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Neutrino interactions

by Rob Hoff
Tags: interactions, neutrino
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James Carter
#19
Jul30-14, 07:59 PM
P: 3
The sum of the masses of the Neutrinos is .320+/-.081 eV; since the three Neutrinos have different masses that would dictate that, when one of the three Neutrinos comes within a distance of 10-16 of a meter of either a Muon, Electron, or Tau particle, weak interactions between the two particles would cause the speed of the Neutrino to change and therefore the mass, subsequently, would change.
Orodruin
#20
Jul30-14, 08:10 PM
P: 680
You do not give a reference, but from your sum of masses it would seem a cosmological bound.

The HM claim is controversial at best and cosmological bounds tend to depend strongly on assumptions and selected data sets. There are currently no experiments putting solid widely accepted lower bounds on the neutrino masses.
Matterwave
#21
Jul31-14, 12:10 PM
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Quote Quote by Orodruin View Post
Matterwave: The reason NC interactions to not appear in the MSW Hamiltonian is that they are equal (up to loop effects of ##\mathcal O(10^{-5})## times the CC contribution). The NC part of the MSW Hamiltonian is therefore essentially proportional to the unit matrix and only contributes to the neutrino flavor evolution with an overall phase. It is therefore customary to drop this contribution and only work with the CC contribution. This is no longer true when dealing with sterile neutrino flavors where the NC part is proportional to the projection operator onto the active states.

Edit: Relatively recent open accessreview on matter effects in neutrino oscillations: http://dx.doi.org/10.1155/2013/972485
The relevant discussion is on pages 2 and 3.

Carter: Your post goes against the last 52 years of research in neutrino physics (the muon neutrino was discovered in 1962). It is possible you have seen analogies of neutrino oscillations to spin precession (the mathematics is the same), but these are simply analogies. Neutrino oscillations are fundamentally based upon and our currently only confirmation of different neutrinos having different masses.
Indeed you are right. But I was told that the cross sections (total, due to both charged and neutral current) for an electron neutrino on an electron is 6-8 times higher than the cross sections for other flavors of neutrinos. This is why I made the statement I made at the beginning.
Orodruin
#22
Jul31-14, 12:23 PM
P: 680
Yes, it is about that difference because of the additional diagram with W exchange which interferes constructively with the Z exchange diagram.

This is why elastic scattering experiments are more sensitive to electron neutrinos but still have some sensitivity to mu and tau flavors. The solar fluxes are summarized in figure 14 at http://t2k-experiment.org/neutrinos/...tandard-model/ (T2K homepage) with the different bands representing results from CC, NC, and ES experiments. The figure is relatively old but the physics behind are still valid.
mfb
#23
Jul31-14, 03:30 PM
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P: 12,081
Quote Quote by James Carter View Post
It is possible that there are no Neutrino Flavors at all; the different Flavors all have the same speed and therefore the same mass. It may be that the observation of change in Neutrino Flavors due to weak interactions with other Leptons is simply the Neutrino changing the direction of its spin to correspond to that of the other Lepton; meaning that the [itex]\upsilon[/itex]e, [itex]\upsilon[/itex][itex]\mu[/itex], and [itex]\upsilon[/itex][itex]\tau[/itex] are all corrisponding Neutrino particles
Quote Quote by James Carter View Post
The sum of the masses of the Neutrinos is .320+/-.081 eV; since the three Neutrinos have different masses that would dictate that, when one of the three Neutrinos comes within a distance of 10-16 of a meter of either a Muon, Electron, or Tau particle, weak interactions between the two particles would cause the speed of the Neutrino to change and therefore the mass, subsequently, would change.
Please give references for your claims. Personal theories are not allowed here.


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