Neutrino Masses Neutrino Masses and Lepton Flavor Physicsand Lepton Flavor Physics

K.S. BabuK.S. BabuDepartment of Physics, Oklahoma State UniversityDepartment of Physics, Oklahoma State University

PHENO 03 PHENO 03

Madison, Wisconsin, May 5, 2003Madison, Wisconsin, May 5, 2003

OutlineOutline

Neutrino Oscillation ResultsNeutrino Oscillation ResultsInterpreting DataInterpreting Data

– Patterns of Neutrino Mass Spectrum Patterns of Neutrino Mass Spectrum – Neutrinoless Double Beta Decay Neutrinoless Double Beta Decay Tests Tests

Theoretical ModelingTheoretical Modeling– Large Neutrino Mixing Large Neutrino Mixing – Unified Quark-Lepton Description Unified Quark-Lepton Description

Lepton Flavor Violation Lepton Flavor Violation – Rare Decays Rare Decays →→→→ee – Lepton Dipole Moments Lepton Dipole Moments

ConclusionsConclusions

Gonzalez-Garcia et al. (2003)

Solar Neutrino Oscillations

Maltoni, et al. hep-ph/0207227

Atmosphere Neutrino Oscillations

Aguilar, et. al hep-exp/0104049

LSND

Patterns of Neutrino Mass SpectrumPatterns of Neutrino Mass Spectrum

Neutrino Mixing versus Quark MixingNeutrino Mixing versus Quark Mixing

Leptons

Quarks

Disparity a challenge for Quark-Lepton unified theories.

and Pattern of Neutrino Masses and Pattern of Neutrino Masses

Pascoli, Petcov, Rodejohann, hep-ph/0212113

(meV)

Neutrino Masses and the Scale of New PhysicsNeutrino Masses and the Scale of New Physics

Very Close to the GUT scale.

Gauge Coupling Unification in MSSMGauge Coupling Unification in MSSM

Structure of Matter MultipletsStructure of Matter Multiplets

Large Neutrino Mixing with Lopsided Mass MatricesLarge Neutrino Mixing with Lopsided Mass Matrices

Quark and Lepton Mass hierarchy:

This motivates:

KSB and S. Barr, 1995

Example of Lopsided Mass MatricesExample of Lopsided Mass MatricesGogoladze, Wang, KSB, 2003

Discrete ZN Gauge Symmetry

S.Barr and KSB,2002

10 Parameters vs. 20 Observables PREDICTIONS

Lopsided Mass Matrix Model in SO(10) Lopsided Mass Matrix Model in SO(10)

FIT

Buras, et al

Georgi-Jarlskog

Neutrino Mass TexturesNeutrino Mass Textures

Fukugita, Tanimoto, Yanagida, 2003

AA4 4 Symmetry and Quasi-degenerate NeutrinoSymmetry and Quasi-degenerate Neutrino

E. Ma, 2002

E. Ma, J. Valle, KSB, 2002

With Arbitrary Soft A4 Breaking

With Complex parameters, arg(Ue3) = /2

Electric Dipole MomentsElectric Dipole Moments

Violates CPViolates CP

Electron:

Neutron:

Phases in SUSY breaking sector contribute to EDM.Phases in SUSY breaking sector contribute to EDM.

SUSY Contributions:SUSY Contributions:

A, B are complex in MSSMA, B are complex in MSSM

Effective SUSY Phase

If parity is realized asymptotically,If parity is realized asymptotically,

EDM will arise only through non-hermiticity induced by RGE.EDM will arise only through non-hermiticity induced by RGE.

Subject to experimental testsSubject to experimental tests

Dutta, Mohapatra, KB (2001)

Seesaw mechanism naturally explains small Seesaw mechanism naturally explains small mass.mass.

Current neutrino-oscillation data suggestsCurrent neutrino-oscillation data suggests

Flavor change in neutrino-sectorFlavor change in neutrino-sector

Flavor change in charged leptonsFlavor change in charged leptons

In standard model with Seesaw, leptonic flavor changing is very tiny.In standard model with Seesaw, leptonic flavor changing is very tiny.

Lepton Flavor Violation and Neutrino MassLepton Flavor Violation and Neutrino Mass

In Supersymmetric Standard modelIn Supersymmetric Standard model

ForFor R activeactive

SUSY Seesaw MechanismSUSY Seesaw Mechanism

If If B-L B-L is gauged, Mis gauged, MRR must arise through Yukawa couplings. must arise through Yukawa couplings.

Flavor violation may reside entirely in f or entirely in Flavor violation may reside entirely in f or entirely in YY

flavor violation in neutrino sector Transmitted to Sleptonsflavor violation in neutrino sector Transmitted to SleptonsBorzumati, Masiero (1986)

Hall, Kostelecky, Raby (1986)

Hisano, et al (1995)

If flavor violation occurs only inIf flavor violation occurs only in f ((Majorana LFVMajorana LFV))

If flavor violation occurs only in Dirac Yukawa If flavor violation occurs only in Dirac Yukawa YY

(with mSUGRA)(with mSUGRA)

LFV in the two scenarios are comparable.LFV in the two scenarios are comparable.

More detailed study is needed. More detailed study is needed.

Neutrino FitNeutrino Fit

For Majorana LFV scenario, take Dutta, Mohapatra, KB 2002

For Dirac LFV scenarioFor Dirac LFV scenario

Same neutrino oscillation parameters as in Majorona LFVSame neutrino oscillation parameters as in Majorona LFV

The two scenarios differ in predictions forThe two scenarios differ in predictions for

F. Deppisch, et al, hep-ph/0206122

Dirac LFV

Dutta, Mohapatra, KB (2002)

Majorana LFV

Correlation between LFV andCorrelation between LFV and B B→→KKss

Hisano and Shimizu, hep-ph/0303071

LFV in SUSY SO(10)LFV in SUSY SO(10)

Masiero, Vempati and Vives, hep-ph/0209303

ConclusionsConclusions

• Neutrino Experiments pinning down oscillation Neutrino Experiments pinning down oscillation parameters.parameters.

• Neutrinoless double beta decay can discriminate Neutrinoless double beta decay can discriminate between various mass patterns.between various mass patterns.

• Large Neutrino Mixing can arise from Unified Large Neutrino Mixing can arise from Unified theories through lopsided mass matrices.theories through lopsided mass matrices.

• Lepton Flavor Violation Lepton Flavor Violation →→→→eeand EDMs and EDMs within reach of experiments.within reach of experiments.