Neutrino Physics Recent Highlights

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					Neutrino Physics : Recent Highlights
The Neutrino Landscape Recent Results : MINOS & MiniBooNE Open Questions ; Future Directions & Projects TEXONO Status & Plans : Highlights
Henry T. Wong / 王子敬 Academia Sinica / 中央研究院

June 2007

@

Neutrino Physics Road-Map
Grand Unified Theories (GUT)

L( -mass) 0
ms;Uij’ ’ s 0
 -Oscil.   s ’  -decays      -spect.dist.   anomal. int.  ………. Cosmology Structures & Compositions of Universe

Particle Physics

Nuclear Physics

Astrophysics

s as Probe ’

Solar Neutrinos

 particular, the SNO NC/CC/ES Comparison In leads to …..

Standard Solar Model + Standard Particle Physics Model

Solution of the “ Neutrino Problem” Solar

Super-Kam. Atmospheric Neutrinos

 disappearing,  OK,  e  Strong evidence : > 15  Better fits for  appearing 

Up-Down Asymmetry & Deficit

KEK-SuperK (K2K)
Accelerator  Flight path 250 km

Deficit of  at far detector  spectral distortion

KamLAND Reactor Neutrinos

+ observations of L/E oscillation signatures from SK atm-    amLAND (averaged)…..

A“ By-Product” :

Earth’ Radiogenic Power : s
 Thermal measurements : 42 TW  Geophysical Model : 16 TW  KamLAND measurement : < 60 TW

Fermilab-NuMi  MINOS

MINOS Detector :
 Magnetized Tracking Calorimeters

MINOS-2006 :  disappearance at 1.27X1020 POT 
 Deficit of  at far detector spectral distortion   6.2 significance @ 

Amplitude of Deficit  sin22 Shape of Deficit   2 m

MiniBooNE’First Results: on LSND’ oscillation s s  e

MiniBooNE Detector

Event Signatures

Underexplained excess of counts at low energy !!!

 2 –: Summary m
PDG 2000: 2002

SK atm. 

SNO solar 

2006
 & MINOS(06):  Consistent Checks to atm. 

SK

Also for Future MINOS:  Search for sub-dominant   oscillations  e  Compare  and  bar oscillations 

MiniBooNE-2007: refute previous LSND +ve results.

  Brute-force best-fit to two-neutrino oscillation for entire E>300 MeV gives, at 18% probability :

Finite  -masses and mixings :  So What ? / What do they mean ?
 -mixing  -mass

M 3X3 VPMNS

V

T

PMNS

The Physics :      ’ Couplings  s  Strengths, New Physics Scales, Symmetry Principles

Three Families of Neutrino Mixing
The Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix :

  crucial unknown towards CP-studies  

Possible CP Violation in Sector:
2 P ( e   )  P ( e   )  16 s 12 c 12 s 13 c 13 s 23

c

23

sin

2 m 12  sin  L sin  4E   

2 m 13   L sin  4E   

m 2  23  L   4E   

Neutrino Masses are Finite !

 2 m
Ņ omaÓ Nr l  3
0=?

Ņn etd Iv r Ó e  2  1

Solar
Atmospheric  2atm m

 2 m

 2  1  e
Normal Hierarchy:  232>0 m

 3  
OR

 
Inverted Hierarchy:  232<0 m

Structure :

Numerically:

Open Questions … ..

I

II
 Normal Vs Inverted Hierarchy ??  Quasi-Degenerate Vs Hierarchical ??

III

Deeper Physical Questions ………..

In particular :
  + Is 12 Cabbibo =  ? /4   = ? Is 23 /4  = 0 ? Is   …….. Mixing angles may reveal deeper/higher energy scale & symmetry principles

Future Experimental Projects
 Long baseline accelerator/reactor experiments (NuMI, CNGS, T2K,  ……) 13 ※Detailed studies of mixing matrices by oscillation studies (e.g NTU’ s Daya Bay)   experiments  ※ Distinguish mass hierarchy, fix absolute mass scales  Direct mass searches in  -decay ※ Probe degenerate mass structures  Neutrino properties (e.g. magnetic moments studies…) ※ How neutrino interacts/couples with outside world  Neutrino as Probe (“ Applied” Neutrino Physics) ※ do astronomy/earth science/reactor monitoring with neutrino sources; understand roles of neutrinos in astrophysics/geophysics

Long Baseline Accelerator Neutrino Projects :

730 km NuMI  MINOS/NOvA

CNGS  OPERA

Neutrino Mass Measurements
cosmology & structure formation 0 decay: 
76Ge

NEMO3 2  

@ LNGS ’ 03 90-’ (71.7 kg×y)

Seljak et al 2006:  < 0.17 eV (95%CL) m

HMGe: |mee| ~ 0.7 eV

astrophysics: SN ToF measurements

decay kinematics: microcalorimeters MAC-E spectrometers
187Re 3H

Next SN: potential for ~1eV sensitivity?

Interplay between Oscillation Results with Neutrino Mass Experiments.

Cosmology

High Energy Neutrino Telescope (e.g. IceCube)
e.g.

Volume ~km3 !!

 TEXONO Collaboration – AS-based and run, groups from China, Turkey & India, close partnership with KIMS group in South Korea  Facilities – Kuo-Sheng Reactor Neutrino Laboratory in Taiwan ; YangYang Underground Laboratory in South Korea.  Program – Low Energy Neutrino and Astroparticle (Dark Matter) Physics

TEXONO Program on Low Energy Neutrino and Astroparticle Physics

Y2L

Reactor Neutrino Interaction Cross-Sections
quality Detector requirements mass

1 counts / kg-keV-day

R&D (ULEGe) :
 Coh. ( N)  < 1 keV T

On-Going Data Taking & Analysis [CsI(Tl)] : Results (HPGe):
  e) (  ~ 1-100 keV T  SM  e) (  > 2 MeV T

Best laboratory sensitivities in Neutrino Magnetic Moments (PRL-03, PRD07
Reactor ON/OFF Residual Plot :

 Background at 10 keV comparable Underground Dark Matter experiments !

Limit: e 7.4 X 10-11  @ 90% CL  < B

 Sensitivities 

m 3 1 ( ij ) 2     ( i )  3 j  8 mi
2

 Reactor Axions : Axions can be emitted in gammadecays AND the power reactor is THE most powerful terrestrial radioactivity source.

Results (PRD-07):
 Improved laboratory limits axion mass 102-106 eV  Exclude DFSZ/KSVZ Models for axion mass 104-106 eV

Future Directions :
 Open new detection channel and detector window down to 100 eV  Physics Goals:  First observation of neutrino-nucleus coherent scattering at KS  Dark Matter Searches at low-WIMP-mass region at Y2L  Improvement on Neutrino Magnetic Moment sensitivities

Expected sensitivity

Threshold ~ 100 eV wtith a 10 g ULEGe Prototype

Summary & Outlook

Neutrinos are important but strange objects history of   physics full of surprises ! Strong evidenceS of massive s & finite mixings ’ Physics Beyond the Standard Model ! More experiments & projects coming up EVEN MORE EXCITEMENT -- STAT TUNED !! Neutrinos may (?) also be avenue to Dark Matter Problem  physics-wise or experimentally