Hi all,
These are our comments I will past in CDS later this morning. Please let me know if something is missing or too aggressive (I realise the text is quite harsh with the proponents and starts by complaining about the paper being unfair to CF ;-) )
Cheers,
Patrick
-----
Dear Proponents,
Here are the comments from the Nikhef group.
Congratulations for this indication of the non-existence of the X(4140). We hope this will contribute to sort out this issue. t is very importnat we get the right message accross, which we understand is difficult given we see fewer or even no X events in much more statistics.
We have a few general comments
1) There are too many references to CDF in the text (20 instances). The paper sounds like we are trying to confirm a CDF result but fail to do so. We should say this is the most precise measurement of the B->psiphiK channel and we do not see an X in it. We think we should limit mentions CDF in the introduction and in the conclusion and focus on LHCb in the remaining parts. As UFRJ we too think the tone is too aggressive towards CDF.
2) The ratio B(B->XK)xB(X->psiphi)/B(B->psiphiK) is spelt out six times in the paper. We suggest to define this ratio once as R(4140) (allowing to also define R(4274)) in the introduction.
3) We are missing a justification for the polynomial background. It seems unphysical as it does not go to 0 at threshold, unlike the phase-space background. The only given justification seems to be "The fitted X(4140) amplitude is not zero even though the data have empty bins in the peak region. This is an artifact of the restrictive three body phase-space function falling rapidly to zero for masses below the X(4140) mass, and failing to describe entries in the left sideband." (the left sideband of what?) This sounds like you dislike the 1.4sigma evidence of a X and choose another background to make it disappear. We are sure this is not the intention and thus this section should be rephrased. Also we think a paper should not quote two limits for the same quantity but stick to one. It is difficult to compare our limit with CDF's value and error. Generally, we think LHCb should give two sided intervals for all measured quantities and transform them into limits to please the PDG at a later stage. But that's an issue for the EB...
Our suggestion is to a) Remove Fig 3b as the background shape is not justified b) Use the result of this fit only to assess the systematic error on R(4140) c) Publish a two-side interval for R(4140) allowing to compare with CDF, and a limit which would thus be 0.07, the second one. d) Replace the unnumbered equations by a table that includes the CDF results. All relevant information is then in one place and not scattered over the text.
A comparison of the level of disagreement (2.4sigma?) between LHCb and CDF could then replace qualitative statements like "well below".
Line by line:
Author list: Lefrancois is misspelled. This is because you use an ancient version of the LHCb style redefining the LaTeX \c command. Update. l. 2-4: The fact that J/psi->mumu and phi->KK is irrelevant here. It should go to line 18. l. 4 and 7: space before footnote. l. 9: Traditional sounds strange in a physics paper. Usual? l. 18: Here say we look for X in B->J/psiphiK with J/psi->mumu and phi->KK. l. 24. Change "long-lived" into "short-lived". - The long-lived particles will not decay inside the LHCb detector. l. 42: "Most efficient" is not well defined. You should at least say it's for this signal. Don't you make any TOS requirements? l. 46 and many others: acronyms and abbreviations like vtx, IP, sig, bkg,... should be roman style. l. 52. Change "These $B^+$ candidates are required ..." to " This $B^+$ candidate is required ... l. 59: - -> --- l. 69: Why use a sideband so far from the peak? It's not even on the plot. There's for sure a good reason which should be made explicit. l. 81, 87 and 94: It's not clear how the three numbers of events (346, 396, 382) compare. Do we need all these numbers? l. 83: we fit _the_ M(KK)... Why binned? l. 85: _a_ Gaussian l. 90: _the_ M(KK) l. 91: what does \pm4 - 14\sigma mean? l. 95: we select_ events l. 99: with _a_ three-body phase-space _pdf_. l.107: Can't you subtract the region below 1030 from the sidebands rather than ignoring it? l.112: the other source: which other source? l.114: the second -> a second l.115: "not zero": your fit is compatible with zero at 1.4sigma. You cannot say it's non-zero. l.121: Does CL here stand for the definition of footnote 4? If so move footnote up here. l.131: Is the disagreement 2.4sigma wrt to CDF's central value (which would be meaningless)? Or does it take CDF's error into account? If so this number should go to the conclusions. l.135+ : Using _a_ Bayesian. Assuming _a_ polynomial. limit on _the_ number of __ signal events. l.135+ (p6): from _the_ simulation. Following the similar -> a similar The first equation has unbalanced parentheses. l.136: "where the limit was made looser" what does that mean? l. 137-140. We should not make assumption on CDF efficiencies. Remove the two sentences: "If we ... events." l. 145: Change "... an upper limit on ... which is well below the CDF result." to "... a 90% CL upper limit of $R(4140) < 0.07$ ." - "well below the CDF result" is not a quantitative statement. Fig. 3: _The_ fit of X... on top of _a_ smooth. To be fair with CDF you should replace the peak representing their central value by a band including a one sigma error.
Tjeerd Ketel wrote:
Dear all, especially not Bfys-staff.
I made an error in the e-mail list for the announcement of the Bfys meeting this afternoon. My excuses. I will check the list name better in the future.
Tjeerd
---------- Forwarded message ---------- Date: Mon, 05 Dec 2011 16:23:11 +0100 From: Tjeerd Ketel tjeerd@nikhef.nl To: Patrick Koppenburg Patrick.Koppenburg@cern.ch Cc: bfys-staff bfys-staff@nikhef.nl Subject: Re: [Bfys-staff] X(4140)
Dear Patrick,
Sorry for the sound quality during the Bfys meeting this afternoon.
As you offered to combine the comments on the B+ -> X(4140)K+ paper, I attach my comments and some that were made in the attachment. Please, select those which you consider to be relevant for a group comment.
Best regards, Tjeerd
Citeren Patrick Koppenburg Patrick.Koppenburg@cern.ch:
Hi all,
Nikhef is assigned as reviewing institute for the B->X(4140)K paper : https://cdsweb.cern.ch/record/1399640?ln=en. I have many comments on that paper. The deadline is 5/12. Should we organise a meeting?
Cheers,
Patrick
--
Patrick Koppenburg Nikhef, Amsterdam http://www.koppenburg.org/address.html _______________________________________________ Bfys-staff mailing list Bfys-staff@nikhef.nl https://mailman.nikhef.nl/mailman/listinfo/bfys-staff
Bfys-staff mailing list Bfys-staff@nikhef.nl https://mailman.nikhef.nl/mailman/listinfo/bfys-staff
Bfys-physics mailing list Bfys-physics@nikhef.nl https://mailman.nikhef.nl/mailman/listinfo/bfys-physics