j-parc neutrino experiment ( t2k )
DESCRIPTION
ICEPP Sympo. @ Hakuba Feb 15-18, 2004. J-PARC Neutrino Experiment ( T2K ). T.Nakaya Kyoto University. January 2004. LOI to the J-PARC office (Jan, 2003) Japan: 45, US:38, Canada: 19, Europe: 31, other Asia: 14. 1. Introduction. - PowerPoint PPT PresentationTRANSCRIPT
11
J-PARCJ-PARCNeutrino Experiment (Neutrino Experiment (T2KT2K))
T.Nakaya T.Nakaya Kyoto UniversityKyoto University
ICEPP Sympo.@ HakubaFeb 15-18, 2004
22
January 2004
LOI to the J-PARC office (Jan, 2003)Japan: 45, US:38, Canada: 19, Europe: 31, other Asia: 14
33
• A next goal of neutrino experiments is to explore the neutrinA next goal of neutrino experiments is to explore the neutrino oscillation phenomena beyond the discovery phase.o oscillation phenomena beyond the discovery phase.– Three generation Matrix (NMS matrix)Three generation Matrix (NMS matrix)– CP ViolationCP Violation,, matter effect, the sign of matter effect, the sign of mm2323
22
– Unexpected physics behind the oscillation phenomena.Unexpected physics behind the oscillation phenomena.
• More complete studies with high statistics by J-PACR neutriMore complete studies with high statistics by J-PACR neutrino experiment: no experiment: – more precisionmore precision
• 2323, , mm222323, oscillation curve, non-oscillation scenario, oscillation curve, non-oscillation scenario
– more sensitivity to a rare processmore sensitivity to a rare process• 1313 ( ( ee), CP Violation, unexpected phenomena.), CP Violation, unexpected phenomena.
1. Introduction1. Introduction
44
~1GeV beamKamiokaJAERI(Tokai)
0.75MW 50 GeV PS
( conventional beam)
Super-K: 22.5 kt
J-PARC 0.75MW + Super-Kamiokande
Start at the beginning of 2009
(hep-ex/0106019)
( Future: Super-JPARC 4MW + Hyper-K ~ J-PARC+SK 200 )
J-PARC Neutrino ExperimentJ-PARC Neutrino Experiment
55
• High statistics by a high intense High statistics by a high intense beam beam• Tune ETune E at the oscillation maximum at the 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(4MW Super JHF)
Off-Axis beam Super-Kamiokande(Hyper-Kamiokande)
Strategy
66
• Dec.20,2003Dec.20,2003– Neutrino project on the draft budget from Neutrino project on the draft budget from
MOFMOF
– 5 years project from JFY2004 ~ JFY20085 years project from JFY2004 ~ JFY2008– Start the experiment at the end of JFY2008.Start the experiment at the end of JFY2008.
J-PARC neutrino J-PARC neutrino facility approved! facility approved!
NewsNews
77
Nuclear and ParticleExperimental Facility
Materials and Life ScienceExperimental Facility
Neutrino experimental hall
Linac(350m)
3 GeV Synchrotron(25 Hz, 1MW)
Nuclear Transmutation
J-PARCJ-PARC (Japan Proton Accelerator Research Complex)
50 GeV Synchrotron(0.75 MW)
J-PARC = Japan Proton Accelerator Research Complex
Construction started in 2001
88
December, 2003
to Kamiokato Kamioka
99
World’s Proton AcceleratorsWorld’s Proton Accelerators
1010
J-PARC Neutrino FacilityJ-PARC Neutrino FacilityJ-PARC Construction2001~ 2007
(0.77MW)
8 bunches/~5s 3.3x1014proton/pulse 3.94 (3.64) sec cycle 1 yr≡ 1021POT (130 days) Near detectors (280m,2km)
Target station
Decay volume
Transport line(Super-cond. Mag.)
1111
decay pipe
Near detector
TargetStation
-pit280m
130m
3NBT
Special FeaturesSpecial Features Superconducting magnetsSuperconducting magnets
Off-axis beamOff-axis beam
ComponentsComponents Primary proton beam linePrimary proton beam line
Normal conducting magnetsNormal conducting magnets
Superconducting arcSuperconducting arc
Proton beam monitors Proton beam monitors
Target/Horn systemTarget/Horn system
Decay pipe (130m)Decay pipe (130m) cross w/ 3NBTcross w/ 3NBT
Cover Off-Axis angle 2~3 deg. Cover Off-Axis angle 2~3 deg.
Beam dumpBeam dump
muon monitorsmuon monitors
Near neutrino detectorsNear neutrino detectors
1212
Development of Superconducting Development of Superconducting magnetsmagnets
Test winding of a coil
Cryo.Sci.C. KEKArc Section(R=105m)SuperconductingSuperconducting combined functioncombined function magnets
•First application in the world•Reduce cost (4028mags).•Larger acceptance
1313
OA3°OA2°OA1°
Osc. Prob.=sin2(1.27m2L/E)
m2=3x10-3eV2
L=295km
Off Axis Beam (2Off Axis Beam (2 - 3 - 3 ))
WBB w/ intentionally misaligned beam line from det. axis
(ref.: BNL-E889 proposal: http://minos.phy.bnl.gov/nwg/papers/E889)
Target
Horns Decay Pipe
Far Det.
~ 3000 CC int./22.5kt/yre: 1.0% (0.2% @ peak);
Decay Kinematics
E
E
=2.0
=1.0
=0
0
1
5)cos(2
22
pE
mmE
Eo
sc.
ma
x.
=3.0
1414
flux for CP violation search (2flux for CP violation search (2ndnd phase?) phase?)
-15%@peak
1021POT/yr(1st phase)
Sign flip by change of horn polarity
FluxCC interaction
Wrong sign BG
cross sectiondifference
1515
DetectorsDetectors
• Muon monitors @ ~140mMuon monitors @ ~140m– Fast (spill-by-spill) monitoring of beaFast (spill-by-spill) monitoring of bea
m direction/intensitym direction/intensity• First Front detectorFirst Front detector @280m@280m
– Neutrino FluxdirectionNeutrino Fluxdirection– Study neutrino interactions.Study neutrino interactions.
• 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
1616
Far detectorFar detectorSuper-KamiokandeSuper-Kamiokande
( since Apr 1996)
40m
41
.4
m50,000 ton water Cherenkov detector
(22.5 kton fiducial volume)
1717
Far detector SK is back Far detector SK is back !!
Sep.-2002, before water filling
Jan.-2003, fully contained event
Full water 10-Dec.-2002w/ half coverage (20%)
Acrylic + FRP vessel
Back to full coverage (40%) Scheduled in winter of 2005
1818
Assume CC Quasi Elastic (QE) reaction
cos
22
pEm
mEmE
N
N
p
beam energy
EE reconstruction in Water Cherenkov reconstruction in Water Cherenkov
+ n → + p
(E , p)
ccQEcc-inelastic
E(reconstruct) – E (True) (MeV)
=80MeV
1R-FC
1919
★Precise measurement of neutrino mixing matrix
Accuracy: sin22θ23 ・・・・・・ 1%
Δm223
・・・・・・・・・・ a few % (<
1×10-4 eV2)
★Discovery and measurement of non-zero θ13
sin22θ13 ・・・・・・ > 0.006
1st Evidence of 3-flavor mixing !
1st step to a CP measurement
Physics Goal at the 1st phase Physics Goal at the 1st phase
2020
3-flavor 3-flavor Oscillation Oscillation
ELmP e /27.1sin2sinsin 223
213
223
2
ELmP x /27.1sin2sincos1 223
223
213
4
Oscillation Probabilities when213
223
212 mmm
e appearance
disappearance
common
21
3
m2atm
m2sun
e
~1
~0.5
2121
ee appearance in T2K (phase 1) appearance in T2K (phase 1)
e0
1RFC w/ 0 cut 22.5kt FV
Back ground for e appearance search• Intrinsic e component in initial beam• Merged 0 ring from
Requirement 10% uncertainty for BG estimation
2222
Tight e/Tight e/00 separation separation• Shower direction from the beam axisShower direction from the beam axis
– coscosee: : from coherent from coherent 00 tends to have a forward peak tends to have a forward peak
• Force to find 2nd ring and…Force to find 2nd ring and…– E(E(22)/E()/E(11++22): The second ring energy is larger for BG): The second ring energy is larger for BG– Likelihood diff. between 1-ring and 2-ringsLikelihood diff. between 1-ring and 2-rings– Invariant mass: Small for Invariant mass: Small for ee
cose
cose E(2)/E(1+2)
E(2)/E(1+2)
Likelihood
Likelihood
M
M
e
BG
2323
sinsin22221313 from from ee appearance (5 years running) appearance (5 years running)
sinsin222211
33
Background in Super-K Background in Super-K (as of Oct 25, (as of Oct 25, 2001)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
(*) will be improved
eff. =42%(66% for QE)
2424
disappearancedisappearance
1ring FC -like
Non-QE
(log)m2=3×10-3
sin22=1.0
~3%
m2
sin22
sin22m
2eV2
Oscillation with m2=3×10-3
sin22=1.0
Reconstructed E (MeV)
(sin22) OAB-2degree
0.01
True m2
sin22
310-3
2525
→→ confirmation w/ NC interactionconfirmation w/ NC interactionNC NC 00 interaction interaction (( + N → + N → + N + + N + 00))
e e CCCC + NC( + NC(~0.5CC~0.5CC) ) ~0 (sin~0 (sin22221313~0)~0) CCCC + NC( + NC(~0.5CC~0.5CC) ) ~0 (maximum oscillation)~0 (maximum oscillation)
NCNC
##00 is sensitive to is sensitive to flux flux.. Limit on Limit on s s ((f(f(ss)~0.1)~0.1))
s
=390±44#0 +
#e-
lik
e
m2323.510-3
CC
NC
26
31322
132
232
132
13
212
13231223122
132
232
122
232
122
132
12
21313223131223122
13
21313223131223122313122
13
3122
232
132
13
sincos4
)21(8
sin)cos2(4
sinsinsinsin8
sinsincos)cos(8
sin4)(
E
aLSSSC
SSSCCSSSCCCS
SSSCCC
SSSCCSSSC
SSCP e
seigenvalue mass: ,
energy, neutrino: length,flight :
,4/
222
2
ijiij
ijij
mmmm
EL
ELm
Sij=sinij, Cij=cosij
T2K oscillation probability (Consider the difference from a reactor measurement)
][]/[6.7
3 GeV
E
cmga
CP conserving
CP
solar
matter effect
[eV2]
-, a -a for e
13
27
e oscillation probability in T2K
sin2213=0.01
matter
total13CPCPsolar
2828
SummarySummary• Precision study of neutrino oscillationPrecision study of neutrino oscillation
– Next step after the discovery Next step after the discovery – We may find a hint for next break-through.We may find a hint for next break-through.
• J-PARC neutrino experiment (2008~)J-PARC neutrino experiment (2008~)– J-PARC 50GeV-PS+Off Axis beam+Super-KJ-PARC 50GeV-PS+Off Axis beam+Super-K– Narrow band beam at the oscillation maximum Narrow band beam at the oscillation maximum
(~ 1GeV)(~ 1GeV)– ee appearance, discovery of appearance, discovery of 1313
(sin (sin 1313>0.006,90%CL)>0.006,90%CL)
2929
Supplement Supplement
3030
ee contamination in the beam contamination in the beamOff-Axis Beam
~1/500
from K
e from + K
Intrinsic background: e /(peak)~ 0.002