All Questions
Tagged with neutrinos special-relativity
36 questions
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2
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114
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Are high-energy neutrinos subject of relativistic time dilation like muons are?
Synchrotron experiments and cosmic-rays hitting our atmosphere have proved many times that high-energy massive muons moving with speeds close to the speed of light are subject to relativistic length ...
- 4,376
1
vote
0
answers
111
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Neutrino oscillations imply neutrino mass — Does the usual argument really hold?
An argument that people put forth is that because neutrinos can undergo changes in lepton flavor midflight, they must "experience time." Since massless particles must travel at the speed of ...
- 8,776
20
votes
3
answers
3k
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A thought experiment about neutrinos
I don't understand all the details of Dirac mass, Majorana mass, and many other "deep" notions.
I have in mind a very simple thought experiment.
Because of neutrino oscillations we know ...
- 4,448
0
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1
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Why is it said that the lightest neutrino is relativistic?
The neutrinos from the cosmic neutrino background have a temperature of $T_\nu=1.945K$, that is an energy of $E=\frac{3}{2}k_BT_\nu$. If the neutrino's mass is around $0.1eV$
$$ \frac{3}{2}k_BT_\nu<...
- 3
1
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3
answers
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Why should a neutrino being nearly massless mean that they travel near the speed of light? [duplicate]
It seems to me that photons travel only at the speed of light due to some intrinsic property of photons but once a particle has mass, its mass (irrespective of how small this mass is) should have ...
- 2,288
2
votes
1
answer
230
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Ultrarelativistic limit for neutrinos: Why is this approximation working?
In this section of the Wikipedia article on neutrino oscillations, a neutrino mass eigenstate $\left|\nu_i\right>$ is written as
$$\left|\nu_i(t)\right> = e^{-i(E_it-\vec p_i\cdot\vec{x})} \left|...
- 147
1
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1
answer
114
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Vacuum Cherenkov Radiation
Hi I was reading this paper (Pair Creation Constrains Superluminal Neutrino Propagation) for an assignment and I came across the following question:
in the article, it is said that if we assume that ...
-1
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1
answer
124
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Since neutrinos have mass, is there a neutrino aether that could be detected by a Michelson-Morley experiment?
If there are trillions of neutrinos per second passing through my body each second, would this density of particles qualify as a neutrino aether? If so, it seems in principle that an interference-...
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1
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1
answer
42
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Is relativity in action while we keep measuring some observable of a, let's say, neutrino?
Imagine a particle moving with non-zero velocity with respect to us. If I keep measuring an observable of the particle, such as position, then does the particle evolve relativistically? For example, ...
0
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1
answer
50
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Limiting the mass of the neutrino for a relativistic case
I came across a question that states
What mass would a neutrino need to still be relativistic today (T = 2.37K) ?
So for a particle to be relativistic we need $pc \gg mc^2$
Well Neutrino was ...
- 3,160
1
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0
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443
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Neutrino's relativistic four-momentum
In an exercise I have to solve there is an apparently contradiction that I can't figure out.
In a pion decay, where a muon and a neutrino are produced, conservation of quadric-momentum states:
\begin{...
3
votes
0
answers
110
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Which Particle would win the race?
I have read this question:
Neutrinos vs. Photons: Who wins the race across the galaxy?
https://en.wikipedia.org/wiki/Neutrino
And it made me curious.
The wiki article says that neutrinos travel at ...
- 29.3k
3
votes
1
answer
238
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Why are there no more galaxies moving as relativistic speeds?
Introductory note: I am not discussing galaxies that are going away from us or that are at the border of the universe.
If there are no preferred frames of reference, no galaxy or matter ensemble can ...
- 5,831
0
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2
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103
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Massive-ness of Neutrinos as a Consequence of Special Relativistic Kinematics?
As I understand it is still unclear if all neutrinos in the standard model are massive. Neutrino oscillations show that certainly not all neutrinos can be massless, but it might still be the case that ...
- 872
0
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1
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t=L in neutrino oscillation
What do we actually mean when we make the so called ultrarelativistic approximation and set the propagation time $T$ equal to the source-detector distance $L$? One would expect $vT=L$, where $v$ is ...
- 565
0
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2
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216
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Do neutrinos travel faster than light? [duplicate]
There are particles like tachyon which moves faster than light theoretically,does this holds good enough for neutrinos?
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3
votes
1
answer
102
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PDG review says "The flavour of a given neutrino is Lorentz invariant."
This the starting paragraph of section 14.1 PDG review (PDF) asserts:
The flavour of a given neutrino is Lorentz invariant.
What does this really mean? A neutrino of a given flavour $\alpha$, i.e.,...
- 27.2k
0
votes
1
answer
74
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relativistic approximation made in 2 flavor neutrino oscillation derivation
Reading a 2 flavor neutrino oscillation derivation I saw the following approximation being made regarding energy and momentum: E-p ≃ m²/2E
I can't see how this step is taken, and what is being ...
-2
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1
answer
386
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Do we have any evidence of slower-than-light neutrinos? [duplicate]
I'm writing a piece on the electron neutrino. There's plenty of excellent material out there, but I'm struggling to find anything definitive about their speed. There is for example evidence from ...
- 11.3k
12
votes
2
answers
604
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Is it possible that all "spontaneous nuclear decay" is actually "slow neutrino" induced?
This thought was inspired by a comment from the current leading answer, by @Sentry, to the question Where are all the slow neutrinos?
This [slow-neutrino induced nuclear decay] will still be an ...
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74
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2
answers
5k
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Where are all the slow neutrinos?
The conventional way physicists describe neutrinos is that they have a very small amount of mass which entails they are traveling close to the speed of light. Here's a Wikipedia quote which is also ...
- 2,746
-1
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3
answers
257
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Is it possible to go faster than the speed of light in vacuum?
If it is possible for particles to go faster than the speed of light in certain events, would it be possible to create a situation in which the barrier of the speed of light can be crossed?
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19
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1
answer
6k
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Physics behind this neutrino-related joke
In the comment section of a newspaper article reporting on the 2015 Nobel Prize for Physics, which was awarded for work on neutrino oscillation, I found the following joke:
"I'm sorry, we do not ...
user55611
0
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1
answer
416
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Is Helicity an intrinsic property of massive Neutrinos?
Hyperphysics states that, unlike an electron, the helicity of a neutrino is invariant because we cannot change to a reference frame where it is different:
This and subsequent experiments have ...
- 569
3
votes
5
answers
4k
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A neutrino has rest-mass and travels at (near) $c$, why isn't its mass/ energy (nearly) infinite?
If the total energy of all three types of neutrinos exceeded an
average of 50 eV per neutrino, there would be so much mass in the
universe that it would collapse. This limit can be circumvented by
...
user59485
1
vote
1
answer
131
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Distance and time measurement in the famous Superluminal Neutrinos Experiment
I tried to understand the technical aspects of the OPERA/CERN experiment, but apparently it takes some professional experience. Therefore I would like to ask someone better acquainted with such ...
- 1,585
8
votes
3
answers
1k
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If a neutrino has a rest frame, why can't a photon have a rest frame as well?
Concerning Rest Frame Wikipedia states:
For example, in the rest frame of a neutrino particle travelling from the Crab Nebula supernova to Earth the supernova occurred in the 11th Century AD only ...
- 221
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1
answer
330
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Concerning a previous possible tachyon observation? [duplicate]
A few years ago there was a story about the Large Hadron Collider where a possible tachyon was supposedly observed. It was later shown it didn't occur yet the incident made me think. If a large ...
- 379
0
votes
1
answer
207
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Neutrinos and Speed of light
Einstein's Special Theory of relativity postulates that the speed of light is same for all frames.
Suppose a neutrino is there moving at the speed of light. Then will that neutrino also be flowing ...
user23503
2
votes
3
answers
237
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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, ...
- 21
2
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3
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681
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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 ...
1
vote
3
answers
359
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How to take into account the reference frames with the revolution and rotation of the Earth in OPERA's superluminal neutrinos?
Since the Earth is moving around the Sun, which is moving around Milky Way, etc... What reference frame is used for the complete motion of the begin/end points (which are non-inertial right?)?
- 21
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4
answers
651
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Does the special theory of relativity form the foundation of modern physics?
Does the Special Theory of Relativity "form" the foundation of Modern Physics?
My question is in reference to Geoff Brumfiel's Scientific American article "Particles Found to Travel Faster than Speed ...
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21
votes
1
answer
2k
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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 ...
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2
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0
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165
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What would the impact be on the physics world if neutrinos DO travel faster than light? [duplicate]
Possible Duplicates:
What would be the immediate effects if light does not go at the maximum speed possible?
Superluminal neutrinos
I was reading this article about a group of scientist thinking ...
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21
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5
answers
5k
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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 ...
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