[Bfys-physics] Comments PAPER-2014-012 - bfys-physics@nikhef.nl

28 Mar 2014


      Hi Vasilis,
Since I only read about 15% of the B->Jpsi pipi paper, I feel that this paper is not yet in a shape that is presentable to the collaboration. I have put my comments below.
Cheers
Jeroen
General comment about the state of this draft:
We feel that the status of this paper is not yet ready for collaboration-wide review. There are too many mistakes in the paper, which make it impossible for institutes to find all of them. This could have been avoided by a more thorough review before. For instance, in large fractions of the text line numbers are missing. This is not acceptable anymore in a CWR. In particular since the problem with the line numbering has been fixed in the LHCb template for more than a year. Not using the LHCb template causes more mistakes, like the captions not being in small font. Also, we think that acknowledgements should have been there as well, even when it is just copied from the template. Further, the paper is very long (almost 30 pages) and mainly aimed at the real experts. We think that a significant reduction of the text would improve the readability of the paper. As it stands, the paper has the quality and size of our ANA notes.
One of the main results/motivations for the paper is to search for a contribution from f0(980). While the small improvement in the likelihood is convincing that there is no significant contribution from f0(980), Figure 5 clearly suggests that this something is going on in the region around 980 MeV. Given the width of the f0, there could be some constructive/destructive interference along the mass of the f0. There seems to be a hint of such an effect in the data, since the fit does not perform so well in this region. Did you check this in more detail in the ANA note? Is it possible to construct the phases such that this oscillating behaviour is described? It is worth discussing this in more detail in the paper, since, as it is now, it sticks out for any external reader.
Comments on the text and figures:
- Abstract: “one-third at 7 TeV center-of-mass energy and the remained at 8 TeV.”  It is not clear what is meant here. One third of what. Is this sentence actually needed for this analysis? You can remove it without loss.
- Abstract: order the 6 interfering states in mass.
- Abstract: “less than |17 degrees|”. The absolute value of 17 is 17. So you should remove the absolute sign ||. Write instead, “the absolute mixing angle between…” Also to be fixed in the conclusions.
- l.5: “Cabibbo-suppressed”. Add the dash.
- l.5: “over what it is in” -> “compared to”
- l.5: “the final state B->JpsiKs”. This is a decay not a final state.
- l.6: Remove “Thus”. Not needed.
- l.6: Remove “in principle”. This makes the statement very weak. In principle only refers to the statistical precision, which limits a P/T measurement.
- l.6: Remove “or limit”. For the same reason as above.
- l.7: “the Jpsi pipi decay channel”. This is not a decay channel, but a final state.
- l.17: the branching fraction is measured with 3 uncertainties. You either need to say what they are (statistical, systematic, etc), or add them quadratically.
- l.42: “where the Jpsi MESON is”
- l.44: “by use of either IP requirements or detachment of the Jpsi from the primary vertex”. IP requirements of what? Of the Jpsi or its daughters? Please check. Also add meson after Jpsi.
- l.52: remove “four variables”. Every reader is able to add 1+3.
- l.53: add colon after “helicity angles”
- l. 53-57: place the symbol for the angle always after the word “angle” and not at the end of the (sub)sentence.
- l.60-61: remove “plotting” and replace “does” -> “do”
- l.69+: Why put the overline suddenly in parentheses here. You have already mentioned in footnote 1 previously that cc in implied. Remove the parentheses.
- l.69+: remove “proper” in proper decay time.
- Eq.3+4: This should not be written in differential form. This makes it inconstant (and thus wrong) with Eqs. 5-9. In this form the amplitude A should be a differential itself since the full functional form it in there (except for the decay time). However, you do not write it as such in the other equations.
- l.70: add a semicolon after “constant”
- l.70: “at the decay time, WHICH is itself”
- l.75: write “|q/p|” the same way as in the equations before.
- Eq.3+4: Since you make the assumptions for q/p and indirect CPV, please simplify these equations from the start.
- l.77+: “B0bar MESON”
- l.110: write “multivariate selection based on a boosted decision tree (BDT) [21].”
- l.164: You constrain the B0 mass to the PDG value for the amplitude analysis. But in l.172 you use the signal fraction from the invariant B mass fit for the angular fit. This looks wrong. You cannot use that number after constraining to the B mass. Maybe you only constrain to the B mass for another fit, but this should be made clear in the text.
- Fig. 5 caption: It is not clear who the red points are obtained. Is it from the mass sidebands? From sWeighted background. Explain this in the caption.
- Fig. 6: Add “simulation” to the title
- l.188: s12 and s13 are already defined.
- l.192: Insert (extra) space between m2_hh and as.
- Fig. 10: “with the levels on z-axis in arbitrary units” That is already written on the axis. Also the labels are not consistent with the caption. Maybe just say “relative efficiency” in the caption.
- l.263: Add comma after however.
- l.296: “efficiency-corrected” add dash.
- Table 5: This should be MINUS lnL everywhere, right?
- Eq.34-37: These are all results, so remove the equation number.
- l.348: isopsin -> isospin
- Eq. 37: C.L -> CL (without dots).
- l.362: add rho(770) in the list of resonances and replace the period by “, where”
- l.364: no dash in fit fractions.
- l.373: “CP-violating” add dash