Birth of Neutrino Astrophysics

1
Birth of Neutrino Astrophysics

• M. Koshiba
• July 21, 2003
• EPS, Aachen

For more details, see my review article
Observational Neutrino Astrophysics Physics
Report, 220 (1992) Nos.56, pp.229-482. The
contents of this talk will appear shortly in
Reviews of Modern Physics.
2
Conception

• There was a very important prenatal event.
• That was the radiochemical work of R.Davis using
  the reaction neCl37 to e-Ar37. The conclusion
  was that the solar neutrinos are only about 1/3
  of what you expect from the Standard Solar Model
  of J.Bahcall.
• This could be considered as the conception of the
  Neutrino Astrophysics and was the impetus for us
  to begin seriously working on the solar neutrinos

3
The experiments

• 1) KamiokaNDE Imaging Water Cerenkov,
• 20 PMT coverage, 3,000tons,
• ca.3MUS
• Feasibility experiment.
• 2) Super-KamiokaNDE the same as above,
• 40 PMT coverage, 50,000tons,
• ca.100MUS.
• Full scale solar neutrino observatory.
• (Both 1,000m underground in Kamioka Mine)
• (NDE for Nucleon Decay Experiment/
• Neutrino Detection
  Experiment))

4
Fish-eye View of KamiokaNDEs Interior
5
50cmf PMT which made the two detectors precision
devices
6
Fish-Eye View of Super-KamiokaNDEs Interior
7
Detector Performances

• Through m in S-KamiokaNDE
• Shots at 50 nanosecond intervals
• 2) Discrimination between electron and muon

8
The m has just entered the detector.
9
(No Transcript)
10
The m has reached to the bottom of the detector,
while the Cerenkov light in water is still on its
way.
11
(No Transcript)
12
(No Transcript)
13
The top e-event has a blurred radial distribution
of Cerenkov photons, while the bottom m-event has
a crisp ring image. The discrimination between e
and m is accomplished with an error probability
of less than 1. The m-event has the decay
electron later.
14
4 Accomplishments of KamiokaNDE

• The astrophysical,i.e., with D,T and E,
  observation of solar neutrinos by means of ne-e
  scattering.
• The observation of the neutrino burst from
  Supernova 1987A by means of anti-ne on p
  producing e plus neutron.
• The discovery at more than 4s of the anomaly in
  the atmospheric nm/ne ratio. Neutrino
  oscillation. Non-zero masses of ns.
• 4) Killed SU(5) by proton decay lifetime and
  SUSYSU(5) also by non-zero masses of ns.

15
(No Transcript)
16
The directional observation of the solar
neutrinos. The timing accuracy is better than
1microsecond.
17
The observed energy spectra of the recoil
electrons. It is consistent with the spectra
expected from the B8 neutrinos. The intensity,
however, is only about a half of that expected
from the theory. The solar neutrino anomaly
discovered by R.Daviss radio-chemical experiment
was confirmed.
18
The detector performance at the beginning of 1987.
19
The observed signal of the supernova neutrino
burst. It was immediately confirmed by IMB
experiment in USA. The combined results, Tn of
4.5MeV and the total n energy output of 3x1053erg
gave strong support to the theoretical model.
20
nm/ne has to be 2 or larger
21
KamiokaNDE data showed the ratio smaller than 2
by more than 4s and nm/nt oscillation was given
as the likely cause.
22
The Neutrino Oscillation

• Consider 2 neutrino case for simplicity.
• The weak eigenstate ym is a superposition of
• ym1 and ym2,namely ym ym1 cos q ym2 sin q
  with a parameter q, the angle between ym and ym1
  .
• The two states, ym1 and ym2, make beat with the
  frequency proportional to E1-E2 m12-m22Dm2,
  since Ep(m2/2p),thereby changing the relative
  intensity of ym1 and ym2.
• This causes a partial transformation of ym to yt.

23
(No Transcript)
24
Super-KamiokaNDEAccomplished Three things so
far.

• Established the solar neutrino observation with
  much better statistics.
• Firmly established, at more than 9s, the non-zero
  masses of ns and their oscillations.
• 3) Non-observation of nucleon decays is giving
  more stringent restriction on the possible type
  of future grand unified theory.

25
(No Transcript)
26
The Sun as seen by ns and its orbit in the
Galactic coordinate. You have to excuse the poor
angular resolution because the neutrino
astrophysics is still in its infantile stage.
27
The energy spectra of the recoil electron is
indeed consistent to that due to the expected B8
decay neutrinos.
28
If the observed anomaly of nm/ne is indeed due to
the n-oscillation, the zenith angle distribution
will show it over the distances of 10km to
13000km.
29
The oscillation parameters of the solar neutrinos
and of the atmospheric neutrinos.
30
(No Transcript)
31
Implications of Non-zero Neutrino Masses

• The right handed neutrinos have to exist.
• Standard Theory has to be modified and SU(5)
• is discarded as possible GUT.
• 2) Very low energy neutrinos will make the
• total reflection at very low temperature. Very
• nice for the future possibility of observing the
• 1.9K Cosmic Neutrino Background.

32
For the sake of giving proper credit, shown here
Is the author list of the supernova neutrino
observation.
33
Here is the author list of the oscillation paper.
34
The newest result from KamLAND. The oscillation
of the anti-e-neutrinos from the reactor. CPT
theorem and the confirmation of
S-KamiokaNDE sin2t 0.833, Dm25.5x10-5eV2
35
First Results from KamLAND Evidence for Reactor
Anti-Neutrino Disappearance K.Eguchi, S.Enomoto,
K.Furuno, J.Goldman, H.Hanada, H.Ikeda, K.Ikeda,
K.Inoue, K.Ishihara, W.Itoh, T.Iwamoto,
T.Kawaguchi, T.Kawashima, H.Kinoshita,
Y.Kishimoto, M.Koga, Y.Koseki, T.Maeda, T.Mitsui,
M.Motoki, K.Nakajima, M.Nakajima,
T.Nakajima, H.Ogawa, K.Owada, T.Sakabe,
I.Shimizu, J.Shirai, F.Suekane, A.Suzuki, K.Tada,
O.Tajima, T.Takayama, K.Tamae, H.Watanabe,
J.Busenitz, Z.Djurcic, K.McKinny, D-M.Mei,
A.Piepke, E.Yakushev, B.E.Berger, Y.D.Chan,
M.P.Decowski, D.A.Dwyer, S.J.Freedman,
Y.Fu, B.K.Fujikawa, K.M.Heeger, K.T.Lesko,
K.-B.Luk, H.Murayama, D.R.Nygren,
C.E.Okada, A.W.Poon, H.M.Steiner, L.A.Winslow,
G.A.Horton-Smith, R.D.McKeown, J.Ritter,
B.Tipton, P.Vogel, C.E.Lane, T.Miletic, P.Gorham,
G.Guillian, J.Learned, J.Maricic,
S.Matsuno, S.Pakvasa, D.Dazeley, D.Hatakeyama,
M.Murakami, R.C.Svoboda, B.D.Dieterle,
M.DiMauro, J.Detwiler, G.Gratta, K.Ishii,
N.Tolich, Y.Uchida, M.Batygov, W.Bugg,
H.Cohn, Y.Efremenko, Y.Kamyshkov, A.Kozlov,
Y.Nakayama, C.R.Gould, H.J.Karwowski,
D.H.Markoff, J.A.Messimore, K.Nakamura, R.M.Rohm,
W.Tornow, A.R.Young, and Y.-F.Wang (KamLAND
Collaboration)   More American than Japanese!
36
Future Possibilities

• A world network of 50,000tons NDEs
  Gran-SassoNDE in Italy, SveNDE in Sweden,
  Super-KamiokaNDE in Japan and one more NDE in
  South America. Besides the very detailed
  observation of the solar neutrinos
• 1-1) Warning to astronomers of the forthcoming
  optical flare-up with very good directional
  accuracy and the detailed observation of
  Supernova neutrino explosion near our Galactic
  center, 4,000events each and
• 1-2) the appearance experiment of nt using
  CERN neutrino beam.
• R and D for detection of Cosmic Neutrino
  background at 1.9K.
• ANNET Anti-Neutrino Natural Emission Tomography.

37
For fun

• From the Dm2s obtained, we can get a possible
  mass spectra of elementary particles using the
  See-Saw mechanism. And if we consider a small
  electromagnetic mass shift occurred in one of
  the phase changes in the very early Universe, we
  get the nice regularity as seen in the last
  slide.
• Anyone of you challenge to explain this
  regularity?

38
(No Transcript)
39
(No Transcript)
40
Thank you for your patience.
M. Koshiba