1
JHFnu (phase I) neutrino oscillation experiment
For JHF-SK Neutrino Experiment collaboration
Atsuko Kondo-IchikawaKEK
NOON03@ Kanazawa Feb. 11, 2003
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12, 23, 13
+
m212, m2
23
MNS (Maki-Nakagawa-Sakata) matrix
Three Flavor Mixing
3
3-flavor Oscillation
ELmP e /27.1sin2sinsin 213
213
223
2
ELmP x /27.1sin2sincos1 223
223
213
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Oscillation Probabilities when 213
223
212 mmm
e appearance
disappearance
common
m1
m2
m3
sinsin
2sin
4)()(
)()(
13
122
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E
Lm
PP
PPA
ee
eeCP
CP in e appearance
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Strategy
High statistics by high intensity beam Tune E at oscillation maximum Narrow band beam to reduce BG Sub-GeV beam for Water Cherenkov
0.75MW JHF 50GeV-PS
Off-Axis beam Super-Kamiokande
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~1GeV beamKamioka
J-PARC(Tokai)
0.75MW 50 GeV PS
( conventional beam)
Super-K: 22.5 kt
JHF 0.75MW + Super-Kamiokande
Plan to start in 2007
(hep-ex/0106019)
4MW 50 GeV PS
Hyper-K: 1000 kt
Future Super-JHF 4MW + Hyper-K(~1Mt) ~ JHF+SK 200
JHF-Kamioka Neutrino Experiment
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Collaboration
Working GroupICRR/Tokyo-KEK-Kobe-Kyoto-Tohoku-TRIUMF
(hep-ex/0106019)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)The neutrino facility construction group
was OFFICIALLY formed at KEK in 2001.LOI was submitted and people from Japan, Canada, France,
Italy, Korea, Poland, Russia, Spain, Switzerland, UK and USA signed up in 2002.
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Far detector : Super-Kamiokande( April 1996 commissioned)
40m
41.4
m
50,000 ton water Cherenkov detector (22.5 kton fiducial volume)
Optically separated INNER and OUTER detector
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J-Parc FacilityConstruction2001~ 2006 (approved)
(0.75MW)
Near detectors (280m,2km)
beam-line budget request submitted
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
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Neutrino beamlineTransport line(Super-cond. Mag.)
Target station
Decay volume130m
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OA3°
OA2°OA1°
Off Axis Beam
(ref.: BNL-E889 Proposal)
TargetHornsDecay Pipe
Super-K.
Quasi Monochromatic Beamx2~3 intense than NBB
Statistics at SK (OAB2deg,1yr,22.5kt)
~4500 tot ~3000 CC e ~0.2% at peak
~102 x (K2K)
Tuned at oscillation maximum ~0.7 GeV
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Neutrino Interaction @~1 GeV& E reconstruction
CC QE ~100% efficiency for NSK
can reconstruct Ep
CC nQE ~100% efficiency for NSK
Bkg. for E measurement
NC ~40% efficiency for NSK
+ n → + p
-
p
(E, p)
+ n → + p + ’s
p’s
-
+ n → + p +
p
(E, p)
’s
cospEm
2mEmE
N
2Nrec
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Detectors
Muon monitors @ ~140m Fast (spill-by-spill) monitoring of bea
m direction/intensity First Near detector @280m
Neutrino intensity/spectrum/direction Second Near Detector @ ~2km
Almost same E spectrum as for SK Water Cherenkov can work
Far detector @ 295km Super-Kamiokande (50kt)
1.5km
295km
0.28km
Neutrino spectra at diff. dist
dominant syst. in K2K
p
140m0m 280m 2 km 295 km
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Possible design of Near Detector at 2km
14(sin22)~0.01 (m2) ~<1×10-4
Measurement of sin2 2θ23 , m223
disappearance
True m232 (eV2)m2
sin22
FC, 1-ring, -like events
Sys. error 10% for near/far
4% energy scale
20% non-QE B.G.
OAB-3o
(m
232 ) OAB-2o
(si
n2 2 )
MeV
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→ confirmation or search for sterile neutrino w/ NC interaction
NC 0 interaction ( + N → + N + 0) e CC + NC(~0.5CC) ~0 (sin22e~0)
CC + NC(~0.5CC) ~0 (maximum oscillation) NC
#0 is sensitive to flux. Limit on s (f(s)~0.1)
OAB
s
=390±44#0 +
#e-
like
m232
3.510-3
CC
NC
100MeV<Evis<1500 MeV.
#ring<3 & e-like
No decay-e
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e appearance in JHF-Kamioka
e0
Back ground for e appearance search• Intrinsic e component in initial beam• Merged 0 ring from interactions
Requirement 10% uncertainty for BG estimation
The 1kt 0 data will be studied for exercise
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0 cut after 1-ring e-like selection
reduce coherent 0
1-ring/2-ring
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sin2213 from e appearance
sin2213
Background in Super-K (as of Oct 25, 2001)
SignalSignal + BG e e total
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
sin2213
m2
Off axis 2 deg, 5 years
Off axis 2 deg, 5 yearsat
Sin2213>0.006 C
HO
OZ
exc
lud
ed
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Key Issues
Extremely severe radiation environment Human exposure at maintenance Damage to instruments
Beam scraper, radiation resident magnets, abort system Large heat load in a short time
cooling scheme, shock wave, quenching Target, Horns, Target station, decay volume, beam dump
Reduction of Systematic errors
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Target
C230 C43
900mmL 30mm,
300mm~z0,rC230~ @
surfaceC70~ @
beam direction
r=0mm,z=300mm
r=1.5mm,z=300mmC70
C230
4 8 3212 (Sec.)
Time Evolution
Only graphite (or Be) can withstand heat load.
Cooling test is on going.
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Decay Volume
空隙(サービスエリア)
TP+11.8m(0.244Sv/h)
土盛り
TP-1.1m TP-1.1m
0.07Sv/h for 1W/m line
(ターゲット・ステーション 地下レベル)
断面図
FQ3AFH2 FQ3B FQ4 FV1 FV2
放射化物保管室
1.40
TS上屋
2.11
3NBT (TP+8m)レベル
3NBT
コンクリート
コンクリート
土盛り
コンクリート
コンクリート
μ ピット機械室( )半地下
汚染検査室
FL=TP-14.3
遮蔽ブロック
Side View
Top view
4MW beam can be accepted.
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空隙(サービスエリア)
Strategy to change peak energy
Dipole magnet
gap 1m×1m×1m
One method is changing the beam axis.
The other…. OAB+Bending Magnet
Target station side view
OAB2o
OAB3o
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OAB vs OAB+Bending
No need to access target and horns.
Easy to change the peak energy
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Schedule & Summary –JHF-Kamioka-
JHF-Kamioka neutrino experiment (2007~) JHF 0.75MW 50GeV-PS+Off Axis beam+Super-K Narrow band beam at oscillation maximum (~ 1GeV) e appearance, discovery of 13 (sin 2213>0.006,90%CL) Budget request submitted, R&D started
Possible upgrade in future 4MW Super-JHF + Hyper-K ( 1Mt water Cherenkov) CP violation in lepton sector
2002 2004 2006 2008 2010
MINOS 2yr
OPERA 5yr
SK rebuild SK-half SK-full
JHF- construction physics run (OAB)