Comments on Run 11+12 Weak Boson asymmetry paper

The comments by the Temple University has three groups of comments provided by Reviewers A, B and C:

 

 

Reviewer A:

 

 

Page 3:

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Line 77-78 Define pseudo-rapidity.

 

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Line 46: Is the Moliere radius common knowledge?

 

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Line 1-4: This came off a little negative to me. Almost as though the TPC at mid-rapidity didn't perform as well as it should have, but the data was salvaged to make a charge separation.

 

Line 26-30: This read very segmented and choppy. I had a really hard time reading this sentence. I would also define the pseudo-rapidity range, a, in the list of bullets that follow Eq. 1.

 

Line 35: Should A_LL be defined in a similar way as A_L was? Maybe even define A_LL after A_L on page 3?

 

Line 50-52: It says that tau(+/-) is not a W(+/-) asymmetry background, but on page 4, Line 22-24 it talks about simulating tau(+/-) background. This is confusing as they seem contradictory. Was the tau(+/-) background corrected for or not? 

 

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Do publications also need their arXiv references? Or should it just be the publication reference?

 

 

Reviewer B:

 

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Line 12: Word "traditional" in "traditional helicity parton distribution functions" doesn't suit.

 

Line 28: Word "fixes" in "fixes the helicity of the incident quarks and ..." , I don't understand why use word like fix here… seems not making sense.

 

Line 72 -74: In the last sentence " The integrated ......respectively", the sentence format seems no correct , feels like it should be written this way, "The integrated luminosities of the datasets for the two years, 2011 and 2012 are 9 and 77 pb -1, respectively." 

 

Line 87: In the sentence starting in line 86 " Primary Vertices ....of 49 cm " segment  "with the TPC " seems not giving the correct understanding ,,using word "with" seems not suiting may be " vertices were reconstructed along the beam axis in  the TPC "  or something like that.

 

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Line 31 : This should be eta > -2 NOT eta > 2. 

 

 

Reviewer C:

 

Title:

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The title should reflect that the papers provides measurements of longitudinal spin asymmetries for weak boson production and NOT just longitudinal single-spin asymmetries for weak boson production. 


Therefore re-write the title: “Measurement of longitudinal spin asymmetries for weak boson production in polarized proton-proton collisions at sqrt(s)=510GeV”

 

Abstract:

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Line 5: ‘The results are compared to theoretical predictions…’

 

Line 7: Quantify x-range already in the abstract as done later: ‘… in the range 0.05<x<016=MW/sqrt(s) probed at RHIC.’

 

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Line 6-8: Re-write first sentence to: ‘In high-energy proton-proton collisions weak boson and Drell-Yan production are dominated by quark/antiquark annihilations.’ The current sentence does not read well mixing plural and singular forms. 

 

Line 12: Delete ‘traditional’ to read: ‘… constrain helicity-independent parton …’. Traditional is not clear at all!

 

Line 14-15: Re-write the sentence to read: ‘In particular, measurements of Drell-Yan production, as well as earlier deep-inelastic (DIS) scattering, have reported …’. 

 

Line 28: End sentence and start: ‘Flipping the proton beam’s helicity 

 

Line 57: You have to distinguish here FOM for single and double spin asymmetries. The sentence before talks about measurement of both, but the sentence starting with line 57 only mentions FOM for single spin asymmetries without specifying that this is the FOM for single spin asymmetries. Re-write the sentence as follows: ‘The beam polarization (P) and luminosity (L) of this data set corresponds to an order of magnitude increase in figure of merit, P2L, relevant for single-spin asymmetry measurements, in comparison to results reported previously by STAR [17] and PHENIX [18].’

 

 

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Figure 2: Why is the region below -2 and above 2 excluded? 

 

 

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Line 7: You are showing two Gaussian fits in Figure 2. It would be most helpful to state in the text by how much both peaks are separated in units of sigma and not leave it up to the reader to determine this. You have the numbers. Please do this! Suggested text after Line 7: ‘…charge sine purity. ‘Both Gaussian peaks are separated by x.x sigma’.

 

Figure 4: ‘… in comparison to theory predictions… .’

 

General remark: You are not making any reference to previous cross-section and and cross-section ratio measurements by STAR. This is a mistake. Please do this for W+/W- and Z/gamma* from STAR!

 

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Figure 5: ‘… in comparison to… .’

 

Line 39: How did you determine the value of x>0.05? Generally, you should quote a range. STAR is certainly NOT reaching values larger than MW/sqrt(s) = 0.16. I would therefore quite a range: 0.05 < x < 0.16. You should NOT give the impression that we are measuring anything beyond 0.16 This is misleading! You know that 0.16 is a hard kinematic limit for MW/sqrt(s).

 

You should change this anywhere this appears:

 

  • Suggested value in abstract, see previous comment.
  • Page 6, Line 39
  • Line 73 in Summary

 

Line 56: You are reporting here the ‘first’ asymmetry measurement of Z/gamma* production. You do not provide any motivation. I would provide at least a similar statement as you do for the ALL measurement focusing on the coupling as you do in Line 48-50 on Page 6.

 

Suggestion after Line 56-58: ‘The single spin-asymmetry for Z/gamma* production is sensitive to combinations of u/ubar and d/dbar polarizations, respectively.’ I do not think that the a formula is necessary, but I would also not leave it up to the reader to figure out what you are really probing with AL for Z/gamma* production.