pp - 1 pp -2 pp -3

H. Bethe

W. Fowler

Solar Fusion Prozesses

HomestakeKamiokande, SK

SNO

Gallex, Sage

Solare Spektrum und Experimente

Das Pionierexperiment: Homestake

Ray Davis, 1966

Neutrino Detektion

37Cl + e 37Ar + e

threshold energy 814 keV

target 615 t Perchlorethylen

exposition to solar neutrinos ~ 60 days

extraction of Ar - atoms

Detection of Ar decay

(T1/2 = 35 days)

Noble price 2002

The Homestake Experiment

Dakota (USA)

Empfindlich auf 7-Be und hauptsächlich auf 8-B Neutrinos

Resultat:

2.56 +_ 0.23 SNU

Sonnenmodell:

7.6 + 1.3 - 1.1 SNU

Beginn des „Solaren Neutrino Problems“ !

Ergebnis Homestake Chlor ExperimentErgebnis Homestake Chlor Experiment

SuperKamiokande

dimensions:

41.4 m (hight)

39.3 m (diameter)

water Cherenkov Detector (~ 50 kton high purity water)

solar- detection by neutrino – electron scattering

Energy threshold ~ 5 MeV (sensitiv to 8B - )

Auch SuperK detects only 45 % of expected events (this is only a bit more than

Homestake (Davis))

Ratenvariation übers Jahr Energie Spektrum

Keine Abweichung von der erwarteten Form des ß-Spektrums

Gallex & GNO

71Ga + e71Ge + e

Integral detection of solar all solar neutrinos !

~5 decays per extraction

Situation nach GALLEX Situation nach GALLEX (~ 20 Jahre nach Homestake)(~ 20 Jahre nach Homestake)

Theoretische Vorhersagen

Hinweis auf nicht standard Eigenschaften der Neutrinos

This was the first evidence for non standard neutrino properties(neutrino decay, oscillation..? )

Hypothesis: Neutrino Oscillation ((B. Pontecorvo)Condition

1) Eigenvalues of weak interaction #mass eigenvalues

2) Neutrinos are massive

ν(e) = ν(1)cos (θ) + ν(2) sin(θ) ν(μ) = ν(1)-sin (θ) + ν(2) cos(θ)

Time development

|νe(t) > = |ν1(0) > exp (-iE1 t ) + |ν2 (0) > exp (–i E2 t)with Ei ² = m1² + p1² und Δ² = m²2 – m²1

P ν(e) = 1- sin² 2θ sin² (1,27Δ²/E²(ν))

SNO: Sudbury Neutrino Observatory

geladene Stromwechselwirkung (cc)

e + D p + p + e

neutrale Stromwechselwirkung (nc)

x + D x + p + n

Elektronstreuung (cc + nc)

x + e x + e nc-events ~ 30 / d

es-events ~ 3 / d

cc-events ~ 30 / d (SSM)

Energie- spektrum

Räumliche Verteilung im Detektor

Richtungsverteilung

Insgesamt kommen genau so viele Neutrinos an wie vorausgesagt!

Sonnen-Sonnen- ändern ändern ihren ihren Flavour!Flavour! (sie verwandeln sich auf dem Weg zur Erde vom e-Typ in den oder -Typ)

Neutrino Flavour Transition prooved

nepe

Detektion von ReaktorneutrinosDetektion von Reaktorneutrinos

Ev > 1.8 MeVEv > 1.8 MeV

promptes event: Ev – 0.77 MeVSpektroskopie)

verzögertes event:MeV)2.2( dpn

180μsec180μsec

Phys. Rev. Lett. 90 (2003) 021802

1.5 x 1011

Gallium

Experiment at ILL

Gösgen

Bugey

Search for neutrino oszillations, solar neutrino astronomy at low energies

Solar neutrinos

Borexino

? ?

Oscillation of Neutrinos from the Atmosphere

Superkamiokande

2

1

cossin

sincos

e

21

22

221 mmm

E

Lm

P ee

2sin)2(sin1

)(22122

Survival probability:

0 1 2 3L in Losz

Neutrino Oscillations

L ≈ 20 km

L ≈ 13000 km

atmosphericneutrinos:Ev ~ GeV

E

LmP atm

atmx

222 27.1

sin2sin)(

Oscillations and Atmospheric NeutrinosPion production and

subsequent decays (incl. muon)

Atmospheric Neutrinos and SuperKamiokande

Charged current reactions

+ N + N` and

e + N e + N`

50 kt Water Cherenkov Detector

SuperKamiokande SuperKamiokande (Japan)(Japan)

ein Detektor mit ca. 50 kton ein Detektor mit ca. 50 kton ReinstwasserReinstwasser

atmosphärische und solare atmosphärische und solare Neutrinos Neutrinos

atm.: CC Wechselwirkungatm.: CC Wechselwirkung

Particle ID and the number of Cherenkov rings

e + N e + N’ + (X)

e + N e + N’ + (X)

Category 1: fully contained events, 1 ring

Here: Electron like event

+ N + N’ + (X)

Category 1: fully contained events, 1 ring

Here: Muon like event

+ N + N’ + + (X)

Fully contained events, multiple rings

Here: Muon event

Multi-ring event

Muon 480 MeV

Electron 0.7 GeV

Muon 1 GeV

Through going muon

zenith angle distributions null oscillation best fit with oscillation data

νμ

νe

Electron events Muon events

Up going Up going Neutrinos

e

No-oscillation

Oscillation

Result atmospheric Neutrino-Oscillations

Best fit:m2

atm = 2.5×10-3

eV2

sin22θatm = 1.0

Best fit:m2

atm = 2.5×10-3

eV2

sin22θatm = 1.0

Confirmed by

•MACRO (Gran Sasso)

•Soudan (USA)

•K2K accelerator long baseline (250 km) experiment

•MINOS (USA) acc. exp. in 2006

What do we know today about neutrino oscillation

• e solar neutrinos

non maximal mixing und

m2 ~ 10-4 eV2

• atmospheric neutrinos

• large mixing ( close to maximal)

m2~ 2.5 x 10-3 eV2

e

Parametrization of Neutrinomixing

Neutrino-mixing matrix: • 3 mixing angles: θ12, θ23, θ13

• 1 CP-violating Dirac-Phase: δ

Neutrino-mixing matrix: • 3 mixing angles: θ12, θ23, θ13

• 1 CP-violating Dirac-Phase: δ

In addition, if Majorana neutrinos:• 2 CP-violating Majorana-phasesIn addition, if Majorana neutrinos:• 2 CP-violating Majorana-phases

3

2

1

1212

1212

1313

1313

2323

2323

100

0

0

0

010

0

0

0

001

cs

sc

ces

esc

cs

sci

ie

θsolθ13, δθatm