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NOON03 @ Kanazawa Feb. 11, 2003. JHFnu (phase I) neutrino oscillation experiment. For JHF-SK Neutrino Experiment collaboration Atsuko Kondo-Ichikawa KEK. Three Flavor Mixing. D m 2 12 , D m 2 23. q 12 , q 23 , q 13 + d. MNS (Maki-Nakagawa-Sakata) matrix. 3-flavor Oscillation. m 3.
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NOON03@KanazawaFeb. 11, 2003 JHFnu (phase I) neutrino oscillation experiment For JHF-SK Neutrino Experiment collaboration Atsuko Kondo-Ichikawa KEK
Three Flavor Mixing Dm212, Dm223 q12, q23, q13 + d MNS (Maki-Nakagawa-Sakata) matrix
3-flavor Oscillation m3 Oscillation Probabilities when m2 m1 • q23 :nmdisappearance • q13:neappearance common • d: CP inneappearance
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
JHF-Kamioka Neutrino Experiment (hep-ex/0106019) Plan to start in 2007 Kamioka ~1GeV n beam Super-K: 22.5 kt J-PARC (Tokai) Hyper-K: 1000 kt 0.75MW 50 GeV PS 4MW 50 GeV PS ( conventional n beam) JHF 0.75MW + Super-Kamiokande Future Super-JHF 4MW + Hyper-K(~1Mt) ~ JHF+SK 200
Collaboration Working Group ICRR/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.
Far detector : Super-Kamiokande (April 1996 commissioned) 50,000 ton water Cherenkov detector(22.5 kton fiducial volume) Optically separated INNER and OUTER detector 41.4m 40m
J-Parc Facility Construction 2001~2006 (approved) nbeam-line budget request submitted (0.75MW) To SK Near detectors (280m,2km)
Neutrino beamline Transport line (Super-cond. Mag.) Target station Decay volume 130m
Super-K. q Decay Pipe Target Horns Off Axis Beam (ref.: BNL-E889 Proposal) • Quasi Monochromatic Beam • x2~3 intense than NBB Tuned at oscillation maximum ~0.7 GeV Statistics at SK (OAB2deg,1yr,22.5kt) ~4500nmtot ~3000nmCC ne~0.2% atnmpeak OA1° OA2° OA3° ~102 x (K2K)
m- nm+ n→ m+ p (Em, pm) qm n p m- nm+ n→ m+ p+ p (Em, pm) qm n p p’s n nm+ n→ n+ p+ p’s n p p’s Neutrino Interaction @~1 GeV& En reconstruction • CC QE • ~100% efficiency for NSK • can reconstruct En (qm,pm) • CC nQE • ~100% efficiency for NSK • Bkg. for En measurement • NC • ~40% efficiency for NSK
Neutrino spectra at diff. dist 1.5km 295km 0.28km Detectors p p n 0m 140m 280m 2 km 295 km • Muon monitors @ ~140m • Fast (spill-by-spill) monitoring of beam direction/intensity • First Near detector@280m • Neutrino intensity/spectrum/direction • Second Near Detector @ ~2km • Almost same En spectrum as for SK • Water Cherenkov can work • Far detector @ 295km • Super-Kamiokande (50kt) dominant syst. in K2K
sin22q Measurement of sin2 2θ23 , Dm223 nm disappearance FC, 1-ring, m-like events Sys. error 10% for near/far 4% energy scale 20% non-QE B.G. d(sin22q23) OAB-3o OAB-2o d(Dm232 ) MeV Dm2 True Dm232 (eV2) d(sin22q)~0.01 d(Dm2) ~<1×10-4
nm →nt confirmation or search for sterile neutrino w/ NC interaction • NC p0 interaction(n + N →n + N + p0) • nmne CC + NC(~0.5CC) ~0 (sin22qme~0) nm CC + NC(~0.5CC) ~0 (maximum oscillation)nt NC #p0 is sensitive to nt flux.Limit on ns (df(ns)~0.1) nmnt OAB CC t nt #p0 + #e-like D=390±44 NC nt nt nmns p0 100MeV<Evis<1500 MeV. #ring<3 & e-like No decay-e Dm232 3.510-3
m e p0 ne appearance in JHF-Kamioka • Back ground for ne appearance search • Intrinsic ne component in initial beam • Merged p0 ring from nm interactions Requirement 10% uncertainty for BG estimation The 1kt p0 data will be studied for exercise
p0 cut after 1-ring e-like selection reduce coherent p0 1-ring/2-ring
sin22q13 from ne appearance at Off axis 2 deg, 5 years CHOOZ excluded Dm2 Off axis 2 deg, 5 years Sin22q13>0.006 sin22q13
Key Issues • Reduction of Systematic errors • 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
r=0mm,z=300mm r=1.5mm,z=300mm (Sec.) 12 32 4 8 Target Only graphite (or Be) can withstand heat load. Time Evolution beam direction Cooling test is on going.
Top view Decay Volume Side View 4MW beam can be accepted.
Strategy to change peak energy One method is changing the beam axis. The other…. OAB+Bending Magnet Dipole magnet gap 1m×1m×1m OAB2o OAB3o Target station side view
OAB vs OAB+Bending No need to access target and horns. Easy to change the peak energy
2002 2004 2006 2008 2010 SK rebuild SK-half SK-full Schedule & Summary –JHF-Kamioka- JHF-n construction physics run (OAB) • JHF-Kamioka neutrino experiment (2007~) • JHF 0.75MW 50GeV-PS+Off Axis beam+Super-K • Narrow band beam at oscillation maximum (~ 1GeV) • ne appearance, discovery of q13 (sin 22q13>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 MINOS 2yr OPERA 5yr