![]() | This ![]() It is of interest to the following WikiProjects: | ||||||||||
|
My references say that baryons are elementary particles, they consist of quarks and cannot be broken down. Mesons also fit this description.
Two web sources for you to examine - [1] and [2]
Also my dictionary says:
Hadron Pronunciation: (had'ron), [key] —n. Physics.
any elementary particle that is subject to the strong interaction. Hadrons are subdivided into baryons and mesons. Cf. quark.
All the sources I've seen don't call baryons as elementary particles, because they are composites, even if they can't be physically ripped apart. I would guess the usage varies, and so suggest that they not be called elementary.
Give some citations - I'm sure we can sort it out. I've given three, but I acknowledge that they are all quoting generalist literature. By the way, the link to boson simply redirects to particle physics... surely they deserve their own article. - MMGB
Well I guess this is a case where infoplease got it wrong - some other sources I have checked confirm this position. If/When we have an article on elementary particles this confusion should be addressed directly.
Someone mentioned that mesons may be a superposition of quark-antiquark pairs, but I think it would be less confusing and more accurate to describe them as a pair where each of the quark and antiquarks may be in a superposition of states (colors and generations). Does this sound fair?
Does anyone know the mass of a baryon? Is it just the mass of a proton? or neutron? --PY
PY, I believe that you are assuming that the baryon is a particle when it is actually a classification of particles. There are dozens of different baryons, each with its own mass.
Keep in mind that there was not a general consensus that hadrons were made of quarks until the mid-1970s. Older references could well describe them as elementary particles simply because their constituents were undiscovered or not generally accepted; even today they are sometimes called elementary particles because of a kind of language inertia. But we probably shouldn't call them that. -- Matt McIrvin 00:29, 1 Oct 2004 (UTC)
This article lacks a table summarising the properties of the mentioned baryons. Obviously a comprehensive table of known baryons would be a bit too large for the article. :) But something like this might be nice: http://hyperphysics.phy-astr.gsu.edu/hbase/particles/baryon.html
A mention of the quantum numbers associated with baryons would be nice as well. (Baryon number, strangeness etc.)
Here's a first attempt, perhaps someone can check that there are no errors in it? (Either of fact or of format :) ). It includes all of the baryons mentioned in the article, in the order mentioned.
Particle | Symbol | Makeup |
Rest mass MeV/ c2 |
B | S | C |
Mean lifetime s |
---|---|---|---|---|---|---|---|
Proton | p | uud | 938.3 | +1 | 0 | 0 | Stable1 |
Neutron | n | ddu | 939.6 | +1 | 0 | 0 | 920 |
Delta | Δ++ | uuu | 1232 | +1 | 0 | 0 | .6×10-23 |
Delta | Δ+ | uud | 1232 | +1 | 0 | 0 | .6×10-23 |
Delta | Δ0 | udd | 1232 | +1 | 0 | 0 | .6×10-23 |
Delta | Δ- | ddd | 1232 | +1 | 0 | 0 | .6×10-23 |
Lambda | Λ0 | uds | 1115.7 | +1 | -1 | 0 | 2.60×10-10 |
Lambda | Λ+c | udc | 2285 | +1 | 0 | 1 | 2.0×10-13 |
Sigma | Σ+ | uus | 1189.4 | +1 | -1 | 0 | 0.8×10-10 |
Sigma | Σ0 | uds | 1192.5 | +1 | -1 | 0 | 6×10-20 |
Sigma | Σ- | dds | 1197.4 | +1 | -1 | 0 | 1.5×10-10 |
Xi | Ξ0 | uss | 1315 | +1 | -2 | 0 | 2.9×10-10 |
Xi | Ξ- | dss | 1321 | +1 | -2 | 0 | 1.6×10-10 |
Omega | Ω- | sss | 1672 | +1 | -3 | 0 | 0.82×10-10 |
1at least 1030
It looks fine to me, except that some numbers aren't being written in proper scientific notation. Instead of 0.6×10-23, for example, it should be 6x10-24. I would edit it myself, but I haven't quite had the time to thoroughly look through the editing system.
After reading your post, I edited the scientific notation of the Deltas.
Are you sure that the neutron has a half-life of nine hundred and twenty seconds? That seems awfully short. Didn't someone have to build a really, really big detector to try to determine the half-life, because it was extremely long? [...] Okay, I looked it up, and neutrons do decay that quickly, but only when not bound inside nuclei. Should this be mentioned? I was led to the impression that we should all be big masses of Hydrogen-1 by now. grendel| khan 23:23, 2005 Mar 11 (UTC)
Thank you to the author of this article. You did a great job explaining in detail the topic; yet not too esoteric that someone without a strong background in physics won't understand the information (such as I). --jorgekluney
Baryons are made from 3 quarks, any quarks. Since there are 6 different quarks, then we have 6^3 combinations of 3 quarks. However, from the Delta+ and the proton, each with quark composition u/u/d, it looks like the spin orientation have to be taken into account. Since each quark can be in +1/2 or -1/2 isospin state, then we have 12 different quarks/quarkstates possible for each of the three quarks, which gives us 12^3 different combinations of three quarks. If we remove the degeneracies (such as ssd (3/2),sds(3/2),dss(3/2)), then we have 364 (12+11+10...+11+10+9...+10+9+8+...3+2+1+2+1+1) distinct combination of quarks/quarkstates.
Now I'm not sure of this, but I think that it is the modulus of the spin that is important, so particles with spin -3/2 and -1/2 really are the same than the particles with spin 3/2 and spin 1/2. Removing these degeneracies leaves us with half the particles, and thus there are 182 distinct baryons that can be made from three quarks.
Did I understand it correctly? It would also be interesting if someone updated the list of baryons to take into account all the possibilities, with placeholders for the undiscovered particles Headbomb 22:11, 22 March 2008 (UTC)
The article makes no mention of baryons with heavy quark content. See for example the summary page from the Review of Particle Physics ( W.-M. Yao et al., Journal of Physics G 33, 1 (2006) ) [3]. Erkcan 16:48, 24 July 2006 (UTC)
Charmed baryons also have their own page -- I'll add a link to it. I'm not convinced that it should be a separate page (as opposed to a section within this one) but since it's nearly empty it's a moot point for now. As far as the ordering within this page goes, I think that introducing the light baryons and the octet+decuplet first and bringing up heavy flavours later is the right thing to do; isospin and strangeness are complicated enough without adding a third dimension right off the bat. Do you have any thoughts on what a heavy baryon section should cover? I had trouble coming up with a middle ground between "very vague" and "painful detail". Physicsdog 07:41, 27 July 2006 (UTC)
I moved the following text from the article to here:
Kingdon 16:21, 10 May 2007 (UTC)
In cosmology, it seems that baryonic matter can refer to both protons and electrons:
Is this a common enough practice to mention in the article? -- Starwed ( talk) 11:47, 28 February 2008 (UTC)
Please note that the diagrams (black-and-white, with pink circles for the states) in the "isospin" and the "baryons" page show the value of the strangeness opposite of the standard convention (which in turn is followed in the "mesons" page and the table above, under the "Include Table?" heading. For example, the Omega- baryon has strangeness -3, but is in the diagram on the "baryons" and the "isospin" pages is shown to have strangeness "3", with the strangeness axis oriented downward. I do not know enough about this wiki editing system to edit the figures and fix this. Tristan ( talk) 02:42, 3 October 2009 (UTC)
Please give input at Talk:Hadron#Hadron overhaul. Thanks. Headbomb { ταλκ κοντριβς – WP Physics} 02:01, 24 January 2010 (UTC)
The article states that the intrinsic parity of a baryon is (-1)^L and therefore the parity of all ground state baryons is positive. It would be useful if some expert on the subject added some scattering process where the relative parity between a Nucleon and a Delta becomes determined. Otherwise the statement seems a little bit unsubstantiated. Kotika98 ( talk) 14:34, 6 July 2010 (UTC)
The Delta (
Δ++
(uuu)) has the spin of all three quarks aligned. What is the particle formed when one of the quarks is anti-parallel to the others? It should have spin 1/2, yet doesn't appear in the octet. Why is that? --
Michael C. Price
talk
10:02, 19 October 2010 (UTC)
"A baryon be a composite particle made of three quarks." What are we, pirates? Hahaha. Fixing it now, but it was too funny not to point out. Bugbrain 04 ( talk) 00:49, 28 January 2011 (UTC)
I'm glad that this article makes no mention of the fanciful claim that Baryons might possibly contain gluons that would then contribute to their total masses, like say the proton article does. Hcobb ( talk) 15:18, 9 January 2012 (UTC)
I know what the author of this wants to say, but it is not correct. The quantum number S is 1/2, the length of the vector is ħ*sqrt(S(S+1)) != S. Impulseigenzustand ( talk) 04:16, 16 July 2013 (UTC)
The parenthetical remark in the following fragment of the article confused me:
As I understood the rest of the article, the difference between Δ (Delta-particles) and N (nucleons) is their spin. In a Δ the spins of the quarks are aligned to give S = 3/2, while in an N one quark has an opposite spin to the other quarks, giving S = 1/2. So the quarks are more similar in a Δ, leading to the question why does Pauli apply to N and not to Δ? Perhaps this needs to be clarified somewhere. -- Jitse Niesen ( talk) 10:19, 14 August 2013 (UTC)
Thanks. That's very helpful in pointing out the right direction. I did one university course on quantum mechanics a dozen years ago, which covered some of this stuff, but not in great detail and I forgot most of it. My mistake was in supposing that the Pauli principle has the narrow meaning of "no two in the same state", while - as I now saw, rather embarrassingly, in the second (!) sentence of Pauli exclusion principle - it refers to the anti-symmetry of the wave function. -- Jitse Niesen ( talk) 11:34, 15 August 2013 (UTC)
Isn't most of the mass of baryons the mass-energy of strong interaction? -- 130.233.162.130 ( talk) 12:42, 8 November 2013 (UTC)
It is striking that the masses of the charged an neutral pions turn out to be equal, even though we have made no assumption about the ratio of mu and md. We shall see below that this ratio is not near unity; isospin is a good quantum number not because the u and d quark masses are nearly equal, but because they are small.
Does any science-minded person who knows Star Trek well know whether it uses the word baryons/baryon in a similar or same way as current science? (It has been said that Star Trek (by some point) often tried to accurately use real science (as known then) mixed with Star-Trek-universe science.) The more info (and in layman's terms) about its use of this, the better. Thanks! Misty MH ( talk) 02:40, 17 February 2014 (UTC)
The comment(s) below were originally left at Talk:Baryon/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.
Comments on article assessment. "Top" importance rating seems pretty obvious to me -- baryons are a very important term, useful in particle physics, cosmology, nuclear physics, etc. I initially rated "GA" because it fit almost all of the assessment criteria on WP:WIAGA, except references. Otherwise it's a wonderful article -- well written, illustrated, factually correct, links to other relevant areas of interest, etc. Wesino 00:34, 29 November 2006 (UTC) |
Last edited at 00:34, 29 November 2006 (UTC). Substituted at 09:03, 29 April 2016 (UTC)
Ok, so t quarks are expected to be unstable, and thus no baryons including them are expected to be stable. My question is this: do these hypothetical baryon configurations have supporting research and names? The article doesn't really speak to this, and my feeling is that it should, since my understanding is that a baryon by definition includes these cases, even if they are not realized in nature.
In other words, the current article is somewhat dismissive, without being thorough. I don't really doubt that these particles aren't realized, but I feel a responsible article on baryon should stick to the definition, and not be dismissive of classes that fit the definition. I also don't feel like it should breathlessly wait for experiments to determine whether they exist or not. That doesn't seem necessary or useful, although experimental results about existence are definitely noteworthy. 75.139.254.117 ( talk) 22:50, 28 December 2016 (UTC)
Editors on this page may want to contribute at: Talk:Exotic baryon#Proposed rename to "Exotic hadron".
Thanks! FT2 ( Talk | email) 18:17, 24 September 2018 (UTC)
Why an odd number (to get spin 1/2?) and why 'valence' ?
Valence quark redirects to quark model but neither clearly explain what they are. Are the non-valence quarks just the virtual quarks in the gluon binding ? Are all three uud quarks in a proton considered 'valence'? Do we need 'valence' in the first sentence ? Are tetraquarks (with an even number of quarks) baryons or not ? - Rod57 ( talk) 11:46, 2 April 2021 (UTC)
There's an argument that hadron may be a better redirect than quark model for valence quark. One can think of valence quarks as the real interacting bound quarks and non-valence quarks as virtual quarks created temporarily by gluon splitting in the course of the valence quarks interacting. uud = the valence quarks of a proton. A tetraquark is more closely related to a meson while pentaquarks are more closely related to baryons. Advolvens ( talk) 23:16, 4 April 2021 (UTC)
As of 2011, more than 40% of the total baryonic budget had not been discovered yet in "representative samples of the universe, found in large galaxy clusters".(Afshordi, Niayesh (March 1, 2012). "Where will Einstein fail? Leasing for Gravity and cosmology". Bullettin of Astronomical Society of India. 40 (1). Astronomical Society of India, NASA Astrophysics Data System: 4. arXiv: 1203.3827. OCLC 810438317. Retrieved June 15, 2021. which also cites A.Simionescu (2011), Baryons in the outskirts of the X-ray brightest galaxy clusters, in Proceedings, Exploring the X-Ray Universe: Suzaku and Beyond (SUZAKU 2011(: Palo Alto, USA, July 20-22, 2011, 5-12).
![]() | This ![]() It is of interest to the following WikiProjects: | ||||||||||
|
My references say that baryons are elementary particles, they consist of quarks and cannot be broken down. Mesons also fit this description.
Two web sources for you to examine - [1] and [2]
Also my dictionary says:
Hadron Pronunciation: (had'ron), [key] —n. Physics.
any elementary particle that is subject to the strong interaction. Hadrons are subdivided into baryons and mesons. Cf. quark.
All the sources I've seen don't call baryons as elementary particles, because they are composites, even if they can't be physically ripped apart. I would guess the usage varies, and so suggest that they not be called elementary.
Give some citations - I'm sure we can sort it out. I've given three, but I acknowledge that they are all quoting generalist literature. By the way, the link to boson simply redirects to particle physics... surely they deserve their own article. - MMGB
Well I guess this is a case where infoplease got it wrong - some other sources I have checked confirm this position. If/When we have an article on elementary particles this confusion should be addressed directly.
Someone mentioned that mesons may be a superposition of quark-antiquark pairs, but I think it would be less confusing and more accurate to describe them as a pair where each of the quark and antiquarks may be in a superposition of states (colors and generations). Does this sound fair?
Does anyone know the mass of a baryon? Is it just the mass of a proton? or neutron? --PY
PY, I believe that you are assuming that the baryon is a particle when it is actually a classification of particles. There are dozens of different baryons, each with its own mass.
Keep in mind that there was not a general consensus that hadrons were made of quarks until the mid-1970s. Older references could well describe them as elementary particles simply because their constituents were undiscovered or not generally accepted; even today they are sometimes called elementary particles because of a kind of language inertia. But we probably shouldn't call them that. -- Matt McIrvin 00:29, 1 Oct 2004 (UTC)
This article lacks a table summarising the properties of the mentioned baryons. Obviously a comprehensive table of known baryons would be a bit too large for the article. :) But something like this might be nice: http://hyperphysics.phy-astr.gsu.edu/hbase/particles/baryon.html
A mention of the quantum numbers associated with baryons would be nice as well. (Baryon number, strangeness etc.)
Here's a first attempt, perhaps someone can check that there are no errors in it? (Either of fact or of format :) ). It includes all of the baryons mentioned in the article, in the order mentioned.
Particle | Symbol | Makeup |
Rest mass MeV/ c2 |
B | S | C |
Mean lifetime s |
---|---|---|---|---|---|---|---|
Proton | p | uud | 938.3 | +1 | 0 | 0 | Stable1 |
Neutron | n | ddu | 939.6 | +1 | 0 | 0 | 920 |
Delta | Δ++ | uuu | 1232 | +1 | 0 | 0 | .6×10-23 |
Delta | Δ+ | uud | 1232 | +1 | 0 | 0 | .6×10-23 |
Delta | Δ0 | udd | 1232 | +1 | 0 | 0 | .6×10-23 |
Delta | Δ- | ddd | 1232 | +1 | 0 | 0 | .6×10-23 |
Lambda | Λ0 | uds | 1115.7 | +1 | -1 | 0 | 2.60×10-10 |
Lambda | Λ+c | udc | 2285 | +1 | 0 | 1 | 2.0×10-13 |
Sigma | Σ+ | uus | 1189.4 | +1 | -1 | 0 | 0.8×10-10 |
Sigma | Σ0 | uds | 1192.5 | +1 | -1 | 0 | 6×10-20 |
Sigma | Σ- | dds | 1197.4 | +1 | -1 | 0 | 1.5×10-10 |
Xi | Ξ0 | uss | 1315 | +1 | -2 | 0 | 2.9×10-10 |
Xi | Ξ- | dss | 1321 | +1 | -2 | 0 | 1.6×10-10 |
Omega | Ω- | sss | 1672 | +1 | -3 | 0 | 0.82×10-10 |
1at least 1030
It looks fine to me, except that some numbers aren't being written in proper scientific notation. Instead of 0.6×10-23, for example, it should be 6x10-24. I would edit it myself, but I haven't quite had the time to thoroughly look through the editing system.
After reading your post, I edited the scientific notation of the Deltas.
Are you sure that the neutron has a half-life of nine hundred and twenty seconds? That seems awfully short. Didn't someone have to build a really, really big detector to try to determine the half-life, because it was extremely long? [...] Okay, I looked it up, and neutrons do decay that quickly, but only when not bound inside nuclei. Should this be mentioned? I was led to the impression that we should all be big masses of Hydrogen-1 by now. grendel| khan 23:23, 2005 Mar 11 (UTC)
Thank you to the author of this article. You did a great job explaining in detail the topic; yet not too esoteric that someone without a strong background in physics won't understand the information (such as I). --jorgekluney
Baryons are made from 3 quarks, any quarks. Since there are 6 different quarks, then we have 6^3 combinations of 3 quarks. However, from the Delta+ and the proton, each with quark composition u/u/d, it looks like the spin orientation have to be taken into account. Since each quark can be in +1/2 or -1/2 isospin state, then we have 12 different quarks/quarkstates possible for each of the three quarks, which gives us 12^3 different combinations of three quarks. If we remove the degeneracies (such as ssd (3/2),sds(3/2),dss(3/2)), then we have 364 (12+11+10...+11+10+9...+10+9+8+...3+2+1+2+1+1) distinct combination of quarks/quarkstates.
Now I'm not sure of this, but I think that it is the modulus of the spin that is important, so particles with spin -3/2 and -1/2 really are the same than the particles with spin 3/2 and spin 1/2. Removing these degeneracies leaves us with half the particles, and thus there are 182 distinct baryons that can be made from three quarks.
Did I understand it correctly? It would also be interesting if someone updated the list of baryons to take into account all the possibilities, with placeholders for the undiscovered particles Headbomb 22:11, 22 March 2008 (UTC)
The article makes no mention of baryons with heavy quark content. See for example the summary page from the Review of Particle Physics ( W.-M. Yao et al., Journal of Physics G 33, 1 (2006) ) [3]. Erkcan 16:48, 24 July 2006 (UTC)
Charmed baryons also have their own page -- I'll add a link to it. I'm not convinced that it should be a separate page (as opposed to a section within this one) but since it's nearly empty it's a moot point for now. As far as the ordering within this page goes, I think that introducing the light baryons and the octet+decuplet first and bringing up heavy flavours later is the right thing to do; isospin and strangeness are complicated enough without adding a third dimension right off the bat. Do you have any thoughts on what a heavy baryon section should cover? I had trouble coming up with a middle ground between "very vague" and "painful detail". Physicsdog 07:41, 27 July 2006 (UTC)
I moved the following text from the article to here:
Kingdon 16:21, 10 May 2007 (UTC)
In cosmology, it seems that baryonic matter can refer to both protons and electrons:
Is this a common enough practice to mention in the article? -- Starwed ( talk) 11:47, 28 February 2008 (UTC)
Please note that the diagrams (black-and-white, with pink circles for the states) in the "isospin" and the "baryons" page show the value of the strangeness opposite of the standard convention (which in turn is followed in the "mesons" page and the table above, under the "Include Table?" heading. For example, the Omega- baryon has strangeness -3, but is in the diagram on the "baryons" and the "isospin" pages is shown to have strangeness "3", with the strangeness axis oriented downward. I do not know enough about this wiki editing system to edit the figures and fix this. Tristan ( talk) 02:42, 3 October 2009 (UTC)
Please give input at Talk:Hadron#Hadron overhaul. Thanks. Headbomb { ταλκ κοντριβς – WP Physics} 02:01, 24 January 2010 (UTC)
The article states that the intrinsic parity of a baryon is (-1)^L and therefore the parity of all ground state baryons is positive. It would be useful if some expert on the subject added some scattering process where the relative parity between a Nucleon and a Delta becomes determined. Otherwise the statement seems a little bit unsubstantiated. Kotika98 ( talk) 14:34, 6 July 2010 (UTC)
The Delta (
Δ++
(uuu)) has the spin of all three quarks aligned. What is the particle formed when one of the quarks is anti-parallel to the others? It should have spin 1/2, yet doesn't appear in the octet. Why is that? --
Michael C. Price
talk
10:02, 19 October 2010 (UTC)
"A baryon be a composite particle made of three quarks." What are we, pirates? Hahaha. Fixing it now, but it was too funny not to point out. Bugbrain 04 ( talk) 00:49, 28 January 2011 (UTC)
I'm glad that this article makes no mention of the fanciful claim that Baryons might possibly contain gluons that would then contribute to their total masses, like say the proton article does. Hcobb ( talk) 15:18, 9 January 2012 (UTC)
I know what the author of this wants to say, but it is not correct. The quantum number S is 1/2, the length of the vector is ħ*sqrt(S(S+1)) != S. Impulseigenzustand ( talk) 04:16, 16 July 2013 (UTC)
The parenthetical remark in the following fragment of the article confused me:
As I understood the rest of the article, the difference between Δ (Delta-particles) and N (nucleons) is their spin. In a Δ the spins of the quarks are aligned to give S = 3/2, while in an N one quark has an opposite spin to the other quarks, giving S = 1/2. So the quarks are more similar in a Δ, leading to the question why does Pauli apply to N and not to Δ? Perhaps this needs to be clarified somewhere. -- Jitse Niesen ( talk) 10:19, 14 August 2013 (UTC)
Thanks. That's very helpful in pointing out the right direction. I did one university course on quantum mechanics a dozen years ago, which covered some of this stuff, but not in great detail and I forgot most of it. My mistake was in supposing that the Pauli principle has the narrow meaning of "no two in the same state", while - as I now saw, rather embarrassingly, in the second (!) sentence of Pauli exclusion principle - it refers to the anti-symmetry of the wave function. -- Jitse Niesen ( talk) 11:34, 15 August 2013 (UTC)
Isn't most of the mass of baryons the mass-energy of strong interaction? -- 130.233.162.130 ( talk) 12:42, 8 November 2013 (UTC)
It is striking that the masses of the charged an neutral pions turn out to be equal, even though we have made no assumption about the ratio of mu and md. We shall see below that this ratio is not near unity; isospin is a good quantum number not because the u and d quark masses are nearly equal, but because they are small.
Does any science-minded person who knows Star Trek well know whether it uses the word baryons/baryon in a similar or same way as current science? (It has been said that Star Trek (by some point) often tried to accurately use real science (as known then) mixed with Star-Trek-universe science.) The more info (and in layman's terms) about its use of this, the better. Thanks! Misty MH ( talk) 02:40, 17 February 2014 (UTC)
The comment(s) below were originally left at Talk:Baryon/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.
Comments on article assessment. "Top" importance rating seems pretty obvious to me -- baryons are a very important term, useful in particle physics, cosmology, nuclear physics, etc. I initially rated "GA" because it fit almost all of the assessment criteria on WP:WIAGA, except references. Otherwise it's a wonderful article -- well written, illustrated, factually correct, links to other relevant areas of interest, etc. Wesino 00:34, 29 November 2006 (UTC) |
Last edited at 00:34, 29 November 2006 (UTC). Substituted at 09:03, 29 April 2016 (UTC)
Ok, so t quarks are expected to be unstable, and thus no baryons including them are expected to be stable. My question is this: do these hypothetical baryon configurations have supporting research and names? The article doesn't really speak to this, and my feeling is that it should, since my understanding is that a baryon by definition includes these cases, even if they are not realized in nature.
In other words, the current article is somewhat dismissive, without being thorough. I don't really doubt that these particles aren't realized, but I feel a responsible article on baryon should stick to the definition, and not be dismissive of classes that fit the definition. I also don't feel like it should breathlessly wait for experiments to determine whether they exist or not. That doesn't seem necessary or useful, although experimental results about existence are definitely noteworthy. 75.139.254.117 ( talk) 22:50, 28 December 2016 (UTC)
Editors on this page may want to contribute at: Talk:Exotic baryon#Proposed rename to "Exotic hadron".
Thanks! FT2 ( Talk | email) 18:17, 24 September 2018 (UTC)
Why an odd number (to get spin 1/2?) and why 'valence' ?
Valence quark redirects to quark model but neither clearly explain what they are. Are the non-valence quarks just the virtual quarks in the gluon binding ? Are all three uud quarks in a proton considered 'valence'? Do we need 'valence' in the first sentence ? Are tetraquarks (with an even number of quarks) baryons or not ? - Rod57 ( talk) 11:46, 2 April 2021 (UTC)
There's an argument that hadron may be a better redirect than quark model for valence quark. One can think of valence quarks as the real interacting bound quarks and non-valence quarks as virtual quarks created temporarily by gluon splitting in the course of the valence quarks interacting. uud = the valence quarks of a proton. A tetraquark is more closely related to a meson while pentaquarks are more closely related to baryons. Advolvens ( talk) 23:16, 4 April 2021 (UTC)
As of 2011, more than 40% of the total baryonic budget had not been discovered yet in "representative samples of the universe, found in large galaxy clusters".(Afshordi, Niayesh (March 1, 2012). "Where will Einstein fail? Leasing for Gravity and cosmology". Bullettin of Astronomical Society of India. 40 (1). Astronomical Society of India, NASA Astrophysics Data System: 4. arXiv: 1203.3827. OCLC 810438317. Retrieved June 15, 2021. which also cites A.Simionescu (2011), Baryons in the outskirts of the X-ray brightest galaxy clusters, in Proceedings, Exploring the X-Ray Universe: Suzaku and Beyond (SUZAKU 2011(: Palo Alto, USA, July 20-22, 2011, 5-12).