Talk:Nuclear structure
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The shell model
[edit]Should the "The Shell model" section be reduced to just the introduction and then let the main article Shell model handle the grunt work of explaining The Shell model? Tempmine (talk) 20:54, 31 March 2009 (UTC)
Quark Shell Model
[edit]I believe the sub-section "Quark Shell Model", listed under "Other Approaches" (actually it's the only text under the "Other Approaches" heading) should be deleted (or significantly revised). The section has a disclaimer that says:
- This section is the sole view of a single author, and not a scientifically accepted theory.
If that's the case, then the section should be removed, per NOR. Some additional things that suggest it should be removed:
- The description is hard to follow, jumping between descriptions of astronomical phenomena, quark types, etc., without properly explaining why this is done.
- The text refers to terms without defining or linking them. E.g. "refractive meniscus", which is not a term associated with quark models (to my knowledge).
- The description is frequently informal. E.g. "and a short life to boot".
- The text reads as an exploratory description rather than a statement of fact. For instance, rather than stating "the model predicts this", the text is worded as a persuasion of the reader.
- There are some statements that seem erroneous (e.g. the statement about the composition of dark matter is wrong: modern science has placed bounds on the composition of dark matter, but the situation is not resolved).
- Conversely there are statements that are vague compared to modern understanding. E.g. "It is theorized generally that each baryon is composed of 3 quarks..." I would say that modern theory has established rather exhaustively the quark makeup of baryons.
- The entire text has no citations, even when making detailed claims. E.g. "By examination, the independent quark would have a mass of at least 400 MeV, probably a lot more..."
- I am unable to find substantiation for this description on searches (either on Google or scholarly search engines).
Overall, the description is totally confusing and doesn't seem to actually say anything. I think the text should be entirely removed since it doesn't contribute anything. On the other hand, if there is a well-formed theory in the literature, then this section should be rewritten to be easier to follow, and to cite these literature sources. Kebes (talk) 15:17, 28 April 2008 (UTC)
I see that user DenverRedhead has restored the Quark Shell Model section, without any explanation. DenverRedhead, can you provide some more information about this content? Is it original research? Is it based on a consensus view in a sub-domain of science? If so, can you provide a selection of references that describe it? If anyone else has information on this model, please help here. I find the current description confusing; it should be improved. Kebes (talk) 18:20, 29 April 2008 (UTC)
DenverRedhead has provided this reference with respect to the "Quark Shell Model":
- G. Musulmanbekova 'Do Nuclei Possess Crystal–Like Structure?' Nuclear Physics A, Volume 734, Supplement 1, 5 April 2004, Pages E80-E83. doi 10.1016/j.nuclphysa.2004.03.025
Another article by the same author apparently has further details on the theory:
- G. Musulmanbekov. Semiclassical correlated quarks model of hadron structure and interplay between hard and soft interactions Nucl. Phys. Proc. Suppl. B 71 (1999). doi 10.1016/S0920-5632(98)00331-4
These publications describe a theory where quark interactions lead to crystal-like nuclear states. Although I'm not an expert in this field, it doesn't appear that this is a theory that is being worked on by many physicists at this time. (E.g. the two publications above have not received any external citations from peer-reviewed sources, as measured by ISI's Web of Science system.) My impression is that this is currently a fringe theory. As such, I think the current amount of article text devoted to it is too large; it is, after all, the longest section! (Longer than any of the most thoroughly researched and accepted models.)
So I propose we cut down the "Quark Shell Model" section to one or two paragraphs that summarize the conclusions of the model, and highlight the ways in which this model differs from other models (notably that it predicts solid crystal-like states for the nucleus; exactly the opposite of the liquid drop model). The pictures could be reduced in number to simply provide one representative crystal-like nuclear state. Unless someone objects, I'll go ahead and make those changes soon. Kebes (talk) 22:09, 30 April 2008 (UTC)
The content has been recreated as its own article, Quark Shell. Can anyone who knows more about it comment on that article's AfD? Thanks, FCSundae (talk) 19:00, 2 May 2008 (UTC) There are other models of the nucleus than the shell model but most of them don't talk about structure. But before you give up on structure, please look at the structure of my models in Talk:Nuclear model. And please dont tell me they cant touch each other.WFPMWFPM (talk) 01:51, 28 May 2008 (UTC) |==Irving Kaplan's Nuclear Physics issued a second edition in 1962. WFPMWFPM (talk) 02:03, 24 October 2008 (UTC)
- The possible existence of a nuclear structure is presently being inhibited by the prevailing opinion that the individual nucleons of the nucleus cannot "touch" or come into close proximity to each other. Thus, the nucleus of EE2He4, with 2 protons and 2 neutrons, cannot be visualized as being a connected composit of the 4 nucleons; notwithstanding that the "spin" of the nucleus is given as being zero. And since each nucleon has spin 1/2 and the spin of the deuteron is given as +1, we should be able to visualize the helium nucleus as being made up of 2 spin +1 deuterons, which would then necessarily have to be spinning contrary to each other, and thus involved in a side to side interconnection. But such a configuration is not proposed as a model for the 2He4 nucleus. WFPM (talk) 19:53, 26 November 2008 (UTC)
- The "prevaling" model of the nucleus no more requires that nucleons in the same quantum orbital cannot "touch" each other than it does for electrons in the same orbital. Pairs of the same type nucleons with the same quantum numbers (save for opposite spins) can occupy the same space in quantum mechanics. That's more than touching each other-- they are IN THE SAME VOLUME EXACTLY. The four nucleons in helium-4 occupy the same volume, since nothing prevents a neutron from occupying the same volume as a proton, if it has ALL the same quantum numbers. They interpenetrate perfectly, and that is why the charge distribution is exponentially symmetrical and decreases from a maximum at the exact center, with no sign of a conventional "volume" where the charge density evens out to a maximal nuclear charge density. This happens in larger nuclei, not He-4. In deuterium, by contrast, the neutron and proton do not occupy the same volume because they are have some component of orbital angular momentum due to the fact that their spins are aligned (the nuclear force is not a central force, but a tensor force with a non-spacially-dependent component). The deuteron, unlike the alpha particle (He-4 nucleus) is prolate, like an American football. The helium nucleus is perfectly spherical. Your private physical "model," user:WFPM, requires that two spinning footballs naturally lock together into something that is spherical with no spin. Good luck with that. SBHarris 17:42, 11 October 2009 (UTC)
- The possible existence of a nuclear structure is presently being inhibited by the prevailing opinion that the individual nucleons of the nucleus cannot "touch" or come into close proximity to each other. Thus, the nucleus of EE2He4, with 2 protons and 2 neutrons, cannot be visualized as being a connected composit of the 4 nucleons; notwithstanding that the "spin" of the nucleus is given as being zero. And since each nucleon has spin 1/2 and the spin of the deuteron is given as +1, we should be able to visualize the helium nucleus as being made up of 2 spin +1 deuterons, which would then necessarily have to be spinning contrary to each other, and thus involved in a side to side interconnection. But such a configuration is not proposed as a model for the 2He4 nucleus. WFPM (talk) 19:53, 26 November 2008 (UTC)
Considering your knowledge and discussion of the functioning of the individual constituents of the "standard model" packages of the accumulated individual protons and neutrons of the atoms, I find it rather unreasonable to then claim that all these packages and their constituents exist within the same volume of space within the alpha particle nucleus. It would seem logical to assume that these packages are rather closely packed within the nucleus, such that their effect on associated nucleons was toward their center of mass, as is assumed for gravitational attraction forces, and that the continued existence and individual functioning of the constituents of each package of nucleon constituents would be a "given". And you are correct in pointing out that the conceptual problems with my models start out contrary to the predominating concept that the OO1H2 deuteron that of a spin 1 atom and that deuteron (triplex paired neutron/proton) additions to the atom involve the addition of a spin + 1 value to the spin value of the composite atom. This is because when I built the models I added the deuterons in the way that was indicated as needed for the accumulation of the magnetized cylindrical magnets, and which turned out to be such that the added "deuterons" had to have a side by side (simplex paired zero net spin) orientation in order to permit the continued accumulation process. This resulted in the first alpha particle having a planar configuration, as well as the second alpha particle, which was then surrounded by 6 side by side deuteron additions, plus an additional alpha particle on top to complete the third (Janet table) period. And each successive period merely involves additional layers, with an additional 4 deuteron additions required to complete every other layer. So what could be simpler? If you get a set of the currently available magnetized spherical "buckyballs" you'll find that they aren't amenable to Hexagonal closest packing configurations, evidently due to their magnetic field compatibility problems, but that magnetized cylindrical magnets are stable in planar accumulation configurations patterns as is shown in my models.WFPM (talk) 20:22, 27 September 2010 (UTC)
Verifiability
[edit]There is not one in-line reference in this highly technical article. As I understand it, Wikipedia requires statements to be verifiable. Can the experts help to provide references? Thanks. --TraceyR (talk) 07:45, 31 March 2009 (UTC)
- I will try in the next days, I already added a couple and expanded the section of Beyond Mean Methods, let me know what you think Raghnar (talk) 14:56, 29 May 2015 (UTC)
Models of the Atomic Nucleus textbook
[edit]The book Models of the Atomic Nucleus by Norman D. Cook (Springer) ISBN 978-3-642-14736-4 has been withdrawn by the publisher Springer, as "new external and internal scientific evaluation of this book revealed severe scientific errors in its content. This book does not meet scientific standards of Springer and does not meet standards of the scientific community. No reference to this book should be given. Springer cordially excuses this faulty publication, it should never have been published. Detailed analysis shows that the author uses methods and conclusions outside scientific standards".
Previous references to this book were removed or corrected from this article. In particular, this includes the false assertion that the prediction of a large mean free path for the nucleons in the nucleus was not confirmed experimentally (see the reference quoted) — Preceding unsigned comment added by Schunck (talk • contribs) 02:28, 12 April 2011 (UTC)
- I had a look at Springer's website just now, where the book is still on sale. What is the source of this statement [name redacted]? I checked online (very briefly) and. other than this talk page, nothing like this statement showed up anywhere. Before removing the references we should be certain that this statement attributed to Springer Verlag is genuine and not some sort of hoax. --TraceyR (talk) 21:59, 13 April 2011 (UTC)
- As of 29 Aug. 2011 the book is still on sale and sample pages can be downloaded. There is still no reliable source to confirm the statement struck out above.--TraceyR (talk) 11:25, 29 August 2011 (UTC)
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- As of 7 July 2012 the book is still on sale and sample pages can be downloaded. --TraceyR (talk) 23:07, 6 July 2012 (UTC)
- While it appears that the book is still on sale, the content of the book appears to be well outside the mainstream of current nuclear structure research, and so it probably shouldn't be one of the two references for the page. Maybe we should add references to Bohr and Mottleson, which is the "standard" text in nuclear structure Ragnarstroberg (talk) 13:56, 1 October 2013 (UTC)
- Indeed the book as very few citations and is well regarded as ininfluential. Nonetheless as been demostrated the lattice model advocated by Cook (and by Cook's own admission) is mathematically equivalent to the Shell Model so I don't see why to cite this barely published book instead of classics of the genres like Bohr and Mottelson or Ring and Shuck for the Mean Field and Collective picture, Talmi or Brussard for the Shell Model, Brink and Broglia for superfluidity...etc... I will try to clean up the article as soon as possible Raghnar (talk) 20:50, 30 May 2015 (UTC)
- Cleaned up the independent particle model section from several major (albeit common) misunderstanding regarding the foundation of nuclear structure: you cannot compare the non-observable properties of different models! The fact that exist cluster configuration in the coupled cluster model do not tell anything about the structure of mean field theories. Exotic decay rate or fission does, and coupled cluster on that respect is not even much more successful than projected mean field in the reproduction of fission or exotic decay. The philosophy of mean field theories is that of independent particle model that reproduces bulk properties, and on top of that introducing many-body correlations that reproduce specific observables, you cannot tackle the shortcomings of mean field models only at the mean field level. Raghnar (talk) 08:23, 31 May 2015 (UTC)
Nuclear structure
[edit]Ojiojo 2405:204:A025:70F4:3FB:969:5750:60B3 (talk) 08:29, 18 June 2022 (UTC)
Removal of reference to the book “The Nature of the Atom - an introduction to the Structured Atom Model”
[edit]When I found this book I posted an edit (26/7/2021) to the Nuclear Structure topic to provide another, admittedly radical, model alongside the several other models described in the topic. Essentially I included the publisher’s description of the book. (Curtis Publishing). On checking the topic again today, I found my entire edit had been removed by Vampiricon (19/8/2021) with the dismissive comment ‘completely unscientific’. No effort had been made to discuss the substance of the substantial volume of work by the authors, Kaal, Otte, Sorensen and Emming. Just because a new theory of nuclear structure lies outside mainstream thinking, that is not sufficient reason to censor any mention of it. Let other readers examine the book for themselves and form their own conclusions. Please reinstate my edit. 2001:44B8:5146:E900:48F:D008:D839:B98F (talk) 20:42, 21 January 2023 (UTC)
- Can I also add the comment, as a newbie to this process, but having read some of the protocols for the editing process, that I think it is rather high-handed of Vampyricon to remove a large block of text (2121 characters) without adequate discussion of their reasons for doing so. The removed text is the publisher’s introductory summary of a 330 page published work by 4 researchers. The content of that book is another model, admittedly ‘non-standard’, but very thorough, well argued and illustrated. The Structured Atom Model deserves consideration and discussion, not arbitrary dismissal. Or have we returned to the days of Galileo, Copernicus and the Spanish Inquisition? 2001:44B8:5146:E900:59B4:1760:2A35:A62D (talk) 20:57, 1 February 2023 (UTC)