From: "JACK L. URETSKY (C)1998; HEP DIVISION, ARGONNE NATIONAL LAB ARGONNE, IL 60439" <JLU@hep.anl.gov>
Date: Sat, 6 Jun 1998 23:34:24 -0500
1. Electromagnetic pair production of neutrinos: The neutrino is neutral, so
it does not couple directly to the photon (there is no coupling to A_mu). There may,
however, for massive neutrinos with charge and magnetic moment structure (like the
neutron) be a coupling to the F_mu_nu field. This was pointed out by T.D. Lee in
,I think, the '50's. The charge and magnetic moment structures are expected to
be very small (governed by the weak scale - everything gets divided by 256 GeV)
so that the electromagnetic production of neutrinos should be essentially
unobservable.
2. We had a seminar a week ago by one of the Kamioka experimenters, so we knew
the substance of what was to be presented at Neutrino '98. Their best value of
the mixing angle is Sin(2-theta)=1. Their parameters are within the range of
the Minos experiment which will send Fermilab nu_mu's to the Soudan mine near
Ely, Minn. That experiment is, as I understand it, an appearance experiment.
The nu_mu's will oscillate into nu_tau's and will be sufficiently energetic
to produce tau's.
The missing link: Nobody has shown yet that the nu_tau is different
from nu_e and nu_mu (although the Z-width implies that there are approximately
3 flavors of light neutrino).
3. The Kamioka result, if confirmed, does give physics <beyond> the standard
model in the sense that the standard model is silent on the subject of
neutrino mass.
Regards,
Jack
"'Is it claimed that Dr. Cook's achievement is a Fact, or is it a
miracle?'
'Why so?'
'Because if it is a Miracle, any sort of evidence will answer, but
if it is a Fact, proof is necessary'"
Mark Twain, "Official Report to the I.I.A.S. (1909)