素粒子物理学の進展2017
2017年８月1日＠京大基研

T2K実験とスーパーカミオカンデ実験による「ニュートリノCPの測定」
中家

剛 (京大理/東大Kavli-IPMU)

1

T2K Neutrino Oscillation Experiment
(ー)

(ー)

Very Intense Neutrino Beam for νμ→νe study
J-PARC
J-PARC

Super-KSuper
KamiokandeSuper
Kamiokande“far”
detector“far”
detector(FD)(FD)

Kamioka
Kamioka

Tokai
Tokai
295
295 kmkm• 470 kW (today)• ~1MW(2020) from~500
collaborators~500 collaborators fro
1.3 MW (2025)
58•institutions,
12 nation

58 institutions, 12 nati

Intense~600
MeVνµ beam for
Intense ~600 MeV νµ beam forneutrino oscillation studies

neutrino oscillation studies• High sensitivity search for θ13• High sensitivity search for θ13• Precision measurement of θ23, Δm2223• Precision measurement of θ23, Δm 23
see “T2K Experiment”
see “T2K Experiment”
arXiv:1106.1238
submitted to NIM 2A

T2K$Collabora6on

~500 members, 59 Institutes, 11 countries3%Super-K Atmospheric Neutrinos

4

Todayʼs Topics•

CP violation in neutrino oscillation•

Neutrino oscillation parameters•

3 neutrinos or more?

•

Mass hierarchy•sin2θ23•

T2K and Super-K results•

In future, T2K-II → Hyper-Kamiokande
5Introduction

6

Neutrino Oscillation
θ12 = 34.4° ± 1.3°
θ 23 = 45° ± 8° (90%CL)
θ13 ≤ 12° (90%CL)OR~2.4x10 eV! νe $! ν1 $
Solar, Reactor§ 0.8 0.55 < 0.21·# ν & =U
# xc
&
¨
¸
ν2
µ
PMNS
U
≈ ¨ − 0.4 0.6
0.7 ¸# ν & Atmospheric,#&Accelerator
¨ 0.4
¸
" 3 %
" ντ %
0
.
6
0
.
7
©
¹

-3

~7.6x10-5eV22~2.4x10-3eV2~7.6x10-5eV2

MNS

δ=?

sij = sin θ ij , cij = cosθ ij§ 0.97 0.23 0.004 ·−iδ ¸% ""U c≈ ¨ 0.23 0 0.97%
s13e0.04 ¸ c12 s12
0 '$ CKM 13¨'$¸¨ 0.008 0.04
s23 '$
0©
1
0 1 ¹'$ −s12 xcc12'$7 −s eiδ δ∼60
'$
0 oc

" 1 0
$
U PMNS = $ 0 c23$ 0 −s c
23
23 & ##
Atmospheric
Accelerator" 0.8$
U PMNS ~ $ −0.4
$ 0.4
#

0.55
0.6
0.6

δ〜unknown

•

13

13

Accelerator
Reactor0.15 % Atmospheric

0.7
0.7

'
'
'
&

&#

0

Solar
Reactor! 0.97#
UCKM ~ # 0.23
# 0.008"

In the framework of 3 neutrinos, the unknowns are•

mass ordering•

CP violation parameter: δCP 7

0 %
'
0 '
0 1 '&

0.23
0.97
0.04

δ=60°

0.004
0.04
~1

$
&
&
&
%

Current values of the oscillation parameters
NuFIT 3.0 (2016)
Normal Ordering (best fit)bfp ±1
3 rangesin2 ✓12

0.306+0.012
0.012

✓12 /

33.56+0.77
0.75

sin2 ✓23

0.441+0.027
0.021

✓23 /

41.6+1.5
1.2

sin2 ✓13

0.02166+0.00075
0.00075✓13 /

8.46+0.15
0.15

CP /

m221
10 5 eV2
m23`
10 3 eV2

Inverted Ordering ( 2 = 0.83)
bfp ±1
3 range

0.271 ! 0.345

0.306+0.012
0.012

31.38 ! 35.99

33.56+0.77
0.75

0.385 ! 0.635

0.587+0.020
0.024

38.4 ! 52.8

50.0+1.1
1.4

0.01934 ! 0.02392

0.02179+0.00076
0.00076

7.99 ! 8.90

8.49+0.15
0.15

261+5159

0 ! 360

7.50+0.19
0.17+2.524+0.039
0.040

Any Ordering
3 range

0.271 ! 0.345

0.271 ! 0.345

0.393 ! 0.640

0.385 ! 0.638

0.01953 ! 0.02408

0.01934 ! 0.02397

277+4046

145 ! 391

0 ! 360

7.03 ! 8.09

7.50+0.19
0.17

7.03 ! 8.09

7.03 ! 8.09

+2.407 ! +2.643

2.514+0.038
0.041

8

31.38 ! 35.99

31.38 ! 35.99

38.8 ! 53.1
8.03 ! 8.93

2.635 !

2.399

38.4 ! 53.0
7.99 ! 8.91



+2.407 ! +2.643
2.629 ! 2.405

Status of δCP

9Three neutrinos and Beyond

Assuming unitarity (3 neutrinos)

10

Through neutrino oscillations, we want to know••

CP violation•

PMNS matrix or beyond. Any source of new CP
violation?

•

the relation with leptogenesis and a quest of thematter - antimatter asymmetry in our universe.

A pattern of the PNMS matrix and the mass ofneutrinos•

A relation with a GUT model
11

T2K results• The new T2K results will be announced at the KEK

Colloquium at 10:00 JST on Friday, August 4th.
•

Title:••

T2K neutrino oscillation results with data up to 2017 Summer

Abstract:•

In 2016, T2K reported the results of neutrino oscillation measurements based on thedata accumulated with 7.5x10^20 protons-on-target from the J-PARC Main Ring (MR)for each of the neutrino beam run and the antineutrino beam run. One of the highlights
then was an indication of CP violation with 90% C.L. Since then, the J-PARC MR beam
power was increased up to 470kW and T2K accumulated another 7.2x10^20 protons-ontarget with neutrino beam in a half-year run. In addition, approximately a 30% increase instatistics was achieved by improvements to the event selection at Super-Kamiokande,
the T2K far detector. In this colloquium, we will present the results of the neutrino
oscillation measurements with all of the data collected up to now and with the new event
selection.
12

Super Kamiokande“far” detector (FD)13

J-PARC

Kamioka

Tokai
295 km~500 collaborators fro
58 institutions, 12 natio

2
2
2
2
2
×(C12
C23
+ S12
S13
S23
+ 2C12 C23 S12 S13 S23 cos δ) · sin2 ∆12

Formula of Oscillation Probability with CP violation
22
2
P (νµ → νe) = 4C13
S13
S23
· sin2 ∆31 Leading

CP violating (flips sign for ν)

2+8C13
S12 S13 S23 (C12 C23 cos δ − S12 S13 S23 ) · cos ∆32 · sin ∆31 · sin ∆212−8C13
C12 C23 S12 S13 S23 sin δ · sin ∆32 · sin ∆31 · sin ∆21

2
2
2
2
2
2
2
+4S12
C13
(C12
C23
+ S12
S23
S13
− 2C12 C23 S12 S23 S13 cos δ) · sin2 ∆21
Solar
aL
2
2
2
2
−8C13 S13
(1 − 2S13 ) · cos ∆32 · sin ∆31
12 S23 ·4Eν
aMatter effect
2
2
2
2
2
+8C13 S13 S23(1 − 2S13 ) sin ∆31
2
∆m13

0.06

2
Leading(θ13)
"
%
Δm
L
2
2 31 2
2
2
2
2
4
2
295km
θ 23 sin
2θ1313sin
Leading
P (νe → νsin
1 − 4C
S13 ·$(C12sin' ∆13 + S12
sin
∆
)
−
4S
C
C
sin
∆12
e) =
23
12 12 13
Total
0.04
# 4E &
Solar
0.02
CPV
2 L/4E , respectively, and Matter
2 ] = 7.56 ×
where Cij , Sij , ∆ij are cos θij , sin
θ
,
∆m
a[eV
ij
ν
2
2 ij
sin
2
θ
sin
2
θ
Δm
L
Δm
0
2
2
31
21 L
10−5 ×12ρ[g/cm233 ]sin
×E].
2νθ[GeV
sin
sin
sin
δ
13
CPV
2sin θ13
4E
4E
CPC(cosδ)
-0.02
~11.8
(6.4
from
1/sinθ
)~0.03
132
π Δm21
sin 2θ12 sin 2θ 23 E1st max
22θ =0.1,δ=π/4)~-0.04[leading] sin δ
(sin
2
2
13
4 Δm32 sin θ 23 sin θ13
E-0.06
E1st max
01
2~ 0.27 × [leading] ×× sin δEν (GeV)
E
2

27%

2

22

• No magic for the 2nd maximum.
is important.
• Energy dependence
14

A door to Neutrino CP violation is opened
2011

2013

2

• νμ→νe oscillation w/ Δmatm discovered by the T2K experiment• Indication in 2011 [PRL 107, 041801 (2011)]• Observation in 2013 [PRL 112, 061802 (2014)]

2011

T2K
νe

2013

T2K
νe

15

Variation of the spectra with category of systematic uncertainties

FRAMEWORK

Nominal value of nuisance parameters
1•st row
is modesselectionof
in observation
ν - modeFourobserved at T2K

νµ→νCC-0π
e , νµ→νe appearance
μ+/-• rings• νµ↛νµ , νµ↛νµ disappearance

Systematic error source• use all information to constrain oscillation parametersconstrainMC:
137.8 by reactor2sinx) 31 ]
2
2
data:
135
constrain
by
ν
disp.
µ
P (⌫µ ! ⌫e ) ⇡ sin 2✓13
⇥ sin ✓23
⇥ [(1(1 x)2switches signfor νµ→νe↵ sin CP+(CP even)

M. Freund, Phys.Rev. D64 (2001) 053003

P (⌫µ ! ⌫µ ) ⇠ 1

4⇥ sin 2✓12 sin 2✓13 sin 2✓23
+O(↵2 )
m221
1
⌘
↵=
⇠
2
m31
30
2

⇥ sin

sin[x 31 ] sin[(1 x)
31
x
1 x

p

m231 L
4E

x⌘

2 2GF Ne E
m231

2

2

2 L
m31

2

(cos 2✓13 sin 2✓23 + sin 2✓13 sin ✓23 )sin

31 ]

4E

• Large θ23: enhances both νµ→νe and νµ→νe• δCP =-π/2: enhance νµ→νe, suppress νµ→νe
EPS-HEP 2017 / 9• Δm 31>0 (normal hierarchy): enhance νµ→νe, suppress νµ→νea Haegel /University of Geneva
2

T2K latest neutrino oscillation results

16

3

Nsignal=Φ σ Ntarget( ε)Oscillation Analysis in T2K
ΦNeutrino flux prediction
w/CERN NA61 result

ND280 νμ measurements

Flux+Cross Section Fit

Neutrino Cross Section
Uncertainties

σ
Ntarget( ε)Osc. Fit:SK Detector/Selection sin22θ , sin2θ , Δm 2,
13
23
32
Uncertainties
δCPν oscillation parameters fixed:• Δm122=7.6×10-5 eV2• sin2θ12=0.32

Neutrino Cross Section
Uncertainties
17

Resultσ

T2K neutrino beam

A (-250 kA ) for ν (an0-ν) enhanced mode

INGRID
nitors the stability
ﬂux and direc0on

90 cm long and 2.6 cm diameter

Muon Monitor
measures the muon proﬁleaXer beam dump

Proton Beam Monitor
measure the proton bea
intensity, direc0on

Beam direc0on is stable to within 1 mrd à 2% shiX of the Ev peak at far detector SK

18

Predicted Neutrino Flux
ND
280

SK

ν

ν

19

Super-Kamiokande• Water Cherenkov detector with 50 kton mass (22.5 kton Fiducial
volume) located at 1km underground

41.4m

Good performance (momentum and position resolution, PID,
charged particle counting) for sub-GeV neutrinos.
[Typical] 61% efficiency for T2K signal νe with 95% NC-1π0 rejection
Inner tank (32 kton) :11,129 20inch PMT
Outer tank:1,885 8inch PMT

39.3m• Dead-time-less DAQ• GPS timing information is recorded
real-time at every accelerator spill
T2K recorded events: All interactions
within a ±500µsec window centeredon the the neutrino arrival time.

20

Atmospheric ν● Data− MCNeutrino Detection at SK Far Detector
Signal ("5 )Signal ("# )Background"5 CCQE"# CCQE"ℓ NC1i K

721

Flux correlations before ND280 %t : zoom

22

T2K DATA COLLECTION HISTORYThis data added fortoday’s results
Published Results➤

Accumulated 14.7x1020 protons-on-target (POT) in neutrino mode and 7.6x1020 POT in
antineutrino mode - full data set presented here➤

29% of the approved T2K POT➤

7.5x1020 neutrino mode, 7.5x1020 antineutrino mode for published results➤➤

Phys. Rev. Lett. 118 (2017) no.15, 151801 - PRL Editor’s Suggestion

Accelerator has achieved stable operation with 470 kW beam power➤

Thanks to high power operation, double
neutrino data in 1 year!
23

17

Todayʼs results
Since
the
Last
PAC
Mee1ng• Based on

Submi&ed
to PRD
24



FINAL Electron (anti-)neutrino events
22

ν-modeRun1-7 Data
(7.48×1020 POT)
Osc. νe CC
Osc. νe CC
νµ/ νµ CC
Beam νe/ νe CC
NC

15

10

Number of events/125 MeV

Number of events/125 MeV

ν-mode50Run5-7 Data
(7.47×1020 POT)
Osc. νe CC
Osc. νe CC
νµ/ νµ CC
Beam νe/ νe CC
NC

3

2

1

0

250

500

750

1000

0

1250

0

250

Reconstructed ν energy (MeV)

500

750

1000

1250

Reconstructed ν energy (MeV)

FIG. 18. The reconstructed energy spectra of the observed ⌫e (left) and ⌫ e (right) CC candidate event samples assuming CCQE
interaction kinematics. The data are shown as points with statistical error bars and the shaded, stacked histograms are theMC predictions. The expectation is based on the parameters of Tab. XIII.

• Neutrino:• Data: 32• MC: 28.55• Anti-neutrino:• Data: 4• MC: 6.28

TABLE XIV. Event reduction for the ⌫e CC selection at the far detector. The numbers of expected MC events divided into
five categories are shown after each selection criterion is applied. The MC expectation is based upon three-neutrino oscillations
with the parameters as shown in Tab. XIII.
⌫-beam mode

MC total⌫µ + ⌫ µCC⌫e + ⌫ e
25CC⌫ + ⌫¯NC⌫µ ! ⌫eCC⌫µ ! ⌫eCC

Data

NMichel e  1

68.26

13.18

23.85

27.79

0.09

3.35

66

FINAL muon (anti-)neutrino eventsg There is only one reconstructed Cherenkov ringh The ring is µ-likei The reconstructed momentum, pµ , is greater than 200 MeV/cj There are less than two reconstructed Michel electronsν-modeNumber of events/100 MeV

Number of events/100 MeV

ν-modeRun1-7 Data20
(7.48×10 POT)νµ CC QE
νµ CC QE
νµ+νµ CC non-QE
νe+νe CC
NC

30

20

Run5-7 Data20
(7.47×10 POT)νµ CC QE
νµ CC QE
νµ+νµ CC non-QE
νe+νe CC
NC

15

10

5
10

0

0

1000

2000

3000

Reconstructed ν energy (MeV)

0

0

1000

2000

3000

Reconstructed ν energy (MeV)

FIG. 20. The reconstructed energy spectra of the observed ⌫µ (left) and ⌫ µ (right) CC candidate event samples assuming
CCQE interaction kinematics. The data are shown as points with statistical error bars and the shaded, stacked histograms are
the MC predictions, and the rightmost bin includes overflow. The expectation is based on the parameters of Tab. XIII.

1192
1193
1194
1195

• Neutrino:• Data: 135• MC: 137.76

to assess the uncertainties. Cosmic-ray muon samples1200
are used to estimate uncertainties related to the FC,1201
fiducial-volume and decay-electron requirements, for the1202
selections of both (⌫–e) and (⌫–µ) CC candidates. The error26
1203• Anti-neutrino:• Data: 66• MC: 68.26

side the ID. The uncertainty due to the Michel electron
tagging efficiency is estimated by comparing cosmic-ray
stopped muon data with MC. The rate of falsely identified Michel electrons is estimated from MC and a 100%

CCQE tuning / NEUT nominal parameter value

Near Detector
Interaction
model: measurements
post-<t constraints→ constraints
Events selected in FGD2, ν mode, CC-0π (postfit)

Cross-section parameters
T2K preliminary

T2K preliminary
NEUT v5.3.2

CC1μ0πμ momentum [MeV/c]
Events selected in FGD2, ν mode, CC-1π (postfit)

Events selected in FGD2, ν mode, CC-other (postfit)

T2K preliminary

T2K preliminary

NEUT v5.3.2

NEUT v5.3.2

CC1μ-otherCC1μ1πμ momentum [MeV/c]Leïla Haegel /University of Geneva

27

NuFact 2016 : T2K near detector constraints

μ momentum [MeV/c]

15

Electron Neutrino Predictions

28

Muon Neutrino Predictions

29

Systematic uncertainties

30

(w/ ND280 constraint)
The e↵ect of the systematic uncertainties on the pre0.2
FSI+SI+PN at SK
5
dicted event rates of the ⌫- and ⌫-mode samples
are summarizedin Tab. XIX and Tab. XX respectively.
The 1 SK detector00020 40 60 80 100 120 140 160 180
Alluncertainties areθ (degrees)
obtained by throwing large sets of toy(w/o ND280 constraint)
experiments, varying only the selected systematicparam−3(w/ ND280 constraint)×
10
eters for each experiment, and calculating the relative
1.2
90 event rates.
uncertainties
from the distributions of the

4.2%
2.5%
2.4%

2.9%
1.5%
3.9%

5.0%
10.5%
9.3%

12.7%
5.5%

12.0%
5.1%

21.9%
14.8%

Systematic uncertainties
80

Number of events

1

70
TABLE XIX. E↵ect of 1 variation of the systematic
uncerTABLE XX. E↵ect of 1 variation of the systematic un
0.8
60
taintieson the predicted event rates of the ⌫-mode
samples.
tainties on the predicted event rates of the ⌫- mode samp
0.6Source of uncertainty
0.4Flux50⌫e CCQE-like ⌫µ ⌫e CC1⇡ +
40
N/N
N/N
N/N
30
3.7%
3.6%
3.6%

(w/ ND280 constraint)
20
Cross section
5.1%
4.0%
4.9%
10
0(w/ ND280 constraint)
0
0
20
40
60
80
100
120
140
160
180
Flux+cross-sectionθ (degrees)(w/o ND280 constraint)
11.3%
10.8% 16.4%(w/ ND280 constraint)
4.2%
2.9%
5.0%
SK
2.5%
1.5% (top),
10.5%
28.FSI+SI+PN{E⌫rec ,✓lep }attemplates
for the⌫e CCQE-like+ detector
3.9%
9.3%
C1⇡SK
(middle) in ⌫-mode and ⌫¯e2.4%
CCQE-like(bottom)
Allcandidate samples. Both signal and background
mode
(w/o
ND280inconstraint)
12.0%
s are
includedthe expected 12.7%
distributions
based 21.9%
on(w/ ND280
constraint)
5.5%The superimposed
5.1%
14.8%
oscillation
parametersof Tab. XIII.
dots correspond to the data.
0.2

Source of uncertainty
Flux(w/ ND280 constraint)
Cross section(w/ ND280 constraint)
Flux+cross-section(w/o ND280 constraint)(w/ ND280 constraint)
FSI+SI+PN at SK
SK detectorAll(w/o ND280 constraint)(w/ ND280 constraint)⌫ e CCQE-like ⌫ µ
N/N
N/N
3.8%
3.8%
5.5%

4.2%

12.9%
4.7%
3.0%
2.5%

11.3%
3.5%
2.1%
3.4%

14.5%
6.5%

12.5%
5.3%

TABLE XX. E↵ect of 1 variation of the systematic1660uncerIX. BIASES ON OSCILLATION PARAMETER
tainties on the predicted event rates of the ⌫- mode samples.
1661
FROM NEUTRINO INTERACTION MODELLIN

ainly due to the larger backgrounds a↵ecting it, andSource of uncertainty⌫ e CCQE-like⌫µrger uncertainties
on the pion FSI
and SI as shown
N/N
N/N
ab. XIX, where the SK systematic uncertainties
are166231

The neutrino interaction uncertainties are one of

7

Events/bin

Events/bin

Oscillation FITBest-fit spectrum

ν
e
30
6

T2K data

35

Ratio

Ratio

0

0

20

20

15

2

10

1

5

Ratio

Ratio

10

0

0.2

0.4

0.6

0.8

1

1.2

4
3
2
1
0

0

Reconstructed neutrino energy (GeV)

0 0.20.40.60.8 1 1.2

0.5

1

1.5

2

2.5

3

Reconstructed neutrino energy (GeV)

0 0.5 1 1.5 2 2.5 3

2.5

Events/bin

Events/bin

Unoscillated prediction

25

3

0

Best-fit spectrum
T2K data

30

4

30
20
10
0

νμ

40

4
3
2
1
0

Unoscillated prediction

5

45

47

Best-fit spectrum

14Best-fit spectrumννμ (GeV)
eenergy (GeV)
ted neutrino
Reconstructed
neutrino energy
2
10
Unoscillated prediction

2

T2K data

0
1

0.2

0.4

0.6

0.8

1

1.2

8
0
6

1

1.5

2

2.5

3

0.5

1

1.5

2

2.5

3

Ratio

0

0.2

0.4

0.6

0.8

1

1.2

0 0.20.40.60.8 1 1.2
3.5

2
1
0

0

0

Reconstructed neutrino energy (GeV)

in

Ratio

0.5

2

0

0

T2K data

1

5

0

10

4

0.5

10
5
0

Unoscillated prediction

Ratio

Ratio

1.5

12

32

Reconstructed neutrino energy (GeV)

0 0.5 1 1.5 2 2.5 3

R

1+
Oscillation FIT w/ CCνe-1π
0
2

Ratio

0

0.2

0.4

0.6

0.8

1

1.2

0

Reconstructed neutrino energy (GeV)

Events/bin

0.5

1

1.5

2

2.5

Reconstructed neutrino energy

0.20.40.60.8 1 1.2

0 0.5 1 1.5 2 2.5

3.5

3

2
1
0

Best-fit spectrum

15 (GeV)neutrino energy (GeVno
Reconstructedenergy2.5

Unoscillated prediction
T2K data

0.4

0.6

10

0.8
1.5

1

1.2

0.2

0.4

0

0.5

1

0.8

1

1.2

1.5

2

2.5

1

0.5

5
0

Ratio

0.2

Ratio

2

15
10
5
0

0

0

0.6

Reconstructed neutrino energy (GeV)

0 0.20.40.60.8 1 1.2

Comparison of the best-fit oscillated MC energy spectra,
unoscillated spectra and T2K data for the five33µ-like sample in ⌫-mode and ⌫-mode (top left and right), single ring e-like appearance sample in ⌫-modwx /wx Disappearance Analysis- CPT test by comparing "# → "# and "# → "# modes

"#

90
80

Events/100MeV

Events/100MeV"#
Unoscillated
Prediction

T2K Run1−7c preliminary70
60

Best-Fit
Data

50
40
30

25

Best-Fit

20

Data
15
10

20
10

5

0
2.5
0
2
1.5
1
0.5
0
0

1

2

3

4

5

6

7

8

1

2

3

4

5
6
7
8
Reconstructed Energy [GeV]

Ratio

Ratio

Unoscillated
Prediction

T2K Run1−7c preliminary

135 events observed

0
2.5
0
2
1.5
1
0.5
0
0

1

2

3

4

1

2

3

4

5

6

7

8

5
6
7
8
Reconstructed Energy [MeV]66 events observed(+10 events since Neutrino 2016)(64.2 events expected)(135.8 events expected)
34

12

X
WXY and opYX Comparison- No hint of CPT violation−3−3

3.8 ×10

3.4

T2K Run1-7 ν 90% CL

T2K Run1-7 ν 68% CL

T2K Run1-7 ν 90% CL

T2K Run1-7 ν 68% CL

Normal Hierarchy

3.2
3
2.8
2.6

2

2

∆ m32 or ∆ m232 (eV2)

3.6|∆ m32| or |∆ m232| (eV2)

3.8 ×10

2.4
2.2
2
1.8
0.2

3.4

0.3

0.4

0.5

0.6

0.7

T2K Run1-7 ν 68% CL

T2K Run1-7 ν 90% CL

T2K Run1-7 ν 68% CL

0.3

0.6

Inverted Hierarchy

3
2.8
2.6
2.4
2.2

1.8
0.2

0.8

T2K Run1-7 ν 90% CL

3.2

2

NH

IH

0.4

0.5

0.7

0.8

2

sin θ23 or sin θ23

sin2θ23 or sin2θ23l.

+

Δ 0+.+ = 2.34, 2.75 ×10l.|} + Q~ at 90% CL

2+
Δ 0 .+

3.6= 2.16, 3.02 ×10|} Q~ at 90% CL

sin+ -+. = 0.32,0.70 Q~ at 90% CL

sin+ -+. = 0.42,0.61 Q~ at 90% CL

3513Full Joint Fit Analysis"5

14

Events/100MeV

Events/100MeV"5

Unoscillated
Prediction

T2K Run1−7c preliminary

12Best-Fit

10

Data

8

3

0.5
200

400

600

800

1000

1200

1400

10
5
0
0

200

400

600

800
1000
1200
1400
Reconstructed Momentum [MeV/c]

Data

1.5

2
0

Best-Fit

2

1

150

Unoscillated
Prediction

T2K Run1−7c preliminary

2.5

4

Ratio

Ratio

6

3.5

0
80

200

400

600

800

6
4
2
0
0

200

400

600

800
1000
1200
1400
Reconstructed Momentum [MeV/c]

32 events observed

1000

1200

1400

4 events observed(+0 events since Neutrino 2016)
STU = −/2
(NH)

STU = Ä(NH)

STU = +/2
(NH)

STU = (NH)

Observed

wÅ

28.7

24.2

19.6

24.1

32

wÅ

6.0

6.9

7.7

6.8

4

36

15

OA Fit results with T2K only data
• FIT neutrino and anti-neutrino data separately.
3

NormalNormal
MH

2

2

1

1

Best fit
PDG 20150ν -modeaν e - 68CL

−1

ν -modeaν e - 68CL
ν -modeaν e - 90CL

0.02

0.04

0.06

0.08

Inverted
Inverted
MH

Best fit
PDG 20150ν -modeaν e - 68CL

−1

ν -modeaν e - 90CL

−2
−3
0

δCP (rad)δCP (rad)3

ν -modeaν e - 90CL
ν -modeaν e - 68CL
ν -modeaν e - 90CL

−2
−3
0

0.1

sin2θ13

0.02

0.04

0.06

0.08

0.1

sin2θ13

FIG. 38. Contours in the sin2 ✓13 – CP plane using T2K-only data, obtained by analysing either the ⌫- or ⌫-mode appear
datasets are compared for both orderings. Both ⌫- and ⌫¯-mode disappearance datasets were used in all fits. The yellow bcorresponds to the reactor value on sin2 ✓13 from the PDG 2015 [72].

)

37

3.6

2000

way as described in Sec. VIII for the Feldman-Cou

on the right plot corresponds to the reactor value on sin2 ✓OA Fit results with T2K only data
3

Fixed Mass Ordering
Best fit
PDG 20152

δCP (rad)39

Normal - 68CL
Normal - 90CL
Inverted - 68CL
Inverted - 90CL

1

TABLE XXIV. Point estimates and 1 confidence intervals 02
under the constant
approximation from an analysis considering T2K oscillation data only.
−1
Normal ordering
Inverted ordering−2Best-fit±1Best-fit±1-1.791 [-2.789; -0.764] -1.382 [-2.296;-0.524]
CP
sin2 ✓13 0.0271 [0.0209; 0.0342] 0.0299 [0.0232; 0.0380] −3
Global minimum
0Parameter

0.02

0.04

0.06

0.08

0.1

sin2θ13-2∆ln(L)-2∆ln(L)1030
is stillconsistent with the reactor measurement at theNormal2
68%9 confidence level.
FIG. 36. 25Two-dimensional constantcontours for osc
Inverted
Normalabove, in this analysis a fifth sample
As8 mentioned
lation parameters CP and sin2 ✓13 using T2K data only. T27selecting⌫e Inverted
candidates at SK with one delayed Michel
20 corresponds to the reactor value on sin ✓13 froyellow band
6
electronin the final state has been added for the thefirstPDG 2015 [72].
4σ
2
5
15
time.
A comparison of thesurface for CP only
4
includingthe four single-ring samples used in previous
10
3σ
CL the inclusion of3
analyses
and the results obtained 90%
with
1962
pared
best-fit results obtained with the T2K-on
the 2fifth sample is shown in Fig. 37. As expected,
a to the
5
+
1σ
1963
data
fit
in
Sec.
XI
A
1,
the
inclusion
of
the
CC1⇡
e-li
90%
CL
1 improvement is observed when the new sample is
small
1σ
1964
sample
in
the
data
fit
with
the
reactorconstraint
resu
included.
0
0
−3
−2
−1
0
1
2
3
0
0.02
0.04
0.06
0.08
0.1
1965
in
a
shift
of
best-fit
value
for
the
phase
towardst
2
Fig. 38 shows a comparisontheδCP (rad) of the constraints in 38
sin θ13 CP
21966
maximally
violating phase of ⇡/2.
in
⌫CP –sin ✓13 plane when appearance channels taken

method are used to evaluate the 90% confidence level withthe proper coverage.
Number of events as a function of θ23

Number of νe candidates

9
Normalsin2 θ23 = 0.55

8Inverted

7
6
5
4
3
2
15

sin2 θ23 = 0.45
δCP = πδCP = +π/2
δCP = 0
δCP = -π/2
20

Data
25

30

35

Number of νe candidates
(

)

39

40

45

FIG
lat
rea
the
pa
the
con

X
WXY and opYX|∆ m232| (10-3 eV2/c4)- Consistent with maximal mixing
3.6
68%CL
90%CL
T2K best-fit

3.4
3.2

Normal Hierarchy

3
2.8
2.6

Daya Bay:oàXÅÅ = X. Z[ ± Ä. Äâ ×dÄlYÅäX
90% CL (NH)

2.4
2.2
2
1.8
0.3

IceCube NOvA (2016) Super-K
T2K Run1-7c preliminary MINOS+
0.35

0.4

0.45

0.5

0.55

0.6

0.65

0.7

sin2 θ23

NH

IH

sinX WXY

0.532jK.KÑÇ
lK.KÇÉ

0.534jK.KÑ.
lK.KÇÇ

|opXYX |[dÄlY eVX ]2.545jK.KÉ1
lK.KÉÑ

2.510jK.KÉ1
lK.KÉ.

40

16

OA Fit results w/ thereactor constraint

The fraction of toy experiments for whichormal and inverted ordering are excluded atfidence is shown for di↵erent true values ofdering. 10,000 toy experiments are used for.
⇡/2 — normal orderingCP =rdering 90% CL
2 CL
ormal 0.243
0.131
ormal 0.216
0.105
verted 0.542
0.425
verted 0.559
0.436: CP = 0 — normal orderingrdering 90% CL
2 CL
ormal 0.104
0.0490ormal 0.130
0.0591verted 0.229
0.137
verted 0.205
0.122⇡/2 — inverted orderingCP =rdering 90% CL
2 CL
ormal 0.124
0.0515ormal 0.102
0.0413verted 0.290
0.194
verted 0.308
0.207Best-fit results and the 1 credible interval
fit without the reactor constraint with the45

TABLE XXIX. Best-fit results and the 1 credible interval of
the T2K data fit with the reactor constraint with the MCMC
analyses including both mass orderings.
ParameterCP2sin ✓13sin2 ✓23
m232

41

±1
[-2.450; -0.880][0.0208; 0.0233][0.490 ; 0.580]
3
eV 2 /c432
4 [-3.000; -2.952] ⇥10
2.539 ⇥ 10 eV /c[2.424; 2.664]⇥10 3 eV 2 /c4
Best-fit-1.7890.02190.534

δCP with reactor θ13

nt (sin+ 2-1. = 0.085 ± 0.005)-2lnL

Measurement (Data)
14
T2K Run1-7c preliminary

12

Normal Hierarchy

10

Inverted Hierarchy
8-2lnLcrit (90% CL)

6-2lnLcrit (2σ CL)

4
2
0

-3

-2

-1

0

1

TABLE XXVI. The fraction of toy experiments for
CP = 0, ⇡ and normal and inverted ordering are exclu
90% and 2
2 confidence is shown for di↵erent true val
13 10,000 toy experiments are us
CP and mass ordering.
each set of values.
True: CP = ⇡/2 — normal ordering
2 CL
CP Ordering 90% CL
0 Normal 0.243
0.131⇡ Normal 0.216
0.105
0 Inverted 0.542
0.425⇡ Inverted 0.559
0.436
True: CP = 0 — normal ordering
2 CL
CP Ordering 90% CL
0 Normal 0.104
0.0490⇡ Normal 0.130
0.05910 Inverted 0.229
0.137⇡ Inverted 0.205
0.122
True: CP = ⇡/2 — inverted ordering
2 CL
CP Ordering 90% CL
0 Normal 0.124
0.0515⇡ Normal 0.102
0.04132
3
0 Inverted 0.290
0.194⇡ Inverted 0.308
0.207(radians)

with sin 2θ =0.085 0.005

δCP•

A constraint of neutrino CPV atTABLE
90%XXVII.
CLBest-fit results and the 1 credible inof the T2K data fit without the reactor constraint wi
MCMC analyses including both mass orderings.

• −0.74
2.09,
at 90%
CL(NH), [-2.09,
δCP = (è~)[-3.13,-0.39]-0.74]Best-fit(IH) at 90% CL
Parameter
±1
42

CP
2

sin ✓13-1.8150.0254[-2.275; -0.628[0.0210; 0.0350

32[2.424; 2.664]⇥10 3 eV 2 /c4

Posterior probability on δCP

nterval
ith the8]43

to the measurement of the CP-violation phase CP as
well as more precise measurements of the atmospheric

Posterior probabilities for the2
mass ordering and sin θ23

TABLE XXX. Posterior probabilities for the mass orderings2and sin ✓23 when fitting T2K data only with an MCMC
method.
sin2 ✓23 < 0.5 sin2 ✓23 > 0.5 Line Total
Inverted ordering
0.060
0.152
0.212
Normal ordering
0.235
0.553
0.788
Column total
0.295
0.705
1

44

Super-K
atmospheric ν
results

45

Complementarity with atmospheric neutrinos
NuclPhysB669,255(2003)
NuclPhysB680,479(2004)r

Solar term: µ/e flux ratio (~2 at low energy)!
!
P2 = |Aeµ|2 : 2ν transition probability νe  νµτ in matter!
R2 = Re(A*eeAeµ)!
I2 = Im(A*eeAeµ)!
Aee : survival amplitude of the 2ν system!
Aeµ : transition amplitude of the 2ν system!

Interference term (δCP)
θ13 resonance term
P(QPoQe)νe appearance (and νμ distortion) is
expected due to MSW effect in the
Earth’s matter- happens in ν in the case of normal
mass hierarchy- in anti-ν in inverted mass hierarchy

Large θ13 value gives us a goodchance to discriminate mass
hierarchy.
“Sub-GeV”“Multi-GeV”

46Ψ(νe)/Ψ0(νe)−1

10
1
0.8
0.6
0.4
0.2
0
-0.2
-0.4
10
•

NH, sin2θ23=0.4, sin2θ13=0.025, δ=40o

(a)

1
0.8
0.6
0.4
0.2
0
-0.2
-0.4

solar terminterference term
θ13 resonance term
total

ν
-1
cosΘν=-0.8

1oPNH, sin2θ23=0.6, sin2θ13=0.025, δ=220C

δ

(c)

-1

10

1

Eν(GeV)

=

10

40°

cosΘν=-0.8(b)sin2θ23 = 0.4 vs 0.6

°
0
2
-12
s
v
10

1
0.8
0.6
0.4
0.2
0
-0.2
-0.4
10

NH, sin2θ23=0.6, sin2θ13=0.025, δ=40ocosΘν=-0.8

110

IH, sin2θ23=0.6, sin2θ13=0.025, δ=40o

(d)

-1

1

Eν(GeV)

mass hierarchy: NH vs IH

Ψ(νe)/Ψ0(νe)−1

1
0.8
0.6
0.4
0.2
0
-0.2
-0.4

cosΘν=-0.8

10Through matter eﬀect (MSW), we study

Masshierarchy⇨ Asymmetry
betweenneutrinos
antineutrinos.
FIG.• 34.
Oscillated⌫e flux relative
to the non-oscillated
flux asa function ofandneutrino
energy for the
upward-goingneutrinos
zenith angle cos ⇥ = 0.8. ⌫¯e is noteﬀect
included in the plots. Thin solid• Octantof θwith
23 ⇨ Magnitude ⌫of resonancelines, dashed lines, and dotted lines correspond to the solar term, the interference term, and the ✓13

Appearance (and νμ→νμ disappearance) interplay

resonance term, respectively (see Eq. 5). Thick solid lines are total fluxes. Parameters are set as•
eﬀects~GeV5 eVenergyregion22 (and2 θ13) ⇨CP3(sin2 ✓12δ, sin
✓13 , sin ✓23 , , m221 ,Interferencem232 ) = (0.31, 0.025,
0.6, 40 in, 7.6⇥10, +2.4⇥10eV2 ) unless oth47
erwise noted. The ✓23 octant e↵ect can be seen by comparing(a) (sin2 ✓23 = 0.4) and (b) (sin2 ✓23 = 0.6).

MassExpected
Hierarchy
Sensitivity
Hierarchy
Sensitivity: Normal
Hierarchy of Hyper-K
Effects: electron-likesamplesGcp = 40 deg.

sinT23 = 0.6

normal hierarchy casenormal hierarchy case
10 yearsFix T13

0.5

0.4

3V

Multi-GeV e-like events

Hierarchy sensitivity, 10 years of At

T13 is fixed : sin22T13 = 0.1
NH, unknown
Intensityof the canmatterhence
electronscaleswith the MC
size
Equivalent Effect ofthe
T23 octant
beeffectlargerand
thanthatfrom appearance
Gcp
of appearance
T13
on electron
normal hierarchy case
 By the time Hyper-K is running, the value of T13 should be very well known
depends
Effect ofthelatteris smaller
themass
expected• Sensitivity
on thisθ, δthanandHoweversensitivity
is a functionof both statistical
the T23 octant and true value of10
Gcpyears
23

uncertainty in each binhierarch (a 2012.8.22
little).

Roger Wendell
Roger Wendell2012.8.22•

3σ mass hierarchy determination for2

sin θ23>0.42 (0.43) in the case of
normal (inverted) hierarchy.
48

9

15

3V

Neutrino true-energy for each subsamp

Super-K
atm νforanalysis
FC
Neutrino true-energy
each subsample
FC

FC
FC

July 18th, 201749

7

Atm. ν ﬂux

50

Atm.-n event rate
Atm. ν event rate @ Super-K

July 18th, 2017~8.3 events per day~1.5 events per day~0.73 events per day

S.Mine(UCI) @ Neutrinos,
51 QUY NHON 201714

SK I-IVAtm.
event
sampledistributions@ Super-K
Zenithνangle
and momentum((19 analysis samples for 3-n oscillation analysis)

SK Pｒｅｌｉｍｉｎａｒｙ

Data
MC(NH)

52

Oscillation Analysis w/ νe and νe samples

Standard$3$ﬂavor$analysis

Take$into$account$all$the$sub5leading$eﬀects$(Δm221$&$maker)$
Presence$of$maker:$maker$eﬀect$on$θ13$"$resolving$mass$hierarchy$
Presence$of$Δm221:$νµ$#$νe$"$resolving$octant$θ23$
Presence$of$interference$"$CP$viola=ng$phase$νe"sample"$$$Mul=5GeV$e5like$ne$$$$Mul=5Ring$e5like$neνe"sample"$$$Mul=5GeV$e5like$ne$$$$Mul=5Ring$e5like$ne

Mul=5Ring$other

Cosine Zenith angle

•
•
•
•

oscillation params:0
flux
ratio
Ne/N eΝΗ#

More$e$for$θ23<π/2

statistical separation based on• # of decay e• # of rings• transverse mom.
More e for π<δCP<2π53Δm232=2.1E-3
Δm221= 7.7E-5
sin2θ23= 0.50
sin2θ12= 0.30
sin2θ13= 0.04
δcp=0oν$through$the$Earth$
Resonance$conversion$
MH/octant$sensi=ve
Energy (GeV)

7$

SK only Results 
SK$only$parameter$determina=on
preliminary$
Inverted
Normal|Δm232|$
2θ
2
sin
23
|Δm 13|

δCP

eV2
Fit$(517$dof)

χ2

sin2θ13

δCP

sin2θ23

|Δm232|eV2

SK$(IH)$

576.08 0.0219$(ﬁx)

4.189

0.575

2.5x1053

SK$(NH)

571.74 0.0219$(ﬁx)

4.189

0.587

2.5x1053

• SK$only$(θ13$ﬁxed):$Δχ2$=$χ2NH5χ2IH=$54.3$(53.1$expected)$• Under$IH$hypothesis,$the$probability$to$obtain$Δχ2$of$54.3$or$less$is$0.031$(sin2θ23=0.6)$and$0.007$(sin2θ23=0.4).$Under$NH$hypothesis,$the$11$
probability$is$0.45$(sin2θ23=0.6).$
54

Samples with large contributions( Up - Down ) / ( Up + Down )$$$$UP5DOWN$$$$$UP+DOWN$
as$a$func.$of$p$

0

-0.2
-0.2

-0.4
-0.4
3

-0.4
-0.4
3

NormalInverted
3

3.5

44
10
2×104
Lepton P [ MeV ]1 $$$$$$$$2.5 	
$$5 $10$$$$$$$20$
	Momemtum$(GeV)$
2×10

44
10
Lepton P [ MeV ]NormalInverted

0

-0.4
-0.4
3

NormalInverted
3

3.5

55

+0.42

0.2
0.2

0

-0.2
-0.2

NormalInverted
2×103

3.5

44
10
2×104
Lepton P [ MeV ]1 $$$$$$$$2.5 	
$$5 $10$$$$$$$20$
	Momemtum$(GeV)$
Multi-Ring
Multi-Ring
e-like ν e-like νe
e

0.4
0.4

44
10
2×104
Lepton P [ MeV ]1 $$$$$$$$2.5 	
$$5 $10$$$$$$$20$
	Momemtum$(GeV)$
2×10

NormalInverted

-2.18

0.2
0.2

-0.2
-0.2

Multi-GeV e-like νeMulti-GeV e-like νe

-0.4
-0.4
3

3.8

( Up - Down ) / ( Up + Down )0( Up - Down ) / ( Up + Down )( Up - Down ) / ( Up + Down )

-2.97

0.2
0.2

3.2 2×103 3.43×103 3.6

e

0.4
0.4

NormalInverted

NormalInverted

0.4
0.4

1 $$$$$$$$$$$2.5$$$5 $$$10$$Momentum$(GeV)$
Multi-GeV
Multi-GeV
e-like ν e-like νeMulti-Ring others

-0.2
-0.2

Normalcontribution
toInverted 2Δχ =χ2NH-χ2IH: +0.35

0.2
0.2

Multi-Ring Other
0.4
0.4

Multi-Ring e-like νeMulti-Ring e-like νe( Up - Down ) / ( Up + Down )Hierarchy$
Sensi=ve$
Samples

0.4
0.4

NormalInverted

-0.92

0.2
0.2

0

-0.2
-0.2

-0.4
-0.4
3

NormalInverted
3.2 2×103 3.43×103 3.6

11$

3.8

44
10
Lepton P [ MeV ]1 $$$$$$$$$$$$2.5$$$5 $$$10$
12$
	
Momemtum$(GeV)$SK+T2K$ν
,$ν$parameter$determina=onµeSKResults
with
T2K
inputsNot a joint analysis, fit external data using publicly available T2K info.
preliminary$|Δm232|$|Δm213|sin2θ23

δCP

eV2
Fit$(585$dof)

δCP

sin2θ23

|Δm232|eV2

644.82 0.0219$(ﬁx)

4.538

0.55

2.5x1053

SK+T2K$(NH) 639.61 0.0219$(ﬁx)

4.887

0.55

2.4x1053

SK+T2K$(IH)$χ2

sin2θ13

• SK+T2K$(θ13$ﬁxed):$Δχ2$=$χ2NH5χ2IH$=$55.2$$$$$$$$$$$$$$$$$$$$$$$$$$$$$(53.8$exp.$for$SK$best,$53.1$for$combined$best)$• Under$IH$hypothesis,$the$probability$to$obtain$Δχ2$of$55.2$or$less$is$
13$
2
2
2
0.024$(sin θ23=0.6)$and$0.001$(sin θ23=0.4).$NH:$0.43$(sin θ23=0.6)$
56

Future57

Seamless program to νCPV
From T2K to T2K-II andHyper-Kamiokande

58

•

Table 1: Number of events expected to be observed at the far detector for 10⇥1021 POT ⌫+ 10⇥1021 POT ⌫¯-mode with a 50% statistical improvement. Assumed relevant oscillation
parameters are: sin2 2✓13 = 0.085, sin2 ✓23 = 0.5, m232 = 2.5 ⇥ 10 3 eV2 , and normal
massw/
hierarchy(MH).stat. (10E21 POT for nu and 10E21 POT for anti-nu)
T2K-II
improved

CP Violation Sensitivity in T2K-II
Signal⌫¯µ ! ⌫¯e
3.8
2.7
71.0
50.5

Beam CC⌫e + ⌫¯e
72.2
72.2
28.4
28.4

Beam CC⌫µ + ⌫¯µ
1.8
1.8
0.4
0.4

Beam CC
3σ sensitivity to CP violationfor Beam CC
Total
⌫µ
⌫¯µ
favorable parameters based on

today⌫µ ! ⌫e +⌫¯µ ! ⌫¯e
7.0
1.0⌫-mode⌫e sample⌫¯-mode⌫¯e sample

True CP
0
⇡/2
0
⇡/2

Total
454.6
545.6
129.2
111.8

Signal⌫µ ! ⌫e
346.3
438.5
16.1
19.2

⌫-mode ⌫µ sample 2612.2
2290.5150.0
21482.1with 672.5• 20 ⌫¯-modeµ sample 1217.5
10 ⌫¯Protons
on TargettheBeam CC⌫e + ⌫¯e
1.6
0.6

NC
30.5
30.5
13.3
13.3

T2K-II
NC
163.1
61.3

upgrade of J-PARC to 1.3MW (~102yearlong run)
before2026.
experiments(sin(2✓13) = 0.085year± 0.005)[21]. However, this uncertainty is correlated be-

tween ⌫ and ⌫¯ beam mode samples and its impact on the observation of a CP asymmetryin T2K data is small.
As will be described in Sec. 4, the current systematic errors, if they are not improved,• J-PARC
PAC gives Stage 1 approval.
will significantly reduce the sensitivity to CP violation with the T2K-II statistics. Any
We improvement
are preparing
the Technical
Designon the systematics
would enhancephysics potential. Here, we describe projected improvements.

Report.

59
Neutrino Flux The neutrino flux prediction [15] uncertainty
is currently dominated by

Accelerator Improvement•

J-PARC MR has achieved 420 kW operation•

MR Power Supply Upgrade is scheduled
on 2018.

•

J-PARC demonstrated 3.41E13 ppb
operation [1 MW equivalent]•

After the upgrade, the aim is 1.3MW or
higher.

T2K-II to Hyper-K

Today
400kW

18 May 2016
T2K
POT total: 1.465×1021

nu-mode POT: 7.12×1020 (48.6%)
nubar-mode POT: 7.53×1020 (51.4%)

Hyper-Kvs. calen
Figure 1:T2K-II
Anticipated MR beam power and POT accumulation

http://www.t2k.org/docs/plotsx/frequentlyupdated/Beam/2016-05-18/t2k_total_pot_18may201660

J-PARC Secondary Beamline Upgrades
However, need upgrades to improve cooling capacity, radiation
containment, and irradiated cooling water disposal for 1+ MW
Component
TargetHorn

He Vessel
Decay
VolumeBeam
Dump
Radiation

Limiting Factor
Thermal ShockCooling Capacity
Conductor Cooling
Stripline Cooling
Hydrogen Production
Operation
Thermal Stress
Cooling Capacity
Thermal Stress
Cooling Capacity
Thermal Stress
Cooling Capacity
Radioactive Air Disposal
Radioactive Water

Current
Acceptable Value
3.3 ⇥ 1014 ppp
0.75 MW
2 MW
0.54 MW
1 MW
2.48 s & 250 kA
4 MW
0.75 MW
4 MW
0.75 MW
3 MW
0.75 MW
1 MW
0.5 MW

Upgraded
Acceptable Value
3.3 ⇥ 1014 ppp>1.5 MW
2 MW>1.25 MW
>1 MW
1 s & 320 kA
4 MW>1.5 MW
4 MW>1.5 MW
3 MW>1.5 MW>1 MW
0.75!1.3 or 2 MW
25 / 3161

circulation systems for the target and the beam window need to be co

Improvementof Neutrino
Flux
witha Upgrade
1. Theupgrade of the waterdisposal system
requireslong constructio•

320kA hornt beam operationand iscurrent,
desired toRadio-active
be done duringwater
the MRdisposal,
long shut down
cooling, cooling, and coolingmize the beam-o↵ period.

• +10% more neutrino ﬂux expected62

ND280
Near Detector Upgrade

Goal of the ND280 upgrade simulatio• People are welcome to joint the ND280 upgrade task force
ND280 (NOW)• The final goal is the simulation
ND280(Upgrade)of different
possible configurations

This is just an image, and the details areframework with very simple configurati• Implemented a GEANT4
under discussions in the T2K collaboration.

•• Start with a certain configuration, for example:

T2K steadily improves- 2thesidesystematic
TPCs + targetuncertainty.
••~18% (2011) →- Produce~9% (2014)→efficiencies~6% (2016)selection[→ ~3% (2020)]- ConstrainInteractions
systematic parameterswith BANFF
Understanding of Neutrino
is essential
for future
to Super-K and estimate new sensitivities with VALO
experiments (T2K-II- Propagate
and Hyper-K)
63

T2K-II Physics Sensitivity• For which true δ2CP values can we ﬁnd CP violation assuming true sin θ23=0.43,

0.50, 0.60?

• The fractional region for which sinδ =0 can be excluded at the 99% (3σ)
CP

C.L. is 49% (36%) of possible true values of δCP assuming the MH is known.

20

20

15

15
10

5

∆ χ2 to exclude sinδCP=0∆ χ2 to exclude sinδCP=0∆ χ2 to exclude sinδCP=0∆ χ2 to exclude sinδCP=0

assuming MH unknown
20

20x1021 POT w/ eff. stat. & sys. improvements
21
7.8x10w/ 2016
sys.improvements
errs.
20x1021
POT w/POT
eff. stat.
& sys.

7.8x1021True
POTsinw/2θ2016
sys. errs.
23=0.4322True
θ23=0.50
True sin
θ23sin
=0.43
2
2
True
θ23=0.60
True sin
θ sin
=0.50

3σ

True sin2θ23=0.60

3σ C.L.

3σ C.L.

99% C.L.

10

99% C.L.

5

5

90% C.L.

00True
δCP(°100)
True δCP(°)

100

assuming MH known
20x1021 POT w/ eff. stat. & sys. improvements
21
21
POT
2016
sys.improvements
errs.
20x107.8x10
POT w/
eff. w/stat.
& sys.
2
True
sinw/
θ2016
7.8x1021
POT
sys. errs.
23=0.43
2
2 sin θ =0.50
True
23
True sin
θ23=0.43
2
2 sin θ =0.60
True
23
True sinθ =0.50

23

10

2

True sin θ23=0.60

3σ C.L.

3σ C.L.
99% C.L.
99% C.L.

5

90% C.L.

90% C.L.

0
−200
0
−200

90% C.L.

0
−200
−100
0
−200
−100

15

15

23

10

20

200

200

3

−100
−100

0

100
(°)1000 δ
True
CP
True δCP(°)

200
200

(b) Assuming the MH is known – measured(Note)
Although
T2K
alone
can't
measureMH,
we can the
help
with
the MH(a) Assuming the MH is unknown.
(b) AssumingMH
is known– measured by(a) Assuming by,
the ie,MHcombining
is unknown.
measurement
T2K + NOVAan outside experiment.
an outside experiment.
64sitivity to CP violation as a function of POT assuming

T2K-II
Sensitivity
ghly equalalternatingPhysics
periods of ⌫-modeand ⌫¯-mode⇡/2)•isAs
given
in Fig.of22.
a function
POT in the case of sin θ23=0.5,
215
w/ eff. stat. improvements (no sys. errors)
w/ eff. stat. & sys. improvements

10

20

w/ eff. stat. improvements & 2016 sys. errors

3σ

3σ C.L.

99% C.L.

5
90% C.L.

2ors)∆ χ to exclude sinδCP=0

δCP=-π/2 and normal MH

0
0

5

10

15

Protons-on-Target (x1021)
65

20

21
21
20x10
w/improvement
20x10
POTPOT
w/improvement

20 40

−3

3 ×10
Stat. only

POT by 2014 , 90% C.L

10 20

Precisions of sin2θ23 and Δm322
0.4
0.00240.5
0.0026

0.60.0028

2∆ m232sin(eVθ223)∆ χ2

2

7.8x1021 POT

10

30
20

20x1021 POT w/improvement2
sin θ23=0.60

0.4

50.0024100.0026

7.8x1021 POT, 90% C.L

Systematics

2.6

0.00260.0028Systematics

20

0.5

0.6

θ
(b) Assuming true sin2 ✓23 =sin0.60.

δ(Δm322)

5

−3

3 ×10

POT by 2014 , 90% C.L

4
3

23

(b) Assuming true sin2 ✓23 = 0.60.

(a) Assuming true sin ✓23 = 0.43.

Stat. only

0.4

2

2

150.0028

Stat. only

20x1021 POT w/improvement, 90% C.L

2.2

0.6

sin θ235

000.0022

0.5
2

10
0

0.0024

POT by 2014 , 90% C.L

2
2.4 (eV )∆ m232

Uncertainty on ∆ m232 (%)

Uncertainty on sin θ23 (%)

POT by 2014

0.00222.4

δ(sin2θ23)
Stat. only
sin2θ23=0.43
Systematics
sin2θ23=0.50

00.7

2 2 ✓23 = 0.60.
(b)Assumingtruesin(a) Assuming true sin ✓23 = 0.43.

2.8

20x1021 POT w/improvement, 90% C.L

2.6

2.2

50 15

10

∆ m23200.3
0.002240

7.8x1021 POT, 90% C.L

2.8

Systematics∆ m232

0

43

20

−3
3 ×10

∆ m232•T2K-II Physics Sensitivity
30

∆ χ2

∆ χ2
∆ χ2

30 60

20x1021 POT w/improvement21

7.8x10 POT, 90% C.L

2.8

Stat. only2
sinSystematics
θ23=0.43

Stat. only

20x10 POT w/improvement, sin
90%2C.L
θ23=0.521

sin2θ23=0.6

2.6

Systematics

2.4

2
2.2

1

0.4

0.5

0.6

2

sin θ2320 (c) Assuming true sin ✓23 = 0.50.
0
5
10

15

20

21

21 the 2016 systematicProtons-on-Target(x10 ) FIG. 25: Expected 90% C.L. sensitivity∆ m232 (eV2)
to m232 and sin2(x10✓23 with
Protons-on-Target)

error. The POT exposure accumulated by 2014 corresponds to 6.9 ⇥ 1020 POT ⌫- +• More physics for Neutrino Interactions and2
2 of sin ✓234.0 ⇥ 1020 POT ⌫¯-mode. For the T2K-II exposure of 20 ⇥ 1021 POT,(d)1
uncertainty(c) Assuming true sin ✓23 = 0.50.
(d) 1 uncertainty of m232 a 50% increase ine↵ective statistics is assumed.

2
non-standard
models
16 T2K
systematic
errorsfora.)sin✓23of= 0.43,
2
FIG. 27:
plotted as function
m2 with the predicted 2016 systematic error.

32
21
66
The full T2K-II exposure of 20 ⇥ 10
21 POT.50.The full T2K-II exposure of 20 ⇥ 10

POT with a 50% e↵ectively statistic improvement

Hyper-Kamiokande

67

Kamiokande family

Introduction

Kamiokande (1983-1996)
3000 ton

Neutrinos from
SN1987a.
Atmospheric neutrino
deficit.
Solar neutrinos.

Super-Kamiokande (1996- )50,000 ton

Atmospheric neutrino
oscillation.
Solar neutrino oscillation
with SNO.
Far detector for KEK-PS(K2K) and J-PARC beam
(T2K): electron neutrino
appearance.
World leading limit on
proton lifetime > 1034
years.
68

Hyper-Kamiokande (⇠2026- )2⇥260,000 ton

Physics programme:
Neutrino oscillations: Mass
Hierarchy, Leptonic CP
violation, ✓23 Octant,...
Nucleon decay: p!e+ ⇡ 0 ,p!K+ ⌫¯,...
Neutrino astrophysics:
Solar neutrinos, Supernova
neutrinos, WIMP searches

Two Super-K like cylindrical tankswith staging.

Hyper-Kamiokande (NewDesign)
2nd tank assumed to be ready 6
http://www.hyperk.org
years later.

Tank dimensions:
One tankI

60m (high) ⇥ 74m(diameter)
I Total Volume: 260 kton.
I Fiducial Volume: 190 kton(⇠ 10⇥ Super-K).
I 40% PMT coverage.
I 40,000 50cm ID PMTs,
6,700 20cm OD PMTs.

Candidate site: ⇠8 km south of Sup
1

Investigating option for 2nd tank in
KEK Preprint 2016-21
ICRR-Report-701-2016-1

More details on tank and calibration•

Cost saving and quick start with one tank ﬁrstHyper-K electronics: see talk M. Zie•

Improving the performance
T. Feusels (UBC, TRIUMF)••

A new PMT has x2 better Photon sensitivity

A new design was reviewed by the international
advisory committee, and endorsed.
69

Design Report(Februry 7, 2016)

Broad science program with Hyper-K• Neutrino oscillation physics• Comprehensive study withbeam and atmospheric neutrinos• Search for nucleon decay• Possible discovery with ~×10
better sensitivity than Super-K• Neutrino astrophysics• Precision measurements of solar ν• High statistics measurements of
SN burst νProtondec
Motivationof Nuc• Detection and study of••relic SN neutrinos••• Geophysics (neutrinography ofinterior of the Earth)• Maybe more (unexpected)

Only
Onlyway
waytotodirectly
directly prob
prov
Two
major
Two
majormodes
modespredic
predicMediated by gauge bosons

p

70

u
u
d

g

g

X

+!
e!

d π0

d

p→e+π03

The
Hyper-KamiokandeTimeline
Hyper-K
construction timeline
FY2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026
2015

Suvey, detailed design

Cavity excavation

Tank construction

Sensorinstallation

Access tunnels
Photosensor development

Operation

Photosensor production

Waterfilling
Beam up to 1.3MW• Assuming funding from 2018
• 2018-1st2025
HK construction.
The
detector
construction in 2018~2025•• 2026 onwards CPV study, Atmospherics Q, Solar Q, Supernova
Cavern excavation: ~5 years•
Q, Proton decay searches,  …
(liner, photosensors)construction:~3afteryearsthe first one.
• Tank• The
2 identicaltank starts operation
6yrs• Water filling: 0.5 yearsndM.Yokoyama (UTokyo)

71

15

のカウントをグラフ化（標準球のカウントを同じにした場合）

Super-K PMT. The time resolution for singHyper-K New Technology
45
6The nominal gain is 107 and can be adju
2.1.3. Performance of Single Photoelectron Detection
8
2200 V. Figure 60 shows the charge distribu
721Hyper-K
PMT~2 which is faster than the 10.6 ns rise time and 18.5 ns FWHM in t
ns FWHM without ringing,
2
3
4

10
the ratio of the height of the single PE peak	Super-K PMT. The time resolution for single PEs is 1.1 ns in for the fast left side of the tran

5

Hyper-Ktime peak in Figure 59 and 7.3 ns at FWHM, which is about half of the ーSuper-K
PMTs. T

Entries (a.u.)1

The single photoelectron pulse in a HQE B&L9 PMT
hascompareda 6.7 ns risetime50%
(10%
90%)
and 1
betterto theof–theSuper-K

50cm high-QE box&line PMT

ー Super-K

would be an
importantfactor to improve the reconstruction performance of events in Hyper-K
Super-K
PMT
	
6
7
8

50cm Super-K PMT

The nominal gain is 107 and can be adjusted for several factors in a range between 1500 V
2200 V. Figure 60 shows the charge distribution, where the 35% resolution inof the single PE

0 -90 -80 -70 -60 9-50better
compared
50%30of 40
the 50Super-K
The peak-to-valley ratio is about 4, defined-40 -30-20 -10 0to the
10 20
60 70PMT.
80 90
10Position angle [degree]-20 valley-15 -10between-50 peaks.
5
10
the
ratio
of
the
heightofthesingle PE peak to that of the
Injection Angle (degree)
Entries (a.u.)

射光子数が一定になる様補正してあるが、QEとCEの固体差が含まれている。
同一光子数を入射したと仮定した場合のカウント値に歴然と差があることが分かる。
50cm high-QE box&line PMT

15Time [nsec]

Entries (a.u.)

Relativesinglephotoelectron
hit efficiency
SinglePhotonEfficiency

96

time peak in Figure 59 and 7.3 ns at FWH
III HYPER-KAMIOKANDE DETECTO
would be an important factor to improve th

20 25
Time [nsec]

50cm high-QE box&line PMTー Hyper-K
FIG. 59. Transit time distribution
single ph50cm Super-Kat
PMT• Single Photon Eﬃciency: x2
ー Super-K
17
toelectron, compared with the Super-K PMT• Time Resolution: x2
dotted line.
• Charge Resolution: x2• Better Physics Sensitivity with the improved-20 -15 -10 -5
detector performance

50cm Super-K PMT

0

5

10

15

20 25
Time [nsec]

11

1
2
3
2.1.4. -1 Gain 0Stability
Charge [photoelectron]

Charge [photoelectron]72

Expected events
350
300

ν beamNumber of events/50 MeV

Number of events/50 MeV

1.3MW, 10×107sec, ν:ν=1.3
νe candidates
Appearance ν mode
Total
Signal νµ → νe
Signal νµ → ν e
BG
νe + νeBGνµ + νµ

250
200
150
100
50
00

0.2

0.4

0.6

0.8

1

300
250

Using fiTQun for π0 rejection

Appearance ν modeν beam

200
150
100
50
00

1.2

0.2

0.4

rec
Reconstructed Energy Eν

1

1.2

21
289

beam νe/νe
contamination

NC

362
444

188
274

10
6

150 δCP=0
Difference from150

(δ= 90) – (δ =0)100(δ= -90) – (δ =0)(δ= 180) – (δ =0)

50
0
-50
-100
-150
0

0.8

rec

Difference of events/50 MeV

Difference of events/50 MeV

ν beam

2,300
1,656

0.6

Reconstructed Energy Eν

SignalWrong sign νμ/νμ
for δ=0(νμ→νe CC) appearance CCν beam

Total
Signal νµ → νe
Signal νµ → νe
BGνe + νeBGνµ + νµ

0.2

0.4

0.6

0.8

1

1.2

Reconstructed Energy Erec(GeV)ν(δ= 90) – (δ =0)100(δ= -90) – (δ =0)(δ= 180) – (δ =0)

50
0

-50
-100
-150
0

0.2

0.4

0.6

0.8

1

1.2

Reconstructed Energy Erec(GeV)ν

δ=0 and 180° can be distinguished using shape information
73

28

CPV sensitivity•

parameter space with >3σ
From discovery toδCP measurement:~7° precision possible

•

error

sinδ=0 exclusion

>3σ

>5σ

δ=0°

δ=90°

78%

62%

7.2°

21°

8

Mass hierarchy known case
HK 2tank staging 10 years

Normal mass hierarchy
sin22θ13=0.1
sin2θ23=0.5

6

5σ

4

3σ

2
0

error of δ (degree)CPσ=√χ 2• Exclusion of sinδ =0• >8σ(6σ) for δ=-90°(-45°)• ~80% coverage of δ

10

-150

-100

-50

0

50

100
150
δCP [degree]60

1.3MW beam
50 1year = 107s

HK 2tank staged40

δCP=90°δCP=0°

30
20
10
0

0

2

4

6

8

Running time (year)
74

10Towards leptonic CP asymmetry
CPV significance for δ=-90°, normal hierarchy
Significance [σ]

10

HK

8

(2 tank staging)

6

DUNE
T2K-II

4(Based on DUNE CDR,
arxiv:1601.05471 Table 2.1,
“optimized” beam design)

T2K
2
NOvA
0

2022

2026

2030

2034

2038

Strategy of Japan-based program~3σ evidence
indication with T2K→T2K-II,>5σ discovery and measurement with HK
Note: “exact” comparison sometimes75difficult due to different assumptions

31

θ23
-5eV2
)~1.4×1032∆ m232δ(Δm2

2and Δm

→ Mass hierarchy sensitivity
in combination with reactor

δ(sin2θ

23)~0.015(for sin2θ

~0.006(for sin2θ

-3
×
10
2.6

2.55

Hyper-K

2.5

Hyper-K + reactor

2.4

23=0.5)2.35

23=0.45)

2.25

2.3

sin2θ23=0.5

90%CL

2.2
0.4 0.42 0.44 0.46 0.48 0.5 0.52 0.54 0.56 0.58 0.6 0.62
sin2θ23

Normal mass hierarchy

Normal Mass Hierarchy∆ m232σ wrong octant rejection

Normal mass hierarchy

2.45→Octant determination,
input to models
10
9
8
7
6
5
4
3
2
1
0

32

-3
×
10
2.6

2.55
Hyper-K + reactor

2.5
2.45
2.4
2.35
2.3
2.25

0.4

0.45

0.5

0.55

2.2
0.35

0.6
2

sin θ2376

sin2θ23=0.45
0.4

0.45

90%CL
0.5

0.55

0.6

0.65
sin2θ3223

Beam + Atm ν combination
θ
23 octant8

δcp Uncertainty

10yr

7
6

∆ χ2 Wrong Octant Rejection∆ χ2 Wrong Hierarchy RejectionMasshierarchy
8

5yr

5
4

3σ

3
2

1yr

1
0

0.4

0.45

0.5
sin2 θ23

0.55

10yr

7
6

δcp Uncertainty

5yr

5
4

1yr

3σ

3

2σ

2
1
0

0.6

0.4

0.45

0.5

0.55

0.6

sin2 θ23• Complementary information from beam and atm ν• Sensitivity enhanced by combining two sources!
77

36

•

Mediated by gauge bosons

ProtonDecay
Proton decay p → 𝒆
is a favoured model of many GUTs.

+
𝟎
+
𝟎
+
!
ProtonDecay
DecaySensitivity,
Sensitivity,p →p→Proton
𝒆
g 𝒆
g
e!
u
+ +𝟎 𝟎X
Proton decay p → 𝒆
is a favoured model ofGUTs.
p manyud π0• Keep looking for GUT with neutrinos.
ddSimilaranalysisin SKwithneutrontagging
Similaranalysisasas
in SK
butbutwithneutrontagging(removeeventswithataggedneutron)thanks(removeeventswithataggedneutron)thanks
+to
0 to
+
0
p→e
π
• Example: p→e π in Hyper-K
improved
improvedPMTs.
PMTs. 3σ discovery potential reaching t ~4 5

3σ discovery potential reaching
g mtp~
0PTEP,
35 35"(sensitivity
p # e+$) ~to PTEP,
10
yrs.
Similarsensitivity
to
10
yrs.
Similar34
34years4
tproton=1.4×10
(SK
90%
CLCL
limit)
tproton=1.4×10years(SK90%
limit)
M
thanksto theneutrontagging.
thankstotheneutrontagging. X
FreeProtonEnhancedFree Proton Enhanced
0 <0Ptot
< 100
MeV/c
signal< Ptot< 100
MeV/csignal
atm.
bkgd
atm.
bkgd

•

0 )= 3.7&1029±0.7 yea
p # e+$to
We%(needpursue both
given the variety of predisearches inc• Need broad※Searches for other m!

BoundProton Enhanced
BoundProton Enhanced
100 < Ptot < 250 MeV/c
100 < Ptot < 250 MeV/c

M.Yokoyama (UTokyo)

LAr discovery potential computed using
LAr discovery
potential
computed using
numbers
from DUNE
CDR 2015.
78 numbers from DUNE CDR 2015.

22

22

Hyper-K Status（2016.3）日本学術会議「マスタープラン２０１７」に提案提出✓ 水槽1基の早期実現（2018年着工、2026年観測開始）を提案✓ （2017.2）重点大型研究計画28件に選定
推進体制、国際協力体制に関する取り組み✓ （2017.3）宇宙線研究所将来計画検討委員会：ICRRの次期主要
プロジェクト✓ （2017.10）連携研究機構（ICRR,IPMU,理学部）の東大内設置✓ （2016.6）KEKプロジェクト実施計画（KEK-PIP）：将来計画の中で、「ハイパーカミオカンデのためのJ-PARC加速器高強度化」を最優先課題✓ （2017.3）海外分担の合意形成（PMTの約半分などを海外分担で実現）

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文科省による予算措置に係るロードマップ2017• ロードマップ2017（案）に選定された• 評価結果
• 「a」 研究者コミュニティーの合意、実施主体、共同利
用体制、妥当性• 「a」 緊急性、戦略性、社会国民の支持• 文科省による概算要求の基盤ができた• 着工に向けた準備が急務• 設計、人員計画、予算計画のさらなる具体化

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まとめ
•

T2K provides the world best measurement of neutrino CP violation.
•

The new results on neutrino CP violation will be released on Friday, August
4th.

•Super-K atm. ν provides the world best measurement of neutrino mass
hierarchy.

•

Hyper-Kamikande is selected as one of seven highest-priority large-scale
projects. The roadmap in Japanese can be found here:•

http://www.mext.go.jp/b̲menu/shingi/gijyutu/gijyutu4/toushin/
1388523.htm or•

http://www.mext.go.jp/b̲menu/shingi/gijyutu/gijyutu4/toushin/̲̲icsFiles/
aﬁeldﬁle/2017/07/31/1388523̲001̲1̲1.pdf(Hyper-K is the third
project from the top in the table of the page 15)83