Neutrino Physics

José BernabéuIFIC-University of ValenciaDecember 2007

History and Interest First evidence of neutrino masses Origin of masses? - Experiment - Beyond Standard Model Dimension 5: Majorana ’s Grand Unification Scale: See-saw Leptogenesis CP-violation Future experiments Neutrino oscillations & Underground Physics

Neutrino Physics

The Birth of the Neutrino

History: Up’s & Down’s 1930 Pauli, 1933 Fermi 1956 Cowan & Reines 1957 Two-component theory: Weyl Argument in

favour of vanishing m Only L in weak interactions

Goldhaber experiment

1958 (V-A) theory CHIRAL Fields enter FOR ALL Fermions

Nothing special for ’s No reason why m =0 BUT: eR, qR needed QED, QCD 1967 Standard Model “choice”: no R m=0 1998 m 0 experimentally…

Dirac Mass 0

Neutrino Experiments

Neutrino flavour oscillations

2512

2

2323

2

108

104.2

eVm

eVm

What is known, what is unknown

81.02sin

00.12sin

122

232

o1013 ?

Majorana neutrinos ? 0: masses and phases

Absolute neutrino masses ? 3 H beta decay

Form of the mass spectrum Matter effect in neutrino propagation

Origin of masses

Why are Neutrino Masses so small?

even for a smooth LOG – scale…

The Pontecorvo MNS Matrix

3

2

1

Ue

100

0

0

0

010

0

0

0

001

1212

1212

1313

1313

2323

2323 cs

sc

ces

esc

cs

scUi

i

For Flavour oscillations U: 3 mixings, 1 phase

Atmospheric K2K MINOS, CNGS

Appearence e!Reactor DisappearenceMatter in Atmospheric

SolarKAMLAND

Neutrino oscillations

)4

sin(4

)4

cos(~

)4

(sin2sin

)4

(sin2sin)(

ceInterferen

213

212

213

Solar

2122

1222

23

cAtmospheri

2132

1322

23

E

Lm

E

Lm

E

LmJ

E

Lmc

E

LmsP e

Appearance probability:

|Ue3| gives the strength of Pe→νμ

After atmospheric and solar discoveries and accelerator and reactor measurements → 13 , CP violation accessible in appearance experiments

δ acts as a phase shift

Beta/EC CERN Beam ?

Two methods:

- Neutrino vs. Antineutrino

- Energy Dependence

LSC: Laboratorio Subterráneo de Canfranc