Ideosphere Forum

Re: fx-discuss: FX claim Neut: judge's statement changed

Author: Kerry Whisnant
Conversation: fx-discuss: FX claim Neut: judge's statement changed ( prev | next ) reply!
Topic: fx-discuss ( prev | next )
In-Reply-To: Jim Gillogly's post
Followed-Up-By: Jim Gillogly's post
Date: Tue Jan 02, 2018 11:41 am
Jim Gillogly
Kerry Whisnant
Jim Gillogly

Yes, the long description is the relevant criterion for judging. As a
researcher in this area, a few comments:

First, it is generally accepted now that neutrinos have mass. Although
the measurements are indirect, there are many different experiments that
indicate this. While there are some alternative explanations for some of
the data, only nonzero neutrino mass can explain the data in its totality.

Second, strictly speaking the electron neutrino does not have a unique
mass. The weak eigenstates -- electron, muon, and tau neutrinos, which
couple to the electron, muon and tau charged leptons, respectively --
are linear combinations of the so-called mass eigenstates (which do have
a specific mass). So the statement of the claim is not well-defined --
the electron neutrino does not have a unique mass, but the neutrinos
states that do have a unique mass are not purely electron neutrino.

I see two primary ways to go here: 1) you could say that the spirit of
the claim is that the lightest neutrino mass eigenstate must be 0.01 eV
or greater, and use that as the criterion, or 2) if you want to assign a
mass to the electron neutrino, you could take the weighted average using
the squared coefficients of the linear combination for the electron
neutrino as weights. Since the claim specifically mentions the electron
neutrino, I would lean toward the latter interpretation (I can provide
the formula if you want to go this route). But if some people entered
this claim thinking it referred to the lightest neutrino, there could be
some controversy. Given the current state of the data, these two
interpretations could very well give different answers.

We currently don't know if the electron neutrino couples more strongly
to the lightest or heaviest neutrino mass eigenstate. If interpretation
2) above is taken, and it is shown that the electron couples more
strongly to the heaviest mass neutrino (which has mass > 0.05 eV) -- a
situation called an inverted hierarchy -- then the claim could be judged
true without actually knowing the precise neutrino masses. If it is
shown that the electron neutrino couples more strongly to the lightest
mass eigenstate -- called a normal hierarchy -- it will be much harder
to reach a conclusion on the claim (you would have to show that the
lightest mass was at least 0.004 eV).

A final comment: no measurement in physics is ever precise -- there are
always experimental uncertainties. In our field we usually require a
5-sigma effect before we consider a claim to be proven. So it might be a
good idea to require something like a 5-sigma confidence level before
the claim is finally judged.

Kerry Whisnant

P.S. I am basically an inactive player in FX who still receives these
emails, and have no stake in this claim.

On 12/31/17 4:47 PM, Jim Gillogly wrote:
> I changed the judge's statement for the Neut claim to reflect my
> response to the query below. As always, please send pointers to
> relevant research that I should take into account.
> Jim
> > I'm writing to inquire about the adjudication of the ideosphere claim
> "Neutrino Mass > 0."
> >
> > In 2015, the Nobel Prize in Physics was awarded to Takaaki Kajita and
> Arthur B. McDonald "for the discovery of neutrino oscillations, which
> shows that neutrinos have mass."
> >
> >
> <
> >
> > Is this enough to settle the claim?
> --
> Jim Gillogly

Kerry Whisnant
Physics & Astronomy
Iowa State University


All trademarks, copyrights, and messages on this page are owned by their respective owners.
Forum: Copyright (c) 2000-2001 Javien Inc All rights reserved. Distributed under the GPL