Neutrino research program with
Nuclear Emulsion at J-PARC
Tsutomu Fukuda （Nagoya Univ. Japan）
on behalf of J-PARC T60 collaboration

10μｍ
The 3rd KMI International Symposium, 6th Jan. 2017 @Nagoya Univ.

2Current situation on neutrino physics
Neutrino oscillation δCP, mass hierarchy
OPERA

T2K

Sterile Neutrinos
 4th generation ? Dark matter ?
MiniBooNE

DayaBay

DUNE
JUNO

LSND

MicroBooNE
JSNS2

T2HK
ICARUS0νdouble beta decay majorana / dirac ? νmass meas.

Cosmic neutrinos
 Ultra-high energy, Supernova,…
SN1987A

PeVνSuperNEMO
KamLAND-ZEN

GERDA2CANDLESSKGd
KM4NeT

IceCube-Gen2

Of course many other neutrino projects are also carrying out or planned.

3Current situation on neutrino physics
Neutrino oscillation δCP, mass hierarchy
OPERA

T2K

Sterile Neutrinos
 4th generation ? Dark matter ?
MiniBooNE

DayaBay

DUNE
JUNO

LSND

MicroBooNE
JSNS2

T2HK
ICARUS0νdouble beta decay majorana / dirac ? νmass meas.

Cosmic neutrinos
 Ultra-high energy, Supernova,…
SN1987A

PeVν
SuperNEMO
KamLAND-ZEN

GERDA2CANDLESSKGdKM4NeT

IceCube-Gen2

Of course many other neutrino projects are also carrying out or planned.

4Motivation• Precise neutrino-nucleus interaction measurement is importantto reduce the systematic uncertainty in future neutrino oscillation
experiments.

• We started a new experiment at J-PARC to study low energy
neutrino interactions by introducing nuclear emulsion technique.
• The emulsion technique can measure all the final state particles
with low energy threshold for a variety of targets (H2O, Fe, C,…).
• Furthermore its ultimate position resolution allow to measureνe cross section and to explore of a sterile neutrino.

MiniBooNE
Water Target Emulsion Chamber

5

Precise measurement ofneutrino-nucleus interactions• CCQE interaction events are used as signal to reconstruct energy in
μT2K/SK.
νｐ• Other interaction modes contaminate due to Final state interaction innucleon and detector inefficiency.
• Energy can’t be reconstructed correctly with these interaction modes.
 Need precise understanding about neutrino interaction. 2p-2h interactionin CCQE samples

Nuclear Emulsion Detector

3D reconstructionReconstruction of track data

Scalability

Analysis on an event by event basis

4π detection

Momentum, dE/dx measurement
150 μmUltra precise measurement

Low BG from nm NC p0 production

67

Recent technical improvements
Readout techniqueHigh Speed Scanning

Detector techniqueHigh Sensitive film

HTS
5,000cm2/h
x70 faster

Time resolution

RMS=1.5sec
Large angle tracking technique
Charge sign ID
νe/νe identification

J-PARC T60 Experiment•J-PARC PAC endorsed as a test experiment.
(PI: T. Fukuda)

A collaborative project with some member of OPERA and T2K89Roadmap
Preliminary measurements RUN Feasibility study at J-PARC

J-PARC T60 experiment
Detector RUN

Detector performance check

Future plan

Target mass: 30- 60kg

Physics RUN Ⅰ

Neutrino-nucleus interaction study
Target mass: 100- 300kg

Physics RUN Ⅱ

Search for sterile neutrino
Target mass: 1- 3ton
Target mass: 6-10ton• The aim of T60 is a feasibility study and detector performance checkto make a future plan.
• We will expand the scale of detector gradually, step by step.

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ν exposure status of T60
PAC July/15/2015

Detector Run

Physics Run60kg Iron
A few kg Water
A few kg Iron・ Data-MC comparison withhigh statistics
・ νe CC interaction detection
・ Emulsion handling @J-PARC・ Demonstration of ν event detection
・ Hybrid analysis with T2K near detector・ ν– Water interaction detection
with Emulsion Detector• We have demonstrated the basic experimental concept at J-PARC site.
• “Detector performance run” was started from last Jan.

Status review of T60

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Status review of T60

Conceptual detector design
2kg iron target ECC

SS floor @J-PARC(Jan. 2015)••••

Emulsion Cloud Chamber is a sandwich structure ofemulsion films and iron plates.
Emulsion detector is placed in front of T2K near detector,INGRID.
Emulsion Shifter is re-used from GRAINE project to givea timing info. to emulsion tracks.
Muon ID is possible by combined analysis with INGRID.

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Status review of T60

Reconstructed track data
Track Quality Selection

All emulsion films were scanned by HTS.
First of all, noise tracks were rejected byevaluating the quality of each tracks.
Then tracks were reconstructed.
all tracksν（|tanθ| ＜ 0.1 ）（1.4＜ |tanθ| ）

PL41
PL01
Penetrated tracks

Iron
2.0cm

Plate by plate, angle by angle
track efficiency

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Status review of T60

dE/dX

Systematic emulsion analysis

Multiple Coulomb Scattering momentum measurement

Hybrid analysis with T2K near detector<Event time>
2015/Mar./22 15:06:35.0

Estimated time resolution
using penetrated muons

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Status review of T60

Water target emulsion chamber
We installed a water target emulsion chamber during ν exposure in May 2015.
Frame typeplastic spacer( 2mm thickness)

Sandwich structure of Emulsion
films and Frame type spacers

Pouring water

Emulsion films (vacuum packed)

First detection of ν- Water interaction
with Emulsion Detector
Interacted in Water region

protonRange~2cm
M.I.P（tanθx, tanθy）=（-0.040, 0.845）
proton（tanθx, tanθy）=（-0.589, -0.074）
Minimum distance(①‐②)=2.4um, depth=620um①②

Status review of T60

Detector Run

We are starting Detector Run tocompare MC with high statistics.

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Status review of T60

Detector installation & ν exposure
2016．Ｊan. 12 @J-PARC

2016．Ｊan. 16

INGRID2016．Ｊan. 14

Status review of T60

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Detector construction

ν beam exposure Hardware treatment and Scan

The beam exposure and film scanning was finished by last year.

Tracking efficiency of one area
(plate by plate, angle by angle)● ：0.0＜|tanθ|＜0.3△ ：0.4＜|tanθ|＜0.6○ ：0.9＜|tanθ|＜1.1△ ：1.4＜|tanθ|＜1.6

19

Status review of T60

Event analysis is now in progress !
Neutrino event candidates

Current status (1ECC, ~1/12 of all)First result will be reported at JPS meeting (March)

Area1Area2

Area3

Area4Area5Area
63 trks

122219202025

46102355535030

161000027010100≧8000000Total

2238

21272533

20Future prospects

We are discussing about future Physics Run.
- R&D of the water target ECC is carrying out in this year.
- 100kg scale Water ECC is assumed. 10k order νμ int. and hundred orderνe int. study in 2018-2019. Plan is optimized by the results of Detector Run.
- Then we will propose an experiment to explore sterile neutrinos with ton
scale detector around 2020.
PAC July/15/2015

Detector Run

Physics Run

60kg Iron
A few kg Water

100kg scale Water

A few kg Iron

Detector R&D,development

21Summary• There are many projects of next generation neutrino experiments which aim
at finding the CP violating phase in the PMNS matrix, probing the neutrinomass hierarchy, search for sterile neutrinos and so on.

• These experiment plan to discover the rare effects and study them bymeasuring neutrino interactions precisely.
Toward these goals, a lot of R&D activities for novel (near) detectors aregoing on in order to reduce systematic uncertainties.
• We are performing a neutrino experiments at J-PARC to study low energy
neutrino - nucleus interactions and exploration of a possible existence ofsterile neutrinos by introducing nuclear emulsion.
• We are carrying out a test experiment at J-PARC (T60) to check the feasibilityand detector performance.
• Beam exposure, film development and film scanning (data taking) for the60kg iron target ECC was successfully done. The analysis is now in progress.
• We continue to expose ν beam for R&D of water target ECC and will make adetailed plan of future Physics Run.

22backup

23Sterileν search24

http://indico.ipmu.jp/indico/conferenceDisplay.py?confId=108（access key: "emulsionhadron"）• We discussed about the possibility of future hadron production experimentwith nuclear emulsion.

Detector Run: 60kg Iron target ECC

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Hardware treatment of the emulsion films
Dark room(Nihon Univ.)

2. Surface silver cleaning

1. Developing

3. Emulsion swelling
Recovering of emulsion thickness

Beam exposuredevelopmentemulsion

After swelling

60μm
Before wiping70.0±3.0μm

After wiping

More than 300 films were completed.

Glycerol water