# Comments from the Jülich group to the NMO paper

This is a merged review prepared by several members of the Jülich group:

*Runxuan Liu, Marco Malabarba, Yury Malyshkin, Luca Pelicci, Mariam Rifai, Hexi Shi, and Cornelius Vollbrecht*.

We tried to homogenize our comments to avoid duplications and to make it easier to go trhough them.

The paper version for the review: [DocDB-9886-v4](https://juno.ihep.ac.cn/cgi-bin/Dev_DocDB/ShowDocument?docid=9886&version=4)

## General Comments

It is clearly seen that different parts of the paper are written by different people. There are many repetitions, and the flow of the paper is quite chaotic. Below are more specific suggestions how the structure can be updated.

### 1. Introduction

There is no Kaiping mentioned, maybe it is fine. And no explanation why the detector is called Jiangmen. It is a place. People out of the collaboration may not know.

### 3. Expected Signal and Background

We propose to change the order of Subsections 3.1, 3.2 and 3.3:

**3.1 Reactor Antineutrino Flux** (no changes)

**3.2 Backgrounds (their origin)**, no cuts

**3.3 IBD Event Section** -- the cuts and the final rates, including the table

We believe this order will be easier to follow. Right now backgrounds are partially introduced, or not properly introduced in Subsection 3.2, while their origins are explained later on.

### 4. TAO

- Remove any details of the analysis, they are naturally explained in the Analysis section. Leave only the description of the TAO detector.
- Subsection 4.3: the part about reactor-off measurement of backgrounds can be separated.

### 5. Analysis and Results

- The list of the updates might be better to be mentioned in the Introduction as motivation of the paper.
- Suggestion: remove mentioning of distinct groups in analysis, just mention different approaches and choose one analysis for discussion. This is not interesting for a reader. If the authors really want to show all three approaches, the details may be given in an appendix.
Please keep in mind that the referees from journal-review are not going to be familiar with and need not to be into such technical details regarding the differences between the three groups, as well as the general audience are supposed to get the essence of the analysis from the explanation given here in the text.

## Technical/Physics comments

- (General) in multiple places, Exposure notations may lead to confusions: 6 years of true data taking time used for most cases - abstract, conclusion etc, where “6” appears to be the round-up of 6.7 years of data taking time (or 6.2 years of exposure) required to reach 3-sigma for NO, with 11/12 reactor duty cycle, running time is then 6.2 years. —> better to avoid the mixture of using different notations, and remark in an early part of the article that the notion exposure if unified as the effective exposure (namely 6.2 year case). And when mentioning the 6 years exposure, use an approximate symbol, or say “about 6 years”.
- “gammas” —> not a good notation in articles. Better use "gamma particles” or use the Greek character $\gamma$-particles.

### 1. Introduction

- L310: specify, at least qualitatively, the relation between the effective mixing angles and mass differences and the parameters in vacuum.
- Fig.1: We do not think that changing sin2theta12 value is a good idea. Actually it is also interesting to see what is the effect of the other oscillation modes with respect to solar only. We suggest to equalize the widths of the two panels to make the details of the oscillation pattern more visible.
- Fig.1: "Oscillation probability" -> "Survival" on the Y axis and in the caption, to be consistent with the text.

### 2. The JUNO Detector

- L391-392: In case available, any reference or dedicated study or number on the quenching of the scattered p/C?
- L393: “visible energy” appears for the first time here, no clear definition. Maybe better to move the line 410 definition of the term here?
- L398: It could be good to add a brief explanation why the slopes appear.
- L410: Evis is defined via Erec (Erec with perfect energy resolution). There are two problems: in caption of Fig.2 it is said to by proportional to the number of emitted photons (from where does it come?) and Erec is not yet defined which makes the definition here not clear.
- L422: add reference for the pull curves.
- L435: temporal instabilities —> what kind of?
- L437: “PE/MeV” appears for the first time, as “PE” is not a SI unit, better to specify it is short for PhotoElectron.
- L448: PMT PDE of 30.1% is only for NNVT, for Hamamatsu it is 28.5%, so the average is ~29%.
- L466: 0.02% for a: should be with the same unit of sqrt(MeV) as in L451??
- L466-468: Shall we promise that the procedure will be the same in future? Maybe we can just remove this sentence?
- L475-478: It is not easy to follow the arguments here. “2.2 MeV as the anchor point .. cross 1 at 2.2 MeV”: if the crossing point at 1 at 2.2 MeV is not shown in Fig.2, then the “anchor point” for which energy scale (gamma calibration scale?) might need to be specified. Positron non-linearity crossing 1 at 3.2 MeV, it is not clear if it is by choice to anchor the positron energy scale at 3.2 MeV (or nuE at 4 MeV), or it is determined by the 2.2 MeV anchor point in the non-lin curve in the gamma energy scale.
- Fig. 2: the caption should be more descriptive of the picture (especially of the inset), right now it seems more of a summary of Sec. 2

### 3. Expected Signal and Background

- L495-496: From the Table 1, Daya Bay is included in the IBD signal rates, which in total add up to 47.1 cpd, consistent with Table 2. However, in Table 3, the IBD is counting 44.1 cpd excluding the Daya Bay component. These numbers should be consistent, and stated in the main text instead of only in Tables.
- Line 502: is it R(E_nu,E_rec)?
- L525-527: Name the discreapancy ("5 MeV") since it is usually called like this everywhere, even if it may be not 100% correct.
- L559-570: All this will be introduced later on. It is not needed here since the section is about the reactor spectrum, not about the analysis. Some details may be moved from here to Section 4.1 if needed.
- L564-565: "almost free” —> means what?
- L582: "new IBD selection" -- it is not really new, since only a new window [4.4, 5.5] MeV is added, the rest is exactly the same as in Yellow Book.
- L588-589: the sentence should be written more clearly: it is not clear if both the prompt and the delayed signals must be in FV or only one of them is required to be in the FV.
- L590: accidental backgrounds appears for the first time without definition.
- L593-594: maybe from "but the performance" can be removed, it should be obvious.
- Fig. 3 Add labels to the inset axes or mention it in the caption.
- L625: comment about 2-cm vertext reco bias. It is not clear where it comes from.
- L648-649: how is it related to the previous sentence? Also, what is the point of this section at all?
- L657-662: 98% rejection matches only for He-8: 40 events/day * 2% = 0.8 events/day. What about Li-9?
- L694: "in the absensce of well-motivated models..." actually, for example, for geoneutrino the spectrum is predicted very well, except the ratio between Th and U components.
- Table 3: in the caption you mentioned 44.1/day in contradiction to Table 2 where Daya Bay is considered.

### 4. TAO

- L704: say what are the shares to the signal of the two TS cores.
- L710: "viewed by [EXACT NUMBER OF SiPM] covering 10 m2 with ..."
- Comment on the possible difference in spectra from reactors of different types.
- L712: “acceptable level” —> some numbers are always a better statement if available.
- L736-738: TAO 25 cm, JUNO 50 cm FV cut: it will be clearer to add the cut means distance from the detector LS volume boundary. Also, it is confusing that in the earlier sections on JUNO FV cuts, the cut is defined by the distance from the center. Better be consistent.
- L753: "no change on the nonlinearity curve" -- only one point has been investigated. Maybe "no change on the energy scale"?
- L765: "As a result, an 0.5% relative" -- not clear how it was obtained and whether it is somehow linked with the previous sentence.
- L775-780: Can it be described only once, for JUNO and TAO together?
- L820: “around 2000 fast neutron” —> This part is very confusing. Maybe something like: "For the data taking time of 3--6 years, the data taken during the reactor-off period will provide sufficient fast neutron statistics at a rate of 2000 event per day, when the muon veto selection is not applied."
- Fig.4: The fast-neutrons component in this figure rises up at lower energy end - quite different from JUNO case in Fig.2 inset. According to L824-825, the shape comes from TAO simulation. Could the difference in shape from JUNO fast-neutron PDF be explained briefly?
- Fig.4: What is the cause of the kinks for the green and orange curves near <~1 MeV?
- Fig.4: Why the orange line is so wiggly?

### 5. Analysis and Results

- Maybe to say that all the updates mentioned in L836-848 became available after the PMOP analysis?
- L859: “mostly converted”: possible to specify the formula of the conversion, and/or and fluctuation introduced?
- L860: “After ...” —> does this mean:
“After the positron annihilates with an electron, the energy of the two gamma particles (2m_e) is added to the total energy deposited by the positron.” ??
If this is the case, the “leakage”(due to gamma, from either e+e- annihilation or after some Compton scattering) appears to be totally neglected…
—> Also it is not so clear the treatment of the positron:
does the annihilation of the positron follow some cross-section data and happen at non-zero kinetic energy,
and the residual kinetic energy propagate to the gamma-gamma is neglected?
Or approximately the positrons annihilate at close to zero kinetic energy?
- Eq(8): Why not denote the positron energy explicitly as $E^{e+}$?
- L862: “boundaries ...”: not clear the boundaries are taken into account for what?
- L861-862: there were no relevant steps for gammas.
- L866-868: What is the reason behind the non-uniform binning? It deserves some remark in the main text where it is defined, and maybe summarize the binning at different energy region in a table.
- L869: If the difference is in the treatment of the kinematics, some plain-word explanation should be included to guide the reader through the Eq(9) to (12) and the paragraph that follows.
- Eq. 10 and 11: in one you integrate on E_i on the other on E_j. Which is the correct one?
- Eq. 10 and 11: the C matrices were not defined previously.
- In general it is very difficult to follow section 5.1, can you provide more details?
- L912: What does "approximately" mean here?
- L930-935: it seems too technical, it can probably be removed
- L944: move 0.04 as uncertainty on delta chi^2 to discussion of delta chi^2
- L987: contains fluctuations --> if statistical, why not simulate more data to reduce statistical effects?
- L1042: the 5sigma should be also added in the text; also is it for both NO true and IO true cases?
- L1043: “matter oscillations” —> “matter EFFECTS”?

## Language/readability and Style comments

### 1. Introduction
- L266: We would rephrase this sentence to remove respectively, like: "Solar (atmospheric) neutrino anomalies can be explained by the transformation of electron (muon) neutrinos into other neutrino flavors as they propagate.
- L279: rest mass OF or IN the mass eigenstate
- L301: "_the_ next generation"
- L280: "an precision" --> "a precision"
- L292: literature without "s"
- L311: U tilde not defined
- L319: "_the_ spectrum"
- L319: "at _the_ JUNO detector"
- L328: Connection with the previous sentense is lost. The previous sentence was about the high energy resolution requirement, while the nest section says "for this purpose using a 20 kton ... at about 52.5 km", which do not help for resolution.
- L333-336: It is better to rephrase like this: "A new improved model energy resolution model [Ref] is developed taking into account ..."
- L338: "_the_ overburden"
- L340: "the inclusion" -> "consideration" because the sentence starts as "Other updates include"
- L341: "taking into account the matter effect".
- L347: "Sensitivity _analysis_"

### 2. The JUNO Detector

- L351: "south China" -> "South China"
- L351: double space in 650 m
- L361: "_of_ >= 99.5%"
- L362: "of _the_ water"
- L362: "The muon cosmic" --> "The cosmic muon"
- L362: split sentence with "The muon cosmic"...into two sentences?
- L363: "The muon veto system _located at the top_ is ..."
- L369: "0.511 MeV" -- make sure to be on the same line (use "~")
- L371: viewed by the PMTs --> detected by the PMTs?
- L377: missing . at the end of the sentence
- L381: move R(E_nu, E_rec) directly behind matrix.
- L382: "of _the_ IBD"
- L426: "An excellent" is too strong. Concider "Fine" or something like this.
- L431: "for the relative energy resolution".
- L433: “annihilation gammas” —> “gammas from the positron annihilation”.
- L439: is updated --> was updated / improves --> was improved
- L447: Suggestion: Data of PMTs batch tests show...?
- L449: measurements
- L451: better modelling OF the reflective surfaces...
- L456: in the sentence "...of them" points to the photons interactions, but the context refers to the PMTs. Maybe "photon interactions in the PMT glass and other optical process occuring within the PMT volumes?"
- L456-458: "after" and "simulations" both repeated twice. It is hard to understand this sentense.
- L457: change second "after" in sentence to "by"?
- L461: syntax of sentence is strange after "by fitting", maybe "By fitting the widths generated by simulating a large number of positrons at several fixed deposited energies with the expression in equation 5, we obtain a = ..."?
- L477: "_gamma_ Evis/Edep"
- L477: "nonlinearity _curve_"
- Fig.2 & L870: "IBD interaction” --> “IBD reaction”; elsewhere in the article consistently and correctly using “IBD reaction”.
- Fig 2 caption: "PDFs"
- Fit 2 caption: "distribution of _ the positrons"
- Fig.2: “from deposited energy” -> “from the deposited energy

### 3. Expected Signal and Background

- L480: “Reaction” -> “Reactor”
- L483: equidistant --> almost equidistant
- L485: due to a non-optimal baseline?
- L499-503: split sentence in two?
- L500: “introduced” —> “to be introduced”.
- L501: amount of data-taking time --> duration of data taking?
- L505: “where” —> above which.
- L516-517 Phrase already written (line 487/488)
- L522: form -> from
- L528: were measured
- L558: next (sub)section is not about TAO, maybe refer to it with its number (section 4?)
- L575: "shielding _from_"
- Figure 3: "main figure stacked" --> "main figure are stacked"
- L577: "due to _the_"
- L576: “handle” —> is definitely not a correct term in this context. maybe “criterion” or some other word.
- L582: was developed or is being developed (?)
- L586: “dominated by” —> personally prefer “dominantly from the”.
- L604: remove brackets
- L604: “single” —> “a single muon”.
- L605: "far apart muons (>3 m)"
- L606: closer than...away --> remove away?
- L625: “2-cm”—> “2 cm” with space in between.
- L634: candidate sample are --> candidate sample is.
- L636: “in the detector material” —> “from the residual contaminations in the detector material”.
- L652: repetition of line 592-593
- L656: “IBD signature The” —> missing “.” in-between.

### 4. TAO

- L702: expression to eliminate any possible... is too strong, maybe "to minimize possible model dependencies"?
- L704: TAO is located at a distance of 30 from...?
- L709: is detected --> are detected
- L710: viewed -> detected by
- L715: suggestion: by the veto system that includes the water tanks and a plastic scintillator on the top of the detector, both instrumented by PMTs.
- L719: repition of line 560 and 567
- L720: "In this analysis, a new analysis framework is developed for the joint analysis of JUNO and TAO experiments". (too many analysis ?)
- Caption of table 4: "JUNO means the quantity is the same as JUNO". it seems a bit confusing as it uses "JUNO" to define itself
- L722: specta --> spectrum
- L725: Consider "TAO helps to constrain"
- L743-744: "as is in the binning ... distribution" -- this part of the sentence is not clear. Is it needed at all?
- L745: the "same steps as for JUNO's matrix" -- there seems to be no earlier mention of the steps regarding the JUNO matrix.
- L746-747: "effect" is used threr times. Try to rephrase.
- L765: an --> a
- L772-L773: "Cherenkov light emission _simulation_ is implemented"
- L796: "and with a spherical ... 1 ton" -- repetition, can be removed from here.
- L799: "... cut, _ is calculated"
- L803: "In total" in what sense?
- L808: "is floated" -- try to find another word, e.g. "kept unconstrained"?
- L812: "92, 54, 155" -- these numbers are given in Table 4. There is no need to write them in the text.
- L821: "removing the muon veto" maybe the verb "remove" should be changed since it could create confusion
- L825-826: "which is fine for this sensitivity study since they will be measured with data-driven methods" remove "which is fine"
- -Table 4: The information in the last two columns is not good for table representation ("see text" entry; FF, FL and NL abbreviations introduced only to use once). We suggest to remove the last two columns and decribe this in text.
- Fig.4: - “IBD interaction” —> “IBD reaction”.

### 5. Analysis and Results

- L861: "with 2m_e" -- better to say in words: "with doubled electron mass" or something like this.
- L870: “formulas” —> “formulae”.
- L878: add "and cos$\theta$"
- L918: prescription --> description?
- L922: "also" -- "only"?
- L932: "uncertainty" -> "constraints" (twice)
- L932: "with _a_ 100%"
- L959: "four hundred" -- does it correspond to Table 5?
- L977: unprecise formulation: matrix components are oscillating?
- Table 5: cross symbol after "fission fraction" in the table and in the caption.
- Table 6: cross symbol after "TAO"
- L1001: replace "are quite different in 2014" -> "oscillation parameters are updated w.r.t PDG2020"
- Fig. 7: expose --> exposure

### 6. Conclusion

- L1039: add normal ordering "is true"
- L1039: “assuming _the_ normal ordering is _true_”.
- L1039: “If _the_ inverted ..."
- L1043 “$\Delta_{CP}$”: the argument on its DEPENDENCE appears probably for the first time in the article, not to mention previously the term is written in $\delta_{CP}$, not consistent with here.