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Archive 1 |
I changed
to
because the former was obviously wrong. Someone with more knowledge should check if this is now correct. 193.171.121.30 11:27, 7 February 2006 (UTC)
Can anybody define these parameters? I guess they correspond to the angles that the mass and flavor eigenvectors form but they are never mentioned in the text. Poszwa 02:48, 20 March 2006 (UTC)
I think the Mixing Matrix might be defined the wrong way round. U_{lk} is the co-efficient of mass state |v_{l}> in weak state |v_{k}>, not the other way round. Not so much wrong, as just different to the general convention I suppose.
I'm not sure how clearly I've put that, but hopefully it makes sense. Can an expert check this? (See, for instance, Author: Giunti, arXiv:hep-ph/0611125v1)
128.250.54.30 07:21, 3 July 2007 (UTC) Alex
The article states that fermions are "matter particles". I think this formulation is awkward, since combining two fermions creates a boson, which could still be a matter particle. I think that comment should be removed. Andersa 12:16, 11 April 2006 (UTC)
I went through a long discussion on PhysicsForums with a student who was convinced that neutrino oscillation was incompatible with the rules of physics, specifically conservation of energy. His problem was that the flavor eigenstate neutrinos do not have well defined mass, so he concluded that the process could not have well defined energies.
I finally got him to at least agree that neutrino oscillation was compatible with the assumptions of QM by describing the situation from the point of view of the neutrino mass eigenstates. See post 47 in http://www.physicsforums.com/showthread.php?t=115360&page=4
When looked on in this way, while flavor eigenstate neutrinos oscillate, the mass eigenstate neutrinos interfere. That is, all three mass eigenstate neutrinos contribute to the combined process of decay (in the sun) and absorption (at the detector), and since the experiment cannot distinguish which of the neutrinos was involved (as their masses are so very small compared to the energies involved), the rules of QM say that one must add together the diagrams for all three masses before computing probabilities.
The result is that the three massive neutrinos interfere with each other in the same manner as a photon interferes with itself in the 2 slit experiment. It's a great illustration of how the rules of QM are used in QFT.
I think that this should be added to the discussion for two reasons. First, it illustrates a principle of QM and Feynman diagrams. Second, it resolves the confusion in the student as to where neutrinos that oscillate go. Unfortunately, while this is all very obvious, I can't find a reference that explains neutrino oscillation in this way. Does that make it incompatible with Wikipedia standards?
I'd type up a short description but I hate wasting my time. Any comments?
Carl
I think that I have added enough to this page to warrant removing the expert tag. If you disagree, please put it back and say why you did so here. -- Strait 18:26, 7 August 2006 (UTC)
How can we describe the mass of any neutrino flavor since they are not mass eigenstates? I ask because there is a flavor - mass table at neutrino, which would seem a contradiction in terms. -- Michael C. Price talk 07:57, 23 August 2006 (UTC)
"I have added the probabilities of oscillations through solar matter. I used Runge Kutta method in maple to solve the coupled equations. I'll add the theoretical discussions soon. Please comment."
Since we know that there are three neutrinos that participate in oscillation, and we know fairly well what the relevant parameters are, I would prefer that the three neutrino model be used for specific real-life cases like propagation through the sun. The two neutrino framework is all well and good when the discussion is pure theory, but it's not actually what happens.
Once you're done writing the new section on solar oscillations, the section near the top called "Solar neutrino oscillation" should be edited to reflect the addition. -- Strait 22:16, 27 November 2006 (UTC)
Oh, also, if you have a good understanding of the MSW effect, you might try to improve that page. (I only just barely understand it myself, so I don't want to try.) -- Strait 22:18, 27 November 2006 (UTC)
This article has been rated as being of "low" importance. I think that a phenomenon which stems directly from the (apparently) fundamental parameters which define the universe, and is the only known way of measuring those parameters, should be rated at least "mid" if not "high". I think that this page is not well described by "Subject is mainly of specialist interest." -- Strait 21:34, 11 December 2006 (UTC)
Adding all the graphs has started to make the article a bit long, in my opinion. Pictures help readers understand the content, so we should leave them. I would rather see something more technical move away. General readers might look at this article after the recent publicity including a NOVA episode devoted to the subject. We could consider reseparating the Maki-Nakagawa-Sakata matrix because it contains all the numerical details unappealing to general readers. This could also discuss experiments that attempt to measure the values. Notice how the Cabibbo-Kobayashi-Maskawa matrix has its own article. Teply 03:33, 19 December 2006 (UTC)
Indeed I did come to this page after viewing the Nova episode, "The Ghost Particle." The question in my mind--not resolved because I don't completely follow the math in the main article about mass and flavors not being congruent: since the masses of the three flavors of neutrino differ by more than six orders of magnitude (2.2 eV, ~170 KeV, ~15.5 MeV), oscillations among flavors, in order to conserve energy, must be accompanied by changes in velocity. Is this correct? At what fraction of the speed of light do solar neutrinos travel as electron neutrinos, and how much does this velocity decrease when they assume the other flavors? 21:08 PDT, 10 April 2008 —Preceding unsigned comment added by 67.161.40.124 ( talk) 04:10, 11 April 2008 (UTC)
Reference 4 is a vaguely related nuclear/detector physics paper that really shouldn't be quoted here. Suggest replacing with the PDG reference: "Yao et al. J Phys G 33, (2006) p156", and the references therein. —Preceding unsigned comment added by 128.250.54.30 ( talk) 07:31, 22 October 2007 (UTC)
This isn't my field, and likely I'm misunderstanding - but what confuses me is that the neutrino seems only to be observed as one of three quantized flavors; yet it seems to know, internally, precisely at what point in its oscillation it is at at any given time. Given the source of the neutrino and approximate momentum it seems like you could come up with a better model of the neutrino's internal state (how likely it was to be a certain flavor and when it would turn into another) than you could actually measure. Does that make its oscillation state a "hidden variable" in the deprecated quantum mechanical sense? 70.15.116.59 ( talk) 23:17, 9 December 2007 (UTC)
As I understand it, neutrinos come in several varieties, such is the electron neutrion, the tau neutrion, and the muon neutrino. In simplest terms, take any one of these neutrinos and add a negative W Boson and you will get an electron, or a tau particle or a muon, accordingly. It is as if the neutrino is the "bucket" that can accept the quaunum of charge, and the boson is like the water that goes into a bucket. As such it is possible that neutrinos DO NOT OSCILLATE, but rather it may be that the sun gives off some muon neutrinos, and that while on the way to earth some muon neutrinos collide with free neutrinos that are drifting in the vacuum, in which case - there is an appropriate transfer of linear momentum from one particle kind to another. So the neutino game might simply be like a game of marbles, or billiards. In such a context; the Nyquist theorem would be irrelevant; since such neutrio oscillations would not imply that free neutrinos oscillate among types, but rather type exchange occurs freely because of interaction with the neutrios that are free in the presumed vacuum. —Preceding unsigned comment added by Lazarus666 ( talk • contribs) 01:21, 9 August 2008 (UTC)
I have removed several edits from 88.68.XXX.XXX that has repeatedly stated that energy and momentum are not conserved by neutrino oscillations (as well as some personal opinions on the matter from the same source). As stated before on this talk page, neutrino oscillations occur because the mass eigenstates (which are the only ones that can possess definite energy and momentum) interfere with each other and that the flavor eigenstates produced in weak interactions are superpositions of these states. The theory is sound, completely analogous to that in the quark sector (although quarks possess properties that rules out any such interference - i.e., charge, large mass differences etc), and experimentally verfied. Of course, neutrinos are not plane waves, or produced with definite energy or momentum as the simplified derivation in the article suggests. However this is by far the easiest way of reasoning and it gives the correct result when compared to a full quantum field theoretical treatment in the ultrarelativistic limit. I would be happy to take any discussion on the theory of neutrino oscillations, but it should be kept here and not through vandalism of the article. -- Blennow ( talk) 09:17, 24 October 2008 (UTC)
I started a full article at Pontecorvo–Maki–Nakagawa–Sakata matrix. Review/Feedback/Expansion are appreciated. Headbomb { ταλκ κοντριβς – WP Physics} 14:11, 4 June 2009 (UTC)
It was stated that sterile neutrinos can oscillate with "normal" neutrinos. I'm trying to understand sterile neutrinos. I'm not clear whether "sterile" just means "right-handed". Are they synonymous for neutrinos (with the usual proviso that we switch left/right for particle/anti-particle)? If sterile neutrinos are just right handed neutrinos then it seems to me that they will have different weak hypercharge (0 for right-handed neutrinos, -1 for the left-handed neutrinos) and X charge. If so, wouldn't that prevent their mixing? -- Michael C. Price talk 06:01, 21 November 2009 (UTC)
Thanks for the feedback. I was being a bit sloppy with my language. By "mixing" I meant the neutrino family oscillations e-mu-tau-e-mu-tau (which preserve quantum numbers), not the Higgs left-right-left-right flipping that give them mass (which, as you correctly observe, will change any quantum numbers carried away by the Higgs).-- Michael C. Price talk 22:01, 21 November 2009 (UTC)
"These approximations are possible because the mixing angle θ13 is very small and because two of the mass states are very close in mass compared to the third." Please remove.. not justified. We do not know that much, there is also a model with a completely different mass hierarchy, that is not yet ruled out by experiment. This is simply a toy model and needs no justification. —Preceding unsigned comment added by 134.176.18.59 ( talk) 16:59, 25 May 2010 (UTC)
, is a bit confusing when E is not specified. —Preceding unsigned comment added by 134.176.18.59 ( talk) 16:26, 26 May 2010 (UTC)
-- 190.188.3.11 ( talk) 14:40, 10 June 2010 (UTC)
Hey guys can you please mention in the article that when you write m_i, you are referring to m_*c^2, when you write p, you are referring to pc and finally, when you write L, you are referring to L/c^2?
I think "propagation and interference" and "Two neutrino case" are very much like Chapter 5 of
Massive neutrinos in physics and astrophysics,Mohapatra, R.N. and Pal, P.B., 2004, Imperial College Pr
-- 134.176.18.59 ( talk) 21:27, 16 October 2010 (UTC)
In the central matrix in the matrix product under Classical analogue of neutrino oscillation (see http://upload.wikimedia.org/math/1/2/1/1214e944a130d2330f77074725ccee73.png) it appears that a minus sign and a plus sign have switched places in the upper row. Shouldn't that row read "g/La - k/m, [+]k/m"? - Episcophagus ( talk) 16:23, 11 June 2011 (UTC)
User Hugozam has created this section and provided all content without any references. I've asked him/her for references, but haven't heard back. Does anybody know if the information is correct and/or have a reference? If not, I suggest we remove the section. — SkyLined ( talk) 15:04, 14 November 2011 (UTC)
Thanks! — SkyLined ( talk) 16:50, 16 November 2011 (UTC)
![]() | This page is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
![]() | This is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
Archive 1 |
I changed
to
because the former was obviously wrong. Someone with more knowledge should check if this is now correct. 193.171.121.30 11:27, 7 February 2006 (UTC)
Can anybody define these parameters? I guess they correspond to the angles that the mass and flavor eigenvectors form but they are never mentioned in the text. Poszwa 02:48, 20 March 2006 (UTC)
I think the Mixing Matrix might be defined the wrong way round. U_{lk} is the co-efficient of mass state |v_{l}> in weak state |v_{k}>, not the other way round. Not so much wrong, as just different to the general convention I suppose.
I'm not sure how clearly I've put that, but hopefully it makes sense. Can an expert check this? (See, for instance, Author: Giunti, arXiv:hep-ph/0611125v1)
128.250.54.30 07:21, 3 July 2007 (UTC) Alex
The article states that fermions are "matter particles". I think this formulation is awkward, since combining two fermions creates a boson, which could still be a matter particle. I think that comment should be removed. Andersa 12:16, 11 April 2006 (UTC)
I went through a long discussion on PhysicsForums with a student who was convinced that neutrino oscillation was incompatible with the rules of physics, specifically conservation of energy. His problem was that the flavor eigenstate neutrinos do not have well defined mass, so he concluded that the process could not have well defined energies.
I finally got him to at least agree that neutrino oscillation was compatible with the assumptions of QM by describing the situation from the point of view of the neutrino mass eigenstates. See post 47 in http://www.physicsforums.com/showthread.php?t=115360&page=4
When looked on in this way, while flavor eigenstate neutrinos oscillate, the mass eigenstate neutrinos interfere. That is, all three mass eigenstate neutrinos contribute to the combined process of decay (in the sun) and absorption (at the detector), and since the experiment cannot distinguish which of the neutrinos was involved (as their masses are so very small compared to the energies involved), the rules of QM say that one must add together the diagrams for all three masses before computing probabilities.
The result is that the three massive neutrinos interfere with each other in the same manner as a photon interferes with itself in the 2 slit experiment. It's a great illustration of how the rules of QM are used in QFT.
I think that this should be added to the discussion for two reasons. First, it illustrates a principle of QM and Feynman diagrams. Second, it resolves the confusion in the student as to where neutrinos that oscillate go. Unfortunately, while this is all very obvious, I can't find a reference that explains neutrino oscillation in this way. Does that make it incompatible with Wikipedia standards?
I'd type up a short description but I hate wasting my time. Any comments?
Carl
I think that I have added enough to this page to warrant removing the expert tag. If you disagree, please put it back and say why you did so here. -- Strait 18:26, 7 August 2006 (UTC)
How can we describe the mass of any neutrino flavor since they are not mass eigenstates? I ask because there is a flavor - mass table at neutrino, which would seem a contradiction in terms. -- Michael C. Price talk 07:57, 23 August 2006 (UTC)
"I have added the probabilities of oscillations through solar matter. I used Runge Kutta method in maple to solve the coupled equations. I'll add the theoretical discussions soon. Please comment."
Since we know that there are three neutrinos that participate in oscillation, and we know fairly well what the relevant parameters are, I would prefer that the three neutrino model be used for specific real-life cases like propagation through the sun. The two neutrino framework is all well and good when the discussion is pure theory, but it's not actually what happens.
Once you're done writing the new section on solar oscillations, the section near the top called "Solar neutrino oscillation" should be edited to reflect the addition. -- Strait 22:16, 27 November 2006 (UTC)
Oh, also, if you have a good understanding of the MSW effect, you might try to improve that page. (I only just barely understand it myself, so I don't want to try.) -- Strait 22:18, 27 November 2006 (UTC)
This article has been rated as being of "low" importance. I think that a phenomenon which stems directly from the (apparently) fundamental parameters which define the universe, and is the only known way of measuring those parameters, should be rated at least "mid" if not "high". I think that this page is not well described by "Subject is mainly of specialist interest." -- Strait 21:34, 11 December 2006 (UTC)
Adding all the graphs has started to make the article a bit long, in my opinion. Pictures help readers understand the content, so we should leave them. I would rather see something more technical move away. General readers might look at this article after the recent publicity including a NOVA episode devoted to the subject. We could consider reseparating the Maki-Nakagawa-Sakata matrix because it contains all the numerical details unappealing to general readers. This could also discuss experiments that attempt to measure the values. Notice how the Cabibbo-Kobayashi-Maskawa matrix has its own article. Teply 03:33, 19 December 2006 (UTC)
Indeed I did come to this page after viewing the Nova episode, "The Ghost Particle." The question in my mind--not resolved because I don't completely follow the math in the main article about mass and flavors not being congruent: since the masses of the three flavors of neutrino differ by more than six orders of magnitude (2.2 eV, ~170 KeV, ~15.5 MeV), oscillations among flavors, in order to conserve energy, must be accompanied by changes in velocity. Is this correct? At what fraction of the speed of light do solar neutrinos travel as electron neutrinos, and how much does this velocity decrease when they assume the other flavors? 21:08 PDT, 10 April 2008 —Preceding unsigned comment added by 67.161.40.124 ( talk) 04:10, 11 April 2008 (UTC)
Reference 4 is a vaguely related nuclear/detector physics paper that really shouldn't be quoted here. Suggest replacing with the PDG reference: "Yao et al. J Phys G 33, (2006) p156", and the references therein. —Preceding unsigned comment added by 128.250.54.30 ( talk) 07:31, 22 October 2007 (UTC)
This isn't my field, and likely I'm misunderstanding - but what confuses me is that the neutrino seems only to be observed as one of three quantized flavors; yet it seems to know, internally, precisely at what point in its oscillation it is at at any given time. Given the source of the neutrino and approximate momentum it seems like you could come up with a better model of the neutrino's internal state (how likely it was to be a certain flavor and when it would turn into another) than you could actually measure. Does that make its oscillation state a "hidden variable" in the deprecated quantum mechanical sense? 70.15.116.59 ( talk) 23:17, 9 December 2007 (UTC)
As I understand it, neutrinos come in several varieties, such is the electron neutrion, the tau neutrion, and the muon neutrino. In simplest terms, take any one of these neutrinos and add a negative W Boson and you will get an electron, or a tau particle or a muon, accordingly. It is as if the neutrino is the "bucket" that can accept the quaunum of charge, and the boson is like the water that goes into a bucket. As such it is possible that neutrinos DO NOT OSCILLATE, but rather it may be that the sun gives off some muon neutrinos, and that while on the way to earth some muon neutrinos collide with free neutrinos that are drifting in the vacuum, in which case - there is an appropriate transfer of linear momentum from one particle kind to another. So the neutino game might simply be like a game of marbles, or billiards. In such a context; the Nyquist theorem would be irrelevant; since such neutrio oscillations would not imply that free neutrinos oscillate among types, but rather type exchange occurs freely because of interaction with the neutrios that are free in the presumed vacuum. —Preceding unsigned comment added by Lazarus666 ( talk • contribs) 01:21, 9 August 2008 (UTC)
I have removed several edits from 88.68.XXX.XXX that has repeatedly stated that energy and momentum are not conserved by neutrino oscillations (as well as some personal opinions on the matter from the same source). As stated before on this talk page, neutrino oscillations occur because the mass eigenstates (which are the only ones that can possess definite energy and momentum) interfere with each other and that the flavor eigenstates produced in weak interactions are superpositions of these states. The theory is sound, completely analogous to that in the quark sector (although quarks possess properties that rules out any such interference - i.e., charge, large mass differences etc), and experimentally verfied. Of course, neutrinos are not plane waves, or produced with definite energy or momentum as the simplified derivation in the article suggests. However this is by far the easiest way of reasoning and it gives the correct result when compared to a full quantum field theoretical treatment in the ultrarelativistic limit. I would be happy to take any discussion on the theory of neutrino oscillations, but it should be kept here and not through vandalism of the article. -- Blennow ( talk) 09:17, 24 October 2008 (UTC)
I started a full article at Pontecorvo–Maki–Nakagawa–Sakata matrix. Review/Feedback/Expansion are appreciated. Headbomb { ταλκ κοντριβς – WP Physics} 14:11, 4 June 2009 (UTC)
It was stated that sterile neutrinos can oscillate with "normal" neutrinos. I'm trying to understand sterile neutrinos. I'm not clear whether "sterile" just means "right-handed". Are they synonymous for neutrinos (with the usual proviso that we switch left/right for particle/anti-particle)? If sterile neutrinos are just right handed neutrinos then it seems to me that they will have different weak hypercharge (0 for right-handed neutrinos, -1 for the left-handed neutrinos) and X charge. If so, wouldn't that prevent their mixing? -- Michael C. Price talk 06:01, 21 November 2009 (UTC)
Thanks for the feedback. I was being a bit sloppy with my language. By "mixing" I meant the neutrino family oscillations e-mu-tau-e-mu-tau (which preserve quantum numbers), not the Higgs left-right-left-right flipping that give them mass (which, as you correctly observe, will change any quantum numbers carried away by the Higgs).-- Michael C. Price talk 22:01, 21 November 2009 (UTC)
"These approximations are possible because the mixing angle θ13 is very small and because two of the mass states are very close in mass compared to the third." Please remove.. not justified. We do not know that much, there is also a model with a completely different mass hierarchy, that is not yet ruled out by experiment. This is simply a toy model and needs no justification. —Preceding unsigned comment added by 134.176.18.59 ( talk) 16:59, 25 May 2010 (UTC)
, is a bit confusing when E is not specified. —Preceding unsigned comment added by 134.176.18.59 ( talk) 16:26, 26 May 2010 (UTC)
-- 190.188.3.11 ( talk) 14:40, 10 June 2010 (UTC)
Hey guys can you please mention in the article that when you write m_i, you are referring to m_*c^2, when you write p, you are referring to pc and finally, when you write L, you are referring to L/c^2?
I think "propagation and interference" and "Two neutrino case" are very much like Chapter 5 of
Massive neutrinos in physics and astrophysics,Mohapatra, R.N. and Pal, P.B., 2004, Imperial College Pr
-- 134.176.18.59 ( talk) 21:27, 16 October 2010 (UTC)
In the central matrix in the matrix product under Classical analogue of neutrino oscillation (see http://upload.wikimedia.org/math/1/2/1/1214e944a130d2330f77074725ccee73.png) it appears that a minus sign and a plus sign have switched places in the upper row. Shouldn't that row read "g/La - k/m, [+]k/m"? - Episcophagus ( talk) 16:23, 11 June 2011 (UTC)
User Hugozam has created this section and provided all content without any references. I've asked him/her for references, but haven't heard back. Does anybody know if the information is correct and/or have a reference? If not, I suggest we remove the section. — SkyLined ( talk) 15:04, 14 November 2011 (UTC)
Thanks! — SkyLined ( talk) 16:50, 16 November 2011 (UTC)
![]() | This page is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |