A Systematic Approach to Studying Quark Energy Loss in Nuclei Using Positive Pions^†

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The comments are in a separate file.

Comments for author File: Comments.docx

Author Response

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below:

1.The measured energy spectra of the pions from various target nuclei should be shown explicitly in the paper to show how they are reproduced by the model.

The reviewer suggests including the measured energy spectra of pions from various target nuclei for comparison with the model. However, it is important to clarify that our study does not rely on a direct modeling framework in the conventional sense. Instead, we perform a normalized shape analysis of carbon compared to deuterium in order to extract quark energy loss from experimental data.

While we acknowledge that explicit presentation of energy spectra would be valuable, we currently do not have permission to publish these spectrum. Instead, we emphasize the consistency of our extracted energy loss results with theoretical expectations derived from the BDMPS formalism. If necessary, we can attempt to construct a phenomenological fit to guide further interpretation, but this goes beyond the scope of our present study.

2.  Proton is a lightest target nucleus to be studied. & 3. Deuteron is not a vacuum. It is a low-density large nuclear target including many mesons inside.

The reviewer states that the proton is the lightest nuclear target and that the deuteron is not a vacuum but a low-density nuclear target containing mesonic effects. We agree that deuterium is not a perfect vacuum; however, in high-energy deep inelastic scattering (DIS) processes at the four-momentum transfer scale considered in this work, mesonic contributions in deuterium are highly suppressed. 
The nuclear density in deuterium is much lower than that in heavier nuclei, making final-state interactions and in-medium modifications minimal compared to denser nuclear targets. As discussed in Frankfurt, Strikman, & Weiss, Ann. Rev. Nucl. Part. Sci. 55, 403 (2005), the assumption that deuterium behaves as a quasi-free nucleon pair in DIS has been extensively validated in experiments from CLAS. Furthermore, at the momentum scales relevant to our study, the interaction length of a propagating quark before hadronization (estimated using formation time arguments from Dokshitzer, Khoze, Mueller, & Troian, Rev. Mod. Phys. 60, 373 (1988)), suggests that medium effects in deuterium are significantly reduced compared to heavier nuclei.

4. Pions produced in a nucleus interact with other nucleons and mesons in the target nucleus,  and lose their energy and also produce another mesons.  Thus experimentally there should be various mesons emitted.  How are they well included in the energy-loss mechanism?

The reviewer refers on meson interactions in the nucleus and their role in energy loss mechanisms. It is true that pions produced in nuclear interactions can experience secondary interactions with nucleons and mesons in the medium, leading to further energy loss. However, our focus is on the primary quark energy loss, which occurs before hadronization. The time dilation effect due to high Lorentz factors ensures that, at high Q², the quark propagates for a considerable distance (~1.5-2 fm/c) before hadronizing, as discussed in Dokshitzer’s QCD treatments.
Moreover, the experimentally accessible energy loss signal is constrained by the kinematics of the reaction. In fixed-target experiments, the available center-of-mass energy limits the number of secondary mesons produced. Studies using Pythia simulations confirm that typical meson multiplicities remain low, usually in the range of 1-2 additional pions. This suggests that while mesonic interactions contribute to overall hadronic dynamics, their impact on the primary quark energy loss signal is relatively small in our kinematic regime.

Reviewer 2 Report

Comments and Suggestions for Authors

Referee report on the manuscript # particles-3431768

by N. Zambra-Gomez, W.K. Brooks, and N. Vlaux

entitled

"Systematic Approach to Studying Quark Energy Loss in Nuclei

Using Positive Pions"

 

The authors present here analysis of quark radiative energy loss in

nuclear matter by using positive pion production data obrained from

the SIDIS experiments, where both the resulting pion and the

scattered electron are measured. The analysis includes all

necessary kinematic cuts to get rid of the background noise and

non-DIS contributions. To quantify the measured energy shift, the

Kolmogorov-Smirnov (KS) test is employed.

I think this paper is of interest for the community and should be

published after addressing the following issuess:

 

- In the Conclusions (lines 292-293), also in the Abstract, the

authors claim that "we explored the hadronization process in nuclear

targets of varying sizes, such as deuterium, carbon, iron and lead."

However, only the carbon data are shown e.g. in Table 3. Where are

the results for other nuclear targets? It should be stated clearly

that only the carbon data are discussed in the paper.

 

Referee report on the manuscript # particles-3431768

by N. Zambra-Gomez, W.K. Brooks, and N. Vlaux

entitled

"Systematic Approach to Studying Quark Energy Loss in Nuclei

Using Positive Pions"

 

The authors present here analysis of quark radiative energy loss in

nuclear matter by using positive pion production data obrained from

the SIDIS experiments, where both the resulting pion and the

scattered electron are measured. The analysis includes all

necessary kinematic cuts to get rid of the background noise and

non-DIS contributions. To quantify the measured energy shift, the

Kolmogorov-Smirnov (KS) test is employed.

I think this paper is of interest for the community and should be

published after addressing the following issuess:

 

- In the Conclusions (lines 292-293), also in the Abstract, the

authors claim that "we explored the hadronization process in nuclear

targets of varying sizes, such as deuterium, carbon, iron and lead."

However, only the carbon data are shown e.g. in Table 3. Where are

the results for other nuclear targets? It should be stated clearly

 

that only the carbon data are discussed in the paper.

 

Some minor remarks.

 

- page 2, line 64.

The reference after "...extensively in [?]" is missing.

 

p.4, l.96.

"...studies,As..." -> "studies, as ..."

 

p.5, l.156.

"...Feynman-X (x_f)." -> "...Feynman-X (x_F) variable."

 

p.6, l.190.

"...is defines" -> "...is defined"

 

p.7, l.235.

"...(KS) our first proof..." ->

         (probably) "...(KS) test. Our first proof..."

 

p.7, ls.237-238.

The phrase "For the same bin and conditions we ." is not finished.

 

p.7., l.240.

"...as shown in 4" -> "...as shown in Table 4"

 

p.9, References.

Names of authors are missing in Refs. 2, 3, 4, 5, and 6.

 

p.9. Acknowledgments.

This part has to be changed. It is written as the first author

would be the sole author of the paper, however both his mentors

 

are included in the list of authors.

 

Author Response

Thank you very much for taking the time to review this manuscript we sincerely appreciate your careful reading of our manuscript and your comments and suggestions. Please find the detailed responses below,

 

1. In the Conclusions (lines 292-293), also in the Abstract, the authors claim that "we explored the hadronization process in nuclear targets of varying sizes, such as deuterium, carbon, iron and lead." However, only the carbon data are shown e.g. in Table 3. Where are the results for other nuclear targets? It should be stated clearly that only the carbon data are discussed in the paper.

The reviewer notice absence of information, thank you for pointing this out. We clarify that we only use carbon data in our analysis, and we have updated the Abstract and Conclusions accordingly to avoid any ambiguity.

2. Minor Remarks:

Missing reference in line 64 (page 2)
Thank you for noting this. We have added the missing reference.

Typographical and grammatical corrections:

• p.4, l.96: Corrected to "...studies, as..."

• p.5, l.156: Modified to "...Feynman-X (x_F) variable."

• p.6, l.190: Corrected to "...is defined."

• p.7, l.235: Changed to "...(KS) test. Our first proof..."

• p.7, ls.237-238: Deleted incomplete phrase.

• p.7, l.240: Corrected to "...as shown in Table 4."

References Section:
We have included the missing author names in references 2, 3, 4, 5, and 6.

Revision of the Acknowledgments Section:
Thank you for pointing this out. We have revised this section to properly reflect the acknowledgments.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I have got through the replies to the referee’s　comments.