto (chair), Steve Playfer EB reviewer : Steven Blusk EB readers : Tim Gershon, Frederic Machefert Analysis note : ANA-2012-030 Deadline : 05-Apr-2013 e-group : lhcb-paper-2013-012-reviewers Link : http://cds.cern.ch/record/1530549 Authors : LHCb Twiki : https://twiki.cern.ch/twiki/bin/viewauth/LHCbPhysics/BsToKstarKstar
The following institutes are requested to make institutional comments: Ferrara, Italy Warwick, United Kingdom Dortmund, Germany EPFL, Lausanne, Switzerland NIKHEF, Netherlands _______________________________________________ Bfys-physics mailing list Bfys-physics@nikhef.nl https://mailman.nikhef.nl/mailman/listinfo/bfys-physics