Neutrino Physics - Istituto Nazionale di Fisica Nucleare

Neutrino Physics
Carlo Giunti
INFN, Sezione di Torino, and Dipartimento di Fisica Teorica, Universita` di Torino mailto://[email protected]
Neutrino Unbound: http://www.nu.to.infn.it
CERN, 12–15 May 2009
C. Giunti and C.W. Kim Fundamentals of Neutrino Physics and Astrophysics Oxford University Press 15 March 2007 – 728 pages
C. Giunti Neutrino Physics CERN, 12–15 May 2009 1

Part I: Theory of Neutrino Masses and Mixing Dirac Neutrino Masses and Mixing Majorana Neutrino Masses and Mixing Dirac-Majorana Mass Term
C. Giunti Neutrino Physics CERN, 12–15 May 2009 2

Part II: Neutrino Oscillations in Vacuum and in Matter Neutrino Oscillations in Vacuum CPT, CP and T Symmetries Two-Neutrino Mixing and Oscillations Neutrino Oscillations in Matter
C. Giunti Neutrino Physics CERN, 12–15 May 2009 3

Part III: Phenomenology of Three-Neutrino Mixing Solar Neutrinos and KamLAND Atmospheric Neutrinos and LBL Three-Neutrino Mixing Absolute Scale of Neutrino Masses Experimental Neutrino Anomalies Conclusions
C. Giunti Neutrino Physics CERN, 12–15 May 2009 4

Part I Theory of Neutrino Masses and Mixing
C. Giunti Neutrino Physics CERN, 12–15 May 2009 5

Fermion Mass Spectrum

m [eV]

1012
t
1011

1010

b

c

109

τ

s

108

µ

ντ

107

d

6

u

10
e

νµ

105

104

103

102

10

νe

1

10−1

C. Giunti Neutrino Physics CERN, 12–15 May 2009 6

Dirac Neutrino Masses and Mixing
Dirac Neutrino Masses and Mixing Dirac Mass Higgs Mechanism in SM Dirac Lepton Masses Three-Generations Dirac Neutrino Masses Massive Chiral Lepton Fields Massive Dirac Lepton Fields Mixing Flavor Lepton Numbers Mixing Matrix Standard Parameterization of Mixing Matrix CP Violation Jarlskog Rephasing Invariant Maximal CP Violation Lepton Numbers Violating Processes
Majorana NeutrinCo. GMiunati sseNseutarinnodPhMysicisxinCgERN, 12–15 May 2009 7

◮ Dirac Equation: (i /

Dirac Mass m) (x) = 0 (/

­)

◮ Dirac Lagrangian: L (x) = (x) (i / m) (x)

◮ Chiral decomposition: L PL

1 ­5

PL

2

1 + ­5

PR

2

R PR PL2 = PR2 = 1

= L+ R PLPR = PR PL = 0

L = Li / L + R i / R m ( L R + R L)

◮ In SM only L =µ no Dirac mass

◮ Oscillation experiments have shown that neutrinos are massive

◮ Simplest extension of the SM: add R
C. Giunti Neutrino Physics CERN, 12–15 May 2009 8

Higgs Mechanism in SM

◮ Higgs Doublet: Φ(x) =

+ (x ) 0 (x )

Φ 2 = ΦÝΦ =

Ý
+

++

Ý
00

◮ Higgs Lagrangian: LHiggs = (D Φ)Ý(D Φ) V ( Φ 2)

◮ Higgs Potential: V ( Φ 2) = 2 Φ 2 + Φ 4

◮ 2 0 and

0 =µ V ( Φ 2) =

22

Õ 2

Φ2

v 2

, with v

µ ◮

Vacuum:

Vmin for

Φ

2

=

v2 2

=

Φ = Ô1 0
2v

◮ Spontaneous Symmetry Breaking: SU(2)L ¢ U(1)Y

◮ Unitary Gauge: Φ(x) = Ô1

0

2 v + H(x)

U(1)Q

C. Giunti Neutrino Physics CERN, 12–15 May 2009 9

H
φ+
C. Giunti Neutrino Physics CERN, 12–15 May 2009 10

φ0