JHF-Kamioka JHF-Kamioka Neutrino Oscillation ExpNeutrino Oscillation Exp

erimenterimentusingusing

JHF 50 GeV PS JHF 50 GeV PS Y.Itow Y.Itow

ICRR,Univ.of TokyoICRR,Univ.of TokyoJul27,2002Jul27,2002 　　

ICHEP02 AmsterdamICHEP02 Amsterdam

• Introduction• Facility• Physics goal• Summary

Where we go ?Where we go ?D

isco

very

Ph

ase

K2KThe 1st long baseline experiment

Atmospheric

Discovery of oscillations

mm23232 2 ~ 1.6 – 3.9×10~ 1.6 – 3.9×10-3-3 eV eV22

sin2223>0.92

Solar

Large mixing ine oscillations

mm12122 2 ~ 3 - 20×10~ 3 - 20×10-5-5 eV eV22

sin2212~0.55 - 0.95

Precision study of 3-flavor mixing matrix

Cos

mic

ray

Pre

cisi

on S

tud

y P

has

e A

ccel

erat

or

12, 23, 13

+

m212, m2

23

MNS (Maki-Nakagawa-Sakata) matrix

3 Flavor Mixing 3 Flavor Mixing

3-flavor Oscillation 3-flavor Oscillation

ELmP e /27.1sin2sinsin 213

213

223

2

ELmP x /27.1sin2sincos1 223

223

213

4

Oscillation Probabilities when 213

223

212 mmm

e appearance

disappearance

common

m1

m2

m3

sinsin

2sin

4)()(

)()(

13

122

12

E

Lm

PP

PPA

ee

eeCP

CP in e appearance

StrategyStrategy High statistics by high intensity High statistics by high intensity beam beam Tune ETune E at oscillation maximum at oscillation maximum Narrow band beam to reduce BGNarrow band beam to reduce BG Sub-GeV Sub-GeV beam for Water Cherenkov beam for Water Cherenkov

0.75MW JHF 50GeV-PS

Off-Axis beam Super-Kamiokande

~1GeV beamKamiokaJAERI(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 ~ JHF+SK 200

JHF-Kamioka Neutrino ExperimentJHF-Kamioka Neutrino Experiment

OrganizationOrganization

Facility Construction GroupFacility Construction Group Officially formed in KEK on Officially formed in KEK on April, 2001April, 2001 The 3rd physics division, IPNS, The 3rd physics division, IPNS,

Cryogenic facility group, Cryogenic Cryogenic facility group, Cryogenic Science Center, w/ strong support from Science Center, w/ strong support from KEK-PS beam channel groupKEK-PS beam channel group

Experiment working groupDec.1999 : formed (ICRR/KEK/Kyoto/Kobe/Tohoku/TRIUMF)Jun.2001 : Letter of Intent (hep-ex/0106019)Mar.2002 : Meeting to discuss possibility to organize international collaboration

JHF-SK Neutrino Working JHF-SK Neutrino Working GroupGroup

ICRR/TokyoICRR/Tokyo--KEKKEK--KobeKobe--KyotoKyoto--TohokuTohoku--TRIUMFTRIUMF

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.

JHF FacilityJHF FacilityConstruction2001～ 2006 (approved)

(0.77MW)

8 bunches/~5s3.3x1014proton/pulse3.94 (3.64) sec cycle1 ｙｒ≡ 1021POT (130 days) Near detectors (280m,2km)

beam-line budget request submitted

Target station

Decay volume

Transport line(Super-cond. Mag.)

OA2°

Osc. Prob.=sin2(1.27m2L/E)

m2=3x10-3eV2

L=295km

osc.

max

.

Off Axis BeamOff 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

Oscillation probablity

Assume CC Quasi Elastic (QE) reaction

cos

22

pEm

mEmE

N

N

p

ccQE

inelastic

+ n → + p +n

EE reconstruction in water Cherenkov reconstruction in water Cherenkov

+ n → + p

(E , p)

beam energy

ccQEcc-inelastic

DetectorsDetectors

Muon monitors @ ~140mMuon monitors @ ~140m Spill-by-spill monitoring of beam dirSpill-by-spill monitoring of beam dir

ectionection First Front detectorFirst Front detector @280m@280m

Neutrino intensity/directionNeutrino intensity/direction Second Front Detector @ ~2kmSecond Front Detector @ ~2km

Almost same Almost same EE spectrum as for SK spectrum as for SK Water Cherenkov can workWater Cherenkov can work

Far detector @ 295kmFar detector @ 295km Super-Kamiokande (50kt)Super-Kamiokande (50kt)

1.5km

295km

0.28km

Neutrino spectra at diff. dist

dominant syst. in K2K

p

140m0m 280m 2 km 295 km

Far detectorFar detectorSuper-KamiokandeSuper-Kamiokande

（ since Apr 1９９６）

４０ｍ

４１

．４

ｍ50,000 ton water Cherenkov detector 　(22.5 kton fiducial volume)

Re-Construction of Super-K Re-Construction of Super-K (Jul 2002)(Jul 2002)

★Precise measurement of neutrino mixing matrix

Accuracy: sin22θ23 ・・・・・・ 1%

Δm223

・・・・・・・・・・ a few %

★Discovery and measurement of non-zero θ13

　　　　　　　　　　　　 sin22θ13 ・・・・・・ > 0.006

1st Evidence of 3-flavor mixing !

1st step to CP measurement

Physics Goal Physics Goal

(si

n2 2

)(

m23

2 )

True m232 (eV2)

OAB-2degree,5yr

(sin22)~0.01 (m2) ~<1×10-4

Measurement of sinMeasurement of sin22 2θ 2θ23 , 23 ,

mm222323 disappearance

~3%

m2

sin22

ee appearance in JHF-Kamioka appearance in JHF-Kamioka

e0

Back ground for e appearance search• Intrinsic e component in initial beam• Merged 0 ring from interactions 10% uncertainty for BG estimation

The 1kt 0 data will be studied for exercise

sinsin22221313 from from ee appearance appearance

sinsin222211

33

Background in Super-K Background in Super-K (as of Oct (as of Oct 25, 2001)25, 2001) SignaSigna

llSignal Signal + BG+ BG ee ee totaltotal

0.10.1 12.012.0 10.710.7 1.71.7 0.50.5 24.924.9 114.6114.6 139.5139.5

0.010.01 12.012.0 10.710.7 1.71.7 0.50.5 24.924.9 11.511.5 36.436.4

0.5 sin2213

m2

Off axis 2 deg, 5 years

Off axis 2 deg, 5 yearsat

Sin2213>0.006 C

HO

OZ

exc

lud

ed

Future upgradeFuture upgradeSuper-JHF(4MW)+Hyper-Super-JHF(4MW)+Hyper-

K(1Mt)K(1Mt)

~1,000 kt

Candidate site in Kamioka

Good for atm. proton decay

Sensitivity(3Sensitivity(3) to CP violation (SuperJHF+Hyper-) to CP violation (SuperJHF+Hyper-K)K)

Chooz excluded@m31~3x10-3eV2

>~27deg

>~14deg

Preliminary

4MW,1Mt2yr for

6.8yr for

JHF1 3 discovery

2002 2004 2006 2008 2010

JHF- construction physics run (OAB)

MINOS 2yr

OPERA 5yr

Global ScheduleGlobal Schedule

SKrebuild

SK-half SK-full

SummarySummary Precision study of neutrino mixing matrixPrecision study of neutrino mixing matrix

Next step after the discovery Next step after the discovery We may find a hint for next break-throughWe may find a hint for next break-through

JHF-Kamioka neutrino experiment (2007~)JHF-Kamioka neutrino experiment (2007~) JHF 0.75MW 50GeV-PS+Off Axis beam+Super-KJHF 0.75MW 50GeV-PS+Off Axis beam+Super-K Narrow band beam at oscillation maximum (~ 1GeV)Narrow band beam at oscillation maximum (~ 1GeV) ee appearance, discovery of appearance, discovery of 1313 (sin (sin 1313>0.006,90%CL)>0.006,90%CL) Budget request submitted, R&D startedBudget request submitted, R&D started

Possible upgrade in futurePossible upgrade in future 4MW Super-JHF + Hyper-K ( 1Mt water Cherenkov)4MW Super-JHF + Hyper-K ( 1Mt water Cherenkov) CP violation in lepton sectorCP violation in lepton sector Bonus ! (Proton Decay ! ) Bonus ! (Proton Decay ! )