# Dark Matter Direct Detection of Classical WIMPs

### Submission summary

 As Contributors: Jodi Cooley Arxiv Link: https://arxiv.org/abs/2110.02359v1 (pdf) Date submitted: 2021-10-10 16:44 Submitted by: Cooley, Jodi Submitted to: SciPost Physics Lecture Notes Academic field: Physics Specialties: High-Energy Physics - Experiment High-Energy Physics - Phenomenology Approaches: Experimental, Phenomenological

### Abstract

One of the highest priorities in particle physics today is the identification of the constituents of dark matter. This manuscript is a supplement to pedagogical lectures given at the 2021 Les Houches Summer School on Dark Matter. The lectures cover topics related to the direct detection of WIMP dark matter, including the distribution of dark matter, nuclear scattering, backgrounds, planning and designing of experiments and a sampling of planned and ongoing experiments.

###### Current status:
Editor-in-charge assigned

### Submission & Refereeing History

Submission 2110.02359v1 on 10 October 2021

## Reports on this Submission

### Strengths

1- Very comprehensive
2-Clearly written
3-Up-to-date
4-Self-contained

### Weaknesses

1-The work is titled "Dark Matter Direct Detection of Classical WIMPs" but the discussion goes well beyond. This is in general the path that the community has taken (going beyond the Lee-Weinberg limit), but it is stated nowhere in the text.

### Report

The lecture notes cover the very active field of direct searches of WIMPs under classical assumptions. It begins with theoretical background and discusses the complete framework under which experimental searches find their motivation. Then experimental approaches are discussed in details and the current scenario is very well presented. The discussion is complete and systematic and it certainly meets the criteria for publication in SciPost Physics Lecture Notes

### Requested changes

1- Page 3 Only semiconductors are mentioned for detecting DM-nucleus scatting, but in the end of the notes other materials are discussed (i.e., CaWO4). In here the reader get the impression that semiconductors are the only viable option and this is not the case. Ic can be canced to Solid state detectors.
2- Page 9 typo "detector" -> "detect"

• validity: top
• significance: top
• originality: low
• clarity: top
• formatting: perfect
• grammar: perfect

### Strengths

1) Level of the text appropriate for pedagocical lectures.

### Weaknesses

1) The text discusses estensively physics associated to DM detectors while aspects as astrophysical inputs and theoretical interpretation of the signals are overlooked.
2) Figures.

### Report

Dark Matter Detection is one of the most relevant topics in Modern Particle Physics hence, in this regards, the manuscript meets the acceptance requirements of the journal. However, only some aspects of DM detection are discussed extensively while others just recevied a small mention. Nevertheless, I think that this text would be a useful introduction, to some aspects of Dark Matter detection, for people new to the field, provided that some changes, are made to the text.

### Requested changes

1) I would suggest a general proof-read of the text. There are some typos and some sentences which should be made more fluent to read.
2) Most of tables and figures are either too big or too small. In particular I would recommend, if possible, to replace fig. 13 with a plot with better resolution and to substantially increase the size of fig. 25 since, in its current status, the text in the panels could be read only by applying a substantiall zoom to the pdf reader.
3) Even if only a short section is devoted to the Dark Matter distribution I would recommend to include extra references besides just reference [1].
4) The acronym WIMP is used before being introduced. Furthermore at the beginning of the text the author that states the word WIMP will refer to just a generic particle candidate without specific assumptions on the mass scale and size of interactions. I do not agree with this choice; first I think it could lead potential confusion to someone interested in consulting the specialistic literature after reading these lecture notes. Furthermore, the lecture notes mostly focus on DM-nucleus scattering. Non-WIMP DM candidates can be probed also through different processes like scattering on electrons. More in general, in the second part of the text, when detection tecniques are discussed in more detail, the word WIMP seems to be used referring to its conventional meaning. For the reasons just illustrated I would recommend the author to modifiy appropriately the text and identify with better clarity which kind of particle DM candidates the discussion of the manuscript applies to.
5) The author correctly notices, after eq. (7), that the typical energy exchanged in DM scattering processes is not sufficient to break the nuclei. However, inelastic scattering processes in which nuclei pass from the ground to an excited state might occur, see e.g. Phys.Rev.D 96 (2017) 2, 022008.
6) I would reformulate the text around equation 88-89. It should be stressed that the $A^2$ enhancement occurs just for SI interactions. Furthermore, the relation between $f_p$ and $f_n$ depends also on how the DM interacts with up and down quarks individually so the assumption $f_p \sim f_n$ is model dependent.
7) Section 3.6 should be completed by showing how the differential rate shown in the previous sections can be expressed in terms of the effective operators.
8) The author should provide a more extensive description, in the main text, of fig. 25.

• validity: -
• significance: -
• originality: -
• clarity: -
• formatting: -
• grammar: -