Light-Nuclei Production in Heavy-Ion Collisions at
Round 1
Reviewer 1 Report
Referee report on the manuscript particles-2222742 by M. Kozhevnikova and Yu. Ivanov.
The paper presents the results on the yields of light nuclei produced in heavy ion collisions at energies between 6.4 GeV and 19.6 Gev in the c.m. frame. To study the light-nuclei production the authors use the THESEUS event generator based on 3-fluid hydrodynamic model coupled to UrQMD as afterburner.
The manuscript is a shortened version of the paper by the same authors (their reference [59]) recently published in Phys. Rev. C (vol. 107, 2023, 024903).
In the agenda to this Issue we see that "The papers submitted to this Special Issue are expected to reflect original work or be a balanced review of a field." - In my opinion, this manuscript cannot be published in its present form, because it lacks either novelty as an original work or significance as a review paper. It contains too many copy pasted fragments from the PRC paper. In the revised version, we authors should re-write the text to avoid self-plagiarism and modify, at least slightly, the presented figures.
Author Response
Response to Reviewer 1 Comments
Point 1:
The manuscript is a shortened version of the paper by the same authors (their reference [59]) recently published in Phys. Rev. C (vol. 107, 2023, 024903).
In the agenda to this Issue we see that "The papers submitted to this Special Issue are expected to reflect original work or be a balanced review of a field." - In my opinion, this manuscript cannot be published in its present form, because it lacks either novelty as an original work or significance as a review paper. It contains too many copy pasted fragments from the PRC paper. In the revised version, we authors should re-write the text to avoid self-plagiarism and modify, at least slightly, the presented figures.
Response 1:
This manuscript is written as project report (proceedings) presented at the Workshop on physics performance studies at NICA (NICA-2022), based on the oral talk by M. Kozhevnikova at this workshop. The results shown in this manuscript are not original, because they were recently published in Phys. Rev. C (vol. 107, 2023, 024903). Therefore, the type of the manuscript is chosen as a project report. This type does not have to contain new results. Nevertheless, we have additionally modified the figures and partially rephrased the text in order to differ from the published version.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Dear Authors,
I have some comments and corrections.
Line15: is connected with search for => is connected with searching for
Line 24:experimental data on the light-nuclei => experimental data of the light-nuclei
Line 74: stable nuclei and and low-lying resonances => stable nuclei and low-lying resonances
lines 145 and 156: these two lines need to rephrasing.
Figures 2,3 and 4 are not for rapidity these figures for pseudorapidity(eta).
I can see clearly the disagree between data and simulation, from your point of view what is the reason of this disagreement? and how can improve the simulated data to get good agreement?
Best regards,
Author Response
Response to Reviewer 2 Comments
Point 1:
Line15: is connected with search for => is connected with searching for
Response 1: The sentence is changed (lines 14-15).
Point 2:
Line 24:experimental data on the light-nuclei => experimental data of the light-nuclei
Response 2: Changes have been made to the text (now: line 23)
Point 3:
Line 74: stable nuclei and and low-lying resonances => stable nuclei and low-lying resonances
Response 3: Changes have been made to the text (now: lines 78-79)
Point 4:
lines 145 and 156: these two lines need to rephrasing.
Response 4: Changes have been made to the text (now: lines 154-157 and 169-170)
Point 5:
Figures 2,3 and 4 are not for rapidity these figures for pseudorapidity(eta).
Response 5: Figures 2, 3 and 4 are for rapidity y = 1/2 ln(E+pz/(E-pz)) because the data from the NA49 experiment, with which we compare our results, is for rapidity distributions.
Point 6:
I can see clearly the disagree between data and simulation, from your point of view what is the reason of this disagreement? and how can improve the simulated data to get good agreement?
Response 6:
The shortcomings of the generator can be related to absence of light-nuclei afterburner in UrQMD and the imperfectness of the proton description. As it is argued, the shortcomings of the proton description are amplified in the case of light nuclei. While a better description of the proton spectra can be achieved by refining the 3FD model, in particular, by choosing another EoS, the problem of light-nuclei afterburner is more severe. We are also going to study the effect of medium effects applied to light-nuclei production.
All this is summarized in the paragraph added in the end of Summary.
Author Response File: Author Response.docx
Reviewer 3 Report
The paper presents the simulation results of light-nuclei production in relativistic heavy-ion collisions. The main contribution is a new light-nuclei production event simulator which is based on the thermodynamical approach. Considering the topic of relativistic heavy-ion collision and quark-gluon plasma in recent years, this is definitely a worthwhile direction to explore.
The paper has very detailed simulation analysis. I have two general comments:
1. The originality of this paper is to update the event generator with a thermodynamical approach. The paper mentioned sufficient information about the advantage of this approach, which is good. It would be better if the author can have few more sentences to describe the details of the approach, although the author has self-cited a paper [36] about it.
2. Overall the performance of new approach cannot beat 3FD with subsequent UrQMD approach, even though different freeze-out energy densities have been explored. I am curious about the root cause of the imperfectness. Is it due to a systematic bias in the event generator approach, or the thermodynamical approach is over-simplified? It is helpful to have a discussion.
I also have two specific comments:
1. Line 95 - 98: the author claims that the new approach (late freeze-out) reasonably well reproduce the conventional approach in the midrapidity region. However, I cannot clearly see this conclusion. The new approach has an additional peak in the midrapidity region in which the conventional approach does not have. It means the rapidity distribution pattern is quite different.
2. In Figure 2, 3, 4, there are both black and white square boxes with error bars. I can tell from the figure legend that the black square boxes correspond to NA49 experiments, but I am confused about the meaning of the white ones.
Author Response
Response to Reviewer 3 Comments
Point 1:
The originality of this paper is to update the event generator with a thermodynamical approach. The paper mentioned sufficient information about the advantage of this approach, which is good. It would be better if the author can have few more sentences to describe the details of the approach, although the author has self-cited a paper [36] about it.
Response 1: The sentences (lines 71-76) describing the details of the thermodynamical approach are added.
Point 2:
Overall the performance of new approach cannot beat 3FD with subsequent UrQMD approach, even though different freeze-out energy densities have been explored. I am curious about the root cause of the imperfectness. Is it due to a systematic bias in the event generator approach or the thermodynamical approach is over-simplified? It is helpful to have a discussion.
Response 2: The 3FD model uses coalescence mechanism of light-nuclei production, so it can produce a better agreement the experiment data by means of tuning a number of fit parameters. In thermodynamical approach of the THESEUS generator, we have only a single universal parameter (related to the late freeze-out) for all light nuclei and collision energies. Therefore, our abilities to fit data are limited. This is from the technical side.
From the physical side, the reproduction of the proton data within the 3FD is good but not perfect. As we argue in the text, the shortcomings of the proton description are amplified in the case of light nuclei. Therefore, the agreement with light-nuclei data is worse. The absence of the UrQMD afterburner for light-nuclei also prevents better description of light nuclei.
All this is summarized in the paragraph added in the end of Summary.
Point 3:
- Line 95 - 98: the author claims that the new approach (late freeze-out) reasonably well reproduce the conventional approach in the midrapidity region. However, I cannot clearly see this conclusion. The new approach has an additional peak in the midrapidity region in which the conventional approach does not have. It means the rapidity distribution pattern is quite different.
Response 3:
“reasonably well” is certainly worse that simply “well”. Therefore, we used this additional “reasonably” in the discussion. A definite achievement of our approach is that for light nuclei it produces a dip at the midrapidity (with or without a slight peak in the center) instead of global peaks for protons at Elab=20A—40A GeV. The reason of these additional peaks in the midrapidity could be that the protons are more peaked after the UrQMD, see Fig. 4. Even agreement with data on proton rapidity distribution at 40A GeV (see Fig. 4) becomes worse after application of UrQMD. This is a shortcoming of the 3FD+UrQMD or the used EoS rather than the way of treatment of light nuclei. The 3FD coalescence is based on nucleon spectra before UrQMD, where global midrapidity peaks for protons are less pronounced.
The corresponding comments are added in the end of Subsect. 3.1.
Point 4:
In Figure 2, 3, 4, there are both black and white square boxes with error bars. I can tell from the figure legend that the black square boxes correspond to NA49 experiments, but I am confused about the meaning of the white ones.
Response 4: The open boxes correspond to the NA49 data reflected with respect to the midrapidity. These comments are added to figure captions.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
In the reply, the authors explain that the type of the manuscript is "project report" and not the "original article". They also modified the text to avoid self-plagiarisms.
I have no further questions and recommend publication of the manuscript in its present form in Particles.
Reviewer 2 Report
I accept to publish this paper in the present form.
Thanks
