Dear Adlene,

Congratulations with this nice paper.
Please find below the comments on behalf of the Nikhef group.

Cheers, Niels et al

General
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* Given the similarities with the Bc->KKpi analysis, was it considered 
  to merge the two analysis in one paper?

Questions
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1) L.11 Is there a paper you can refer to concerning the sensitivity to the
Beyond the Standard Model physics?

2) L.70/71 We do not understand what the different production fractions 
have to do with the fiducial cuts?

3) L.167 We tried to get a back-of-the-envelop limit: 
if you measure 0 events, then the upper limit is ~4 events?
Then we get the limit : (eff_u/eff_c)*(4/1644)*BR(B+) = 6 x 10^-9,
rather than 3.6 x 10^-8 ?

4) L.167 Did you use the J/psi mass constraint and/or known J/psi lineshape to
achieve optimal sensitivity in the Rp^J/psi limit?

5) Fig.5 Why would you plot p-values for negative Rp values ?



Textual remarks
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1 Introduction

L.8 "with a null change" -> "with no change"
L.9 "treating" -> "taking two-body and quasi-two-body modes into account"
L.10 "Due to their rareness ... particles." -> 
"Due to the small predicted branching fraction, the observation of these 
processes is a challenge, and is sensitive to other types of bc annihilation 
involving particles beyond the Standard Model."

3 Reconstruction

L.26 "of the b quark to fragment into the Bc+"
Caption Fig.1: "represents the limits" -> "represents the lower limits"
L.84 [Insert an extra sentence here?] 
"No special PID requirements are imposed to select the final state protons."
L.91 [split and rephrase?] "... lines in Fig.1. Simulated pseudoexperiments
showed an improved sensitivity compared to a single fit to the highest 
signal purity region, BDT>0.18."

4 Fits

L.107-110 [You say that you also fitted in the full pp spectrum. 
Then you should also give the fit result.]
L.109 " ...<3.15 GeV/c2, separately. The results ..." 
Fig.3 [Please add vertical dashed lines at the place of the Bc mass.]

5 Efficiencies

Fig.4 [The figures come out too black on a b/w printer.]

7 Results

L.167 [Could you present the final results as separate equatons $$...$$ ?]