Neutrinos are light, uncharged leptons. The neutrino tag should be applied to question relating to neutrino properties or interactions involving neutrinos.
59
votes
13answers
6k views
Superluminal neutrinos
I was quite surprised to read this all over the news today:
Elusive, nearly massive subatomic particles called neutrinos appear to travel just faster than light, a team of physicists in Europe ...
31
votes
5answers
146 views
Models of neutrinos consistent with OPERA's results
I guess by now most people have heard about the new paper (arXiv:1109.4897) by the OPERA collaboration which claims to have observed superluminal neutrinos with 6$\sigma$ significance. Obviously this ...
25
votes
1answer
484 views
Neutrinos vs. Photons: Who wins the race across the galaxy?
Inspired by the wording of this answer, a thought occurred to me. If a photon and a neutrino were to race along a significant stretch of our actual galaxy, which would win the race?
Now, neutrinos ...
16
votes
3answers
714 views
How do we know Dark Matter isn't simply Neutrinos?
What evidence is there that dark matter isn't one of the known types of neutrinos?
If it were, how would this be measurable?
16
votes
1answer
281 views
Where do high-energy neutrinos come from?
Last week the IceCube South Pole Neutrino Observatory published a press release reporting the possible discovery of two neutrinos with energies of over 1 PeV.
Would anyone here be willing to help me ...
15
votes
6answers
4k views
What would be the effects on theoretical physics if neutrinos go faster than light?
Earlier today, I saw this link on Facebook about neutrinos going faster than the speed of light, and of course, re-posted. Since then, a couple of my friends have gotten into a discussion about what ...
15
votes
2answers
1k views
What happened to the idea of tachyonic or other superluminal neutrinos?
While hunting around for information about the recent OPERA measurement that hints at superluminal neutrinos, I discovered that this idea was actually considered back in the 1980s. Wikipedia lists as ...
12
votes
3answers
91 views
If neutrinos travel faster than light, how much lead time would we have over detecting supernovas?
In light of the recent story that neutrinos travel faster than photons, I realize the news about this is sensationalistic and many tests still remain, but let's ASSUME neutrinos are eventually proven ...
12
votes
1answer
303 views
How are neutrino beams emitted at CERN?
As far I know they come from accelerator collisions, but I have read confusing things like magnetically focused. How could neutrinos be guided magnetically if they aren't affected by
the ...
11
votes
4answers
1k views
Are neutrinos Majorana particles?
That is, are they identical to their anti-particles? (Any results of double beta decay experiments?)
10
votes
2answers
370 views
Reproducing the OPERA result
Are there any other facilities that would be capable of independantly verifying the opera result? In other words, a completely different source/detector for $\nu_{\mu}$ beams?
Alternatively, there ...
10
votes
1answer
131 views
The transit of Venus and solar neutrino rates
The following question was posed at the end of Maury Goodman's June 2012 long-baseline neutrino newsletter.
During the Venus transit of the sun, were more solar neutrinos
absorbed in Venus, or ...
9
votes
5answers
647 views
9
votes
2answers
87 views
Can neutrino detectors tell what direction the neutrinos came from?
I was reading this question and got to thinking. Can neutrino detectors give us any clue where the neutrinos came from or when a supernova may occur? I was unsure and decided to ask that here.
9
votes
1answer
234 views
Neutrino Oscillations and Conservation of Momentum
I would like to better understand how neutrino oscillations are consistent with conservation of momentum because I'm encountering some conceptual difficulties when thinking about it. I do have a ...
9
votes
3answers
637 views
Why do or don't neutrinos have antiparticles?
This was inspired by this question. According to Wikipedia, a Majorana neutrino must be its own antiparticle, while a Dirac neutrino cannot be its own antiparticle. Why is this true?
8
votes
2answers
633 views
How can neutrinos oscillate though the lepton flavors have differing masses?
Since the total mass-energy for the neutrino presumably does not change when a neutrino changes lepton flavor, though the mass is different, what compensates for the gain or loss of mass? Does the ...
8
votes
1answer
254 views
Are right handed neutrinos actually antineutrinos and vice versa?
Is it experimentally ruled out that right-handed neutrinos are actually antineutrinos, and left-handed antineutrinos are neutrinos ?
8
votes
4answers
409 views
strange modulation of radiactive decay rates with solar activity
Recently i found out this uber strange article about nuclear decay rates being somehow showing seasonal variations with a high correlation with sun activity. Two very precise questions:
1) has this ...
6
votes
2answers
322 views
Neutrino oscillations versus CMK quark mixing
I wish to describe in simple but correct terms the analogy between the Cabibbo–Kobayashi–Maskawa (CMK) and Pontecorvo–Maki–Nakagawa–Sakata (PMNS) matrices.
The CMK matrix describes the rotation ...
6
votes
2answers
202 views
How is the distance between Geneva detector and the Gran Sasso one measured?
Does anyone know how is the distance between detectors in the now famous neutrino experiment measured? Also, how was the time of flight measured?
5
votes
3answers
604 views
How can neutrinos “beat light”?
Article in the CERN newsletter "symmetry breaking" has the following statement:
"Neutrinos are often the first particles to bring news of events in space to Earth, beating even light.". What does this ...
5
votes
2answers
545 views
“Dear radioactive ladies and gentlemen” - Letter by Wolfgang Pauli
In 1930, Wolfgang Pauli wrote a letter to Lise Meitner for a convention in Tübingen, considering the problem of beta decay.
Does anybody know, where to find the original letter online ?
5
votes
1answer
130 views
Are there any reasonable attempts at explaining the OPERA result
as there's so many papers on the opera result and it's a struggle flicking through them all combined with my limited knowledge meaning I cannot well differentiate silly nonsensical papers from ones ...
5
votes
2answers
117 views
Do neutrinos of any flavor get trapped in black holes?
This question has been bothering me a bit. I know that neutrinos have super small mass and they interact via the weak force. Since they have a non-zero mass, they should be affected by black holes and ...
5
votes
1answer
100 views
Mechanisms of mass generation for Dirac neutrinos
If neutrinos are Majorana particles, one way of explaining their small masses is the seesaw mechanism.
Now say I'd like my neutrinos to be Dirac, for symmetry to the quark sector. What mechanisms ...
4
votes
4answers
500 views
When the speed of light has been measured, recently?
Yes, it is weird, absurd, but I can't stop thinking that the would-be superluminal
neutrino speed has been computed by an arithmetic operation (space/time) and not by direct comparison with a ...
4
votes
4answers
544 views
Why are neutrino oscillations considered to be “beyond the Standard Model”?
Is this just a historical artifact - that the particle physics community decided at some point to call all of the pre-oscillation physics by the name the "Standard Model"? The reason I ask is because ...
4
votes
4answers
412 views
Neutrino versus Anti-neutrino Detection
Is there a that detection method in use that can distinguish between a neutrino from its anti-neutrino?
4
votes
3answers
181 views
Could we prove that neutrinos have mass by measuring their gravitational signature?
It is now said that neutrinos have mass. If an object has mass then it also emits a gravitational field. I appreciate the neutrinos mass is predicted to be small, but as there are so many produced ...
4
votes
2answers
238 views
Sterile Neutrinos as Dark Matter
There has been recent activity by astrophysicists to determine whether a fourth flavor of neutrino, a sterile neutrino, exists. It would likely be more massive than electron, muon or tau neutrinos. ...
4
votes
1answer
55 views
Is it proven that all “solar” neutrinos are coming from the Sun direction?
In "Observation of 8B solar neutrinos in the Kamiokande-II detector" (Phys.Rev.Lett., 63, 16(1989), http://prl.aps.org/pdf/PRL/v63/i1/p16_1) the Figure 2 shows that only small percentage of registered ...
4
votes
1answer
706 views
What do “tachionic” neutrinos mean for QG?
Reading about the spectacular Opera claim, I`m (again ;-P) wondering if a confirmation of superliminous neutrinos could help settle some still open quantum gravity issues ...?
In this post, Lumo ...
4
votes
2answers
312 views
Where did the idea of a neutrino come from?
Exactly what paper by W. Pauli introduced the idea for the existence of a neutrino and how was its existence confirmed experimentally (who did that and in what paper)?
4
votes
2answers
392 views
The Opera Neutrino Experiment and the Supernova 1987
So this probably stems from my massive ignorance about post-Newtonian physics but the supernova results of 1987 which measured neutrinos arriving 3 hours before the light from the supernova have been ...
4
votes
1answer
328 views
Neutrino Speed in Supernova
I've read that neutrinos in supernova can be affected by "neutrino refraction." Is this analagous to the refraction of light, and if so, is the speed of these neutrinos similarly reduced from their ...
4
votes
2answers
396 views
Consequences for causality if superluminal neutrinos were explained by extra dimensions
One suggestion for explaining superluminal neutrinos (assuming for the sake of argument that the OPERA results should hold up) is that the neutrinos have taken a route through extra dimensions, with ...
3
votes
2answers
615 views
Why do neutrino oscillations imply nonzero neutrino masses?
Neutrinos can pass from one family to another (that is, change in taste) in a process known as neutrino oscillation. The oscillation between the different families occurs randomly, and the likelihood ...
3
votes
1answer
298 views
Microsecond trading with neutrinos
The Spread Networks corporation recently laid down 825 miles of fiberoptic cable between New York and Chicago, stretching across Pennsylvania, for the sole purpose of reducing the latency of ...
3
votes
1answer
152 views
Solar neutrino predictions
The solar neutrino problem has been "solved" by discovering that neutrinos have mass and they oscillate. So how accurate are now our predictions about the number and types of solar neutrinos that ...
3
votes
1answer
91 views
Neutrino Oscillation and their gravitational implications
As I understand neutrinos, there are three different flavors, all with different masses. Although the masses of these neutrinos have not been directly measured, their mass differences have been. ...
3
votes
1answer
330 views
neutrinos by formation of “neutron pairs”
Here :
http://www.newscientist.com/article/dn20084-neutron-star-seen-forming-exotic-new-state-of-matter.html
are news on superfluidity in a neutron star. The necessary bosons they say are pairs of ...
3
votes
0answers
477 views
Can neutrinos travel faster than the speed of light? [duplicate]
Possible Duplicate:
Superluminal neutrinos
What would be the immediate effects if light does not go at the maximum speed possible?
This is a hot topic right now, so I thought we should ...
2
votes
3answers
364 views
If it turns out that neutrinos do travel at faster than lightspeed, how will the success of special relativity be explained?
As per in the title. If it turns out that neutrinos do travel faster than the speed of light, how will the success of special relativity be explained? My apologies if this has been asked before; I've ...
2
votes
2answers
107 views
How much energy is carried away by neutrinos in matter-antimatter annihilation?
Some people say that neutrinos carry away most of the energy, some others say just a fraction. So what is the truth ? what is the percentage of energy lost due to neutrinos ?
2
votes
2answers
108 views
What is difference between the different 'flavours' of neutrinos?
Moreover, how-come scientist know that muon-neutrino are different from electron-neutrino when they didn't even know what the difference was? Did they interact differently with other particles?
2
votes
1answer
225 views
How 'Faster Than Light' Neutrino Was Product of Loose Cable at CERN?
A "faster than light" neutrino discovery was actually the result of a loose cable.
A fiber-optic cable in a GPS receiver at the European Center for Particle Physics ( CERN) near Geneva
Can someone ...
2
votes
2answers
604 views
Are neutrinos affected by gravity?
Layman here, but EE and BS physics. I know that light is affected by gravity. But are neutrinos? During the collapse of a star into a neutron star, as the electrons join protons to form neutrons ...
2
votes
3answers
148 views
When a high speed neutrino just misses an old neutron star, why isn't it trapped?
Suppose a neutrino is seen travelling so fast that its Lorentz gamma factor is 100,000. It races past an old, no longer active neutron star, narrowly missing it. As far as the neutrino is concerned, ...
2
votes
1answer
191 views
Do neutrinos 'become' other types of particles between oscillations?
In light of the recent kurfuffle of FTL neutrinos I wonder, do neutrinos 'become' other particles between their oscillations between the different flavors of neutrino? I'm slightly familiar with ...
