Neutrinos Ghost Particles of the Universe Georg G Raffelt MaxPlanckInstitut f ür Physik München Germany Neutron Proton Gravitation Gravitons Weak Interaction W and Z Bosons ID: 597866
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Slide1
Neutrinos – Ghost Particles of the Universe
Neutrinos
Ghost
Particles of the Universe
Georg G. Raffelt
Max-Planck-Institut f
ür Physik, München, GermanySlide2
Neutron
Proton
Gravitation (Gravitons?)
Weak
Interaction (W and Z Bosons)
Periodic System of Elementary Particles
Electromagnetic
Interaction (Photon)
Strong
Interaction (8 Gluons)
Down
Strange
Bottom
Electron
Muon
Tau
e-Neutrino
m
-Neutrino
t
-Neutrino
n
t
n
m
n
e
e
m
t
d
s
b
1
st
Family
2
nd
Family
3
rd
Family
Up
Charm
Top
u
c
t
Quarks
Leptons
Charge
-
1/3
Down
Charge
-
1
Electron
Charge
0
e-Neutrino
n
e
e
d
Charge
+
2/3
Up
uSlide3
Where do Neutrinos Appear in Nature?
Nuclear Reactors
Particle Accelerators
Earth Atmosphere
(Cosmic Rays)
Earth Crust
(Natural Radioactivity
)
Astrophysical
Accelerators
Soon
?
Sun
Supernovae
(Stellar Collapse
)
SN 1987A
Cosmic Big Bang
(Today 330
n
/cm
3
)
Indirect
EvidenceSlide4
Pauli’s Explanation of the Beta Decay Spectrum (1930)
Niels Bohr
:
Energy
not
conserved
in
the quantum
domain?
“Neutron”
(1930)
Wolfgang Pauli
(
1900–1958
)
Nobel Prize 1945
“Neutron”
(1930)
“Neutrino”
(E
. Fermi
)Slide5
Neutrinos from the Sun
Reaction-
chains
Energy
26.7 MeV
Helium
Solar radiation: 98 % light
2
% neutrinos
At Earth 66 billion neutrinos/cm
2
sec
Hans Bethe (1906
-
2005, Nobel prize 1967)
Thermonuclear reaction chains (1938)Slide6
Sun Glasses for Neutrinos?
8.3 light minutes
Several light years of lead
needed to shield solar
neutrinos
Bethe & Peierls 1934:
…
this evidently means
that one will never be able
to observe a neutrino
.Slide7
First Detection (
1954 – 1956)
Fred Reines
(1918 – 1998)Nobel prize 1995
Clyde Cowan
(1919 – 1974)
Detector prototype
Anti-Electron
Neutrinos
from
Hanford
Nuclear Reactor
3 Gammas
in coincidence
p
n
Cd
g
g
gSlide8
First Measurement of Solar Neutrinos
600 tons of
Perchloroethylene
Homestake solar neutrino
observatory (
1967–2002
)
Inverse beta decay
of chlorineSlide9
Cherenkov Effect
Water
Elastic scattering or CC reaction
Neutrino
Light
Light
Cherenkov Ring
Electron or Muon
(Charged Particle)Slide10
Super-Kamiokande Neutrino Detector (Since 1996)
42 m
39.3 mSlide11
Super-Kamiokande: Sun in the Light of NeutrinosSlide12
Neutrino Flavor Oscillations
Bruno Pontecorvo
(
1913–1993)Invented nu oscillations
Two-flavor mixing
Each mass eigenstate
propagates
as
w
ith
Phase difference
implies flavor oscillations
Oscillation
Length
Probability
z
Slide13
Japanese
Nuclear Reactors
80 GW (20% world capacity) Average distance 180 km Flux 6
10
5
cm-2 s-1
Without oscillations 2 captures per day
KamLAND Long-Baseline
Reactor-Neutrino ExperimentSlide14
Oscillation of Reactor Neutrinos at KamLAND (Japan)
Oscillation pattern for anti-electron neutrinos from
Japanese power reactors as a function of
L/EKamLAND Scintillatordetector (1000 t)Slide15
Atmospheric Neutrino Anomaly
Zenith-angle distribution of atmospheric
neutrinos
in Super-Kamiokande [hep-ex/0210019]
Half of the muon neutrinos
from below are missingSlide16
Long-Baseline Experiment K2K
K2K Experiment
(KEK to
Kamiokande)has confirmedneutrinooscillations,to be followedby T2K (2010)Slide17
Current Long-Baseline Experiments
FermiLab–Soudan (MINOS)
CERN – Gran SassoSlide18
v
v
Three-Flavor Neutrino Parameters
Three mixing angles
,
,
(Euler angles for 3D rotation),
,
a CP-violating “Dirac phase”
, and two “Majorana phases”
and
Relevant for
0
n
2
b
decay
Atmospheric/LBL-Beams
Reactor
Solar/KamLAND
m
e
t
m
e
t
m
t
1
Sun
Normal
2
3
Atmosphere
m
e
t
m
e
t
m
t
1
Sun
Inverted
2
3
Atmosphere
72–80 meV
2
2180–2640
meV
2
Tasks and Open
Questions
Precision for
q
12
and
q
23
How large is
q
13
?
CP-violating phase
d
?
Mass ordering
?
(normal vs inverted)
Absolute masses
?
(hierarchical vs degenerate)
Dirac or Majorana
?Slide19
Antineutrino Oscillations Different from Neutrinos?
Dirac phase causes different 3-flavor oscillations
for neutrinos and antineutrinos
Distance [1000 km] for E = 1 GeV same as
Slide20
Neutrino Carabiner
Named for a subatomic
particle
with almost zero mass, …
n
Greek “nu”
Now also in colorSlide21
“Weighing” Neutrinos with KATRIN
Sensitive to
common mass scale
m for all flavors because of small mass differences from oscillations Best limit from Mainz und Troitsk m < 2.2 eV (95% CL) KATRIN can reach 0.2 eV Under construction Data taking foreseen to begin in 2012
http://www-ik.fzk.de/katrin/Slide22
“KATRIN Coming” (25 Nov 2006)Slide23
Pie Chart of Dark Universe
Dark
Energy 73%
(Cosmological Constant) Neutrinos 0.1
-
2%
Dark Matter
23%
Ordinary Matter 4%
(of this only about 10% luminous)Slide24
Cosmological Limit on Neutrino Masses
JETP
Lett. 4 (1966) 120
Cosmic neutrino “sea”
112 cm
-
3
neutrinos + anti-neutrinos per flavor
For all
stable flavors
Slide25
Weakly Interacting Particles as Dark Matter
Almost
40 years ago,
beginnings of the idea of weakly interacting particles (neutrinos) as dark matter
Massive
neutrinos are no
longer
a good candidate (hot dark matter)However, the idea of weakly
interacting massive particles (WIMPs) as dark matter is now standardSlide26
What is wrong with neutrino dark matter?
Galactic Phase Space (“Tremaine-Gunn-Limit”)
Maximum mass density of a degenerate
Fermi gas
Spiral galaxies
m
n
>
20–40 eV
Dwarf galaxies
mn >
100–200 eV
Neutrino Free Streaming (Collisionless Phase Mixing)
Neutrinos
Neutrinos
Over-density
At
T
<
1
MeV
neutrino scattering in early
universe is ineffective Stream freely until non-relativistic Wash out density contrasts on small scales
Neutrinos
are “Hot Dark Matter”
Ruled out by structure formationSlide27
Structure Formation with Hot
Dark Matter
Neutrinos with
Smn = 6.9 eVStandard LCDM ModelStructure fromation simulated with Gadget code
Cube size 256 Mpc at zero redshift
Troels Haugbølle, http://
users-phys.au.dk/haugboelSlide28
Power Spectrum of Cosmic Density Fluctuations
Tegmark, TAUP 2003Slide29
Power Spectrum of CMB Temperature Fluctuations
Acoustic Peaks
Sky
map of CMBR temperature
fluctuations
Multipole
expansion
Angular
power spectrum
Slide30
Latest Angular Power Spectrum (WMAP 7 years)
Komatsu et al. (WMAP Collaboration), arXiv:1001.4538
Ratio
1
st
/3
rd
peak
fixes zeqSlide31
Radiation Content at CMB Decoupling
Existence of cosmic neutrino sea clearly confirmed by precision cosmology
All analyses find mild indication for excess radiation Planck data will fix Neff to ±0.26 (68% CL) or better Komatsu et al. (WMAP Collaboration), arXiv:1001.4538
WMAP alone
+ Large-scale structure
(LSS) and H
0Slide32
Weak Lensing -
A Powerful Probe for the Future
Unlensed
Lensed
Distortion of background images by foreground matterSlide33
Mass-Energy-Inventory of the Universe
10
-
3
10
-
2
10
-
1
1
W
Assuming
h
= 0.72
Luminous
Total
Baryons
L
Dark Matter
1
10 eV
Tritium (
Mainz/Troitsk
)
Neutrinos
Super-K
Future Tritium (KATRIN)
Weak lensing tomography
CMB & LSS
10
-
2
10
-
1Slide34
Are Neutrinos their own Antiparticles?
Matter
Quarks
-
1/3
+
2
/3
d
u
s
c
t
b
e
Leptons
-
1
0
1
st
Family
2
nd
Family
3
rd
Family
Charge
Weak
Interaction
Strong
Int’n
Electromagnetic
Int’n
Gravitation
Anti-Leptons
Anti-Quarks
0
+
1
-
2
/3
+
1/3
Anti-Matter
Strong
Int’n
Electromagnetic
Int’n
Much less anti-matter in the
universe: Baryon asymmetry
of the Universe (BAU)
0
0
„Majorana Neutrinos”
are their own antiparticles
Slide35
Solar Neutrinos vs. Reactor Antineutrinos
Fissionable
nucleus
Neutron
Nucleus
splitting
Fission products
w/ neutron excess
unstable nuclei effectively decay by
Detection by inverse
decay
Reines and Cowan 1954–1956
Energy
26.7 MeV
Ray Davis radiochemical detector (1967–1992)
Amounts to neutino capture by neutron
Does not work for reactor
flux!
Slide36
Role of Neutrino Helicity (Handedness)
Basic production process
in reactors
Basic production process
in the Sun
Cowan & Reines
detector
in fast-moving rocket,
overtakes small-mass solar
Majorana
neutrinos:
Helicity flip
anti-neutrino
property
depends
on
Lorentz frame
Anti-neutrinos always
right-handed helicity
Neutrinos always
l
eft-handed helicitySlide37
Neutrinoless
bb Decay
Some nuclei decay only by
the bb mode, e.g. Ge-7676Ge
76
Se
76
As
0+2
-2+
0
+Half life
1021 yr
Standard 2
n
mode
0
n mode, enabledby Majorana mass
Measured
quantity
Best limit
from
76
Ge
Slide38
GERDA Germanium Double Beta Experiment
Bare enriched Ge-76 array in liquid Ar,
located in Gran Sasso
Phase I (being commissioned)18 kg (HdM/IGEX) + 15 kg natural Ge
Test claim of Klapdor-Kleingrothaus
Phase II, O(100 kg years)
Add
20 kg enriched new detectors
Degenerate masses:
75–130 meV
Phase
III, O(1000
kg years)
with Majorana collaboration?1-ton scale
Inverted hierarchy:
24–41
meV
Several other large projects worldwide
Slide39
See-Saw Model for Neutrino Masses
eV
Planck
mass
GUT
scale
Electroweak
scale
QCD
scale
Cosmological
constant
Mass matrix for one family of ordinary and heavy r.h. neutrinos
Diagonalization
One light and one heavy Majorana neutrinoSlide40
Leptogenesis by Majorana Neutrino Decays
Heavy sterile
neutrino N
Lepton
Higgs
N
N
+
CP-violating
decays
of
heavy sterile neutrinos by
interference
of tree-level
with
one-loop diagramSlide41
Baryogenesis by Leptogenesis?
Dark
Energy 73%
(Cosmological Constant) Neutrinos 0.1
-
2%
Dark Matter
23%
Ordinary Matter 4%
(of this only about 10% luminous)Slide42
Applied Neutrino PhysicsSlide43
Reactor MonitoringSlide44
Neutrino Monitoring of Nuclear Reactors
San Onofre
Nuclear Reactor
(California)Neutrino measurements withSONGS1 detector (1m3 Scintillator)
3.4
GW
thermal power Produces
3800
neutrino reactions/day
in 1 m3 liquid scintillator
Relatively small detectors can measure nuclear
activity without intrusion Of interest for monitoring by International Atomic Energy Agency (IAEA)Slide45
Geo Neutrinos: What is it all about?
We know surprisingly little about
the Earth’s interior
Deepest drill hole 12 km Samples of crust for chemical analysis available (e.g. vulcanoes) Reconstructed density profile from seismic measurements Heat flux from measured temperature gradient 30-44 TW (Expectation from canonical BSE model 19 TW from crust and mantle, nothing from core
)
Neutrinos escape unscathed
Carry information about chemical composition, radioactive energy
production or even a hypothetical reactor in the Earth’s coreSlide46
Geo Neutrinos
Expected Geoneutrino Flux
Reactor Background
KamLAND Scintillator-Detector (1000 t)Slide47
Latest KamLAND Measurements of Geo Neutrinos
K. Inoue at Neutrino 2010Slide48
AAP 2011 Vienna
http://
aap2011.in2p3.fr/Slide49
Sanduleak -69 202
Sanduleak
-
69 202Large Magellanic Cloud
Distance 50 kpc
(160.000 light years)
Tarantula Nebula
Supernova 1987A
23 February 1987Slide50
Neutrino Signal of Supernova 1987A
Kamiokande
-II (Japan)
Water Cherenkov detector2140 tonsClock uncertainty 1 minIrvine-Michigan-Brookhaven (US)Water Cherenkov detector6800 tonsClock uncertainty 50 ms
Baksan Scintillator Telescope
(Soviet Union), 200 tons
Random event cluster
0.7/day
Clock uncertainty +2/-54 s
Within clock uncertainties,
all signals are contemporaneousSlide51
2002 Physics Nobel Prize for Neutrino Astronomy
Ray Davis Jr.
(
1914–2006)Masatoshi Koshiba(*1926)“for pioneering contributions to astrophysics, inparticular for the detection of cosmic neutrinos”Slide52
Crab Nebula
Physics Opportunities with
Supernova Neutrinos
Georg Raffelt, Max-Planck-Institut für Physik,
München
2
nd
Schr
ödinger Lecture
Tuesday, 10 May 2011, 16
ctSlide53
Cosmic Rays
Air Shower:
10
19 eV primary
particle
100 billion secondary
particles
at sea level
Victor Hess (
1911/12)
100 years later we are still asking
What are the sources
for
the primary
cosmic
rays?
Slide54
Neutrino Beams: Heaven and Earth
Target:
Protons or Photons
Approx. equal fluxes of
photons & neutrinos
Equal neutrino fluxes
in all flavors due to
oscillations
F. Halzen (2002)
pSlide55
Nucleus of the Active Galaxy NGC 4261 Slide56
Scott Amundsen Base at the South PoleSlide57
IceCube Neutrino Telescope at the South Pole
Instrumentation of 1 km
3
antarcticice with 5000 photo multiplierscompleted December 2010
Deep Core installed 2010
Search for dark matterSlide58
IceCube Neutrino Sky
IceCube Collaboration,
arXiv:1012.2137 and Gaisser at Neutel 2011
Full-sky map, based on 40 stringsSlide59
ANTARES -
Neutrino Telescope in the MediterraneanSlide60
Luminescent Ceatures of the Deep Sea
40
K
2 minP.Coyle, Neutel 2011Slide61
Three Mediterranean Pilot Projects
Nemo
Antares
2500 m
3500 m
4500 mSlide62
Towards a km3 Detector in the Mediterranean
http://www.km3net.orgSlide63
Frontiers of Neutrino Physics
Matter-Antimatter-Issues
Majorana masses (neutrinoless double beta decay)
Oscillation difference between and (Dirac phase)Baryon asymmetry of the universe (leptogenesis)Absolute MassExperimental determinationRole in cosmology for structure formationExploring the Universe with NeutrinosSources of high-energy cosmic raysNext galactic supernova
Diffuse SN neutrino background in the universe
Sun
Earth
Reactor monitoring
Slide64
Neutrinos at the center
n
Astrophysics &
Cosmology
Cosmic Rays
Elementary
Particle
Physics