Post on 15-Jan-2016
Neutrino Oscillation Physics Neutrino Oscillation Physics at a Neutrino Factoryat a Neutrino Factory
Rob Edgecock RAL/CERN-ABRob Edgecock RAL/CERN-AB
OutlineOutline
• Neutrino Factory accelerator
• “ “ detector
• Reminder of phenomenology
• Atmospheric parameters
• Sign of m223
• 13 and
• Degeneracies
• Conclusions
Neutrino Factory AcceleratorNeutrino Factory Accelerator
Important parameters:Important parameters:
Muon energyMuon energy = 20 or 50 GeV Intensity= 20 or 50 GeV Intensity= 10= 102121 muon decays/year
Neutrino Factory AcceleratorNeutrino Factory Accelerator
Advantages of a Neutrino Factory:Advantages of a Neutrino Factory:
• Muon decay:Muon decay:
• Pure beam of equal numbers of Pure beam of equal numbers of and and ee
• Can look for:Can look for:
• First requires “simple” detectorFirst requires “simple” detector
• High intensity (especially High intensity (especially ee))
• Precisely known intensity and compositionPrecisely known intensity and composition
• Precisely known energy spectraPrecisely known energy spectra
ee
e
e
Neutrino Factory DetectorsNeutrino Factory Detectors
Magnetised iron calorimeter
20m long 10m radius 40kT
Events in 1 year:Events in 1 year:
1.0x1052.4x1061.2x1063500km
1.1x1055.9x1073.5x107732km
Signalsin213=0.01
Baseline CC CCe
Neutrino Factory DetectorsNeutrino Factory Detectors
For For ee or or identificationidentification
Liquid argon TPC, etcLiquid argon TPC, etc
e-id up to 5 GeVe-id up to 5 GeV
Neutrino Factory DetectorsNeutrino Factory Detectors
LANNDDLANNDD
- 70kT70kT
- 61m x 44m61m x 44m
- up to 1Tup to 1T
- 18.5MA18.5MA
- coil: 71kTcoil: 71kT
- yoke: 677kTyoke: 677kT
PhenomenologyPhenomenology
P(e) to lowest order in the matter effect:
where
To first order, ignoring matter effect and CP:To first order, ignoring matter effect and CP:
PhenomenologyPhenomenology
20 GeV 20 GeV NF at NF at
3500km3500km
PhysicsPhysics
• Precise measurement of atmospheric parametersPrecise measurement of atmospheric parameters
• Sign of Sign of mm222323
• 1313
•
• Solar parametersSolar parameters
• ee
PhysicsPhysics
From Bueno et al Nucl Phys B589 (2000) 577
Characterise as: - electrons - right-sign muons - wrong-sign muons - others
Plots are for: E = 30 GeV L = 7400 km 1020
decays 10 kT detector
Atmospheric ParametersAtmospheric Parameters
Fitting to plots, after kinematic cutsFitting to plots, after kinematic cuts
No background Perfect resoln
Background and resoln
Resolutions achieved:Resolutions achieved: 1% in1% in10% in10% in
223m
232sin
Sign of Sign of mm22
Only Only ee have CC interactions with have CC interactions with electrons in matterelectrons in matter
eeffective massffective mass
Modifies transition probability:Modifies transition probability:
EnGA eF22
E
LmP e 4
sinsin2sin2232
232
132
E
mP m
e 4
27.1sinsin2sin
2232
232
132
wherewhere
21313
213
2
132
2cos2sin
2sin2sin
xm
21313
2 2cos2sin xL
223m
Ax
Sign of Sign of mm22
Integrated
Energy bins
2x102x102020 muon decays SMA muon decays SMA parametersparameters
………….in case where one/both solar parameters small!.in case where one/both solar parameters small!
• Determined from a fit to energy spectraDetermined from a fit to energy spectra
• This time, wrong sign muons dominateThis time, wrong sign muons dominate
No background Background
90% CL90% CL
732km
3500km
7332km
• Probably the most important parameterProbably the most important parameter
•
• The good newsThe good news
23131223131213 sinsinsinsin2sin2sin2sin2
1~)()( cPP ee
• The bad news…….matter effect…….The bad news…….matter effect…….
• ………….and correlations……...and correlations……..
• ………….and degeneracies.and degeneracies
13=8o, =-90o, 0o, 90o, 180o
DegeneraciesDegeneracies
Degeneracy: 2 or more parameter sets fit the same data
Three types, all of which can effect measurement of & 13:
1313 ',',
223
223 mm
4,
2 232323
(1)
(2)
(3)
They limit the accuracy of the parameter measurement
,',' 1313 ee
PP
,',' 1313 ee
PP (1)
DegeneraciesDegeneracies
E
Lm
E
Lm
44cot2sincotcos'
,'212
213
12231313
13
large
NB depends on L/E possible solutions
• Two baselines and E-dependence at NF
• NF + SB combination
• Two off-axis detectors
• e as well as e
13=8o, =-90o, 0o, 90o, 180o
DegeneraciesDegeneracies
NuFact at 2810km + SB at 130KM
NuFact at 732km + SB at 130KM
large
small
Silver ChannelSilver Channel
Golden:Golden:
Silver:Silver:
e
e
40kT magnetised iron at 3000km40kT magnetised iron at 3000km
4kT emulsion at 732km4kT emulsion at 732km
Parameters:Parameters: = 90= 90oo
= 5= 5oo
Lines of Lines of equivalent equivalent probabilityprobability
Solve ambiguities for all Solve ambiguities for all and and 11oo
SensitivitiesSensitivities
Intermediate and long baseline best Intermediate and long baseline best Resolution: Resolution: ~0.1~0.1o o for for 1313
~20~20oo for for
ComparisonsComparisons
90% CL
JHF-HK = 4MW, 1000kT; 6 years , 2 years
NuFact-II = 5.3 x1020 useful /yr, 50kT; 4 years
ComparisonsComparisons
ConclusionsConclusions
• Neutrino Factory is the ultimate long baseline facilityNeutrino Factory is the ultimate long baseline facility
• In one year……In one year……
atmospheric parameters:atmospheric parameters:
sign of :sign of : 400400sinsin2213 13 :: 4 x 104 x 10-4 -4 at 90% CLat 90% CL ::
9090oo to <2 x 10 to <2 x 10-5 -5
• The only serious competition from combinations of othersThe only serious competition from combinations of others
• Can also do a wide range of other physics:Can also do a wide range of other physics:- short baseline, high intensity neutrino physics- short baseline, high intensity neutrino physics - -
high intensity slow muon physicshigh intensity slow muon physics - test - test bed for other projects: bed for other projects: muon collidermuon collider
proton machines proton machines
1% in 1% in 10% in10% in
223m
232sin
223m