KEK K2K& Next Generation Long Baseline Experiment · J-PARC, Ja pan Proton Accerelator Research...
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NEAR DETECTOR DECAY VOLUME TARGET STATION SUPER-COND. MAGNETS DUMP/MUON MONITOR 10 -4 10 -3 10 -2 10 -1 10 -3 10 -2 10 -1 1 sin 2 2θ13 ∆m 2 (eV 2 ) Expected 90% sensitivity contour on (∆m13 2 , sin 2 2θ13) compared with the CHOOZ exclusion plot. The sensitivities to sin 2 2θ23 and ∆m23 2 as a function of true ∆m23 2 . δ θ sin 2 2 OA2˚ ∆m 2 10 1 0.002 0.004 0.006 0.002 0.004 0.006 -1 10 -2 10 -3 10 -4 δ∆m 2 (eV 2 ) (eV 2 ) ∆m 2 (eV 2 ) OA3˚ OA2˚ OA3˚ OAB 2degree (5years) CHOOZ excluted 3 GeV Synchrotron V Synchr 50 0 GeV Synchrotron GeV Synchrotr 295 295km km Future Plan Future Plan K2K K2K 250 250km km KEK 295km K2K Current Experiment Current Experiment Current Experiment 250km Future Plan TOKAI KAMIOKA A KEK-beam produced Super-Kamiokande event 0 2 4 6 8 10 12 0 1 2 3 4 5 E ν rec Events 10 -4 10 -3 10 -2 0 0.2 0.4 0.6 0.8 1 sin 2 2θ μe sin 2 2θμe ∆m 2 (eV 2 ) ∆m 2 (eV 2 ) 10 -4 10 -3 10 -2 10 -1 0 0.1 0.2 0.3 0.4 0.5 K2K(90%CL) K % CHOOZ(90%CL) O % SK atm. . allowed (90%CL) d L K2K-I oscillation analysis plots (a) Reconstructed Eν distribution for the single ring muon-like samples, overlayed with various MC expectations. (b) Allowed regions of oscillation parameters in νμ disappearance mode. The best fit point is indicated by the star. (c) Excluded region of oscillation parameters in νe appearance mode, in comparison with results of the other experiments. Best fit with oscillation Without oscillation (entry normalization) Normalized to the expected number of events (44) σ 90%C.L. 99%C.L. (a) (b) (c) Bird's-eye view of the neutrino beam-line at KEK. It provides a 98% pure wide-band <E ν >=1.3 GeV muon neutrino beam from the KEK 12 GeV PS. A near detector system is located 300 m downstream from the target. Installation of a new near detector module, Sci-Bar, is taking place since January 2003. J-PARC, Japan Proton Accerelator Research Complex. Neutrino beamline facilities will be constructed at 50 GeV Proton Synchrotron (PS), which will provide a beam ~100 times more intense than KEK-PS. Intermediate neutrino detector at 2 km from target Super-Kamiokande after its recovery from the accident (ICRR, Univ.of Tokyo, 2002/09). KS probability = 64.3 % 118 POT events 0 10 20 30 40 50 60 70 0 10 20 30 40 50 60 1999 ~ 2001 2003 K2K-I K2K-II Number of observed events at SK vs number of protons on target (POT). 56 K2K-I events + 16 K2K-II events are plotted. Blue line is averaged rate (1.14 events / 10 1POT). P P 1 1 2 2 GeV PS GeV PS GeV PS NG NG NG NG G G N N N N G G RIN RIN RI RI RI RI I R R B R B R BR BR KB KB K B B K K K K EK EK E N N B B EK EK E KE KE K K K K K KEKB RING KEKB RING KEKB RING East East East Counter Hall Counter Hall Counter Hall North North North Counter Hall Counter Hall Counter Hall Primary Beam -line Primary Beam -line Primary Beam -line Muon Pit Muon Pit Muon Pit Near Detectors Near Detectors Near Detectors Decay Tunnel Decay Tunnel Decay Tunnel (200m) (200m) (200m) Target Station Target Station Target Station A project involving a next-generation long baseline neutrino oscillation experiment connecting 295 km between J-PARC 50 GeV Proton Synchrotron and Super-Kamiokande is being proposed. It is designed to observe the first signal of ν e appearance and to measure a finite θ13 value. A 2˚~3˚ off-axis (OA) neutrino beam is being considered. An intermediate neutrino detector will also be constructed at 2 km from the target. The possibility of measuring a CP violation effect using an anti-neutrino beam, after apparatus upgrades in the future, is also being discussed. Next Generation Long-Baseline Neutrino Oscillation Experiment at J-PARC Progress of K2K: New Analysis for Phase-I and Successful Start of Phase-II http://neutrino.kek.jp/ http://www-nu.kek.jp/jhfnu/ K2K, the first long-baseline neutrino oscillation experiment in operation, has collected one-half of its planned 10 20 protons on target through July 2001 (K2K-I). We have collected 56 events in Super-Kamiokande, compared to the expectation, 80.1 +6.2 . We use 29 single-ring muon like events to study the energy spectrum distortion. The probability that these results are caused by statistical fluctuation without neutrino oscillation is less than 1 %. A limit for ν e appearance mode has been obtained: sin 2 2θ μe < 0.15 at ∆m 2 = 2.8x10 -3 eV 2 . The new phase of the experiment, K2K-II, which started after the recovery from the Super-Kamiokande accident, will provide sufficient statistics for further study on neutrino oscillation. As of April 21 st , 16 more events have been obtained, compared to the expectation, 26.6 +2.3 . -2.6 -5.4 KEK KEK K2K & Next Generation Long Baseline Experiment
Transcript of KEK K2K& Next Generation Long Baseline Experiment · J-PARC, Ja pan Proton Accerelator Research...
NEAR DETECTOR
DECAY VOLUMETARGET STATION
SUPER-COND. MAGNETSDUMP/MUON MONITOR
10-4
10-3
10-2
10-1
10 -3 10-2 10 -1 1sin22θ13
∆m
2(e
V2
)
Expected 90% sensitivity contour on (∆m132, sin22θ13)
compared with the CHOOZ exclusion plot.
The sensitivities to sin22θ23 and ∆m232
as a function of true ∆m232.
δθ
sin
22
OA2˚
∆m2
10
1
0.002 0.004 0.006 0.002 0.004 0.006
-1
10-2
10-3
10-4
δ∆m
2(e
V2
)
(eV2)∆m2(eV2)
OA3˚
OA2˚
OA3˚
OAB 2degree (5years)
CHOOZ excluted
3 GeV SynchrotronV Synchr
500 GeV SynchrotronGeV Synchrotr
295295kmkmFuture PlanFuture Plan
K2K K2K
250250kmkm
KEK
295kmK2K Current Experiment
Current ExperimentCurrent Experiment250km
Future PlanTOKAIKAMIOKA
A KEK-beam produced Super-Kamiokande event
0
2
4
6
8
10
12
0 1 2 3 4 5
E ν rec
Even
ts
10-4
10-3
10-2
0 0.2 0.4 0.6 0.8 1
sin22θµe
sin22θµe
∆m
2(e
V2)
∆m
2(e
V2)
10-4
10-3
10-2
10-1
0 0.1 0.2 0.3 0.4 0.5
K2K(90%CL)K %
CHOOZ(90%CL)O %
SK atm..allowed (90%CL)d L
K2K-I oscillation analysis plots
(a) Reconstructed Eν distribution for the single ring muon-like samples, overlayed with various MC expectations.
(b) Allowed regions of oscillation parameters in νµ disappearance mode. The best fit point is indicated by the star.
(c) Excluded region of oscillation parameters in νe appearance mode, in comparison with results of the other experiments.
Best fitwith oscillation
Without oscillation(entry normalization)
Normalized to theexpected numberof events (44)
1σ90%C.L.99%C.L.
(a) (b)
(c) Bird's-eye view of the neutrino beam-line at KEK. It provides a 98% purewide-band <Eν>=1.3 GeV muon neutrino beam from the KEK 12 GeV PS.
A near detector system is located 300 m downstream from the target.
Installation of a new near detector module, Sci-Bar,is taking place since January 2003.
J-PARC, Japan Proton Accerelator Research Complex.Neutrino beamline facilities will be constructed at 50 GeV Proton Synchrotron (PS),
which will provide a beam ~100 times more intense than KEK-PS.
Intermediate neutrino detector at 2 km from target
Super-Kamiokande after its recoveryfrom the accident (ICRR, Univ.of Tokyo, 2002/09).
KS probability = 64.3%
1018 POT
even
ts
0
10
20
30
40
50
60
70
0 10 20 30 40 50 60
1999 ~ 2001 2003K2K-I K2K-II
Number of observed events at SKvs number of protons on target (POT).
56 K2K-I events + 16 K2K-II events are plotted.Blue line is averaged rate (1.14 events / 1018 POT).
PPP
111222 GeV PSGeV PSGeV PS
NGNGNGNGGGGGNNNNNNNNGGGGRINRINRIRIRIRIIIRRRRB RB RB RB RKBKBKKBBBBKKKKKKKKEKEKEE NNNNBBBBEKEKEEKEKEKKKKKKKKKKKEKB RINGKEKB RINGKEKB RING
EastEastEastCounter HallCounter HallCounter Hall
NorthNorthNorthCounter HallCounter HallCounter Hall
Primary Beam -linePrimary Beam -linePrimary Beam -line
Muon PitMuon PitMuon Pit
Near DetectorsNear DetectorsNear Detectors
Dec
ay T
unne
l
Dec
ay T
unne
l
Dec
ay T
unne
l(2
00m
)(2
00m
)(2
00m
)
Target StationTarget StationTarget Station
A project involving a next-generation long baseline neutrino oscillation experiment connecting 295 km between J-PARC 50 GeV Proton Synchrotron and Super-Kamiokande is being proposed. It is designed to observe the first signal of νe appearance and to measure a finite θ13 value. A 2̊ ~3̊ off-axis (OA) neutrino beam is being considered. An intermediate neutrino detector will also be constructed at 2 km from the target. The possibility of measuring a CP violation effect using an anti-neutrino beam, after apparatus upgrades in the future, is also being discussed.
Next Generation Long-Baseline Neutrino Oscillation Experiment at J-PARC
Progress of K2K: New Analysis for Phase-I and Successful Start of Phase-II http://neutrino.kek.jp/
http://www-nu.kek.jp/jhfnu/
K2K, the first long-baseline neutrino oscillation experiment in operation, has collected one-half of its planned 1020 protons on target through July 2001 (K2K-I). We have collected 56 events in Super-Kamiokande, compared to the expectation, 80.1+6.2 . We use 29 single-ring muon like events to study the energy spectrum distortion. The probability that these results are caused by statistical fluctuation without neutrino oscillation is less than 1 %. A limit for νe appearance mode has been obtained: sin22θµe < 0.15 at ∆m2= 2.8x10-3 eV2 . The new phase of the experiment, K2K-II, which started after the recovery from the Super-Kamiokande accident, will provide sufficient statistics for further study on neutrino oscillation. As of April 21st, 16 more events have been obtained, compared to the expectation, 26.6+2.3 .-2.6
-5.4
KEKKEK K2K& Next Generation LongBaseline Experiment
