Talk:T2K experiment/GA2

GA Review

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Reviewer: Eviolite (talk · contribs) 14:24, 3 January 2022 (UTC)

Will start looking at this article later today or tomorrow - it's rather long so I may not get to it all in one day. eviolite (talk) 14:24, 3 January 2022 (UTC)

GA review (see here for what the criteria are, and here for what they are not)

1. It is reasonably well written.

   a (prose, spelling, and grammar): b (MoS for lead, layout, word choice, fiction, and lists):

2. It is factually accurate and verifiable.

   a (reference section): b (citations to reliable sources): c (OR): d (copyvio and plagiarism):

3. It is broad in its coverage.

   a (major aspects): b (focused):

4. It follows the neutral point of view policy.

   Fair representation without bias:

5. It is stable.

   No edit wars, etc.:

6. It is illustrated by images and other media, where possible and appropriate.

   a (images are tagged and non-free content have fair use rationales): b (appropriate use with suitable captions):

7. Overall:

   Pass/Fail:

I have less time than I expected today, so will probably only get to some broad comments.

• No copyvio detected, though that doesn't check offline sources or PDFs - will have to check individual sections later.
  • Though, most sources appear to be CC-BY, so it wouldn't bave to be rewritten (just attributed with {{Creative Commons text attribution notice}}).
• Images all have accurate licenses (Flickr CC-BY images, images extracted from CC-BY papers, and own work diagrams.) All clearly relevant.
• History is stable.
• Sources are all reliable, though there are many primary sources - this leads to possible original research concerns. I will check more later for each section; if there are many issues they will definitely need to be rectified.
• Article is very broad/comprehensive, though I do have concerns about the size of the article - it is not near the point of splitting, but many sections are solely sourced to primary sources and WP:BALASP suggests that it should be discussed in terms of what impartial secondary sources say.
• Article layout is fine.
• I have concerns about the lead. There are references in the lead which should not be there (see WP:LEADCITE), but the primary issue is that lots of information is not backed up in the body (such as the information about continents). See Wikipedia:Manual of Style/Lead section#Relative emphasis, Significant information should not appear in the lead if it is not covered in the remainder of the article, although not everything in the lead must be repeated in the body of the text..

That's all I have time for today, will look at specific sections later. eviolite (talk) 03:54, 5 January 2022 (UTC)

Also pinging Artem.G, previous reviewer, to see if they have any comments on the above (of course don't feel pressured to reread the article or post any, just curious) eviolite (talk) 04:05, 5 January 2022 (UTC)

Looking a bit more finely:

Physics program

• Much of this is incomprehensible to people without background knowledge. See WP:MTAU and WP:GACR#1a. What is a mixing angle? What are oscillation parameters? What is a disappearance study? There needs to be a section for background, notably why these measurements are important and what they even are.
• "world-class results" sounds promotional - what is "world-class"?
• I can't find much of the info in the paragraph starting "$\delta _{CP}$ takes values..." in any of the sources.
• "NOvA provided a less precise measurement of δCP, which is in slight tension with the T2K result. The T2K best-fit point lies in the region disfavoured by NOvA at the confidence level of 90%." also appears to be original research.

Neutrino beam

• "Protons collide with a graphite target, [...] forming a muon antineutrino beam." Failed verification, probable OR.
• "T2K is the first experiment in which the concept of off-axis neutrino beam was realized." also fails verification, the paper cited references a previous paper describing that technique and says "adopts".
• Again, language like "In this neutrino energy range, the dominant type of neutrino interactions are charged current quasielastic interactions, for which it is possible to reconstruct the energy of the interacting neutrino only on the basis of the momentum and direction of the produced charged lepton." is not accessible to a broad audience.

Near detectors

• Details like "The light produced by traversing charged particles in the plastic scintillator bars and planes is collected by wavelength-shifting fibres and detected by Hamamatsu Multi-pixel photon counters located at one or both ends of the fibres" are too specific to be helpful, while these sections lack a higher-level description of what these things actually do. I still don't know what the point of this signal readout is, for example.
• More of the same as above, in each subsection - details like the mass of specific elements within objects, dimensions of various parts (without conversions, varyingly in customary and metric for some reason) etc don't help.
• "Different target material [...] forces us to rely" - what is "us" referring to? If you are affiliated with the T2K experiment please read the guidelines on editing with a conflict-of-interest; otherwise, note that first and second person pronouns should be avoided regardless.

Super-Kamiokande

• Can't find things like "Due to relatively large mass, muons usually do not change their direction and thus produce a well-defined cone of Cherenkov light observed by PMTs as a clear, sharp ring. In contrast, electrons, because of smaller mass, are more susceptible to scattering and almost always produce electromagnetic showers, observed by PMTs as a ring with fuzzy edges." in source, though it could be in [40] which I cannot access.

History

• This section seems fine outside of grammatical issues.

Future plans

• This is again, a giant amount of difficult-to-understand technical jargon, but it also has the issue of being largely speculative with only hypotheses about the experiment. It has the additional issue of essentially none of these plans being discussed in independent secondary sources (that are at least referenced anyway), so per WP:BALASP it should not receive this much attention in the article (as should all of the minor details, again.)

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Based on the above I unfortunately believe this warrants a fail as, in my opinion, it is pretty far from meeting criteria 1a (understandability to a broad audience), 2c (original research), 3b (does not go into unnecessary detail), something not easily rectified in 7 days. In addition, this article needs a copyedit (which would also fall under 1a), perhaps from WP:GOCE - there are spelling and grammar errors plus other awkwardly phrased sentences that took several tries to understand, and the lead needs to be clean up pursuant to MOS:LEAD. Inconsistency within lists is also an issue to be copyedited out.

For the detail issue I would recommend not going so much in detail about the future plans, as nearly all sources related to them are primary and because none of it has actually happened yet. If there is a point at which these follow-up experiments gain significant coverage, I can see that section being split off into its own article as well. I also don't believe a paragraph for every single sensor is necessary as again there is nothing from non-primary sources.

In general, to sum up, much of the niche details sourced only to T2K papers and plans should be cut down, while a background section discussing the science behind the experiment should be added. eviolite (talk) 21:02, 5 January 2022 (UTC)