1. Results in Neutrino Physics & Astrophysics : Highlights
Overview
Highlights in Neutrino Oscillation Results from Atmospheric, Solar, Accelerator and Reactor Neutrino Experiments
Future Directions & Projects
Outlook
Henry T. Wong / 王子敬
Academia Sinica / 中央研究院 @

2. Neutrino Physics Road-Map
Grand Unified Theories (GUT)
L(n-mass)0
Structures & Compositions of Universe
mn’s;Uij’s 0
n-Oscil.
mn’s
n-decays
0nbb
b-spect.dist.
anomal. int.
……….
Particle Physics
Cosmology
Nuclear Physics
Astrophysics
n’s as Probe

3. Neutrino Sources n‘s everywhere: 300 per c.c.
Observed window
n‘s everywhere:
300 per c.c.
from sun, supernovae, cosmic rays, reactors, accelerators, astrophysical sources, & relic Big Bang …

4. Cross Sections Challenges of Neutrino Experiments :
Strong
Electro-magnetic
Weak
 l(H2O)  250 light years !
Challenges of Neutrino Experiments :
“How to Beat the Small Cross-Section?”
i.e. By building Massive Detectors
 while keeping cost/background Low !

5. at least as much neutrinos by mass as visible matter !

6. Solar Neutrinos

7. Super-Kamionkande
※ Water Cerenkov detector: 50k tons, viewed by 11,000+ =50 cm PMTs in 1000 m underground site in central Japan
※ Physics: solar n, atmospheric n , long baseline accelerator n, proton decays ..
※ Accidents (PMTs imploded) Nov 01,
50% PMT data again end of 02 !!
No major deterioration in data quality

8. The Sun IS Burning !!
Measurement of Eccentricity of Earth’s Orbit !!!

9. Sudbury Neutrino Observatory (SNO)
※ 1 kton Heavy Water Cerenkov detector:
shielded by 7k ton of water viewed by 9456 PMTs located 2000 m underground in Canada.
※ Physics: Solar n …

11. Solution of the “Solar Neutrino Problem”
Standard Solar Model + Standard Particle Physics Model
Solution of the “Solar Neutrino Problem”

13. Atmospheric Neutrinos Up-Down Asymmetry & Deficit
nm disappearing, ne OK,
Strong evidence : > 15s
Better fits for nt appearing
Up-Down Asymmetry & Deficit

14. KEK-SuperK (K2K) Accelerator n Flight path 250 km
Deficit of nm at far detector
 spectral distortion

15. KamLAND Long Baseline Reactor n ave. flight path of 160 km
 (sensitive to 20% of world’s reactors !)
ave. flight path of 160 km
1 kton liquid scintillator in old Kamiokande site
probe “LMA” for solar n
historical results only 5 years from approved !!!!

17. A “By-Product” : Earth’s Radiogenic Power :
Thermal measurements : 42 TW
Geophysical Model : 16 TW
KamLAND measurement : < 60 TW

18. Neutrino Oscillations (in 2-family language)
Neutrinos produced & detected as ne, nm , nt (“flavor eigenstates”)
Propagate as n1 , n2 (“mass eigenstates”)
Probability of producingνe & detecting as νe :
 Matter Effect : Origin – ne+e (CC+NC) Vs nm +e(NC)
3 families
at resonance

19. Dm2 –  : Summary
2002
PDG 2000:
SK atm. n
SNO solar n

20. 2004
K2K : Consistent Checks to atm. n SK

22. + observations of L/E oscillation signatures from SK atm-n & KamLAND (averaged)…..

24. Three Families of Neutrino Mixing
The Maki-Nakagawa-Sakata (MNS) matrix :
Q13 : crucial unknown towards CP-studies
Possible CP Violation in n Sector:

25. Normal Hierarchy: Dm232>0 Inverted Hierarchy: Dm232<0
Neutrino Mass Structures :
Normal Vs Inverted Hierarchy ??
Quasi-Degenerate Vs Hierarchical ??
Dirac Vs Majorana ??
Dm2atm
Dm2
Dm2
Normal Hierarchy: Dm232>0
Inverted Hierarchy: Dm232<0
0 = ?

26. Deeper Physical Questions ………..
In particular :
Is q12+qCabbibo = p/4 ?
Is q23=p/4 ?
Is q13 = 0 ?
……..
Mixing angles may reveal deeper/higher energy scale & symmetry principles

27. neutrino mass structures may reveal GUTs scale physics (e. g
neutrino mass structures may reveal GUTs scale physics (e.g. See-Saw Mechanisms) :

28. Future Experimental Projects
Long baseline accelerator/reactor experiments (NuMI, CNGS, T2K, q13 ……)
※Detailed studies of mixing matrices by oscillation studies
0nbb experiments
※ Distinguish mass hierarchy, fix absolute mass scales
Direct mass searches in b-decay
※ Probe degenerate mass structures
Neutrino properties (e.g. magnetic moments studies…)
※ How neutrino interacts/couples with outside world
Neutrino from sky and earth
※ do astronomy/earth science with neutrino sources, understand roles of neutrinos in astrophysics/geophysics

29. Long Baseline Accelerator Neutrino Projects :
730 km
NuMI  MINOS
CNGS  Icarus/OPERA

30. 0nbb
Candidate Isotopes

31. Neutrino Mass Measurements
0nbb decay:
b decay kinematics:
microcalorimeters
MAC-E spectrometers
cosmology &
structure formation
astrophysics:
SN ToF measurements 3H
NEMO3
LNGS ´90-´03
(71.7 kg×y)
|mee|= eV
D.N. Spergel et al: Smn < 0.69 eV (95%CL)
S.W. Allen et al: Smn = 0.56 eV (best fit)
SuperK, SNO, OMNIS + grav.waves:
potential for ~1eV sensitivity?
187Re
2nbb

33. IceCube High Energy Neutrino Telescope
e.g.
Volume ~km3 !!

34. TEXONO Research Program in Taiwan
KS NPS-II : 2 cores  2.9 GW
KS n Lab: 28 m from core#1

35. Reactor Neutrino Interaction Cross-Sections
On-Going Data Taking:
SM s(ne)
T > 2 MeV
R&D :
Coh. (nN)
T < 1 keV
Results & More Data:
mn(ne)
T ~ keV

36. min. 700 m of rock overburden
TEXONO  Y2L
Install 5 g ULB-ULEGe at Y2L on January 2005
Study background and feasibility for CDM searches
may evolve into a full-scale (1 kg) CDM experiment
Yangyang (襄陽) Lab (Y2L)
min. 700 m of rock overburden

37. Sensitivity Plot for CDM-WIMP search with
1 kg ULEGe at 100 eV threshold ………

38. Summary & Outlook Neutrinos are important but strange objects
history of n physics full of surprises !
Strong evidenceS of massive n’s & finite mixings
Physics Beyond the Standard Model !
More experiments & projects coming up
EVEN MORE EXCITEMENT !