Diurnal Variations of the Count Rates from Dark Photons in PHELEX

Round 1

Reviewer 1 Report

The study of dark matter is an important field in modern physics. As a possible candidate, dark photons have attracted researchers’ attentions.

In this paper, the authors have reported the PHELEX experiment, i.e., PHoton–ELectron EXperiment, to search for the dark photons (DPs) of cold dark matter using a multicathode counter technique. New data, a novel upper limit for the constant of kinetic mixing, and the first results of measurements of the diurnal variations in solar and stellar frames have been presented.

This paper is interesting and useful for the community. Some improvements are needed before its publication in Particles.

L46: A reference is needed for Eq. (1).

L47: If you want to start a new paragraph, “where” may be revised to “Here,”

L67: A reference is needed for Eq. (2).

L68: If you want to start a new paragraph, “where” may be revised to “Here,”

L69: rho_CDM should not be italic.

L78: A reference is needed for Eq. (3).

L79: If you want to start a new paragraph, “where” may be revised to “Here,”

L79: “m_gamma’ is the mass of a DP” repeats that on L48.

L79: eta should be italic.

L82: The units in Eq. (4), for examples, Hz, eV, GeV, cm^3, m^2 should not be italic.

L82: A reference is needed for Eq. (4).

L119-120: The names of quantities on the axes are needed, but not only the units (mV and ms).

L199-120: Is the big (small) pulse from muon (single electron)? Please mark them in the plot.

L129: The name of quantity on the x-axis is needed, but not only the unit (Days).

L135-140: The format is not normal.

L166: The units of alpha and eta on the axes are needed.

L166: The name of quantity on the third axis is needed, but not the unit (Hours).

L168: eta should be italic.

L171: eta should be italic.

L176: Is there any unit for the quantity on the y-axis?

A section of conclusion is needed. You may reorganize two sections (results and discussion) to three (results, discussion, and conclusion).

L211-234: The formats of references should be the style of Particles.

L221: e+e- should be e^+e^-.

 

Author Response

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Reviewer 2 Report

see attached document.

Comments for author File: Comments.pdf

Author Response

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One of Referee comments is in pdf with Figure, so we attach only our answers.

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Reviewer 3 Report

The paper reports results from the PHELEX experiment. Although the results are interesting the quality of the manuscript and clarity of arguments is not good. The authors should reply to the following comments and make a deep revision of content and style before it can be considered for publication.

-The authors seem to use c=1 in their eq (2) and (3) but I do not see any convention on this. 

-It seems there is a typo in eq.(4) as factors regarding \rho_{CDM} and A seem to be affected by -1/2 instead of 1/2. 

-RMCC is a parameter is not sufficiently discussed, even if present in additional references; they should explain the R/ \eta  ratio in eq. (4). I am not sure why the authors use the same symbol \eta in Fig. 5 to describe an  angle. Is it related to the quantum efficiency? If so, not clear why in my opinion.

 

-In section 3 it is not clear why either degenerate electrons play a role in low-density matter. Are the authors refering to low T high density matter? It should not from their terrestrial experimental setting. In Fig.3 temperature is shown, what are the energetic effects steaming from this? is thermal energy involved in the efficienty and count rate?

-At the end of section 3 they derive a limit on the \xi parameter from eq. (4), that I previously reported having a typo. It is not evident how they obtain this number since they do not give information of the rest of parameters.

-Fig.5 is really tiny to read the numbering, so I suggest they split it into 3 vertical panels.

-It would be nice to see how the time period is obtained from Fig. 6. and what is the actual correlation of maxima to minima in that figure.

 

 

Author Response

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Round 2

Reviewer 2 Report

A few references should be added to existing limits on kinetich mixing parameter in the same mass region (even if with different method):

Essig et al PHYSICAL REVIEW D 96, 043017 (2017)

SENSEI collaboration PHYSICAL REVIEW LETTERS 122, 161801 (2019)

DAMIC Collaboration PHYSICAL REVIEW LETTERS 123, 181802 (2019)

Replace in section 5 "Conclusion": 

line 204: can --> could

line 207: can --> could

line 208: it follows --> it would follow

line 209: result support --> result supported

line 210: is --> would be

 

 

Author Response

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Reviewer 3 Report

I am very surprised that the authors did not follow previous suggestions and therefore my first report  remains not answered.  Mainly points 3, 5 and 7 regarding further explanations in the manuscript. Even there are no additional explanation in the letter back to reviewer.

In my opinion the manuscript under its present form does not deserve to be published yet as there are uncertainties that need to be fully and carefully clarified.

Author Response

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