NEUTRINO PHYSICS

1
NEUTRINO PHYSICS
Very briefly - in all textbooks - M.
Tytgats course
Born in 1930 - 40 years of Fermi theory -
1968 The Standard Model - since 2000
evidence for massive neutrinos
The main subject of this course
Pierre VILAIN ULB, Brussels
2
CONTENTS
I Brief history II The Standard
Neutrino III Massive Neutrinos IV Formalism
of neutrino oscillations V Overview of the
experimental situation VI Discussion and outlook
3
I Brief Neutrino History
1930
Neutrino invented by Pauli to preserve E
conservation in nuclear ? decay
4
1933
E. Fermi develops the ?-decay theory and proposes
the name neutrino
Local 4-fermions interaction
More modern version
n
"spectator" quarks
Hweak ? G (Yp g? Yn) (Ye gµ Yn)
Weak Charged Currents (CC)
Neutrino cross-section
10-10 Electron cross-section
No detection for 23 years
? 1.1 10-5 GeV-2
5
1956
F. Reines and C. Cowan The (anti)neutrino
exists !
At Savannah River nuclear plant
1959
R. Davis The neutrino and the antineutrino !
6
1956
T.D. Lee and C. N. Yang predict P violation
1957
C.S. Wu et al observe maximum P violation
V-A theory
Vector Axial vect. Ye gµ YnL
º n "left" º n (helicity -1) for mn 0
In terms of quarks
To recover the original definition of GF
7
1962
L. Lederman, M. Schwartz and J. Steinberger
First Neutrino beam at BNL
Le , L? separately conserved
1999
DONUT experiment First detection of ??
interaction
8
PROBLEMS
In the quark sector GDS ¹ 0 GDS 0 ?
NO ! One observes GDS ¹ 0 1/20 GF Cabbibo 1963
The state coupled to u by weak CC interaction
is a mixture of d et s Jµ u gm (1 g5) (a
d b s ) with a2 b2 1 a cos qc, b
sin qc or Jµ u gm (1 g5) d with
Notation Yu ? u ,etc
d' cos qc . d sin qc . s
sin qc 0.22
Expt
Since then 3 generations u (u,c,t ) d
(d,s,b) with d VCKM d and VCKM 3x3
(unitary ?) matrix
9
A bigger problem of the 4- fermions
theory Unphysical results at high energy Ex ne
e- e- ne s (E C.M.)2 The theory gives (at
tree level)
Divergent !
Solution? Exchange a particle of mass M
g
ne
e-
e-
ne
G
q2
Þ
W
g
ne
e-
ne
e-
Þ
At  low energy q2 ltlt M2W At "high" energy q2 gtgt
M2W
BUT the divergence is still there at higher orders
10
II The Standard Neutrino
Electroweak Theory (see M. Tytgats
course) Invariance under local symmetry
transformations of the gauge group SU(2)L ?
U(1)Y - SU(2) group of weak isospin ?
isotriplet of gauge bosons - U(1) group of
weak hypercharge ? single gauge
boson Left-handed quarks and leptons in SU(2)
doublet Right-handed
singlet
Interaction energy density of quarks and leptons
with gauge bosons
Higgs, Englert, Brout Spontaneous Symmetry
Breaking
11
Physical particles W , ? and Z0
12
1973 in GARGAMELLLE bubble chamber
Weak neutral current discovery in CERN PS
neutrino beam
And also
13
In the 80s -high energy neutrino beams
- bigger detectors

• weak couplings with a few precision
• - quark structure of the nucleon

BEBC
The most recent NuTeV
CHARM-II
CDHS
14
At tree level, on an isoscalar target composed of
u,d quarks only
1 if only standard source of SU(2) symmetry
breaking
But measured ratios must be corrected for
various effects - radiative corrections (?
dependence in Mtop , Mhiggs ) - heavy quark
effects (? dependence in charm threshold) -
higher twist,. Theoretical systematic
error ? 1
15
?N experiments before NuTeV
16
NuTeV Much lower systematic error if one uses

• -Insensitive to sea quarks
• Charm error from valence d quark
• only (Cabbibo suppressed)
• BUT
• it requires very pure ? and ? beams

At FermiLab Tevatron Sign Selected Quadrupole
Train
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NC/CC separation
detailed Monte Carlo many calibrations
19
NuTeV fit (? ? 1 , mc parameter constrained by
expt)
20
3? discrepancy with St. Model !?
21
? as free parameter
New Physics ? - Extra Z , .
22
NuTeV result supported by the 2? discrepancy on
N? ???
23
Summary the neutrinos in the Standard Model
(forgetting the NuTeV anomaly)

• spin ½ , colorless, electrically neutral
• 3 families (or flavors or generations)
  associated to e, ? and ?
• Ll conserved leptonic number for each family l
• (strictly speaking, B-L must be
  conserved for the SM to be renormalizable)
• ?eL and eL form a SU(2) doublet (idem for
  ? and ?)
• no ?eR
• - no Dirac mass term
  (see next chapter)
• - no Majorana mass term
  
• Neutrinos are massless ? no mixing, no
  magnetic moment

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III Massive Neutrinos
Why ? - Best explanation of the experimental
results ( see later) - All fermions, but
neutrinos, have both L and R fields - Most Grand
Unification models predict m? ? 0 How to
accommodate the (so successful ) S.M. ?
Remember - m? 0 imposed by local U(1) gauge
invariance ? e.m. charge conservation - m? 0
not protected by gauge symmetry but imposed by
construction in the Minimal S.M.
- no ?R
- Le,?,?
conserved ( global symmetry) ? look at possible
extensions of the S.M. A more difficult question
why are the neutrino masses so small ?
25
Origin of mass in the SM
Quark fields
SU(2) doublet
SU(2) singlet
Terms in the Lagrangian describing the
interaction with the Higgs doublet
Invariant under SU(2)
26
Spontaneous Symmetry Breaking
See M. Tytgat
To get the physical fields u,d,c,s Diagonalize
m and m using 4 unitary matrices
27
Neutral current terms
For instance
GIM mechanism no flavor changing NC
Charged current terms
Quark mixing matrix VCKM
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Neutrino fields
Introducing chiral fields One gets,as for quarks,
the so-called Dirac mass terms
Note LD is invariant for the U(1)
transformation which corresponds to
the conservation of the total lepton number L

• BUT other Lorentz scalars possible using the
  C-conjugate partners
• Majorana mass terms
• with L fields
• with R fields

29
Notes
Most general terms
(M can be shown to be symmetric)
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To find the physical neutrino states find a
unitary matrix U such that UMUT diag(m1, m2,)
If Majorana mass terms are present, the physical
mass states are Majorana neutrinos are their
own antiparticle
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Dirac or Majorana neutrinos ?
(1 family to simplify)
Dirac 4 states ?L (?L )C
?R (?R )C

• - Le -1, produces e in CC
• at high E mainly ve hel.

• - Le 1, produces e- in CC int.
• at high E mainly ve helicity
• (with m/E admixture of ve hel.)

Sterile no CC,NC int. in SM (but interact with
Higgs)
Majorana only 2 states spin-up or spin-down
We are used to call ? (anti-? ) the state
produced with an e (e- ) But what is produced
with an e is a L-chiral object superposition
of (mainly) spin-down state (tiny) spin-up
state of the SAME Majorana ? If we could flip the
spin of this object, it would produce the wrong-
sign lepton ! Possible experimental test see
later 0???
32
The seesaw model
(simplified, only 1 family)

• Seesaw m ? when M? Nice but
• what is the new physics scale?
• not so obvious with 3 families
• Playground for model builders

33
IV Neutrino mixing and oscillations
eigenstates of the CC weak int.
34
Usual parametrization of the P-MNS matrix U
Pontecorvo(1957) Maki,Nakagawa,Sakata (1962)
NOTE - oscillation expts not sensitive to
Majorana phases - CP violation
phase ? not observable if ?13 0 -
in effective 2? formalism 1 angle ? à la
Cabbibo
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From Y. Smirnov
Simplified ( 2 families) picture of mixing
vacuum mixing angle
n2 sinq ne cosq nm
ne cosq n1 sinq n2
inversely
n1 cosq ne - sinq nm
nm - sinq n1 cosq n2
coherent mixtures of mass eigenstates
flavor composition of the mass eigenstates
n2
ne
n2
n1
wave packets
n1
inserting
n2
nm
n1
Flavors of eigenstates
Interference of the parts with the same
flavor depends on the phase difference
Df between n1 and n2
The relative phases of the mass states in ne
and nm are opposite
36
Vacuum oscillations
From Y. Smirnov
Propagation in vacuum
Flavors of mass eigenstates do not change
Determined by q
Admixtures of mass eigenstates do not change
no n1 lt-gt n2 transitions
n2
ne
n1
Df Dvphase t
Df 0
Dm2 2E
Dvphase
Dm2 m22 - m12
Due to difference of masses n1 and n2 have
different phase velocities
oscillations
effects of the phase difference increase which
changes the interference pattern
37
Propagation in vacuum (2 families, for instance
?e and ?? )
() A more serious quantum mechanical treatment
with wave packets give the same result for all
practical situations
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In practical units
39
Damping
Distortion of the energy spectrum
40
General 3? Oscillation probability
41
If strong mass hierarchy effective 2-family
approximation
Physics governed by ? Dm2
? flavor composition of n3 only
42
Example of 2-family approximation large mixing
and strong mass hierarchy
oscillation damping for large Dm2 dispersion and
resolution in L/E
43
From Y. Smirnov
Matter effects

ne
e
Elastic forward scattering
Potentials
Ve, Vm
W
ne
V 10-13 eV inside the Earth for E 10 MeV
e
Difference of potentials is important
for ne nm
ne density of electrons
Ve- Vm 2 GFne
Refraction index
n - 1 V / p
Refraction length
10-20 inside the Earth
l0 2p / (Ve - Vm)
lt 10-18 inside the Sun
n - 1
2 p/GFne
10-6 inside the neutron star
44
Eigenstates in matter
From Y. Smirnov
in matter
in vacuum
Effective Hamiltonean
H H0 V
H0
V Ve - Vm
n1m, n2m
n1, n2
Eigenstates
depend on ne, E
m1m, m2m
m1, m2
Eigenvalues
m12/2E , m22/2E
H1m, H2m
Mixing in matter
ne
n1
n2m
n1m
q
n2
nm
qm
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Resonance
In resonance

sin2 2qm 1
Mixing in matter is maximal Level split is minimal
ln l0 cos 2q

Refraction length
Vacuum oscillation length

A Yu Smirnov
46
From Y. Smirnov
The MSW adiabatic conversion
Mikheyev,Smirnov(1986) Wolfenstein(1978)

H H(t) depends on time
Non-uniform matter density changes on the way
of neutrinos
n1m n2m are no more the eigenstates of
propagation -gt n1m lt-gt n2m transitions
qm qm(n e(t)) mixing changes in the
course of propagation
ne n e(t)
However
if the density changes slowly enough
(adiabaticity condition) n1m lt-gt n2m
transitions can be neglected
Well verified in the Sun or the Earth
Flavors of eigenstates change according to the
density change
determined by qm
Admixtures of the eigenstates, n1m n2m, do
not change
fixed by mixing in the production point
Phase difference increases
according to the level split
which
changes with density
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From Y. Smirnov
In the Sun 3 regimes depending on E?

P sin2 q
n0 gtgt nR
Non-oscillatory transition
n2m n1m
n2 n1
interference suppressed
Resonance
Mixing suppressed
n0 gt nR
Adiabatic conversion oscillations
n2m n1m
n2 n1
n0 lt nR
Small matter corrections
n2m n1m
n2 n1
ne
48
From Y. Smirnov
49
Matter effects Plot of contours of equal
survival probability
50
V Overview of the experimental situation

• Direct mass measurements
• - Tritium ? decay
  end-point
• - 0? double ? decay
• - constraints from
  cosmology
• Oscillations
• - Solar ?
• - Reactor ?
• - Atmospheric ?
• - Accelerator ?
• - (Supernova ?, UHE ?)
• (Other processes magnetic moment, ? decay,
  ??e?,)

51
Tritium ? decay end-point
Why tritium? 1- low E0 ?18.6 keV relative m??
effect larger 2- lowest Z
smallest Coulomb effect
3- low density gaseous source e- energy loss
small 4- high activity
T1/2 12.3 y
Very high E resolution counts
rate Very low background
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The Mainz experiment
Guiding magnets
High field electrodes
Electrons are magnetically guided around
magnetic field lines into the spectrometer.
Accepted solid angle 2 p. In spectrometer
broad beam of electrons almost parallel to
magnetic field lines and running against an
electrostatic potential. Integrating high-energy
pass filter Only the electrons which pass the
electrostatic barrier are reaccelerated and
collimated onto the detector. Scanning the
electrostatic retarding potential ? Ee spectrum
54
status of present tritium experiments
Troitsk
Mainz gaseous T2-source
quench-condensed solid
T2-source
electrostatic retarding spectrometers with
magnetic adiabatic collimation
analysis 1994-99, 2001
analysis 1998/99, 2001
both experiments have reached their intrinsic
limit of sensitivity
55
Effective ? mass from neutrino-less bb decay
56
Signature of 0???-decay
Calculation of nuclear matrix elements
Smeared by energy resolution
57
Moscow-Heidelberg experiment Example of active
source experiment
5 Ge crystals diodes total 11 kg - 86 enriched
76Ge in Gran Sasso Laboratory
?(E) ? E 0.7 10-3
Present status upper limits
58
Constraints from cosmology
From Pastor (Venice 2003)
Not directly detectable !
CMB n? ? 410 cm-3
CM?B n? ?
Neutrinos influence several cosmological scenarios
BUT
Fascinating subject but no time to go into
details
59
Standard Cosmology
At Tltltme, the radiation content of the Universe
is Effective number of relativistic neutrino
species
60
Neff fixes the expansion rate during BBN
?(Neff)gt?0 ? ? 4He
WMAP ?B h2 0.0230.001
hH/100km/sec/Mpc ? 0.7
61
CMB DATA INCREASING PRECISION
WMAP
Map of CMBR temperature Fluctuations
Multipole Expansion
Angular Power Spectrum
62
Effect of Neff on CMB

• Neff modifies the radiation content
• Changes the epoch of matter-radiation equivalence

Relic ? do exist !
WMAP 2dF
(95 c.l.)
63
Constraints on m?
? as Dark Matter
BUT ? stream freely until non-relativistic ( HOT
Dark Matter) ?First structures formed when
Universe became matter-dominated
Effect of Massive Neutrinos suppression of
Power at small scales
? MORE CONSTRAINTS ON mn
64
2dF Galactic Redshift Survey ( 250000 galaxies)
Power spectrum of density fluctuations
?m0.3 ??0.7 h0.7
??0.05
??0.01
??0
2dFGRS Elgarøy et al 2002
65
mn 0 eV
mn 1 eV
Simulation from
Ma 96
mn 7 eV
mn 4 eV
66
COMBINED ANALYSIS OF CMB, 2DF AND LY-ALPHA DATA
BY THE WMAP TEAM (astro-ph/0302209 )
95 c.l. but model dependant, systematics,
More conservative
Hannestad astro-ph/0303076 (also Elgarøy Lahav,
astro-ph/0303089)
Near future PLANCK (CMB)
SDSS (106 galaxies) ? 0.1 eV
sensitivity
A challenge for future direct mass measurements.
67
Solar Neutrino Experiments
Solar neutrinos spectrum Detectors / experiments
thresholds
Super-K, SNO Cerenkov
Homestake
GALLEX,GNO,SAGE
68
Low threshold radio-chemical counting experiments
The glorious Homestake expt (1968-99) 31 years of
datataking, 2000 int.ions
Gallium experiments GALLEX, GNO (under Gran
Sasso) , SAGE (Baksan mine) 1992-97
1998- 1991-
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Real-time water Cerenkov experiments Kamiokande
II Super-K 1987-95
1996-
71
Real-time heavy-water Cerenkov experiment
Sudbury Neutrino Observatory (SNO) (2001-2003)
72
Phase 2 add salt ? higher ?neutron (results
soon)
73
Measured event rates v.z.SSM predictions (Bahcall
et al.)

• No astrophysical or
• instrumental explanation
• ?e disappearance

74
SNO 2002 evidence for FLAVOR CHANGE
75
Other main Super-K pre-SNO 2002 observations
No zenith angle variation Due to Earth matter
effect
Best oscillation fit (pre-SNO)
No seasonal variation length in vacuum
No nB spectral distortion E dependence of
oscillation prob
76
Best oscillation fit (all data combined)
Large mixing MSW solution
Dm2 6.8 10-5 eV2
tan2q 0.40
77
Profile of the effect
Adiabatic solution

npp
nBe
nB
Survival probability
Earth matter effect
sin2q
I
II
III
ln / l0 E
Non-oscillatory transition
Conversion with small oscillation effect
Conversion oscillations
Oscillations with small matter effect
A Yu Smirnov
78
Reactor Neutrino Experiments
No effect seen
79
KamLAND several reactors at more than 100 km
? Sensitive to the LMA Solar parameters
80
R versus mean reactor distance
Nobs NBG Nno-OSC
0.611 0.085 (stat) 0.041 (syst)
81
solar data KamLAND
Dm2 7.3 10-5 eV2
tan2q 0.41
Nice confirmation - with - independent
of solar matter effects
82
Atmospheric Neutrino Experiments
The magic free of charge atmospheric neutrinos
beam line

• 20 lt L lt 13 000 km
• Within small computable corrections due
• to geomagnetic effects Up/Down flux symmetry
  at neutrino emission
• F(q) F(p-q) q zenith angle
• But beam composition and spectra relies on
  models

83

• Lack of events with muons confirmed by several
  experiments By far most complete and precise
  results provided by Super-Kamiokande

SK can distinguish e-like events fuzzy Cerenkov
ring ?-like events
sharp measure
E(e or ?) measure ? (e or ?) ?
zenith angle of the neutrino
84
The Super-K events topology based Cerenkov ring
No obvious difference but Particle Id 100
Sharp m-like ring
Fuzzy e-like ring
85
Zenith angle distributions
Purity ltEgt
Best ????? fit No oscillation
86
Fit assuming
90 c.l.
87
Possible sterile content
Limits on ?13
88
Accelerator Neutrino Experiments
1)
K2K the KEK to Kamioka Long Base Line experiment
No Oscillation
Best oscill. fit
89
Data taking going on
90
Neutrino oscillation at accelerator beam dumps
2)
91
LSND experiment _at_ LANSCE, Los Alamos
Situation still unclear
167 tons liquid scintillator ltLgt 29 m Data
till 1999
Karmen-II experiment _at_ ISIS, Rutherford Lab
56 tons liquid scintillator ltLgt 15 m Data
till 2001
Wait 2005 results from MiniBoone (FNAL)
WMAP limit
IF signal confirmed need a sterile ?
92
3)
Search for ?? appearance at high E accelerator

93
Out of 106 events
94
Oscillation summary
Solar ?
Atm. ?
Reactor ?
LSND ???
95
VI Discussion and outlook
96
Matter effects
97
All wrong!
Rather a surprise !
?3
?2
?1
98
The next steps
a) Increase precision on solar parameters

• SNO salt phase
• Neutron Capture Detectors
• (He3 counters)
• ? NC/CC ratio ? ?sol
• KamLand more statistics
• improve ?m2
• geothermic ?

NEW!
Nucl-ex/0309004 SNO Coll. Hep-ph/0309130
Maltoni et al. At 3 ? 0.22 ? sin2 ?sol ? 0.39
5.4 ? ?m2 ? 9.5 10-5 eV2
99
b) Check the E dependance of solar survival
prob.ty

• KamLand Borexino decrease threshold to detect
  solar Be7 ?
• (Background from radioactivity)
• pp neutrinos real-time detection
• some ideas but difficult
• SNO, SK threshold down to 4 MeV

100
c) See the oscillation dip
In 2005 L750 km FNAL to Soudan mine ltEgt a
few GeV
101
d) Observe the ?? appearance
CNGS beam in 2006 L750 km (CERN to Gran
Sasso) ltEgt
20 GeV
ICARUS
Liquid Argon TPC very good e-shower identificati
on kinematics ? Separate ?e CC and ?? CC (with
??e)
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OPERA
104
A hybrid experiment
105
How to select the ? interaction brick ?
Sampling by Target Tracker planes ( X,Y )
Selected brick
Brick wall
10 cm

• Emulsion-Scintillator strip Hybrid Target
• Tracker task
• select bricks efficiently
• High scanning power low background allow
  coarse tracking

Selected bricks extracted daily using dedicated
robot
106
Determination of ?m2
(mixing constrained by SuperKamiokande)
Exemple if observed events expected for
SK best fit
assuming the observation of a number of events
corresponding to the expected number for the
given ?m2
107
e) Improve the limit on sin2 2?13 (now 0.1)
Crucial for the design of future big experiments
!

• 2 ways to reach 0.01
• Chooz-like reactor expt with 2 detectors
• (to lower systematics on ? flux)

Several sites being discussed
108

• Long Baseline (MINOS, ICARUS, OPERA)
• ?e appearance

109
miniBOONE
f) Check the LSND signal
Results in 2005
Sensitivity 2 years
Results 2005
110
Some remaining big questions

• Mass hierarchy normal or inverted ?
• CP violation ?CP ? 0 ?
• Baryogenesis from Leptogenesis ?
• Absolute mass scale ?
• Dirac or Majorana ?
• Origin of masses and mixings ?

111
Mass hierarchy normal or inverted ?
Earth matter effects
Long Baseline
through earth matter Effect strongly
depends on sin2 2?13
112
CP violation ?CP ? 0 ?
Long Baseline
through earth matter Strongly depends on sin2
2?13 and correlated with matter effects
113

• To disentangle the two questions, one needs
• very pure beams
• very intense beams
• several experiments at different and large L/E
• very big detectors
• A lot of money..

PROJECTS - NUMI off-axis (waiting
proposals) - Superbeams JAERI to
SuperK (phase 1 approved)
designs at Cern and in US
- Neutrino Factory, (RD phase)
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Next generation LBL experiments in
JapanJ-PARC-Kamioka neutrino project
nm beam of 1GeV
Kamioka
Super-K 50 kton Water Cherenkov
JAERI (Tokai-mura)
0.75 MW 50 GeV PS
Mt Hyper Kamiokande
4MW 50GeV PS
1st Phase (x102 of K2K)
2nd Phase

• nm? nx disappearance
• nm? ne appearance
• NC measurement

• CPV
• proton decay

Hayato
116
Sensitivities in first phase(5yrs)
Hayato
Search for ne appearance
nm disappearance
d(sin22q23)
0.01
excluded by reactor
OAB-2degree
x20
d(Dm232 )
110-4
True Dm232 (eV2)
0.5
d(sin22q)0.01 in 5 years d(Dm2) lt110-4 in 5
years
Sensitive sin22q13gt0.006 (90) sin22q13gt0.018
(3s)
117
Superbeam 4 MW Linac
118
Neutrino factory Muon storage ring
119
0.75 MW, calo 10 kt
4 MW, calo 50 kt (L3000 km, E50 GeV)
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Absolute mass scale ?
?
Sensitivity
123
All masses linked to lightest by oscillations
H. Robertson
124
Neutrinoless Double-beta Decay
Dirac or Majorana ?

• Matrix element ? ltmnegtSimniUei2 about 1eV
  now
• m3Ue32ltltm3 and we can typically ignore m3
• ltmnegtm1cos2q12eif m2sin2q12
• possible cancellation due to unknown Majorana
  phase
• Fortunately, they cannot cancel exactly because
  cos2q12sin2q12cos22q12gt0.07 (1s)

Signal depends on mass spectrum

• Degenerate All 3 gt 0.1 eV with small
  splittings
• ltmnegt gt m cos22q12gt0.07m
• Inverted m30, m1m2(Dm223)1/2 0.05 eV
• ltmnegt gt (Dm223)1/2 cos22q12gt0.0035eV
• Normal m1m20, m3(Dm223)1/2 0.05 eV
• ltmnegt may be zero even if Majorana

125
NEMO3

• Recently commissioned detector
• Frejus Underground Lab 4800 mwe
• 6.9 kg enriched 100Mo
• Full tracking Calorimetry
• Backgrounds look promising working on Radon
  Improvements

For 7 kg of 100Mo(Qbb 3.038 MeV)
after 5 years data taking
126
CUORE CUORICINO

• Prototype (Cuoricino) Commissioned
• Reach in ltmngt to 0.32 ev
• Cryogenic Calorimetry in TeO2 crystals
• Scalable Design CUORE 1000 crystals
• No Enrichment!

First results
127
Many other experiments in preparation
Majorana/Genius Robust and well known
technique Requires 500kg (10ton?)of Enriched
Ge Reach in ltmvgt 0.03 - 0.05 ev

• Germanium
• Cobra
• MOON
• EXO
• XMASS
• Candles
• GSO

Cd(Zn)Te semiconductor Reach in ltmngt 0.71 ev
34 ton Mo sheets
1(10) ton enriched Xe in TPC
10 ton liquid Xe
Background is a real challenge!
128
Conclusions

• Enormous progress in recent years
• Solar neutrino problem solved!
• Still some loose ends
• Many forthcoming experiments
• Three-generation oscillation is most probable
• but LSND not yet ruled out
• Cosmological constraints beginning to be
  interesting
• Next q13 key to mass hierarchy, CP violation
• Long-baseline or reactor
• New super beams

THEORY on origin of masses and mixings ?
129
Very partial list of references
//www-e815.fnal.gov
NuTeV //eps2003.physik.rwth-aachen.de/index.php
Transparencies from K. Lesko Neutrino
experiments
H. Murayama Theoretical Neutrino Physics
G. Drexlin
KATRIN //axpd24.pd.infn.it/conference2003/venice03
.html Transparencies from S. Pastor
Neutrinos and Cosmology
A. Yu. Smirnov MSW effect and solar
neutrinos Hep-ex/0306010 J.L. Vuilleumier
Direct mass measurements 0306073
B. Kayser Physics with
Superbeams, Nu Factory 0306072 B.
Kayser Neutrino Physics
where are we going? 0305152 J.
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