2. Future neutrino experiments
The road-map…
and a few itineraries
Three family oscillations
Low energy Super-beam: JHF
CERN-SPL … and beta-beam
Neutrino Factory
Neutrino Factory R&D
and new developments:
EMCOG, MICE, ring cooler
BENE and design studies
Conclusions

3. Physics with accelerators can be divided broadly into two classes
Physics at the high energy frontier (LHC, NLC, CLIC).
Presently this searches experimental confirmation of our
explanations for the electroweak symmetry breaking. Higgs, Supersymmetry etc..
2. Precision measurements of particle properties and rare processes
B factories, neutrino physics, m-> e g, tests of QED and QCD
Neutrinos are fascinating because it was recently discovered that they have a mass and…
That their masses are VERY different from those of the other particles.
The mass and mixing
of neutrinos seem to
originate at very high
energies
(see-saw mechanism)
Today we will describe new types of accelerators for neutrino physics (and more):
NEUTRINO FACTORIES and BETA BEAMS

4. neutrino definitions
the electron neutrino is present in association with an electron (e.g. beta decay)
the muon neutrino is present in association with a muon (pion decay)
the tau neutrino is present in association with a tau (Wtn decay)
these flavor-neutrinos are not (as we know now) quantum states of well defined mass (neutrino mixing)
the mass-neutrino with the highest electron neutrino content is called n1
the mass-neutrino with the next-to-highest electron neutrino content is n2
the mass-neutrino with the smallest electron neutrino content is called n3

5. Neutrino Oscillations (Quantum Mechanics lesson 5)
source
propagation in vacuum -- or matter
detection L
weak interaction
produces
‘flavour’ neutrinos
e.g. pion decay p  mn
¦nm> = a ¦n1 > + b ¦n2 > + g ¦n3 >
weak interaction: (CC)
nm N  m- C
or ne N  e- C
or nt N  t- C
P ( m  e) = ¦ < ne ¦ n (t)>¦2
Energy (i.e. mass) eigenstates
propagate
¦n (t)> = a ¦n1 > exp( i E1 t)
+ b ¦n2 > exp( i E2 t)
+ g ¦n3 > exp( i E3 t)
t = proper time  L/E

6. Lepton Sector Mixing
Pontecorvo 1957

7. Oscillation Probability
Hamiltonian= E = sqrt( p2 + m2) = p + m2 / 2p
for a given momentum, eigenstate of propagation in free space are the mass eigenstates!

8. To complicate things further: matter effects
elastic scattering of (anti) neutrinos on electrons
ne,m,t
ne,m,t ne e- Z W- e- e- ne e-
all neutrinos and anti neutrinos do this equally
only electron neutrinos ne e- W-
These processes add a forward amplitude to the Hamiltonian,
which is proportional to the number of elecrons encountered
to the Fermi constant and to the neutrio energy.
The Z exchange is diagonal in the 3-neutrino space
this does not change the eigenstates
The W exchange is only there for electron neutrinos
It has opposite sign for neutrinos and anti-neutrinos (s vs t-channel exchange)
D=  22 GF neEn THIS GENERATES A FALSE CP VIOLATION ne e-
only electron anti- neutrinos

9. Hflavour base= D=  22 GF neEn nm,t ne En or density
This is how YOU can
solve this problem:
write the matrix,
diagonalize,
and evolve using,
Hflavour base=
This has the effect of modifying the eigenstates of propagation!
Mixing angle and energy levels are modified, this can even lead to level-crossing. MSW effect
antineutrino
neutrino
nm,t
m2n ne
m2n
En or density
En or density
oscillation is further suppressed
resonance… enhances oscillation
oscillation is enhanced for neutrinos if Dm21x >0, and suppressed for antineutrinos
oscillation is enhanced for antineutrinos if Dm21x <0, and suppressed for neutrinos
since T asymmetry uses neutrinos it is not affected