Neutrino Masses, Leptogenesis and Beyond

The Incredible Foresight of ETTORE MAJORANA

Haim HarariErice, August 2006

A1 A2 + e-

e-

-Decay

N1 N2 + e-

e-

e-

e-

e-

-Decay

N1 N2 + e-

e-

e-

e-

e-

Missing EnergyMissing Momentum

-Decay

N1 N2 + e- +

e-

e-

e-

e-

“Dear RadioactiveLadies & Gentleman”

-Decay

n p + e- +

np

np

e-

e-

e-

e-

e-

-Decay

-Decay

d u + e- +

np

np

e-

e-

e-

e-

e-

e-

d

The Elusive Neutrino

No Electric ChargeNo Strong InteractionsSpin = ½Only Weak InteractionsSmall or Zero Mass

1016

If 1016 reach earth - one will hit something somewhere.

With one thousand tons of water, and 1016 every second since the big bang - 1 EVENT !!! Pauli: “I have done

a terrible thing!”

Creating Nuclei

n p + e- +

p n + e+ +

Creation of starsCreation of heavy elementsEnergy of the sunEnergy of starsExploding stars: supernova

The only way to convert a proton into a neutron

or vice versa – involves the neutrino!

n e- + p

p e+ + n

(Can you tell from ?)

The SUN

4p He4 + 2e+ + 2 + Energy

Other Processes

1957 - Neutrino Observed

Reines - Cowan

Big Problem: DETECTING Huge Problem: ELIMINATING BACKGROUND

Reactor n

+ p e+ + n

e+ + e- 2

n + Z Z’ +

The Foresight

Can you tell a neutrino from an

anti-neutrino?

MAJORANA

may be its own antiparticle !

Is Massless or Very Light ?

“Direct” experiments m (e) < 10 eV

TheoryNo good reason for massless Simple argument for very light . is only “chargeless” particle.

All quarks and leptons “Dirac Mass” also “Majorana Mass”

Is Massless or Very Light ?

m

“See-Saw”

M1 ~ O()

M2 ~ O(m2/

0 mm

Majorana Mass

Gell-Mann, Ramond, Slansky, Yanagida

Theorists predicted a new meson with a certain mass.

A particle was found soon after, having the right mass.

A second particle, very slightly heavier, was found soon after.

The second particle turned out to be the predicted meson.

The first particle turned out to be an unexplained heavy lepton,

identical to the electron in all its properties, except its mass.

Theorists predicted a new meson with a certain mass.

A particle was found soon after, having the right mass.

A second particle, very slightly heavier, was found soon after.

The second particle turned out to be the predicted meson.

The first particle turned out to be an unexplained heavy lepton,

identical to the electron in all its properties, except its mass.

Yukawa ~100MeV

Anderson-Neddermeyer ~100MeV

Powell

m (e) = 0.51 MeV m () = 106 MeV

Theorists predicted a new meson with a certain mass.

A particle was found soon after, having the right mass.

A second particle, very slightly heavier, was found soon after.

The second particle turned out to be the predicted meson.

The first particle turned out to be an unexplained heavy lepton,

identical to the electron in all its properties, except its mass.

m(e) = 0.51 MeV m() = 106 MeV

GIM D ~2000GeV

Perl ~1800MeV

SLAC-LBL

D

m() = 1782 MeV

One or Two Neutrinos

e

The schizophrenic

p

p

p

P

Detector

Brookhaven 1962

Is the “partner” of the

same as the “usual” ,

which comes with e ?

+ + +

-6 -5 -4 -2-3 -1 -0 1 2 3 4 5 6 7 8 9 10 11 12

eV meV eV MeVkeV GeV TeV

ud

ee

( )

( )

0

-1e

2/3

-1/3du

1stGeneration Q

e?

Leptons

Quarks

-6 -5 -4 -2-3 -1 -0 1 2 3 4 5 6 7 8 9 10 11 12

eV meV eV MeVkeV GeV TeV

ud

ee

( )

( )

0

-1e

2/3

-1/3du

1stGeneration Q

sc

2nd

cs

( )

( )1970 GIM: “CHARM”

e? ?

Leptons

Quarks

-6 -5 -4 -2-3 -1 -0 1 2 3 4 5 6 7 8 9 10 11 12

eV meV eV MeVkeV GeV TeV

ud

ee

( )

( )

e? 0

-1e

2/3

-1/3du

1stGeneration Q

sc

2nd

cs

( )

( )“The Standard Model”

tb

( )

( )

bt

3rd

Quarks

Leptons

? ?

ud( ) c

s( ) tb( )

“Mass Eigenstates”

“Weak Eigenstates”Mixing

MixingAngles(small)

Cabibbo

Is Massless or Very Light ?

m

“See-Saw”

M1 ~ O()

M2 ~ O(m2/

0 mm

Majorana Mass

Gell-Mann, Ramond, Slansky, Yanagida

-12

-9

-6

-3

0

3

6

9

12

15

18

21

24

27

30

PeVTeV

GeVMeV

keV

eV

meV

eV

neV

Planck

GUT

S.M.

tbc su de

e

Pij = Sin 2 2ij Sin 2 (1.27 m2ij)

KmGeV

LE

· eV2

- Oscillations

An Identity CrisisReactor e

Accelerator

Sun e

e

Mass

EigenstatesGenerationEigenstates

APPEARANCE

DISAPPEARANCE

Three Mixing Angles

e 12 23

e 13

- Oscillations

Pij = Sin 2 2ij Sin 2 (1.27 m2ij)

KmGeV

LE

· eV2

LE m2 << 1 P ~ 0

m2 >> 1 P= ½ Sin2 2ijLE

m2 ~ O(1) probe mLE

Reactors:

Accelerators:

E L Probe m2

MeV

GeV

m

km

eV>~

eV>~

If mj >> mi m2ij ~ mj

2

All experiments were :

e e

e x

x

- Oscillations

Hence: limits only on 12

Allowed Excluded

m2 eV2

1000

100

10

1

0.1

Sin2 2

Cosmological Dark Matter

The universe is

95% is Dark matter or Dark EnergyWhat is the Dark Matter? Cosmic Background

Radiation: 2.7°K

per cm3: 400 110 e

110

110

If m(e ) + m() + m(~ O(few e)

Closed

Open

flat

Dark matter would be Hence: Crucial to search for

oscillations at O(eV)

“CHORUS”CERN 1990 - 98

No events

cannot account for most

of the dark matter in the universe!

Cosmological Dark Matter

Accelerator x

400 ton C2Cl4

Cle + A37

Homestake

Solar Neutrinos

The sun emits 1038 per second.

1029 go to direction earth.

Per 100 ton detector - 40 hits per month

Kamiokande Super - Kamiokande

+ n e + p

Kamiokande

ton/clean water

GALLEXGae + Ge71

30 ton

GALLEXGae + Ge71

30 ton

SNO

1000 ton D2O (+2 ton Salt) 10,000 phototubes

e + d e + p + p (charged Current)

x + dx + p + n (Neutral Current)

x + e x + e (Elastic Scattering)Count total – flux and e - flux

Solar Model is Right!

Neutrinos Oscillate

Neutrinos have Mass

m() ~ 8 meV

12 Large

L ~ 180 km

E ~ O (MeV)

Probe: ∆m2<<eV2

Kamland – Japan

KAM

RR

RR

= 2

Cosmic Radiation

Pions created in atmosphere

In -decay: N()

N(e)

Energetic protons arrive

= 1.2 !!!

KAMIOKANDE:

N()

N(e)m () ~ 50 meV

atmosphere

earth

e

e

p

70% Dark Energy

25% Dark Matter

4% H, He

0.5% Heavy Nuclei

0.5% Neutrinos

The Universe

m() ~ 50 meV

m() ~ 8 meV

m(e) ~ smaller

Large angles!

Also K2K, MINOS, others

-6 -5 -4 -2-3 -1 -0 1 2 3 4 5 6 7 8 9 10 11 12

eV meV eV MeVkeV GeV TeV

ud

ee

( )

( )

e? 0

-1e

2/3

-1/3du

1stGeneration Q

sc

2nd

cs

( )

( )“The Standard Model”

tb

( )

( )

bt

3rd

Quarks

Leptons

? ?

-6 -5 -4 -2-3 -1 -0 1 2 3 4 5 6 7 8 9 10 11 12

eV meV eV MeVkeV GeV TeV

ud

ee

( )

( )

e? 0

-1e

2/3

-1/3du

1stGeneration Q

sc

2nd

cs

( )

( )“The Standard Model”

tb

( )

( )

bt

3rd

Quarks

Leptons

Supernova SN87A

Feb.23, 198707:35 UT20 Neutrinos Detected(KAM, USA)

Emitted: 1057Reached Earth 1028Reached Detectors 1017Detected 20

A few hours later: Seen by telescope

Why are we here?

Sakharov-1967 B-Violation (also L-Violation)CP-ViolationNon-equilibrium (also no “wash-out”)

B-Violation (and L-Violation)

p-decayGUT scale or higherNot seen (but SN87A!)-oscillations and mass

CP-Violation

KM phase for quarks (requires 3 generations)CP-violation in leptons (requires 2 generations)

WHEN AND HOW DID IT HAPPEN?WHEN AND HOW DID IT HAPPEN?

Why are we here?

IT IS NOT ENOUGH TO TRADE B for L WE MUST ALSO CREATE B-L

IT IS NOT ENOUGH TO TRADE B for L WE MUST ALSO CREATE B-L

At Big Bang: B=0 , L=0 (also B-L=0) We need to create a nonzero B (also B-L?)

If we could create a nonzero L

and then trade B for L,

we could create a positive B.

“Leptogenesis” (other theories: GUT, electroweak) :

B and L violation in the standard model (but no B-L)

(qiqjqk) (qiqjqk) (qiqjqk) (ℓiℓjℓk)i,j,k = generations

“SPHALERON”: Connecting degenerate ground states

L and B can change (together) each by 3 UNITS (for Ng = 3)

B – L is conserved (and must be nonzero)

B + L is violated e.g. (B + L) = 6 is allowed

THE STANDARD MODEL CREATES (together) B AND LTHE STANDARD MODEL CREATES (together) B AND L

“instanton” terms:

QUARKS and LEPTONS

Note: ↔

is possible

ud

du

e-

e+

The universe is made of

Neutrino oscillations m() ≠ 0, very small

m() ~m2

MSeesaw mechanism: 0 mm M

L=0 AT BIG BANG BUT L ≠ 0 PROCESSES ARE ABUNDANT !

L=0 AT BIG BANG BUT L ≠ 0 PROCESSES ARE ABUNDANT !

<> ≠ 0, - mixing, heavy neutrino with mass M

Hence: is a Majorana neutrino

LEPTOGENESIS

The particle, which is its own antiparticle, is responsible for having

more particles than antiparticles in the universe

ERGO SUMERGO SUMNEUTRINONEUTRINO

At Big Bang: B = L = 0.

COGITOCOGITO

Majorana: L≠0 and (B-L)≠0 are allowed.Hence, the universe has L≠0 and B-L≠ 0 .LEADING TO B≠0 !!!(Elaborate quantitative estimates).

e.g. Buchmueller-Peccei-Yanagida

No evidence for subquarks and subleptons.

No reasonable dynamical theory

Perhaps it all happens

at the subparticle level !?

WarningWarning

.

And in 2056 – for Majorana’s 150th birthday

Why Qi = 0 for q’s and ℓ’s in one generation?

[ Qi = (-1) + (0) + 3(+2/3) +3(-1/3) = 0 ]

Why q and ℓ have simple charge ratios?

(0, -1)( +2/3, -1/3 )

Why three colors and three generations?

PREONS?PREONS? TOY MODELS?TOY MODELS?

Why p and e+ have same charge?

The Quark - Lepton Connection

Rishons HH+Seiberg

T

V

1 0 1

0 1 -1

0

0

-1-1

-1 1

T

V 0 3 3

3 3- 1/3

+ 1/33 3

0 3 3

Buchmann+Schmid

Anomaly cancellation: NH = NC = NG = 3

SU(3)H Singlets

Q SU(3) SU(3)H C

N N 3(B-L)T V

“Matter”

e+

u

d

TTT

TTV

TVV

VVV

(+1)

(+2/3)

(+1/3)

(0)

1

3

3

1

color

“Antimatter”

VVV

VVT

VTT

TTT

d

u

e-

(0)

(- 1/3)

(- 2/3)

(-1)

1

3

3

1

color

e- TTT

p TTT(TT)(VV)(VV)

e+ TTT

p TTT(TT)(VV)(VV)

Rishons

HH+Seiberg

T

V

1 0 1

0 1 -1

0

0

-1-1

-1 1

T

V 0 3 3

3 3- 1/3

+ 1/33 3

0 3 3

SU(3)H Singlets

Q SU(3) SU(3)H C

N N 3(B-L)T V

“Matter”

e+

u

d

TTT

TTV

TVV

VVV

(+1)

(+2/3)

(+1/3)

(0)

1

3

3

1

color

“Antimatter”

VVV

VVT

VTT

TTT

d

u

e-

(0)

(- 1/3)

(- 2/3)

(-1)

1

3

3

1

color

TO BREAK B-L WE NEED TO BREAK NSimplest J=0, Q=0, SU(3)H – singlet, SU(3)C – singlet

IS <VVVVVV> : BREAKS L, HENCE CREATES B

<VVVVVV>≠0 ERGO SUM<VVVVVV>≠0 ERGO SUM

V

Measuring Masses and Angles

Clues for Theory “Beyond the Standard Model”

Neutrino Astronomy

UHE Cosmic Neutrinos

Dark Matter

Z in Nucleosynthesis

- Less Double -Decay

- Decays

- Magnetic Moments

Heavy Sterile

Neutrino Masses, Leptogenesis and Beyond

ETTORE MAJORANAWAS NO FOOL

WAS BRILLIANT !!!