JHF-Kamioka Neutrino Oscillation Experiment using JHF 50 GeV PS

1
JHF-Kamioka Neutrino Oscillation
ExperimentusingJHF 50 GeV PS

• Introduction
• Facility
• Physics goal
• Summary

• Y.Itow
• ICRR,Univ.of Tokyo
• Jul27,2002
• ICHEP02 Amsterdam

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Where we go ?
Discovery Phase
Cosmic ray
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3 Flavor Mixing
Dm212, Dm223
q12, q23, q13 d
MNS (Maki-Nakagawa-Sakata) matrix
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3-flavor Oscillation
Oscillation Probabilities when

• q23 nm disappearance

• q13ne appearance

common
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Strategy

• High statistics by high intensity n beam
• Tune En at oscillation maximum
• Narrow band beam to reduce BG
• Sub-GeV n beam for Water Cherenkov

0.75MW JHF 50GeV-PS
Off-Axis n beam
Super-Kamiokande
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JHF-Kamioka Neutrino Experiment
(hep-ex/0106019)
Plan to start in 2007
1GeV n beam
Kamioka
JAERI (Tokai)
Super-K 22.5 kt
0.75MW 50 GeV PS
( conventional n beam)
JHF 0.75MW Super-Kamiokande
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Organization

• Experiment working group
• Dec.1999 formed (ICRR/KEK/Kyoto/Kobe/Tohoku/TRIU
  MF)
• Jun.2001 Letter of Intent (hep-ex/0106019)
• Mar.2002 Meeting to discuss possibility to
  organize
• international collaboration

• Facility Construction Group
• Officially formed in KEK on April, 2001
• The 3rd physics division, IPNS, Cryogenic
  facility group, Cryogenic Science Center, w/
  strong support from KEK-PS beam channel group

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JHF-SK Neutrino Working Group

• ICRR/Tokyo-KEK-Kobe-Kyoto-Tohoku-TRIUMF

Y. Itow, T. Kajita, K. Kaneyuki, Y.Obayashi,
C.Saji, M. Shiozawa, Y. Totsuka (ICRR/Tokyo) Y.
Hayato, A.Ichikawa, T. Ishida, T. Ishii, T.
Kobayashi, T. Maruyama, K. Nakamura, Y. Oyama,
M. Sakuda (KEK) S. Aoki, T.Hara, A. Suzuki
(Kobe) T. Nakaya, K. Nishikawa (Kyoto) T.
Hasegawa, K. Ishihara (Tohoku) A.Konaka (TRIUMF,
CANADA)
In addition to the above user group, the neutrino
facility construction group is OFFICIALLY formed
at KEK.
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JHF Facility
Construction 20012006 (approved)
Transport line (Super-cond. Mag.)
n beam-line budget request submitted
(0.77MW)
Target station

• 8 bunches/5ms
• 3.3x1014proton/pulse
• 3.94 (3.64) sec cycle
• 1yr1021POT (130 days)

Decay volume
Near detectors (280m,2km)
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Off Axis Beam
(ref. BNL-E889 Proposal)
Osc. Prob.sin2(1.27Dm2L/En)

• Quasi Monochromatic Beam
• x23 intense than NBB

Oscillation probablity
Dm23x10-3eV2 L295km
osc.max.
Statistics at SK (OAB2deg,1yr,22.5kt) 4500
nm tot 3000 nm CC ne 0.2 at nm peak
OA2
102 x (K2K)
nm
Tuned at oscillation maximum
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En reconstruction in water Cherenkov
Assume CC Quasi Elastic (QE) reaction
m
p
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Detectors
p
p
n
140m
0m
280m
2 km
295 km

• Muon monitors _at_ 140m
• Spill-by-spill monitoring of beam direction
• First Front detector _at_280m
• Neutrino intensity/direction
• Second Front Detector _at_ 2km
• Almost same En spectrum as for SK
• Water Cherenkov can work
• Far detector _at_ 295km
• Super-Kamiokande (50kt)

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Far detectorSuper-Kamiokande
(since Apr 1996)
50,000 ton water Cherenkov detector (22.5 kton
fiducial volume)
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Re-Construction of Super-K (Jul 2002)
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Physics Goal
?Precise measurement of neutrino mixing matrix
Accuracy sin22?23 1
?m223 a few ?Discovery
and measurement of non-zero ?13
sin22?13 gt 0.006
1st Evidence of 3-flavor mixing !
1st step to
CP measurement
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Measurement of sin2 2?23 , Dm223
nm disappearance
sin22q
3
Dm2
d(sin22q)0.01 d(Dm2) lt110-4
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ne appearance in JHF-Kamioka

• Back ground for ne appearance search
• Intrinsic ne component in initial beam
• Merged p0 ring from nm interactions

10 uncertainty for BG estimation
The 1kt p0 data will be studied for exercise
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sin22q13 from ne appearance
Off axis 2 deg, 5 years
at
CHOOZ excluded
Dm2
Off axis 2 deg, 5 years
Sin22q13gt0.006
0.5 sin22q13
sin22q13 Background in Super-K (as of Oct 25, 2001) Background in Super-K (as of Oct 25, 2001) Background in Super-K (as of Oct 25, 2001) Background in Super-K (as of Oct 25, 2001) Background in Super-K (as of Oct 25, 2001) Signal Signal BG
sin22q13 nm ne nm ne total Signal 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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Future upgradeSuper-JHF(4MW)Hyper-K(1Mt)
Good for atm. n proton decay
1,000 kt
Candidate site in Kamioka
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Sensitivity(3s) to CP violation (SuperJHFHyper-K)
Chooz excluded
_at_Dm313x10-3eV2
dgt14deg
dgt27deg
Preliminary
JHF1 3s discovery
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Global Schedule
2002
2004
2006
2008
2010
JHF-n construction
physics run (OAB)
SK rebuild
SK-half
SK-full
MINOS 2yr
OPERA 5yr
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Summary

• Precision study of neutrino mixing matrix
• Next step after the discovery
• We may find a hint for next break-through
• JHF-Kamioka neutrino experiment (2007)
• JHF 0.75MW 50GeV-PSOff Axis beamSuper-K
• Narrow band beam at oscillation maximum ( 1GeV)
• ne appearance, discovery of q13 (sin
  q13gt0.006,90CL)
• Budget request submitted, RD started
• Possible upgrade in future
• 4MW Super-JHF Hyper-K ( 1Mt water Cherenkov)
• CP violation in lepton sector
• Bonus ! (Proton Decay ! )