Future Prospect of Accelerator-based Neutrino Oscillation Experiments and other next generation experiments

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Future Prospect of Accelerator-based Neutrino
Oscillation Experimentsand other next generation
experiments

• Two of the essential gradients of lepto-genesis
• CP violation
• D(B-L) ?0 Majorana

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3 slits interferometer- possibility of CP
violation in nm?ne
Interferences
ne
n3 n1 n2 n3 n2 n1
3 slits
Dm23 x 10-3
n3 n2 n1
ne
nm
Interference

• Comparable amplitudes
• ? anti-n ?

ne
solar,Kamland Dm28 x 10-5
production
detection
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Importance of nm ? n e Appearanced CP
Violation in Lepton Sector in 3 generations
scheme

• ne disappearance 1- Pee ab Uai 2
  Real
• nm?ne at Dm2 3 x 10-3 eV2 interference of two
  Dm2s
• ?( small Ue3 small Dm122 ) Two comparable
  terms ? CPV

CPV ? sinq12 sinq23 sinq13 Dm212 (L/E)
sind Solar and Atmospheric n Solar LMA
solution? (large q12, relatively large Dm212)
Near max. mixing in atmospheric (q23p/4)
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Searches for non-zero q13
?13 with accelerator experiments

• ltE?gt O(GeV) ? appearance experiments
• P(?m??e) 1- sin2q23sin22?13sin2(1.27?m231L/E)
  many terms
• ? Appearance measurement of q13.
• ? P(nm?ne) also depends on d and
  mass hierarchy.

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Current Proposals on Reactor Experiments

• Acc LBL exp. and Reactor q13 exp. are
  complementary.
• Appearance signal versus Disappearance signal.
• Statistics Limited versus Systematic Limited
• Large CPV effect versus Pure q13 effect.
• Similar Time scale (2010)

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3-flavor Oscillation (simplified)
m3
Oscillation Probabilities when
m2
m1

• q23 nm disappearance

• q13ne appearance

common
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ne appearance probability at L/E 103 (km/GeV)
q13
CP conserving
solar n
matter effect
mass hierarchy
Sijsinqij, Cijcosqij

• Small numbers
• S13
• sinF21 0.03

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nm ? ne Appearance Measurements

• L/E3 x 102 (km/GeV)
• Three contributions
• 1 Term which is same for neutrinos and
  anti-neutrinos
• 2 CP violating term (constant in E)
• 3 Matter effect ( proportional to L or E at
  constant L/E)
• It is almost impossible to change distance or
  neutrino energy
• To get 23
• Compare Neutrinos and Anti-neutrinos
• Compare with reactor data
• CPV Make matter effect small
  (where 2 gt3)
• Low energy and relatively
  short distance
• Mass hierarchy Compare with higher energy
  measurements 3

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nm?ne oscillation probability in sub-GeV neutrinos
Depends on many parameters
matter
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Accelerator NeutrinosNear future

• T2K
• Nova

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T2K Collaboration

• 12 Countries
• Canada, France, Germany, Italy, Japan
• Korea, Poland, Russia, Spain,
• Switzerland, UK, USA
• 60 Institutes, 300 Ph.D. members
• Still growing
• Proposed in 2000, budget approved in 2004

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Non-zero mass of neutrinos ! Flavor Physics esp.
history of neutrino studies show full of
surprises ( Kamiokande for Kamioka Nucleon decay
Experiment ! )

• Emphasis lepton ID and the determination of En
• En and Detector technology
• 1. Look for un-expected in precision measurements
  of oscillation
• parameters
• 3 generation frame-work (paradigm) ?
• Consistency of Dm2 in disappearance and
  appearance processes
• Sub-process of flavor changing process ( in
  addition to oscillation)?
• Oscillation pattern
• 2. ne appearance
• The last mixing to be found
• q2345o q1234o, test q13 to 3o
• Determine future direction of neutrino experiment
  
• Lead to only one practically possible test of CPV
  in leptons
• Complex phase in mixing in light neutrinos ?
  leptogenesis?

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Main features of T2K

• The distance (295km) and Dm2 (2.5x10-3 eV2 )
• Oscillation max. at sub-GeV neutrino energy
• sub-GeV means QE dominant
• Event-by event En reconstruction
• Small high energy tail
• small BKG in ne search and En reconstruction
• Proper coverage of near detector(s)
• Cross section ambiguity
• Analysis of water Cherenkov detector data has
  accumulated almost twenty years of experience
• K2K has demonstrated BG rejection in ne search
• Realistic systematic errors and how to improve
• Accumulation of technologies on high power beam

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Beam energy QE is the best known process
1 10 En
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Narrow intense beam Off-axis beam
????_at_ Dm23x10-3eV2
Anti-neutrinos by reversing Horn current
OA0
nm flux
p decay Kinematics
OA2
OA2.5
0
OA3
En (GeV)
1
2
2.5
3
0
8
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Statistics at SK (OAB 2.5 deg, 1 yr, 22.5 kt)
2200 nm tot 1600 nm CC ne 0.4 at nm peak
0
2
pp (GeV/c)

• Quasi Monochromatic Beam
• Tuned at oscillation maximum
• Far/near simpler to evaluate

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Quasi-Elastic process
dE 60 MeV dE/E 10
QE
inelastic
CC 1p
En (reconstructed) En (true)
NC 1p
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PID in SK
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ne appearance q13
Off axis 2 deg, 5 years
at
CHOOZ excluded
Dm2
Off axis 2 deg, 5 years
sin22q13gt0.006
sin22q13
sin22q13 Estimated background in Super-K Estimated background in Super-K Estimated background in Super-K Estimated background in Super-K Estimated background in Super-K Signal (40 eff.) Signal BG
sin22q13 nm (NC p0) ne beam nm ne total Signal (40 eff.) Signal BG
0.1 12.0 10.7 1.7 0.5 24.9 114.6 139.5
0.01 12.0 10.7 1.7 0.5 24.9 11.5 36.4
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Sensitivity to q13 as a fuction of CP-phase d
d
d
KASKA 90 (NuFact04)
KASKA 90 (NuFact04)
sin22q13
d ?-? for n ?anti-n
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Disappearance En reconstruction resolution

• Good resolution of En determination is critical
  to observe depth of the dip (measure of sin22q)

dE60MeV lt10 meaurement
non-QE resolution
QE
inelastic
1-sin22q
En (reconstructed) En (true)
Dm2
10 bin High resolution less sensitive to
systematics
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Precision measurement of q23 , Dm223 possible
systematic errors and phase-1 stat.

• Systematic errors
• normalization (10(?5(K2K))
• non-qe/qe ratio (20 (to be measured))
• E scale (4 (K2K 2))
• Spectrum shape (Fluka/MARS ?(Near D.))
• Spectrum width (10)

OA2.5o
d(sin22q23)0.01 d(Dm223) lt110-4 eV2
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T2K Physics Sensitivity
nm disappearance
ne appearance (Strong d dependence )
(OA2.5?)
Stat. only
--68CL --90CL --99CL
Daya Bay 90 (NuFact04)
CHOOZ 90
Goal d(sin22q23)0.01
(0.08 MINOS EPS2007) d(Dm232)lt510-5
eV2
sin22q13
gt10 times improvement from CHOOZ Neutrino ?
Anti-neutrino, Reactor
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Status of JPARC
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J-PARC Facility
Hadron Beam Facility
Materials and Life Science Experimental Facility
Nuclear Transmutation
J-PARC Japan Proton Accelerator Research Complex
Joint Project between KEK and JAERI
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JPARC
Tunnel Tour
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The Neutrino Beam-Line
Target-Horn System
Target Station
Muon Monitoring Pit
Final Focusing Section
295km to Super-Kamiokande
Preparation Section
100m
SCFM at ARC Section
Beam Dump
Decay Volume
Near Neutrino Detector
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Full Reconstruction (October 2005 April 2006)
6000 ID PMTs were produced from 2002 to 2005 and
were mounted from Oct.2005 to Apr.2006.
All those PMTs were packed in acryic and FRP
cases.
Mount PMTs on a floating floor.
Pure water was supplied and SK-III data taking
has been running since July 11, 2006.
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Schedule of T2K
2004
2005
2006
2007
2008
2009
K2K
T2K construction
April 2009 n commissioning
SK full rebuild
Linac

MR

• Possible upgrade in future
• 4MW Super-J-PARC Hyper-K ( 1Mt water Cherenkov)
• CP violation in lepton sector
• Proton Decay

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Next stepMany possibilities

• Intensity Upgrade of MR
• R/D for upgrade/replacement of SK with a new
  hyper massive detector

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CPV and mass hierarchyIF q13 has reasonable
valueFunding agency
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CP Asymmetry
cross section, detection efficiencies ratios
for e/m differences in neutrino and
anti-neutrino Studied by T.Kobayashi
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Contamination of wrong sign components
nm beam
nm beam
right sign
wrong sign
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Cross sections
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CP asymmetry in T2K
dp/4 q12p/8
Both correction need to be estimated at 10 level
matter
F, s, e
Pure CPV
F,s,e cor.
ACPAobs-0.040.1
matter corr.
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Water Cherenkov Detector
2nd Phase (201x?) Hyper-Kamiokande(540kt)
1st Phase (2009, 5yrs) Super-Kamiokande(22.5kt)
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Other Possible choice
?
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Sensitivity for CPV in T2K-II
CHOOZ excluded sin22q13lt0.12_at_Dm3123x10-3eV2
Dm2126.9x10-5eV2 Dm3222.8x10-3eV2 q120.594 q23
p/4
stat5syst.
stat2syst.
(signalBG) stat only
stat10syst.
no BG signal stat only
T2K 3s discovery
T2K-I 90
3s CP sensitivity dgt20o for sin22q13gt0.01
with 2 syst.
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Proton decay limit from Super-K 100k ton year
already
Proton Decay may be there, just around the
corner Ultimate GUTs phenomena
2.9x1030 yr (minimal SUSY SU(5) )
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T2K to Korea ?
L1000-1200km, ? 1.0?-4.0?
Korea
J-PARC
hep-ph/0607255
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Nova at FNAL