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Jan 16, 2002 @IIAS. The JHF-Kamioka Neutrino experiment. Tsuyoshi NAKAYA (Kyoto U.) for JHF-SK working group. Introduction Overview of the experiment Physics sensitivity in Phase-I Physics sensitivity in Phase-II Summary and Conclusion. - PowerPoint PPT Presentation
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The JHF-Kamioka Neutrino experimentThe JHF-Kamioka Neutrino experiment
1. Introduction
2. Overview of the experiment
3. Physics sensitivity in Phase-I
4. Physics sensitivity in Phase-II
5. Summary and Conclusion
Tsuyoshi NAKAYA (Kyoto U.)for JHF-SK working group
Jan 16, 2002@IIAS
JHF is an tentative name, and will be renamed soon.
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JHF-SK Neutrino Working GroupICRR/Tokyo-KEK-Kobe-Kyoto-Tohoku-TRIUMF
15,5
Y. Itow, T. Kajita, K. Kaneyuki, M. Shiozawa, Y. Totsuka (ICRR/Tokyo)
Y. Hayato, T. Ishida, T. Ishii, T. Kobayashi, T. Maruyama,
K. Nakamura, Y. Obayashi, M. Sakuda (KEK)
S. Aoki, T.Hara, A. Suzuki (Kobe)
A. Ichikawa, T. Nakaya, K. Nishikawa (Kyoto)
T. Hasegawa, K. Ishihara, A. Suzuki (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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1.Introduction
~1GeV beamKamiokaJAERI
(Tokaimura)
0.77MW 50 GeV PS
( conventional beam)
Super-K: 22.5 kt
4MW 50 GeV PS
Hyper-K: 1000 kt
Phase-I (0.77MW + Super-K)Phase-II (4MW+Hyper-K) ~ Phase-I 200
The experiment will start in 2007.The experiment will start in 2007.
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Lepton Sector Mixing
12, 23, 13
+ m2
12, m223
MNS (Maki-Nakagawa-Sakata) matrix
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oscillation
GeVE
kmLeVmP
PGeVE
kmLeVmP
e
e
22232
132
132
22232
134
232
27.1sinsin2sin)(
)(27.1
sincos2sin1)(
at 23~/4 and 13~0
GeVE
kmLeVmP
PGeVE
kmLeVmP
ee
e
222322
222322
27.1sin2sin)(
)(27.1
sin2sin1)(
2
31322
2322 22sin
2
12sin,2sin2sin ee U
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Targets of JHF-SK experiment
• Confirmation of
• Discovery of eat m2atm.
• Precise measurement of neutrino oscillation. (observation of oscillation peak)
• CP violation in neutrino oscillation.
• Confirm or Reject LSND anomaly.
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2. Overview of the experiment
Construction2001~ 2006 (approved)
JHF MINOS K2K
E(GeV) 50 120 12
Int.(1012ppp)
330 40 6
Rate(Hz) 0.29 0.53 0.45
Power(MW)
0.77 0.41 0.0052
JAERI@Tokai-mura(60km N.E. of KEK)
Super Conductingmagnet for beam line
Near detectors@280m and@~2km
1021POT(130day)≡ “1 year”
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beam at JHF
• Principle– Intense Narrow Band Beam
– Beam energy is tuned to be at the oscillation maximum.
• High sensitivity
• Less background
– ~1 GeV beam energy for Quasi-elastic interaction.
E(reconstruct) – E (True) (MeV)
m2=1.6~4x10-3eV2
E=0.4~1.0GeV
=80MeV + n → + p
p
(E , p)
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Off Axis Beam
WBB w/ intentionally misaligned beam line from det. axis
(ref.: BNL-E889 Proposal)
Target Horns Decay Pipe
Far Det.
~ 3100 int./22.5kt/yr w/ 80m long decay volumee: 1.0% (0.2% @ peak)
Decay Kinematics
~2°
E(Present design; 130m 40% more)
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detectors at JHF
1 Mton (fiducial) volume: Total Length 400m (8 Compartments)
Super-K
40m
Total Length 400m (8 Compartments)
Phase-I: Suker-K22.5kt (50kt)
Phase-II: Hyper-K1Mton (fiducial) volume:
We are investigating the possible site at Kamioka.
70m
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Near Detectors ( Detectors at two locations are essential.)
@280m (1~10 events/spill/100ton) Fine Grained w/ magnet.– Measure direction and spectrum.– Measure wrong sign component (see CP section).– Will be used for interaction study with NBB.– Non-oscillation physics.
@~2km (0.1 events/spill/100ton) Water Cherenkov + Fine Grained– Measure spectrum and e background since they are s
ame as those at Kamioka.– Test LSND anomaly if Mini-Boone failed to test it or di
scovered the new physics.
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Far/Near Spectrum Ratio
spectrum
0.28km
1.5km
295km
At >1.5km, the source is treated as a point source
Low Ep High Ep
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3. Physics sensitivity in Phase-I (w/ Super-K)
5years (51021POT) running precise measurement of m223 and 13
(m223 )e (13 , open window for CP study) w/ NC interactions. (confirmatio
n)stringent limit on the non-oscillation scenario a
nd the existence of s.Sensitivity (goal):sin22sin22CLm2eV2
atsin22m2eV2
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→ confirmation 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
m2323.510-3
CC
NC
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e appearance
C.C. N.C. Beam e Osc’d e
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/0 sep. 3.5 23.0 21.9 152.2
red.eff. 0.03% 0.6% 7.5% 50.4%
.4<E<1.2 1.8 9.3 11.1 123.2
red.eff. 0.02% 0.2% 3.8% 40.8%
e0
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e appearanceBackground rejection against NC 0 is improved.
sin22e=0.05 (sin22e 0.5sin2213)
3 ×10-3
×20 improvement
CHOOZ
sin22e
m2
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disappearance
1ring FC -like
Reconstructed E (MeV)
Oscillation with m2=3×10-3
sin22=1.0
No oscillation
Non-QE
(linear)
(log)
m2=3×10-3
sin22=1.0
~3%
Ratio after BG subtraction
m2
sin22
sin22m
2eV2
Fit with 1-sin22・ sin2(1.27m2L/E)
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4. Physics sensitivity in Phase-II (w/ Hyper-K)
2 years (101021POT) for and 6 years (301021POT) for running
Search for CP violation in oscillation.standard: e vs e
non-standard: vs w/ NC Search for e
Search for proton decays.
Sensitivity (goal):sin22CLdiscovery
atm122eV2m23
2eV2
proton•B(pe0, K) > 1035 years
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CP violation in oscillation
sinsin
2sin
4)()(
)()(
13
122
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E
Lm
PP
PPA
ee
eeCP
L=295km : small matter effectE~1 GeV : large CP asymmetry
Acp
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flux for CP violation search.
-15%@peak
1021POT/yr(1st phase)
Sign flip by change of horn plarity
Flux CC interaction
Wrong sign BG
cross sectiondifference
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CP Violation Study• Compare e with e
N(e-)
N(e+)
NO CP violationw/o matter effect.
m122
eV2m23
2eV2
sin22
02.02000~2000~
2000~2000~
)()(
)()(
eNeN
eNeN
Asymmetry discovery
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5. Summary and Conclusion
• The experiment is expected to start in 2007 at the same time of the completion of JHF 50 GeV PS.– The experiment is not approved yet, and we need your
STRONG support to put the experiment on track.
• The features of the experiment are:– MW class 50 GeV proton accelerator (0.77MW 4MW)
– ~1GeV Narrow band neutrino beam at the oscillation maximum (L=295km).
– Gigantic Water Cherenkov detectors with/ neutrino energy reconstruction by quasi-elastic interaction. (22.5kton 1000kton)
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Physics Reach (see hep-ex/0106019)
• Phase-I (0.77MW + 22.5kt): NC interaction:Establish and limit on s
: sin22e : sin22CL : m2eV2
atsin22m2eV2• Phase-II (4MW + 1000kt):
e : sin22CLe vs e : discovery
atm122eV2m23
2eV2proton•B(pe0, K) > 1035 years