🚀 go-pugleaf

clark@bork.nist.gov (Charles Clark) writes:
> ... what has happened to the 17 keV neutrino ?

sichase@csa2.lbl.gov (sci.physics demigod Scott Chase) writes:
> A Japanese group published a strong negative result some months ago which 
> has many people starting to lean towards the "No 17-KeV neutino" position.
> People here at LBL, some of whom still have experiments in progress, seem
> to still keep their minds open.

One interesting new result I heard was from Norman (of LBL) himself.  Their
old experiment, beta decay of 14-C, saw a kink at 17 keV; I think I heard a
statistical significance of 9 sigma.  Their new experiment, inner
bremstrahlung from 55-Fe, sees no kink, contradicting the result of their
first experiment by 7 sigma.  It was amusing hearing Norman describe both
results in the same talk.  To my untrained eye the 55-Fe data (null result)
looked a lot more convincing.

Somebody else did an experiment with 2 different radioactive elements mixed
together, in a way that was supposed to subtract out much of the
theoretical uncertainty associated with these experiments, and they also
got a null result.

It is still true that all positive results have been in solid state
detectors, but not all solid state detectors get positive results.  Yet
Norman claimed to be able to show it is not a solid state effect.  The
positive results are statistically significant, and something funny is
going on, but the negative results argue very strongly against a 17 keV
neutrino.  I think there must be some other, very obscure explanation.

Scott says,
> Until this issue [solid state vs. magnetic spectroscopy] is settled,
> it seems to me that the entire question remains open.

There is still a big mystery.  Isn't science fun?

--
Staccato signals of constant information,  |  -- David Brahm
A loose affiliation of millionaires and    |  (brahm@cco.caltech.edu)
  billionaires and Baby ...                |---------------------------
These are the days of miracle and wonder,  | Disclaimer:  I only speak
And don't cry, Baby, don't cry, don't cry. |   for the sensible folks.