Fermilab, May, 2003

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Fermilab, May, 2003 Takaaki Kajita, ICRR, U.
Tokyo
The JHF-Kamioka neutrino project
Outline
Introduction JHF-Kamioka neutrino project
-overview- Physics in phase-I Phase-II
Summary
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Introduction
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SK atmospheric neutrino data
1489day FCPC data 1678day upward going muon
data

• Whole SK-1 data have been analyzed.

1-ring e-like 1-ring µ-like multi-ring
µ-like up-going µ
stopping
lt 1.3GeV
No osc.
Through going
Osc.
gt 1.3GeV
Up-going Down-going
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Oscillation parameters
?µ??t 90C.L.
Limit on ?13
Kamiokande
Soudan-2
SK
MACRO
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K2K
250km
En
En
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K2K data and oscillation
Data 1999 July 2001
NSK ( of event) 56 events observed
80.16.2/-5.4 ev. exptd null oscillation prob.
1.3

Best fit point (sin22q , Dm2) (1.0,
2.8x10-3eV2)
Consistent with SK atm.
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Next
MINOS (end of 2004) Detail
study of oscillations.
CNGS (OPERA, ICARUS) (2006) t appearance.
Next2
JHF-Kamioka neutrino project
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JHF-Kamioka neutrino project -overview-
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Main goals
Main physics goals in JHF-I neutrino exp.
?Precise determination of neutrino oscillation
parameters. Accuracy sin22?
1 ?m2
a few ?Discovery and measurement of non-zero
? sin22? gt 0.01
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13
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Main physics goal in JHF-II
?Discovery and measurement of non-zero CP phase
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JHF-Kamioka neutrino project overview-
lt 1 GeV ?µ beam
0.75 MW 50 GeV PS
50 kton Water Cherenkov
Future
Future
1Mt Hyper Kamiokande
4MW 50GeV PS
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Present collaboration
UK Poland France Switzerland Italy
Spain
Korea Japan China
Russia
Canada USA
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J-PARC(JHF) Facility
Construction 20012006 (approved)
n beam-line detectors budget request will be
submitted soon.
(0.75MW)
JHF NuMI (FNAL) K2K
E(GeV) 50 120 12
Int.(1012ppp) 330 40 6
Rate(Hz) 0.275 0.53 0.45
Power(MW) 0.75 0.41 0.0052
To SK
Near detectors (280m,2km)
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Primary proton beamline Overview-
50GeV PS
Preparation section Normal conducting
Arc R105m Super conducting Dipole
Quadrapole combined function magnet

• Single turn fast extraction
• 8 bunches/5ms
• 3.3x1014proton/pulse
• 3.64 sec cycle
• 1yr1021proton on target(POT)

Final Focusing Section Normal conducting
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(No Transcript)
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J-PARC construction
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J-PARC LINAC construction (Apr.03)
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The beam Off axis beam
2.50.5?
(ref. BNL-E889 Proposal)
800 CC ?µ / year
Ep vs. E?
2200 CC ?µ / year
OA1
0.0?
E?
OA2
1.0?
OA3
1.5?
2.0?
3.0?
5.0?
Ep
Max. osc. energy for 310-3eV2
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Target and horns (preliminary design)
Target Graphite (f25-30mm) w/ water cooling
Temperature rise due to radiation
320kA
Horn
320kA
320kA
1.5m 0.5m 2.0m
3.5m 2.5m
Need much more detailed studies
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Decay tunnel design
130 meters
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Decay pipe cooling and heat simulation
Non-static heat simulation 0.5yr_at_4MW, 0.5yr no
beam Upto 30yrs Max _at_ 29.5yr
Iron part Max 54o
Concrete Max 121o
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Detector system
p
p
n
140m
0m
280m
2 km
295 km
?
µ
?
SK
Near detector _at_2km (_at_50m underground)
Muon detector
Water Cherenkov detector
Fine grained scintillater detector
8m
? beam
8m
15.2m
5m
Total mass 1000ton
Fid. Mass 100ton
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Event rate Far/near ratio
2
6 /100ton/spill _at_280m
_at_280m
2
Not a good place.
1
(ffar / fnear)(Lfar / Lnear)
0
_at_2km
0.1 /100ton/spill _at_2km
OK !
1
Distance from target (km)
Water Cherenkov Impossible _at_280m (Total mass gt
100 tons)
0
0
1
2
3
E?(GeV)
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Near detector _at_1.84km
Candidate site (Owner Tokai-village (local
government))
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Physics in Phase-I
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Reconstruction of E?
For single Ch ring events
Eµ, ?µ
E?
Super-K w/ JHF beam
Quasi-elastic
JHF E?
Non-QE
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Quasi-elastic and other interactions
High E? non-quasi-elastic interactions cause
problems. Minimize the high energy (above the
max. osc. energy) neutrino flux.
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Single ring (muon-like) in Super-K
Data sample SK Monte Carlo, Fully-contained
single-ring, muon-like events.
p
p
Event fraction
Typical JHF neutrino energy
Important to run the experiment with low energy
beam.
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Measurement of sin 2?23
(OA 2deg)
OA 3deg
1
OA 2deg
2 4 10-3eV2
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?m2 dependence of the sensitivity
Off-axis angle should be adjusted to about 0.1
deg.
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?13
Present status
Allowed
Signal for non-zero ?13 in JHF-SK (?µ??e)
BG (NC p0 .)
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?e beam contamination
OAB (2degree)
nm
0.2
m-decay
ne
K-decay
?e/?µ ratio0.2 at the spectrum peak.
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Number of signal events and BG
Dm23x10-3eV2, sin22q130.1
OAB 2deg., 5yrs
nmC.C. nmN.C. Beam ne Osc'd ne
Generated 10713.6 4080.3 292.1 301.6
1ring e-like 14.3 247.1 68.4 203.7
red. eff. 0.1 6.1 23.4 67.5
e/p0 sep. 3.5 23.0 21.9 152.2
red.eff. 0.03 0.6 7.5 50.4
.4ltEnlt1.2 1.8 9.3 11.1 123.2
red.eff. 0.02 0.2 3.8 40.8
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e/p0 separation

• Shower direction w.r.t. beam
• (1) cosqne p0 tend to have a forward peak
• Force to find 2nd ring and
• (2) E(g2)/E(g1g2) Large for BG
• (3) Likelihood diff. between 1 and 2-ring
  assumptions
• (4) Invariant mass Small for ne

(1)
(2)
(3)
(4)
Select
BG
?e
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Measurement of sin22?13
?m2
JHF sensitivity
Expected signal for
CHOOZ limit
1/20
OA 2deg 5yrs
sin22?13
2
sin 2?13 ?µ(CCNC) Bean ?e Oscd ?e SignalBG
0.1 11.1 11.1 123.2 145.5
0.01 11.1 11.1 12.3 34.5
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Phase-II
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JHF Phase-II
?0.77 ? 4 MW beam power ?1 Mton detector
(Hyper-Kamiokande)
106 events
CP Violation
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Assumptions
(unless otherwise stated)
Solid line w/ matter Dashed line w/o matter
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Neutrino and anti-neutrino runs
1021pot/yr (1st phase)
Important to understand the wrong sign
contamination
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Expected CP violation signal(1)
sin22q130.1
Dm31lt0
3s stat only
3s stat2 syst.
of e events including BG
90C.L. stat only
90C.L. stat2 syst.
Dm31gt0
CP phase
of e- events including BG
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Expected CP violation signal (2)
sin22q130.01
Dm31lt0
3s stat only
3s stat2 syst.
of e events including BG
90C.L. stat only
90C.L. stat2 syst.
Dm31gt0
CP phase
of e- events including BG
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3s CP sensitivity
CHOOZ excluded sin22q13lt0.12_at_Dm3123x10-3eV2
sin22?13
stat5syst.
stat2syst.
(signalBG) stat only
stat10syst.
no BG signal stat only
JHF-I No indication for sin22?13
sind
3s CP sensitivity dgt20o for sin22q13gt0.01
with 2 syst.
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Decay Pipe Common for SK/HK
Possible site for Hyper-K
SK
8 km
Beam center
HK
Common off-axis angle (2-3 degrees) for both
Super-K and Hyper-K
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Summary
? Main goals of JHF-Kamioka neutrino project
(Phase-I) ?Precise determination of neutrino
oscillation parameters. Accuracy
sin22? 1 ?m2
a few ?Discovery and measurement
of non-zero ?13 sin22? gt
0.01 ? Main goals of JHF-Kamioka neutrino
project (Phase-II) ?Discovery and measurement
of non-zero CP phase ? Design works are in
progress hoping to start the experiment by (the
end of 2007 or) early 2008.
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