Neutrino PhysicsNeutrino Physics

L. Oberauer, TU München

Graduiertenkolleg

Bad Honnef, August 2006

ContentContent

Neutrino sourcesNeutrino sources

Intrinsic propertiesIntrinsic properties

oscillationsoscillations

masses and mixing parametermasses and mixing parameter

Neutrinos as probesNeutrinos as probes

from the Earthfrom the Earth

from astrophysical sourcesfrom astrophysical sources

Charge 0 -1 +

2/3 -1/3

Why are neutrinos intresting ?

Neutrinos undergo only weak interactions

•Neutrinos are neutral – intrinsic properties

•Neutrinos as probes – astrophysical applications

Interactions w w

,e w,e,s

Natural Neutrino Sources

(experimentally verified)

Sun

(since 1970)

Earth (since 2005)

Supernovae (1987)

Atmosphere (since ~1990)

Natural Neutrino Sources

(not yet verified)

Big Bang

Active galactic nuclei

Supernovae remnants ?,

Gamma ray bursts ?,

Supernovae relic neutrinos ?...

Energy Spectra of Astrophysical neutrinos

thermal sources

Non-thermal sources

Neutrinos (homemade)

Nuclear Reactors

(beta decays of fission products: e)

Accelerators

pion production and subsequent decay in flight:

Intrinsic Neutrino Properties

• Neutrino masses ?

• Neutrino mixing ?

• Dirac or Majorana particle ?

• CP violation ?

• Neutrino magnetic moment ?

Neutrino oscillations observed,

Missing mixing angle 13

Absolute masses and hierarchy ?

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 Neutrinos

Pion 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

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

Oscillations and Solar Neutrinos

Neutrino Energy in MeV

MeV7.2622He4 4 eep

The Solar Neutrino Problem

Solar Model

0,5

Sudbury Neutrino Observatory Sudbury Neutrino Observatory SNOSNO

charged current interaction (cc)

e + D p + p + e neutral current interaction (nc)

x + D x + p + n

elastic Neutrino-Electron scattering (cc

+ nc)

x + e x + e

1kt Cherenkov Detector with heavy water

SNO ResultSNO Result

Flavour transition Flavour transition discovered: 7 sigma !discovered: 7 sigma !Reasonable Reasonable agreement with solar agreement with solar modelmodel

Neutrinos from the Sun (e) transform into or

Solar Neutrino OscillationSolar Neutrino Oscillation

Determination of Determination of

1212 ~ 34 ~ 3400

e e

mm22 ~ 8 x 10 ~ 8 x 10-5-5 eV eV22

Confirmation by reactor Confirmation by reactor experiment experiment KamLANDKamLAND

The solar matter effect – evidence by The solar matter effect – evidence by GALLEX/GNOGALLEX/GNO

GALLEX/GNO

SNO

• Evidence for matter effect inside the Sun

• m2 > m1

• Why are neutrino masses so small?

• GUT

• Leptogenesis

Survival probability electron neutrino

pp- 7Be

8B

Phys. Rev. Lett. 90 (2003) 021802

Evidence for Oscillation

ILL 1979ILL 1979

Gösgen (1986)Chooz (1998)

nepe Reactor Experiments

Bugey (1994)

KamLAND: Energy spectrumKamLAND: Energy spectrum

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

θsol

θ13, δθatm

Parametrization Neutrino mixing

Flavor Eigenstates Mass Eigenstates

2 mixing angles are measured:

CP violating phase New experiments

1313 from reactors? from reactors?

P(P(eeee) = 1 ) = 1

– – coscos441313 sin sin22 2 21212 sin sin22((mm22solsol L/4E) – L/4E) –

sinsin22 2 21313 sin2 ( sin2 (mm22atmatm L/4E) L/4E)

no CP termsno CP terms

no matter effectsno matter effects

P

L/E(km/MeV)

solar

atmospheric

Letter of Intent: Double-Letter of Intent: Double-ChoozChooz

• d~1.05 km

• P~8.4 GW

• 300mwe far detector

• no excavation for far detector

Far Detector (~300mwe shielding)

Near Detector for reactor monitoring

Double-CHOOZDouble-CHOOZ(far) Detector(far) Detector

Puit existant

Gamma catcher: scintillator with no Gd

7 m

7 m

BUFFER Mineral Oil

7 m

Shielding steel and external vessel

Target- Gd loaded scintillator: ~ 85 /d (far) and ~ 4 103/d (near)

photomultipliers

Inner veto

Sensitivity of Double ChoozSensitivity of Double Chooz

Exclusion limit 90% cl for

dm2 = 2.8 10-3 eV2

and a final systematic uncertainty of 0.6%

732 km

LNGS

Neutrino beam from CERN to Gran Neutrino beam from CERN to Gran SassoSasso

Precision Tracker (PT)Universität Hamburg:

Precision Tracker (PT)Universität Hamburg:

DetectorDetector

8.3kg

Aktives Target:200.000 Blei-Emulsions-Ziegel= ca. 1.800 Tonnen

Universität Münster

full mixing, 5 years run @ 4.5 x1019 pot / year

signalsignal

((mm22 = = 1.1.99 x 10 x 10-3-3 eV eV22))

signalsignal

((mm22 = = 2.2.44 x 10 x 10-3-3 eV eV22))

signalsignal

((mm22 = = 3.0x 103.0x 10-3-3 eV eV22))

BKGDBKGD

OPERAOPERA1.8 kton fid.1.8 kton fid.

6.66.6(10)(10) 10.510.5(15.8)(15.8) 16.416.4(24.6)(24.6) 0.70.7(1.1)(1.1)

+ brick finding+ brick finding

+ 3 prong decay+ 3 prong decay8.08.0(12.1)(12.1) 12.812.8(19.2)(19.2) 19.919.9(29.9)(29.9) 1.01.0(1.5)(1.5)

Background Background reduction reduction 8.08.0(12.1)(12.1) 12.812.8(19.2)(19.2) 19.919.9(29.9)(29.9) 0.80.8(1.2)(1.2)

(…) with CNGS beam upgrade (X 1.5)

→→ sensitivitysensitivity

BOREXINO sees neutrinos from BOREXINO sees neutrinos from CERN (August 2006) !CERN (August 2006) !

Cosmic muons (background)

Time of flight (CERN to LNGS) ~ 2.4 ms

Data analysis of 30 h measurement and 55 t water as target

First neutrino events in BOREXINO

ΘΘ1313 with accelerator physics with accelerator physics

with

(anti-v)

Neutrino appearance:Neutrino appearance:

θ13 , δCP, Mass hierarchy but degeneracy & correlation effects!

Present limit from CHOOZ: sin2(213) < 0.2

Present limit from CHOOZ: sin2(213) < 0.2

Neutrino Superbeam ProjectsNeutrino Superbeam ProjectsJapan: Japan: – T2K – phase I: T2K – phase I:

0.75MW (JPARC)0.75MW (JPARC) + SuperK (22.5kt) (ab 2009) + SuperK (22.5kt) (ab 2009) sinsin22221313>0.006 (90%) (5 Jahre)>0.006 (90%) (5 Jahre)

– T2K – phase II: T2K – phase II: 4 MW + HyperK (500-1000 kt) (≥ 2015)4 MW + HyperK (500-1000 kt) (≥ 2015)

USA:USA:NOvA: Fermilab NuMI beam (0.4 MW) +NOvA: Fermilab NuMI beam (0.4 MW) +off-axis detector (surface!, 50kt) (ab 2009)off-axis detector (surface!, 50kt) (ab 2009)

Sensitivity of future experiments Sensitivity of future experiments onon θθ1313

90% CL90% CL

from Huber, Lindner, Rolinec, Schwetz, Winter hep-ph/0403068

← reactor

← super beam

Absolute Neutrino Mass Absolute Neutrino Mass MeasurementsMeasurements

Kinematic tests (tritium decay)Kinematic tests (tritium decay)

Search for the neutrinoless double-Search for the neutrinoless double-beta decaybeta decay

CL%95eV2.2eV1.22.22.1 22

mm

Mainz Data (1998,1999,2001)

Direct Mass Experiments: Tritium Direct Mass Experiments: Tritium ββ-Decay-Decay

e -33 eHe H e -33 eHe H

222i

iei mUm

E0 = 18.6 keV

KATRIN

~70 m beamline, 40 s.c. solenoids

The KArlsruhe TRItium Neutrino Experiment

The KArlsruhe TRItium Neutrino Experiment

Commissioning in 2008

mv < 0.2eV (90%CL)

Neutrinoless Double-Beta-Neutrinoless Double-Beta-DecayDecay

0: (A,Z) (A,Z+2) + 2e-

d

d

u

u

e-

e-

W-

W- e

e

L=2

Majorana nature, Mass scale, Majorana CP phases

mee = |i Uei ² mi |Effective neutrino mass:

21 233

222

211

ie

ieeee eUmeUmUmm

CL) (90% eV 35.0ee

mHeidelberg-Moskau Collaboration, Eur.Phys.J. A12 (2001) 147

IGEX Collaboration, hep-ex/0202026, Phys. Rev. C59 (1999) 2108

H.V. Klapdor-Kleingrothaus, A. Dietz, O. Chkvorets, I.V. Krivosheina, NIM A, 2004

Peak at 2039 keV in the Heidelberg-Moscow experiment !

Effect or background ??

Evidence for neutrinoless Double-beta Decay ?

Wanted: New experiments !

• GERDA ( 76Ge)

• Cuoricino (130Te in cryogenic detectors)

• NEMO (different isotopes in large drift-chambers)

• COBRA (116Cd)

• SNO+ (150Nd)

…and many more projects

Phase I: 20kg enriched (86%) 76Ge, vgl. HDMPhase II: 35-40kgPhase III: ~500kg

GERGERmanium manium DDetector etector AArrayrrayMethod:

HP Ge-diodes (enriched in 76Ge) in cryogenic fluid shield(optional active) .

Qββ = 2039 keV

HP Ge-diodes (enriched in 76Ge) in cryogenic fluid shield(optional active) .

Qββ = 2039 keV

GERDA Sensitivity & Neutrino GERDA Sensitivity & Neutrino MassMass

| m

ee|

in e

V

Lightest neutrino (m1) in eV

F.F

eruglio, A. S

trumia, F

. Vissani, N

PB

659

H.V. Klapdor-Kleingrothaus, A. Dietz, O. Chkvorets, I.V. Krivosheina, NIM A, 2004Phase I:

Phase II:

Phase III:

Neutrinos as ProbesNeutrinos as Probes

……from the Earth and from from the Earth and from Astrophysical ObjectsAstrophysical Objects

Geo-NeutrinosGeo-Neutrinos

Direct neutrino observation:• what is the contribution of radioactivity to the Earth‘s heat flow (~ 40 TW) ?

• direct test of the Bulk Silicate Earth model

• what is the energy source of the Earth magnetic field ?

• test of unorthodox models (i.e. breeder reactor in the core)

First detection in KamLAND

Nature, 28. July 2005

Geo-neutrino energy spectrum

reactors

reactors

background

Excess due to Geo-neutrinos

Future Neutrino ObservatoriesFuture Neutrino ObservatoriesUnsegmented 50 kt liquid scintillator

LENAHyperKamiokande (1 Mt Water Cherenkov)

…Liquid Argon ~100 kt TPC

LAGUNALAGUNA

Large Aparatus for Grand Unification and Large Aparatus for Grand Unification and Neutrino AstronomyNeutrino Astronomy

European initiative (France, Germany, European initiative (France, Germany, Italy, Switzerland, UK, Poland, Finland)Italy, Switzerland, UK, Poland, Finland)

Aim: Design studies for all 3 kinds of Aim: Design studies for all 3 kinds of detevtors (water Ch, scintillator, liquid detevtors (water Ch, scintillator, liquid argon) until ~ 2010 argon) until ~ 2010

Physics goals of future Neutrino Physics goals of future Neutrino ObservatoriesObservatories

Gravitational collapseGravitational collapseStar formation rate in the early universeStar formation rate in the early universeThermonuclear fusion reactionsThermonuclear fusion reactionsBaryon number violation (Proton decay)Baryon number violation (Proton decay)Leptonic CP – violationLeptonic CP – violationGeophysicsGeophysicsIndirect search for Dark MatterIndirect search for Dark MatterActive Galactic Nuclei – UHE NeutrinosActive Galactic Nuclei – UHE Neutrinos

One example for LENA: Detection of the One example for LENA: Detection of the Diffuse Supernova Neutrino Background Diffuse Supernova Neutrino Background

(DSNB) ?(DSNB) ?

• up to now only limits

• flux and spectral shape depend on

Star formation rate

Gravitational collapse model

Star formation rate

Star formation: Large uncertainties

Optical and infrared observations

LENA: 70 until 120 events in 10 years

1 < z < 2: around 25%

Pulse shape analysis: distinction between models of supernova mechanism

Extremely Large ObservatoriesExtremely Large Observatories

Km3 Cherenkov detector in the mediterranian sea

Km3 Cherenkov detector at the South Pole (Ice Cube)

Amanda

Frejus

Eν E-3.8

A change in the slope would indicate a non-atmospheric component

Atmospheric neutrino Waxmann-Bahcall limit: Model-independent upper bound

= 2 = 00-03 combined

Diffusive sources

Limits from Amanda

Ice-Cube ~ 3 10-9

ConclusionsConclusions

• New results recently

• Neutrino masses and mixing established

• Physics beyond the standard model

• New window to astrophysical observations