Vector Quarkonia at the LHC with Jethad: A High-Energy Viewpoint
Round 1
Reviewer 1 Report
The paper reviews the theoretical formalism relevant to the description of quarkonium production at high-energy colliders in certain kinematic domains.
In particular the author concentrates on quarkonium production associated with another quarkonium or jet at a large rapidity distance. Transverse momenta are assumed to be large in comparison to masses of particles involved. One expects this domain to be sensitive to small-x resummation effects, and indeed the author's approach is based on BFKL formalism.
The applications are restricted to vector mesons, but extension to other states pose no problems of principle. The review is largely concerned with contributions of the author with his collaborators. However a rather comprehensive list of references is given.
There is not yet a comparison to experimental data, and the review rather emphasises the theoretical concepts and the description of a software package "JETHAD" developed by the author. To the best of my knowledge it is not yet publicly available.
I have read the paper with some gain to my understanding, and I think it is a useful addition to the literature which deserves to be published.
I have the following suggestions:
1. In the abstract: the novel ZCW19+ determination --> the novel ZCW19+ determination of fragmentation functions
2. There appear to be a number of typos in the coefficient functions in Appendix A (27,28,29).
Comparing to (30) I believe that in the logarithms one has to replace in denominators x --> x_Q, otherwise above cited functions would be independent of x.
Finally, there are a number of simple typos/grammatical lapses, such as:
line 22: since might couple --> since they might couple
line 120: must encoded --> must be encoded
line 121: regulated by --> governed by
Author Response
I thank the Referee for her/his careful reading and for her/his valuable comments.
I list here answers to points raised.
For the sake of readability, the corresponding changes and/or additions in the revised version of the manuscript have been marked up in blue color by making use of the “Changes” package in LaTeX.
Furthermore, following the recommendations of the Editorial Office, minor style changes in text writing have been made to reduce the overlap with other published articles, in particular [Eur. Phys. J. C 82 (2022) 10, 929]. They are highlighted in red color by making use of the user-defined “\revision” command.
Answers to Referee's points:
1. A sentence in the abstract has been improved by taking care of Referee's suggestion.
2. Thanks for spotting typos in Eqs. (27) to (29) in Appendix. They have been corrected.
3. Typos/grammatical lapses on lines 22, 120, and 121 of the previous version (new lines 72, 205 and 206) of the manuscript have been fixed.
Further remarks:
A. The affiliation has been slightly updated.
B. Some references were automatically updated via BibTeX.
C. A brief introduction of general QCD features, together with an incomplete list of QCD portals beyond SM has been added in two new paragraphs of the Introduction (lines 76-92). Correspondingly, new Refs. [1-18] have been added.
D. A short discussion on top quarkonia has been added (Introduction, lines 126-138), together with new Refs. [27-44].
E. A short sentence explaining what "quarkonium production puzzle" means has been added in the Introduction (see lines 141-143).
F. A short discussion on the connection between quarkonia, NRQCD and exotic hadrons (tetra- and penta-quarks) has been added (see lines 239-241), together with eight more references [143-150].
G. A dictionary with acronyms has been added at the beginning of the manuscript, right after a new table of contents.
H. Added new Refs. [123,354,489,490,509-512].
Reviewer 2 Report
Summary:
This article discusses theoretical models currently available for quarkonia production and reviews the successes and challenges of each model. The authors then discuss a new approach to vector quarkonia models that uses hybrid factorization for differential cross sections that could prove beneficial for studies at high transverse momentum and far forward rapidities.
General comments: This is a well written paper with a very informative introduction to the topics discussed.
Detailed Comments:
line 11
previously observed in observables sensitive to -> previously seen in observables sensitive to
line 22
since might —> since they might
line 24
peerless chance —> might suggest different wording… I’m not very familiar with this phrase
line 27
understand —> in understanding
line 28
contains —> contain
line 31
photon was announced was discovered. —> photon was announced.
line 43
mechanism was proposed —> mechanism proposed
line 44
the charm one —> the charm flavor (?)
line 49
lowers —> weakens
line 54
it was named —> was named
line 56
charm ones —> charm quarks
line 58
fairly identified —> fairly easily identified (?)
line 62 - line 64
seems like a lot of commas
line 67
like the J/psi and chi_c ones —> like the J/psi and chi_c states
line 74
lightly —> slightly
line 81
To overcome issues of CSM —> To overcome these divergence issues associated with the CSM
line 82
cure —> solve
line 84
More in general —> More generally,
line 101
can be still emitted as decay —> can still be emitted as the decay
line 103
called direct fraction —> called the direct fraction
line 109
relative transverse seperation —> relative transverse momentum seperation
line 120
must encoded in collinear fragmentation functions —> must encode collinear fragmentation functions
line 125
short distance one —> suggest to be more specific about what “one” means here
line 126
it is magnified —> suggest to be more specific about what “it” means here
it becomes dominant -> same comment
line 150
came recently out as —> recently became a
line 193
from more details —> for more details
line 155
the ones —> those
line 159
peerless opportunity —> might suggest different wording… I’m not very familiar with this phrase
line 171
turn out —> turns out
line 225
the long-distance dynamics from the short-distance one —> the long-distance from the short-distance dynamics.
line 226
This allows —> This decoupling allows
line 236
entered Regge limit —> entered the Regge limit
line 239
perturbative calculation —> perturbative calculations
line 240
by resummed —> by resumming
line 248
Using the BFKL jargon, they —> suggest to make more clear what ‘they’ means here
lines 248-250
This sentence is a little confusing. Please consider revising.
line 260
are the ones for —> suggest to be more specific about what “ones” means
line 282
at leading twist —> maybe briefly state what this means
line 287
factorization scales —> factorization scale
line 296
the found optimal ... than the natural ones —> the optimal .. than the natural scales.
line 305
come out —> emerges (?)
line 306
then on —> also from
line 341
We will compare our NLL predictions with LL ones —> We will compare our NLL predictions with current LL predictions
line 362
corresponding ones obtained —> corresponding patterns obtained
line 424
The first ones —> suggest to be more specific about what “ones” means
line 426
The second ones —> same
line 429
since charm ones are generated —> same
line 451
Thus, Hb sensitive distribution are even more stable than Λc ones —> Thus, Hb sensitive distributions are even more stable than Λc distributions
line 624
highlight of deltaY-distributions --> highlight deltaY-distributions
line 625
the one —> that
line 626
but still favorable for quarkonium plus jet channel, but still favorable —> but still favorable for the quarkonium plus jet channel
line 648
larger than MS ones —> larger than MS predictions
line 629
with the corresponding ones taken —> with the corresponding predictions taken
line 630
inside corresponding LL/LO ones —> suggest to be more specific about what “ones” means
line 662
as useful tool —> as a useful tool
line 668
We came out with the important message —> Our key finding is
line 672 and line 685
the ones reachable —> suggest to be more specific about what “ones” means
line 684
Futures investigations —> Future investigations
line 701
An other —> Another
References:
I don’t recall seeing more than 400 references before. This is quite a lot. There may be additional editing needed for the references. If so, you may consider reducing the references to a number that is more manageable.
Minor corrections needed in an otherwise very well written article.
Author Response
I thank the Referee for her/his careful reading and for her/his valuable comments.
I list here answers to points raised.
For the sake of readability, the corresponding changes and/or additions in the revised version of the manuscript have been marked up in blue color by making use of the “Changes” package in LaTeX.
Furthermore, following the recommendations of the Editorial Office, minor style changes in text writing have been made to reduce the overlap with other published articles, in particular [Eur. Phys. J. C 82 (2022) 10, 929]. They are highlighted in red color by making use of the user-defined “\revision” command.
Answers to Referee's points:
1. Many thanks for the series of suggestions on grammar and style. Text has been improved by following those recommendations.
2. Concerning the number of references, I would like to motivate why it has increased since the first version. On the one side, I agree with the Referee that their number is large. At the same time, I believe that it is still reasonable for a review article. Vice versa, it would have been too much for a regular research article. Considering that a preprint version of the manuscript already exists (arXiv:2305.14295) and that (I believe) all the references are connected and relevant for the topic, I would prefer not to remove any of them. Then, following the recommendations of the other Referees and suggestions received privately from other colleagues, some new citations have been added.
Further remarks:
A. The affiliation has been slightly updated.
B. Some references were automatically updated via BibTeX.
C. A brief introduction of general QCD features, together with an incomplete list of QCD portals beyond SM has been added in two new paragraphs of the Introduction (lines 76-92). Correspondingly, new Refs. [1-18] have been added.
D. A short discussion on top quarkonia has been added (Introduction, lines 126-138), together with new Refs. [27-44].
E. A short sentence explaining what "quarkonium production puzzle" means has been added in the Introduction (see lines 141-143).
F. A short discussion on the connection between quarkonia, NRQCD and exotic hadrons (tetra- and penta-quarks) has been added (see lines 239-241), together with eight more references [143-150].
G. A dictionary with acronyms has been added at the beginning of the manuscript, right after a new table of contents.
H. Added new Refs. [123,354,489,490,509-512].
Reviewer 3 Report
The paper is a comprehensive, highly specialized review on heavy vector meson (quarkonia) production at LHC energies. As such it collects and extends the state-of-the-art of this special branch of "applied QCD".
A dictionary of the many acronyms would be for the reader's benefit.
The brief history of the field in Introduction could be supplemented by a few remarks on top quarkonia.
The Abstract ends by "quarkonium production puzzle". In a first reading I missed a discussion of that issue in the text.
The abstract also advertises "precision studies of high-energy QCD", but I miss a discussion of features of QCD (naively: number of colors and quark families [in adjoint or fundamental representations], portals beyond SM - beginning with axions and higher-dimension terms in the lagrangian or Dark Gluons etc.) which can be tested.
line 556: a reader cannot see the mentioned delta functions.
Often, a sentence is interrupted by a ":" at the begin of some lists.
line 44: I miss a "which".
The quantity Lambda_QCD is called "QCD scale", not only "hadronisation scale".
Author Response
I thank the Referee for her/his careful reading and for her/his valuable comments.
I list here answers to points raised.
For the sake of readability, the corresponding changes and/or additions in the revised version of the manuscript have been marked up in blue color by making use of the “Changes” package in LaTeX.
Furthermore, following the recommendations of the Editorial Office, minor style changes in text writing have been made to reduce the overlap with other published articles, in particular [Eur. Phys. J. C 82 (2022) 10, 929]. They are highlighted in red color by making use of the user-defined “\revision” command.
Answers to Referee's points:
1. A dictionary with acronyms has been added at the beginning of the manuscript, right after a new table of contents.
2. A short discussion on top quarkonia has been added (Introduction, lines 126-138), together with new Refs. [27-44].
3. A short sentence explaining what "quarkonium production puzzle" means has been added in the Introduction (see lines 141-143).
4. A brief introduction of general QCD features, together with an incomplete list of QCD portals beyond SM has been added in two new paragraphs of the Introduction (lines 76-92). Correspondingly, new Refs. [1-18] have been added.
5. The sentence on line 556 of the previous version (new line 648) of the manuscript has been improved.
6. Some ":" in the text have been removed.
7. A "which" has been inserted in the sentence on line 44 of the previous version (new line 111).
8. In Section 2.1 \Lambda_{\rm QCD} now reads as "the QCD scale".
Further remarks:
A. The affiliation has been slightly updated.
B. Some references were automatically updated via BibTeX.
C. A short discussion on the connection between quarkonia, NRQCD and exotic hadrons (tetra- and penta-quarks) has been added (see lines 239-241), together with eight more references [143-150].
D. Added new Refs. [123,354,489,490,509-512].
