massive neutrinos

Georg Raffelt, Max-Planck-Institut für Physik, München, Germany From Here to Infinity, Oxford, England, 13-15 December 2002

Massive NeutrinosMassive Neutrinos

Georg RaffeltMax-Planck-Institut für Physik, München,

Germany

Georg RaffeltMax-Planck-Institut für Physik, München,

Germany

From Here to Infinity: Extending Frontiers in Cosmology

A Weekend Symposium to Celebrate the Sixtieth Birthday of Joseph Silk Oxford, England, December 13-15, 2002

From Here to Infinity: Extending Frontiers in Cosmology

A Weekend Symposium to Celebrate the Sixtieth Birthday of Joseph Silk Oxford, England, December 13-15, 2002

News from the Ghost ParticlesNews from the Ghost Particles


AtmosphericAtmospheric SolarSolar LSNDLSNDSystemSystem

Status of Evidence for Neutrino OscillationsStatus of Evidence for Neutrino Oscillations

StatusStatus EstablishedEstablished EstablishedEstablished UnconfirmedUnconfirmed

TestTest Long BaselineLong Baseline KamLAND 12/2002KamLAND 12/2002 MiniBooNE 2004 ?MiniBooNE 2004 ?

Three mass eigenstates withThree mass eigenstates withmm11 << m << m22 << m << m33 ~ 50 meV (hierarchical) ~ 50 meV (hierarchical)mm11 ~ m ~ m22 ~ m ~ m33 >> 50 meV (degenerate) >> 50 meV (degenerate)

SimplestSimplestinterpre-interpre-tationtation

Experimental orExperimental orStatisticalStatistical

FlukeFluke

e e e eChannelChannel

2sin2 2sin2 0.90.911 0.20.20.60.6 0.0010.0010.030.03

22 eV/m 22 eV/m LMALMA 0.2-2 or 6.50.2-2 or 6.5310)45.1( 410)22.0(

Mutually inconsistent, even with a sterile neutrinoMutually inconsistent, even with a sterile neutrinoEvidenceEvidence forfor physicsphysics beyondbeyond flavorflavor oscillations (CPT violation ...) ?oscillations (CPT violation ...) ?ImplicationImplication

A MiniBooNEA MiniBooNEconfirmation of LSND wouldconfirmation of LSND would

be another revolutionbe another revolution ..Too good to be trueToo good to be true ??


Kamland Reactor Neutrino Experiment (Japan)Kamland Reactor Neutrino Experiment (Japan)

Japanese nuclear reactorsJapanese nuclear reactors60 GW (20% world capacity)60 GW (20% world capacity)

• Witout OscillationsWitout Oscillations 2 Neutrino captures / day2 Neutrino captures / day• Data taking sinceData taking since 22 January 200222 January 2002

First Kamland results earlier this weekFirst Kamland results earlier this weekat “Texas in Tuscany” and hep-ex/0212021at “Texas in Tuscany” and hep-ex/0212021


Three-Flavor Neutrino Parameters (Ignoring Three-Flavor Neutrino Parameters (Ignoring LSND)LSND)

1

2

3

e 13 13 12 12

23 23 12 12

23 23 13 13

i

i

1 C S C S

C S 1 S C

S C 1S C

e

e

1

2

3

e 13 13 12 12

23 23 12 12

23 23 13 13

i

i

1 C S C S

C S 1 S C

S C 1S C

e

e

CP-violating phaseCP-violating phase12 12C cos etc., 12 12C cos etc.,

AtmosphericAtmospheric Chooz LimitChooz Limit SolarSolar

2 2m meV 2 2m meV

SolarSolar2424 --240240

AtmosphericAtmospheric14001400 --60006000

33 ranges rangeshep-ph/0211054hep-ph/0211054

2332 60 2332 60 1227 41 1227 41 13 14 13 14

ee

ee

11SunSun

NormalNormal

22

33

AtmosphereAtmosphere

ee

ee

11SunSun

InvertedInverted22

33

AtmosphereAtmosphere

Tasks and Open QuestionsTasks and Open Questions

• Precision for Precision for 12 12 andand 2323

((12 12 < 45º and < 45º and 23 23 45º 45º ?) ?)

• How large is How large is 1313 ??• CP-violating phaseCP-violating phase ??• Mass orderingMass ordering ? ? (normal vs inverted)(normal vs inverted)• Absolute massesAbsolute masses ?? (hierarchical vs degenerate)(hierarchical vs degenerate)• Dirac or MajoranaDirac or Majorana ??

Tasks and Open QuestionsTasks and Open Questions

• Precision for Precision for 12 12 andand 2323

((12 12 < 45º and < 45º and 23 23 45º 45º ?) ?)

• How large is How large is 1313 ??• CP-violating phaseCP-violating phase ??• Mass orderingMass ordering ? ? (normal vs inverted)(normal vs inverted)• Absolute massesAbsolute masses ?? (hierarchical vs degenerate)(hierarchical vs degenerate)• Dirac or MajoranaDirac or Majorana ??

CosmologyCosmologyCosmologyCosmology


Tritium Endpoint SpectrumTritium Endpoint Spectrum

Electron spectrum N(E)Electron spectrum N(E)

EE

mm

Scaled-up spectrometer (KATRIN) may reach 0.3 eVScaled-up spectrometer (KATRIN) may reach 0.3 eVCurrently in preparation - Results in > 5 yearsCurrently in preparation - Results in > 5 years

Mainz Experiment, PLB 460 (1999) 219Mainz Experiment, PLB 460 (1999) 219

m < 2.8 eV (95% CL)m < 2.8 eV (95% CL)

Troitsk Experiment, ibid. 227Troitsk Experiment, ibid. 227

m < 2.5 eV (95% CL)m < 2.5 eV (95% CL)

TheseTheseexperimentsexperimentshave reachedhave reached2.2 eV2.2 eV(Neutrino(Neutrino 2002)2002)

Tritium Beta DecayTritium Beta Decay

Endpoint energy 18.6 keVEndpoint energy 18.6 keVe

33 eHeH e

33 eHeH


Cosmological Limit on Neutrino MassesCosmological Limit on Neutrino Masses

A classic paper:A classic paper: Gershtein & ZeldovichGershtein & Zeldovich JETP Lett. 4 (1966) 120JETP Lett. 4 (1966) 120

4.0eV94

mh2

4.0

eV94

mh2

Cosmic neutrino “sea”Cosmic neutrino “sea” ~ 112 cm~ 112 cm-3-3 neutrinos + anti-neutrinos per neutrinos + anti-neutrinos per flavor flavor

mm < 40 eV < 40 eV For allFor allstable flavorsstable flavors


Neutrino Mass Limit from 2dF Galaxy SurveyNeutrino Mass Limit from 2dF Galaxy Survey

Elgaroy et al., Elgaroy et al., astro-ph/0204152astro-ph/0204152

= = 0.010.01

= = 00

Similar limits basedSimilar limits basedon the 2dF survey on the 2dF survey • HannestadHannestad astro-ph/0205223astro-ph/0205223• Lewis & BridleLewis & Bridle astro-ph/0205436astro-ph/0205436

= = 0.050.05

mm < 2.2 eV < 2.2 eV

at 95% CLat 95% CL(statistical)(statistical)

Depends on priors forDepends on priors forother parametersother parameters


PLANCK Sensitivity to Neutrino MassPLANCK Sensitivity to Neutrino Mass

Maximum Maximum temperature multipoletemperature multipole that can be that can bemeasured to cosmic-variance precisionmeasured to cosmic-variance precision

Maxim

um

M

axim

um

pola

riza

tion

mu

ltip

ole

pola

riza

tion

mu

ltip

ole

th

at

can

be

th

at

can

be

measu

red

to c

osm

ic-v

ari

an

ce p

reci

sion

measu

red

to c

osm

ic-v

ari

an

ce p

reci

sion

0.07 0.07 eVeV

0.07 0.07 eVeV

0.13 0.13 eVeV

0.13 0.13 eVeV

0.25 0.25 eVeV

0.25 0.25 eVeV

Steen HannestadSteen Hannestadastro-ph/0211106astro-ph/0211106

11 sensitivity to sensitivity to mm


1010-2-2 1010-1-1 11 10 10 eVeV

3m 3

m

1010-3-3 1010-2-2 1010-1-1 11 Assuming h = 0.75Assuming h = 0.75

Mass-Energy-Inventory of the UniverseMass-Energy-Inventory of the Universe

luminousluminous TotalTotalBaryonsBaryons

Dark MatterDark Matter

Tritium Tritium Mainz/TroitskMainz/Troitsk

KATRIN, SDSS (Future)KATRIN, SDSS (Future)

PLANCK+SDSS (“Optimistic” future)PLANCK+SDSS (“Optimistic” future)

Super-KSuper-K NeutrinosNeutrinosNeutrinosNeutrinosSuper-KSuper-K 2dF Galaxy Survey2dF Galaxy Survey


Additional active Additional active neutrinos beyondneutrinos beyondstandard populationstandard population

of of ee, , , ,

How Many Relic Neutrinos?How Many Relic Neutrinos?

Sterile Sterile (right-handed) (right-handed) statesstates

Populated by Populated by LL R R

transitionstransitions

Electromagnetic Electromagnetic dipole momentsdipole moments

Excluded by energy loss Excluded by energy loss of globular cluster stars of globular cluster stars

Oscillations/collisionsOscillations/collisions Hot/warm/cold DMHot/warm/cold DMpossiblepossible

Right-handed currentsRight-handed currents Excluded by energyExcluded by energyloss of SN 1987A loss of SN 1987A

Dirac massDirac mass Not effectiveNot effectivein eV rangein eV range

Additional familiesAdditional familiesExcluded by ZExcluded by Z00 width width

(N(N = 3) = 3)

Chemical potentials Chemical potentials

for for ee, , , , PossiblePossible

Standard thermal population in one flavorStandard thermal population in one flavor 3113 cm112nn

3113 cm112nn


BBN Limits on Neutrino FlavorsBBN Limits on Neutrino Flavors

Burles, Nollett & Turner, Burles, Nollett & Turner, astro-ph/9903300astro-ph/9903300

• At BBN one flavorAt BBN one flavor contributes aboutcontributes about 16% to cosmic16% to cosmic mass-energy mass-energy densitydensity• Extra flavors Extra flavors modifymodify expansion expansion parameterparameter accordinglyaccordingly

Conservative limitConservative limit

NNeffeff < 1 < 1

3.43.4 3.23.2 3.03.0


BBN and Neutrino Chemical PotentialsBBN and Neutrino Chemical Potentials

• e e beta effect can compensate expansion-rate effect of beta effect can compensate expansion-rate effect of • No significant BBN limit on neutrino number densityNo significant BBN limit on neutrino number density

Energy density in one neutrino flavor with Energy density in one neutrino flavor with degeneracy parameter degeneracy parameter = = /T/T

effN

424

2

715

730

1T1207

effN

424

2

715

730

1T1207

Expansion RateExpansion Rate

EffectEffect

(all flavors)(all flavors)

Beta equilibriumBeta equilibrium

effect foreffect for

electron flavorelectron flavor epn e epn e

Helium abundance essentially fixed by Helium abundance essentially fixed by n/p ratio at beta freeze-out n/p ratio at beta freeze-out

Effect on helium equivalent to Effect on helium equivalent to NNeffeff -18 -18 ee

epn T/mme

pn

epn T/mme

pn

NNeffeff < 1 < 1 ee < 0.06 < 0.06


Chemical Potentials and Flavor OscillationsChemical Potentials and Flavor Oscillations

• Our knowledge of the cosmic nuOur knowledge of the cosmic nu density depends on the solution ofdensity depends on the solution of the solar neutrino problemthe solar neutrino problem• KamLAND most relevant experimentKamLAND most relevant experiment

• Lunardini & Smirnov, hep-ph/0012056 Lunardini & Smirnov, hep-ph/0012056 • Dolgov, Hansen, Pastor, Petcov, RaffeltDolgov, Hansen, Pastor, Petcov, Raffelt & Semikoz, hep-ph/0201287& Semikoz, hep-ph/0201287• Abazajian, Beacom & Bell,Abazajian, Beacom & Bell, astro-ph/0203442astro-ph/0203442• Wong, hep-ph/0203180 Wong, hep-ph/0203180

nono SMA or VACSMA or VAC

maybemaybe LOW (depends on LOW (depends on 1313))

yesyes Solar LMA solutionSolar LMA solution

Flavor equilibrium before n/pFlavor equilibrium before n/pfreeze outfreeze out ??

Stringent Stringent ee limit limit

applies to all flavors applies to all flavors

||ee|| 0.07 0.07

Cosmic neutrino densityCosmic neutrino densityclose to standard valueclose to standard value

Extra neutrino density Extra neutrino density NNeffeff 0.0064 0.0064

Only one common nu Only one common nu chemical potentialchemical potential

Flavor mixing Flavor mixing (neutrino oscillations)(neutrino oscillations)

Flavor lepton numbersFlavor lepton numbersnot conservednot conserved


Baryogenesis in the Early UniverseBaryogenesis in the Early Universe

Sakharov conditions for creating the Sakharov conditions for creating the BBaryon aryon AAsymmetry of the symmetry of the UUniverse (niverse (BAUBAU))• C and CP violationC and CP violation• Baryon number violationBaryon number violation• Deviation from thermal equilibriumDeviation from thermal equilibrium

Particle-physics standard modelParticle-physics standard model• Violates C and CPViolates C and CP• Violates B and L by EW instanton effectsViolates B and L by EW instanton effects (B – L conserved)(B – L conserved)

• However, electroweak baryogenesis not However, electroweak baryogenesis not quantitativelyquantitatively possible within particle-physics standard modelpossible within particle-physics standard model• Works in SUSY models for small range of Works in SUSY models for small range of parametersparameters

Andrei SakharovAndrei Sakharov1921 - 19891921 - 1989

A.Riotto & M.Trodden: A.Riotto & M.Trodden: Recent progress in baryogenesis Recent progress in baryogenesis Ann. Rev. Nucl. Part. Sci. 49 (1999) 35Ann. Rev. Nucl. Part. Sci. 49 (1999) 35


Leptogenesis by Majorana Neutrino DecaysLeptogenesis by Majorana Neutrino Decays

A classic paperA classic paper


See-Saw Model for Neutrino MassesSee-Saw Model for Neutrino Masses

NeutrinosNeutrinosCharged LeptonsCharged Leptons

Lagrangian for Lagrangian for particle massesparticle masses

cRRLmas Rs L Rg e g

1NL h.c.MNN

2 cRRLmas Rs L Rg e g

1NL h.c.MNN

2

Dirac massesDirac masses from couplingfrom coupling to standardto standard Higgs field Higgs field

HeavyHeavy Majorana Majorana masses masses

MMjj > 10 > 101010 GeV GeV

LL R

R

0 gN

Ng M

LL R

R

0 gN

Ng M

DiagonalizeDiagonalize DiagonalizeDiagonalize

2 2

LL R

R

gM

0N

N0 M

2 2

LL R

R

gM

0N

N0 M

Light Majorana massLight Majorana mass


EquilibriumEquilibriumabundance ofabundance ofheavy Majoranaheavy Majorananeutrinosneutrinos

W. Buchmüller & M. Plümacher: Neutrino masses and the baryon asymmetryW. Buchmüller & M. Plümacher: Neutrino masses and the baryon asymmetryInt. J. Mod. Phys. A15 (2000) 5047-5086Int. J. Mod. Phys. A15 (2000) 5047-5086

Leptogenesis by Out-of-Equilibrium DecayLeptogenesis by Out-of-Equilibrium Decay

CP-violating decays byCP-violating decays by interference of tree-levelinterference of tree-level with one-loop diagramwith one-loop diagram

8M2

Decay g 8M2

Decay g


Real abundanceReal abundancedetermined bydetermined bydecay ratedecay rate

CreatedCreatedlepton-numberlepton-numberabundanceabundance


Real abundanceReal abundancedetermined bydetermined bydecay ratedecay rate


Leptogenesis by Majorana Neutrino DecaysLeptogenesis by Majorana Neutrino Decays

In see-saw models for neutrino masses, out-of-equilibriumIn see-saw models for neutrino masses, out-of-equilibrium decay of right-handed heavy Majorana neutrinos providesdecay of right-handed heavy Majorana neutrinos provides source for CP- and L-violationsource for CP- and L-violation

Cosmological evolution:Cosmological evolution:• B = L = 0 early onB = L = 0 early on• Thermal freeze-out of heavy Majorana neutrinosThermal freeze-out of heavy Majorana neutrinos• Out-of-equilibrium CP-violating decay creates net LOut-of-equilibrium CP-violating decay creates net L• Shift L excess into B by sphaleron effectsShift L excess into B by sphaleron effects

Sufficient deviation Sufficient deviation from equilibrium from equilibrium distribution of heavy distribution of heavy Majorana neutrinos at Majorana neutrinos at freeze-outfreeze-out

Limits Limits onon YukawaYukawa couplingcouplingss

Limits onLimits on masses masses ofof ordinaryordinary neutrinosneutrinos

Requires Majorana neutrino masses below 0.2 eVRequires Majorana neutrino masses below 0.2 eVBuchmüller, Di Bari & Plümacher, PLB 547 (2002) 128 [hep-ph/0209301]Buchmüller, Di Bari & Plümacher, PLB 547 (2002) 128 [hep-ph/0209301]


Leptogenesis – A Popular Research TopicLeptogenesis – A Popular Research Topic Langacker, Peccei & YanagidaLangacker, Peccei & Yanagida Mod. Phys. Lett. A 1 (1986) 541Mod. Phys. Lett. A 1 (1986) 541

Campbell, Davidson & OliveCampbell, Davidson & Olive NPB 399 (1993) 111NPB 399 (1993) 111

Fukugita Fukugita & & YanagidaYanagida PLB 174 (1986) 45PLB 174 (1986) 45

Gherghetta & JungmannGherghetta & JungmannPRD 48 (1993) 1546PRD 48 (1993) 1546

Muryama & YanagidaMuryama & YanagidaPLB 322 (1994) 349PLB 322 (1994) 349

Dine, Randall & ThomasDine, Randall & Thomas NPB 458 (1996) 291NPB 458 (1996) 291

WorahWorahPRD 53 (1996) 3902PRD 53 (1996) 3902

Buchmüller & PlümacherBuchmüller & Plümacher PLB 389 (1996) 73 PLB 389 (1996) 73

Ma & SarkarMa & SarkarPRL 80 (1998) 5716PRL 80 (1998) 5716

JeannerotJeannerotPRLPRL 7777 (1996)(1996) 32923292

Lazarides, Schaefer & ShafiLazarides, Schaefer & Shafi PRD 56 (1997) 1324PRD 56 (1997) 1324

PlümacherPlümacherNPB 530 (1998) 207NPB 530 (1998) 207

Lazarides & ShafiLazarides & ShafiPRD 58 (1998) 071702PRD 58 (1998) 071702

Flanz & PaschosFlanz & PaschosPRD 58 (1998) 113009PRD 58 (1998) 113009

Ellis, Lola & NanopoulosEllis, Lola & NanopoulosPLB 452 (1999) 87PLB 452 (1999) 87

Berger & BrahmachariBerger & BrahmachariPRD 60 (1999) 073009PRD 60 (1999) 073009

Carlier, Frére & LingCarlier, Frére & LingPRD 60 (1999) 096003PRD 60 (1999) 096003

Akhmedov, Rubakov & SmirnovAkhmedov, Rubakov & SmirnovPRL 81 (1998) 1562PRL 81 (1998) 1562

Giudice, Peloso, Riotto & TkachevGiudice, Peloso, Riotto & TkachevJHEP 9908 (1999) 014JHEP 9908 (1999) 014

Frére, Ling, Tytgat & v.ElewyckFrére, Ling, Tytgat & v.ElewyckPRD 60 (1999) 016005PRD 60 (1999) 016005

Barbieri, Creminelli, Strumia & TetradisBarbieri, Creminelli, Strumia & TetradisNPB 575 (2000) 61NPB 575 (2000) 61

BergerBergerPRD 62 (2000) 013007PRD 62 (2000) 013007

Hambye, Ma & SarkarHambye, Ma & SarkarPRD 62 (2000) 015010PRD 62 (2000) 015010

GoldbergGoldbergPLBPLB 474474 (2000)(2000) 389389

Asaka, Hamaguchi, Kawasaki & YanagidaAsaka, Hamaguchi, Kawasaki & YanagidaPRD 61 (2000) 083512PRD 61 (2000) 083512

Dick, Lindner, Ratz & WrightDick, Lindner, Ratz & WrightPRL 84 (2000) 4039PRL 84 (2000) 4039

Lalakulich, Paschos & FlanzLalakulich, Paschos & FlanzPRD 62 (2000) 053006PRD 62 (2000) 053006

Rangarajan & MishraRangarajan & MishraPRDPRD 6161 (2000)(2000) 043509043509

Mangano & MieleMangano & MielePRDPRD 6262 (2000)(2000) 063514063514

Bastero-Gil & King Bastero-Gil & King PRD 63 (2001) 123509PRD 63 (2001) 123509

Joshipura, Paschos & RodejohannJoshipura, Paschos & Rodejohann NPB 611 (2001) 227NPB 611 (2001) 227

Falcone & TramontanoFalcone & Tramontano PRD PRD 6363 (2001) 073007(2001) 073007

Hambye, Ma & SarkarHambye, Ma & Sarkar NPB 602 (2001) 23NPB 602 (2001) 23

Hirsch & KingHirsch & KingPRD 64 (2001) 113005PRD 64 (2001) 113005

Branco, Morozumi, Nobre & RebeloBranco, Morozumi, Nobre & RebeloNPB 617 (2001) 475NPB 617 (2001) 475 AND MANY MORE ...AND MANY MORE ...


Neutrinoless Neutrinoless Decay Decay

76Ge76Ge

76Se76Se

76As76As

O+O+

2–2–

2+2+

O+O+

Some nuclei decay onlySome nuclei decay onlyby the by the mode, e.g. mode, e.g.Some nuclei decay onlySome nuclei decay onlyby the by the mode, e.g. mode, e.g.

Half life ~ 10Half life ~ 102121 yr yrHalf life ~ 10Half life ~ 102121 yr yr

N 2ee i ei i

i 1m U m

N 2ee i ei i

i 1m U m

MeasureMeasure

ddquantityquantity

eem 0.35eVeem 0.35eVBest Best limitlimitfrom from 7676GeGe

00mode, enabledmode, enabledby Majorana massby Majorana mass Standard 2Standard 2modemode


Summary of Current Neutrinoless Summary of Current Neutrinoless Decay Decay LimitsLimits

O.C

rem

on

esi

at

Neu

trin

o 2

00

2O

.Cre

mon

esi

at

Neu

trin

o 2

00

2


Summary of Future Summary of Future Decay Projects Decay ProjectsO

.Cre

mon

esi

at

Neu

trin

o 2

00

2O

.Cre

mon

esi

at

Neu

trin

o 2

00

2


Matter Inventory of the UniverseMatter Inventory of the Universe

Dark Energy ~ 70%Dark Energy ~ 70%(Cosmological Constant?)(Cosmological Constant?)

Dark MatterDark Matter~ 25%~ 25%

Baryonic Matter ~ 5%Baryonic Matter ~ 5%(~10% of this luminous)(~10% of this luminous)

NeutrinosNeutrinos min. 0.1%min. 0.1% max. 6%max. 6%

massive neutrinos

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