road map of future neutrino physics a personal view
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Road Map of Future Neutrino Physics A personal view. Ken Peach Round Table discussion at the 6 th NuFACT Workshop Osaka, Japan 26 th July – 1 st August 2004. Key questions. Is the LSND effect real? (Desperately waiting for MiniBooNE) If LSND effect real - PowerPoint PPT PresentationTRANSCRIPT
Road Map of Future Neutrino PhysicsA personal view
Ken PeachRound Table discussion at the 6th NuFACT Workshop
Osaka, Japan
26th July – 1st August 2004
Ken PeachNuFact04, 26th July to 31st August 2004, Osaka, Japan
Key questions1. Is the LSND effect real?
• (Desperately waiting for MiniBooNE)• If LSND effect real
• What happens to the Standard Model?• What experimental programme is required?
2. Is 13>0?• Need T2K, “child-of-CHOOZ”, …
• If 13=0 (or <<1o)• Why?• What next?
3. What is the absolute mass scale?• KATRIN, 0, cosmology/astrophysics?
• It makes a difference if mlightest = 0eV, 10-10eV, 10-1eV
4. Do neutrinos have a Majorana component?• 0
• If not, why not?• If yes
• How to measure the phases?• What is the Majorana mass mechanism?
Ken PeachNuFact04, 26th July to 31st August 2004, Osaka, Japan
Let us assume
• LSND is not confirmed
• 13>0
• 13 precisely– Need to understand the hierarchy of the angles
• Phase angle precisely– Need to look for CP/T violation– may not be large
• Determine the sign of m223
– Possibly parasitic on one of the above
• Determine the absolute mass scale– KATRIN, 0, cosmology/astrophysics
• Look for 0
… then we need to measure…
When?
Note
LSND apart
SK, SNO, KL, K2Kshow that
non-standard effects
are
smallsmall
Ken PeachNuFact04, 26th July to 31st August 2004, Osaka, Japan
Oscillations: What to Measure?
Neutrinos
e disappearance
e appearance
e appearance
disappearance
e appearance
appearance
… and the corresponding antineutrino interactions
Note: the beam requirements for these experiments are:
high intensity known flux
known spectrum known composition (preferably no background)
Ken PeachNuFact04, 26th July to 31st August 2004, Osaka, Japan
CP sensitivitydomain of 99% CL effect for maximal CP violation
Bouchez
Degeneracies – need complementary measurements
(baselines, energies, flavours, channels)
Ken PeachNuFact04, 26th July to 31st August 2004, Osaka, Japan
How to get there?
Build the Neutrino Factory as soon as
possible
Numi/CNGS,Off-Axis Beams, SuperBeams,
Beta Beam,Neutrino Factory
The Fast Train The Slow Train
Ken PeachNuFact04, 26th July to 31st August 2004, Osaka, Japan
How to choose?
The Fast Train• Advantages
– fastest route• (possibly)
– cheapest route• (possibly)
• Disadvantages– money
• (big commitment)
– politics• (related to money)
The Slow Train
• Advantages– incremental
• (duplication?)– lower risk
• (e.g. if no CPV)
• Disadvantages– costs more
• (duplication)– may never get there
• (why measure better?)
Ken PeachNuFact04, 26th July to 31st August 2004, Osaka, Japan
A Neutrino Factory is …
… an accelerator complex designed to produce >1020 muon decays per year directed at a detector thousands of km away
Principal Components
High Power H(-) sourceProton
DriverTarget Capture
Co
olin
g
Muon Acceleration
‘near’ detector (1000-3000km)
‘far’ detector (5000-8000km)
Muon
Storage
Ring
‘local’ detectors
Ken PeachNuFact04, 26th July to 31st August 2004, Osaka, Japan
Neutrino Factory Challenges
• Technology– Proton driver
• RCS or LINAC?– Proton energy?
• HARP, E910, MIPP– Target
• MW beam power– Mercury, solid, liquid-cooled, pellet, …
– Pion/muon collection and/or cooling• Magnetic Horns or Solenoids?• Phase Rotators, FFAG’s, cooling (ring, linear, …)?
– RF and acceleration• RLA’s or FFAG’s?
– Muon Storage Ring• Racetrack, triangular or bow-tie• Conventional or FFAG?
Options
2
6
3
2 x 6
2
3 x 2
5184
72
Some don’t work – divide by 2
¾ don’t make any sense
36
9
Not all match efficiently
~ 9 feasible NF designs!!!!
Ken PeachNuFact04, 26th July to 31st August 2004, Osaka, Japan
Neutrino Factory R&D
• High Power proton drivers – MW power, ns pulses
• RF – 30% of the cost?
• Cooling– How much? (20% of
the cost?)
• RLA or FFAG?– Which is cheaper?
BNL Feasibality Study 2
Ken PeachNuFact04, 26th July to 31st August 2004, Osaka, Japan
Summary
• My view
– we will need a neutrino factory
• especially if the neutrino sector is more complicated than 3 generation mixing
– there are enough technology options to be confident that it will work
• but we need demonstrators
– need to avoid (too much) duplication• (how many Megaton Water Cerenkov’s equal one
Neutrino Factory?)