General Interest - current developments in neutrino physics
From: "JACK L. URETSKY (C) 1996; HEP DIV., ARGONNE NATIONAL LAB, ARGONNE, IL 60439" <JLU@hep.anl.gov>
Date: Sun, 2 Jun 1996 19:00:49 -0500 (CDT)
From: SMTP%"MCG@hep.anl.gov" 2-JUN-1996 15:44:16.72
To: JLU
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Subj: May 1996 Long-baseline Neutrino Newsletter
Date: Sun, 02 Jun 1996 15:19:43 -0500 (CDT)
From: Maury Goodman at Argonne <MCG@hep.anl.gov>
Subject: May 1996 Long-baseline Neutrino Newsletter
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Long-Baseline Neutrino News May 1996
*** Hans Bethe gives neutrino opinions
At a colloquium celebrating Argonne's 50th anniversary, Hans
Bethe said, "I believe the MSW theory to interpret the solar
neutrino data. I believe therefore the masses of the neutrinos
which have been deduced." (He concluded that the square of the
nu-mu mass was the MSW solution, the nu-tau mass was larger and
the nu-e mass was smaller.) His prejudice was for the low mixing
angle solution. He didn't believe LSND; saying "I believe the
statistics of the solar neutrino experiment greatly exceeds that
of LSND..." and went on to say that a Fermilab experiment will
increase the statistics by 100, and "If they see the same result
at Fermilab, I will hide my head in shame." Hans, whatever
the neutrino sector has in store for us, hold your head high!
*** LSND energy spectrum
In addition to the signal for nu-e-bars above calculated
backgrounds, the shape of the energy distribution for the LSND
contains additional evidence for oscillations. While the
distributions aren't that different, a kolmogorov test of the
energy shape favors the oscillation hypothesis over an unknown
source of mu- decays at rest.
*** Superkamiokande sees sun
In last month's issue, it said the detector turned on 12:01 on
April 1st; it should have said 00:01. And the fraction of
dead tubes is under 1/3%. The Radon levels are already
below Kamiokande 3, and I've heard they have a "clean" signal
already for nu-e scattering from the sun.
*** SPY finishes run
The "Secondary Particle Yield" group collected 12 days of data
for hadron yields from a Be target from 450 Gev p's. They
measured 135, 67.5(matching the two lowest momenta of Atherton et
al.), and 40,30,15,10 and 7 GeV (extending the momenta range).
Negatives were also measured at 67.5, 40, 15, 10 and 7 GeV.
Information is available at http://www.cern.ch/NA56/
*** SNO and neutral currents
SNO is planning on measuring the Neutral Current reaction using
two different methods, one would be with the NCD 3He detectors
and the other would be with salt. The collaboration has not yet
reached a decision as to which method will be used first. It is
likely that the decision will be reached only after the detector
is running. SNO's intent is to have both options ready to be
used within 6 months after fill, so that it will have a choice.
*** Neutrino telescopes go forward and back, South and North
Dumand is awaiting a funding decision so that it can fix its
junction box. Nestor has been having some disagreements within
its collaboration about how to proceed. Amanda is taking data,
but analysis is slowed due to a low rate of getting the data from
the South pole to its institutions. A link gets it to
Miami fast enough, but the Miami to Madison baud rate is slow.
Meanwhile an Alaska senator has encouraged the NSF to spend
some of its "polar studies" money at the north pole, and an
icebreaker may be stationed there full time. It could deploy
phototubes there from the ice? One cynic, however, described the
idea as a combination of all the disadvantages of Dumand with the
disadvantages of Amanda.
*** 50 GeV machine in Japan: JHP
The new hadron accelerator planned for KEK, the Joint Hadron
Project, is being planned by KEK and the INS which is moving
from Tokyo to Tsukuba in 1997. The 50 GeV machine, 10 microA and
..3 Hz, will be fed by a 3 GeV 200 microA booster, which will
displace the 12 GeV PS. They hope for construction money in
1998, and with a 5 year construction schedule, 1st beam is in
2003. To get high current, there is a new advanced lattice and
imaginary transition (27i). Initial intensity is 2 10^14 ppp and
a 3.1 s cycle time. With money for upgrades they can approach
their space charge limit of 7 10^14 ppp at 2.7 s. Cost is $750M.
The schedule has two impacts on the KEK to SuperK long-baseline
experiment. Early construction means less running for the 12GeV
experiment (1998-????) which will be limited by statistics, but
earlier running (???? + 4) for a high statistics 50GeV run.
*** MINOS recommendation highlight for URA; Krebs visits
In a letter accompanying URA's annual report, Fred Bernthal
wrote of a momentous FNAL year, including "a DOE High Energy
Physics Advisory Panel recommendation in favor of supporting
Fermilab's proposed long-baseline neutrino 'oscillation'
experiment, a project designed to detect the signature of
non-zero mass in those elusive sub-atomic particles."
DOE undersecretary Martha Krebs visited Soudan this month and
had a good time.
*** Notable new references
<+> Kolb, Mohapatra and Teplitz, New Supernova Constraints on
Sterile Neutrino Production, hep-ph/9605350, May 1996
<+> Fritzsch and Xing, Lepton mass hierarchy and neutrino
oscillations, Physics Letters B372 (1996) 265-270. Large mixing,
degenerate neutrino masses accounts for solar, atmospheric and
hot dark matter. Long-baseline experiments "of high interest".
<+> Roos, Dangers of unphysical region. hep-ex/9605008 This
paper looks at fits to -m^2 in beta decay fits to neutrino mass.
Part of the problem may be treating non-gaussian distributions
as gaussian.
<+> S. Wojcicki, "Prospects in Neutrino Physics", NuMI-183.
An excellent review of neutrino phenomena.
<+> Gonzalo Parente and Enrique Zas, Neutrino Induced Events in
the Auger Detector,
<+> Is CP violation observable in Long-baseline
Neutrino Oscillation Experiments?" hep-ph/9605413. This says yes
if highest nu mass 10 eV, few percent effects will be seen.
<+>Fogli, Lisi and Monanino, Matter-enhanced three-flavor
oscillations and the solar neutrino problem, (hep-ph/9605273),
The three-flavor formalism is extended to solar nu data.
<+>Fogli, Lisi and Monanino, 3-flavor oscillations at
long-baseline experiments (hep-ph/9604415)
<+>Gandhi et al, "New predictions for Nu telescope event rates",
AZPH-Th-96-02
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Also at (new 4/96) http://www.hep.anl.gov/ndk/longbnews/index.html
Maury Goodman mcg@hep.anl.gov 708-252-3646