Questions --------- 1) L.26-29 What do you mean with "when the angular momentum is properly considered"? We think you mean that the CP eigenvalue of Ds*K is opposite to DsK due to the relative angular momentum of the final state. We'd suggest a small rephrasing of L.26-29: "The Bs->Ds*K decays are particularly interesting because the formalism to determine gamma is the same as for the Bs->DsK decays, apart from the CP eigenvalue of the final state due to the relative orbital momentum of the Ds*K final state." 2) L.105. You say "hadrons misidentified as photons". Is this dominated by pi0's? If so, perhaps you could consider replacing 'hadrons' by 'neutral pions'? 3) L.142 You say you fix the width of your signal peak, scaled by the width of the signal by data/mc difference. How did you get the width from data, ie. how was the scale parameter determined? We would also suggest then to rephrase "scaled by a variable parameter". 4) L.160 Why is the sideband Delta-m cut [185, 205] chosen so close to (partly inside) the peak? [205, 225] and [225, 245] seem more reasonable. Since comb. bg. is the dominating systematic, we're wondering if this is the reason. 5) Fig.3 left. How come that the Bs->Dsrho events do not peak at the Bs-mass? (Perhaps indeed you often miss one photon from the pi0 decay?) 6) L.192 You say the uncertainty due to Ds*pi cross feed comes from the limited knowledge of its BR. Do you use the PDG value, or your own yield determination? 7) L.195-201 Why do you use the difference between the simulation and the simulation weighted to match the data as systematic uncertainty? That seems overly conservative. Why not reweight the simulation and then take the effect of the uncertainties on the weights to determine the systematic? 8) Tab.1 What do you mean with the absolute variation? The caption suggest this is the variation on R*, but the 10^-4 suggest it is the BR? 8) L.209 Any statement about the significance of that measurement? 9) L.222 Is there no theory and/or comparison of (Bs->Ds* K/pi) / (Bs-> Ds K/pi) i.e. vector over scalar Ds modes? Is it not relevant? Text ------------------------------------------------------------------------------- Abstract: through the decay chain Ds*-> Dsgamma and Ds->KKpi. Consider adding the result for the absolute Bs->Ds*K BF you obtain in the paper (L.221) 1 Intro ------- The introduction needs a bit of work. You only mention the actual decay you're considering (without brackets around the stars) in the third paragraph, and you don't really say anywhere in the introduction that you're going to measure R* in this paper. Consider writing earlier and more clearly (a) what you've measured and (b) why you've measured it (which you do already nicely in the very first paragraph). L.17: "The weak phase ... CKM parameters." -> "The weak phase gamma is the angle of the unitarity triangle with the worst precision." L.18: Move the footnote ref 1 to either after "rates" or after "-> D0 K+," L.19: "analogous" (in what respect?) is unclear here. That is only explained in L.34. Please re-order and specify. L.20: Restricting the brackets to the subscripts makes this easier to read, ie "B_(s) -> D_(s) h" L.22: Same as in L.20, consider putting brackets around the subscript "s" rather than mentioning both mixing types explicitly. L.24: Why statistical? L.25: "... based on approximately ... data." -> "... based on the LHCb data recorded in 2011 corresponding to 1.0 fb-1." L.27: CP -> \CP (also elsewhere) L.39: You mention "the following", but the next few number have only a single uncertainty. L.41-42: supports -> is compatible with. We do not "support" the B factories. L.44: "Vector decays" seems a bit ambiguous, as that might mean the Ds* decays. Also mention the fact that Ds* is vector earlier, since that is central to the analysis. L.45: "hadronic machines" -> consider "detectors in a hadronic environment" (LHCb is not a hadronic machine) L.49: "of _the_ time-dependent CP" L.54: "was evaluated according to:" -> "is evaluated according to" [no semi-colon] L.55: remove : L.57: X -> $X$. 3 Selection ----------- L.89: "pion or kaon of opposite charge." rather than "The net ... be zero." L.92: the -> any (we presume that's the case. Else explain how the PV is selected.) L.93: good-quality L.95: Consider leaving out that photon confidence is a variable, ie: "A cut on photon confidence level is used..." (if you do this, also remove "variable" in L.98) L.97: pi0's -> "pi0 decays" L.99: "calorimetric cluster" -> "calorimeter cluster" L.101: Replace "Due to the small ... a few hundred MeV/c2" by "The small value of Delta M = M(Ds*-) - M(Ds-) = 140 MeV/c2 does not add very much to the average transverse momentum of the photons of a several hundreds of MeV/c2". L.103: "a few hundred MeV"/"several hundreds of MeV" is vague and sounds like you're not sure, but you probably have a value (+uncertainty) for this quantity. L.104: "resulting backgrounds": resulting from what? L.107: Add "and a pm 70 MeV/c2 window, respectively,", in line 130 the more realistic value of this 70 is given. "known values" -> "current world-average values" or similar L.108: Ds-K(pi) -> DsX (since you defined that) (no dash) Fig.2: Suggest M(KKpi) rather than Ds. Add "without background" after "signal". Probably "simulations" with "s" is better. Where is a description of these simulations? Without the correction in line 101, Delta M is not clearly defined. L.122: "Eight additional" -> "A further eight" L.123: "final state" -> "final-state"; "are used" -> "are also used". L.125: Remove "preselection and" and "as each other"; consider "use identical selection requirements." L.130: "known mass" -> see comment on L.107 L.131: "... is observed around the expected value DeltaM = 143.8 MeV." 4 Yield ------- L.135-136: Consider merging these paragraphs, as right now the first consists of only a single sentence L.140: "Ds Pi (K)" Again you can use DsX or Dsh, or just leave this out L.146-148: "Fully... signal". Suggested rephrasing: "Fully reconstructed background events are due to B0 decays to the same final states as the Bs0 signal, Ds*pi and Ds*K." L.148: Why "resonant"? L.150: Remove brackets around "(or fake)" and add "track" after "photon" L.155: We suggest to add "... contributions in the Ds*K fit, which are estimated from the known branching fractions." L.156: "mis-PID" -> "misidentification" L.160: "obtained from the" -> "obtained from events falling inside the" L.170-171: Repeats line 102 Fig.3: The labels are much too small. Left: Add charges to the decay in the legend: "Bs->Dsrho" -> "Bs0->Ds-rho+" Fig.4: Is that figure essential in this paper? It seems more adapted for additional material. 5 Systematics ------------- Your enumeration for carriage returns and incomplete sentences is inconsistent and does not work well (why did you not use description?). We suggest to make it to normal sentences and paragraphs with indents. L.173/174: After the result, in L.213, you come back to a systematic on the relative efficiencies. This can be better described here. We would suggest to modify the first sentence: "The systematic uncertainties on R* can be separated in uncertainties on the relative event yields (due to the modelling of the background) and on the relative selection efficiency (due to BDT and PID cuts)." L.175: "both as absolute and relative" -> "both as an absoulte and as a relative" L.176: "described corresponds" -> consider inserting "in the following text" L.178-181: MeV/c^2 L.184-194: Guidelines suggest not to use single-sentence paragraphs. L.185: We suggest a rephrase: "being a variable parameter in the fit, is studied by varying ..." -> "which is allowed to vary in the fit, is studied by fixing the B0->Ds*K yield at its expected value, with a Gaussian constraint corresponding to its uncertainty." L.190: This comes twice, suggest to skip the first: "into Ds*K, " L.195: Ref. [3] L.195: After the result, in L.213, you come back to a systematic on the relative efficiencies. This can be better described here. We would suggest to add a sentence before L.195: "The uncertainty on the relative selection efficiency originates from uncertainties on the agreement between data and simulation leading to an uncertainty on the BDT selection efficiency, and from uncertainties on the PID selection efficiency." L.197: Remove "extensive" L.198: "on" -> "out" L.201: "on the BDT" -> "due to the BDT selection" L.202: We suggest a rephrase: "The uncertainty on the pi and K PID efficiencies of the bachelor particle have been extracted..." L.204: "the kinematic quantities" -> we don't use *all* kinematic quantities; specifiy or remove "the" L.205: systematics -> systematic uncertainty. L.206: mention somewhere that the quadratic sum of the individual contributions are the ones used in the final result. Table 1: why is cross-feed in "" in one case but not the other. Captialise first letter of each cell Left-align leftmost column Fig.5: would be more appropriate for additional material for talks. A rotated picture with horizontal bars is more suited and will show the difference between total and statistical uncertainty better for R*(LHCb). A table is of course the best way to represent a comparison of four numbers with uncertainties, unless we do not want to give the other three numbers. Caption: from Ref. [2]. Add "experimental uncertainties for R(*)(LHCb) are shown by additional side bars". Plot: Draw a line between the 2 R and R* measurements as they are different things. y Label : R^{(*)} L.211-213: We suggest not to discuss the sources systematic uncertainties here. How about this rephrasing instead: "The result R* is obtained from the ratio of event yields (0.062+-0.004 (stat)+...-... (sys) ), multiplied by the ratio of efficiencies (1.095+0.012-0.015)." L.213: "turns out to be" -> "is determined to be" L.215: Skip "very" L.218: R does not represent a decay mode. Replace "both R* ,vector, and R, scalar decays" by "both values of R and R*". May add ", although the theoretical uncertainty of R* is relatively large". If you want to mention "scalar" and "vector" do it earlier in the paper (see also comment on L.44) L.219: We suggest to add the explicit value used: "B(B0s->Ds*pi)=2.0+-0.5x10^-3 obtained by ..." L.221: "bf" -> "\BF" Add brackets around the value and uncertainties Add comma at end of eqn L.222: "errors" -> "uncertainties" Add "," after systematic. Add "uncertainties" after "B(...)".