Neutrino Arrival Time: 3 Periods or 1?

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Discussion Overview

The discussion revolves around the arrival time of neutrinos produced in a short time frame and the implications of their mass eigenstates on travel time. Participants explore whether these neutrinos will arrive at distinct times due to their differing rest masses or simultaneously due to oscillation effects. The scope includes theoretical considerations and potential experimental challenges.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions whether neutrinos produced over a short period will arrive at three separate times due to differing mass eigenstates or at the same time due to oscillation effects.
  • Another participant emphasizes the ambiguity in the phrase "producing a lot of neutrinos over a short period of time," suggesting that the interpretation affects the outcome.
  • A different participant notes that while the time-evolution can be described using independent mass eigenstates, achieving a precise production of neutrinos with well-defined energy and time could lead to observable separation of mass eigenstates over distance.
  • Concerns are raised regarding the feasibility of testing these scenarios, particularly with low-energetic neutrinos, due to the extremely small separation expected over vast distances.
  • Further speculation includes the potential for gamma ray flashes to emit neutrinos, although this remains an open question.

Areas of Agreement / Disagreement

Participants express differing views on the implications of neutrino production and arrival times, with no consensus reached on whether they will arrive separately or simultaneously.

Contextual Notes

Limitations include the dependence on precise definitions of neutrino production conditions and the unresolved nature of testing the proposed scenarios due to the minuscule expected separations over astronomical distances.

snorkack
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If you produce a lot of neutrinos over a short period of time, and then let them travel a distance long enough that their rest mass makes an appreciable difference in their travel time compared to photons emitted at the same time:

Will they arrive:
1) At 3 separate periods of time because the 3 mass eigenstates each have a different rest mass, speed and arrival time, or
2) At the same time, because each neutrino oscillates through all 3 mass eigenstates, and over several oscillation periods has a single average speed and a single valued average rest mass?
 
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It depends on what exactly you mean by "If you produce a lot of neutrinos over a short period of time".
 
You can always describe the time-evolution in terms of the independent mass eigenstates (neglecting interaction with matter on its path). The production is a superposition of those 3. If you somehow manage to produce a neutrino with a very precise, well-defined energy and production time, I would expect separation of the mass eigenstates with flight distance.
However, I do not see any way to test this - even with low-energetic neutrinos from fusion processes, the gamma factors are somewhere at ~10^9, giving v=(1-10^18)c or 1ns separation after several years (and light-years!) of flight.
 
mfb said:
However, I do not see any way to test this - even with low-energetic neutrinos from fusion processes, the gamma factors are somewhere at ~10^9, giving v=(1-10^18)c or 1ns separation after several years (and light-years!) of flight.

Or 1 ms after 10^15 seconds... meaning 30 million years.

Hundreds of millions to a few milliard lightyears are typical distances to gamma ray flashes.

Do gamma ray flashes emit any neutrinos?
 

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