[PPT] - Future Outlook: Experiment Future Outlook: Experiment Future Outlook: PowerPoint Presentation

SLIDE 1

Future Outlook: Experiment Future Outlook: Experiment Future Outlook: Experiment Future Outlook: Experiment

Yoichiro Yoichiro SUZUKI SUZUKI Yoichiro Yoichiro SUZUKI SUZUKI

Kamioka Observatory, Institute for Cosmic Ray Research, Kamioka Observatory, Institute for Cosmic Ray Research, and and and and Institute for the Physics and Mathematics of the Universe, Institute for the Physics and Mathematics of the Universe, The University of Tokyo The University of Tokyo The XXIII International Conference on N t i Ph i d A t h i N t i 2008 Neutrino Physics and Astrophysics, Neutrino2008, May‐31 Christchurch, New Zealand Christchurch, New Zealand

2008/5/30

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Y. Suzuki @NEUTRINO2008, Christchurch, New Zealand

SLIDE 2

Preface Preface

My talk is neither

neither a summary talk nor nor general y y g view in future.

This is a quite biased and personal view

biased and personal view of a direction of the future future large scale neutrino experiments ‘ ’ ‘Ultimate’ Experiments beyond beyond the next the next generation experiments:

more than 20 years from now (or more)
more than 20 years from now (or more)
Please relax and have a dream together

Note for the audience

This talk may contain hazardous opinion and may spoil you (PG40).

Note for the audience

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Y. Suzuki @NEUTRINO2008, Christchurch, New Zealand

It is your own responsibility to listen me.

SLIDE 3

10th anniversary of the Discovery of the Neutrino Oscillation

It t t d At h i N t i A l

It started as an Atmospheric Neutrino Anomaly

(νμ deficits in 1988, by Kamiokande)

Background of the Proton Decay Search – Background of the Proton Decay Search

e‐like like μ‐like like

νµ - ντ

20 40 60 80 100 120 140 160 180 200

1
0.8
0.6
0.4
0.2

0.2 0.4 0.6 0.8 1 Multi-GeV µ-like+P.C. Multi-GeV µ-like+P.C. Multi-GeV µ-like+P.C. cosθ number of events

Super Kamiokande Preliminary

( 1.0, 2.2×10-3 )

νµ - ντ

20 40 60 80 100 120 140 160 180 200

1
0.8
0.6
0.4
0.2

0.2 0.4 0.6 0.8 1 Multi-GeV µ-like+P.C. Multi-GeV µ-like+P.C. Multi-GeV µ-like+P.C. cosθ number of events

Super Kamiokande Preliminary

( 1.0, 2.2×10-3 )

It took 10 years to establish as an Real Effect

Momentum ( Momentum (MeV MeV/c) /c)

νµ - ντ

20 40 60 80 100 120 140 160 180 200

1
0.8
0.6
0.4
0.2

0.2 0.4 0.6 0.8 1 Multi-GeV µ-like+P.C. Multi-GeV µ-like+P.C. Multi-GeV µ-like+P.C. cosθ number of events

Super Kamiokande Preliminary

( 1.0, 2.2×10-3 )

It took 10 years to establish as an Real Effect

– Convincing Evidence came from Super‐K (1998)

High Statistical Measurement

High Statistical Measurement High Statistical Measurement High Statistical Measurement

Independent of the Flux calculation

Independent of the Flux calculation

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SLIDE 4

More than 30 years More than 30 years

S l t i bl

Solar neutrino problem:

– Started in late 60 – Solved in 2001 (SNO +SK)

High statistical experiments

High statistical experiments High statistical experiments High statistical experiments

Flux independent evidence (SNO+SK, SNO

Flux independent evidence (SNO+SK, SNO NC+CC) NC+CC) NC+CC) NC+CC)

Discovery of Neutrino Oscillation has really changed the world has really changed the world

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Y. Suzuki @NEUTRINO2008, Christchurch, New Zealand

4

SLIDE 5

Number of Talks @N98 & N08

18

@

12 14 16

?

6 8 10 Neutrino98

?

2 4 6 Neutrino2008

SLIDE 6

After the establishment of the neutrino oscillation

We now have well motivated ‘standard’ menu

‘standard’ menu to do.

– Physics parameters to be measured! b d – Questions to be answered ?

– θ13 ! – CPV ?, CP phase ! – Majorana or Dirac ?, Majorana mass ! – Mass hierarchy ? – Absolute mass ! – ………

Though the above list are significant and important,

there are no big puzzles or problems puzzles or problems like solar neutrino problem or atmospheric anomaly.

In any way we are guided to the fruitful and promising

future !????? future !?????

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SLIDE 7

Ultimate experiment after the next

Since we will build a huge detector and d bi f i h l spend big amount of money with large number of scientists

1) Cover the standard list standard list as much as possible 2) Include other

ther scientific possibility or new opportunity

new opportunity 2) Include other

ther scientific possibility, or new opportunity

new opportunity as much as possible

θ13 may not be determined positively! 13 may not be determined positively! θ13 may not be determined positively! 13 may not be determined positively! DB decay may not be accessible! DB decay may not be accessible!

3) Need bread and butter bread and butter science )

need ‘measurements’ as well as searches need ‘measurements’ as well as searches

Build Build GOOD Versatile detectors GOOD Versatile detectors Build Build GOOD Versatile detectors GOOD Versatile detectors

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SLIDE 8

Limit myself to discuss two example, because of the limitation of the time the limitation of the time 1) Neutrino Oscillation Experiments, and 2) Double Beta Decay Experiments

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SLIDE 9

‘Standard’ ‘Standard’ Next Next Neutrino Oscillation Experiments Neutrino Oscillation Experiments

Aim to study CPV, Mass hierarchy
Megaton Scale Detector + Upgraded Accelerator

Megaton Scale Detector + Upgraded Accelerator

Typical Detector 0.5 Mton (fiducial Volume)

UNO 440kton Hyper-K 540kton

Other Subjects

– Proton Decay (1035 years for eπ0) SN i – SN neutrinos

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SLIDE 10

Is the Proton Decay sensitivity of 1035 years for eπ0 (10 years of running) strong enough? running) strong enough?

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SLIDE 11

What is the best goal for the proton decay search

d l d d

νK,

, μK : strong model dependence

Prediction of Dimension 6 in SUSY GUT

– Less model dependent – Reasonable range: 10 1035

35～10

1036

36 yr

yr for e for eπ0 Reasonable range: 10 10 10 10 yr yr for e for eπ From coupling unification From coupling unification Search up to Search up to ～10 1036

36 yr

yr is quite important and is quite important and Search up to Search up to ～10 1036

36 yr

yr is quite important and is quite important and add significant value to the neutrino oscillation exp. add significant value to the neutrino oscillation exp.

S i i i f S i i i f ill id h i f h ill id h i f h Sensitivity for Sensitivity for eπ0

0 will guide the size of the

will guide the size of the experiment experiment

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SLIDE 12

Sensitivity for p Sensitivity for pe+π0

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→eπ0 sensitivity (90%, 3σ CL)

SK-I limit 92ktyr 5.4 x 1033 yrs (90%CL)

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→eπ0 sensitivity (90%, 3σ CL)

SK-I limit 92ktyr 5.4 x 1033 yrs (90%CL)

5 Mt detector 5 Mt detector 10 yrs operation 10 yrs operation

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→eπ0 sensitivity (90%, 3σ CL)

SK-I limit 92ktyr 5.4 x 1033 yrs (90%CL)

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→eπ0 sensitivity (90%, 3σ CL)

SK-I limit 92ktyr 5.4 x 1033 yrs (90%CL)

pe+π0 sensitivity

5Mt detector

∼7x10 7x1035

35 yrs

yrs

10 yrs operation 10 yrs operation

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→eπ0 sensitivity (90%, 3σ CL)

SK-I limit 92ktyr 5.4 x 1033 yrs (90%CL)

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→eπ0 sensitivity (90%, 3σ CL)

SK-I limit 92ktyr 5.4 x 1033 yrs (90%CL)

HK, UNO 10 years 10 yrs

92 ktyr

∼1x10 1x1035

35 yrs

yrs ∼3x10 3x1034

34 yrs

yrs

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→eπ0 sensitivity (90%, 3σ CL)

SK-I limit 92ktyr 5.4 x 1033 yrs (90%CL)

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→eπ0 sensitivity (90%, 3σ CL)

SK-I limit 92ktyr 5.4 x 1033 yrs (90%CL)

SK 2020

92 ktyr 5.4x1033yr (90%C.L.)

0.5Mt detector 0.5Mt detector 10 yrs operation 10 yrs operation

∼3x10 3x10 yrs yrs

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→eπ0 sensitivity (90%, 3σ CL)

SK-I limit 92ktyr 5.4 x 1033 yrs (90%CL)

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→eπ0 sensitivity (90%, 3σ CL)

SK-I limit 92ktyr 5.4 x 1033 yrs (90%CL)

Sk I+II Sk I+II SK (22.5 SK (22.5 kt kt) ) 25 yrs operation (2020) 25 yrs operation (2020) effective: close to 0.5Mt effective: close to 0.5Mtｙ exposure exposure

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→eπ0 sensitivity (90%, 3σ CL)

SK-I limit 92ktyr 5.4 x 1033 yrs (90%CL)

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→eπ0 sensitivity (90%, 3σ CL)

SK-I limit 92ktyr 5.4 x 1033 yrs (90%CL)

Normal cut: 90%CL 3σ CL Tight cut: 90%CL (41% eff) (17% eff)

To reach 10 To reach 1036

36 years, need 200Mty

years, need 200Mty exposure exposure‐‐ ‐‐10Mt 20years, but 5Mt 10Mt 20years, but 5Mt

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→eπ0 sensitivity (90%, 3σ CL)

SK-I limit 92ktyr 5.4 x 1033 yrs (90%CL)

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→eπ0 sensitivity (90%, 3σ CL)

SK-I limit 92ktyr 5.4 x 1033 yrs (90%CL)

3σ CL (17% eff)

exposure exposure 10Mt 20years, but 5Mt 10Mt 20years, but 5Mt 10years reaches to ~7x10 10years reaches to ~7x1035

35yr.

yr. If detector is expandable, then we If detector is expandable, then we can start with 5Mt or less can start with 5Mt or less 2008/5/30

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Y. Suzuki @NEUTRINO2008, Christchurch, New Zealand

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

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Exposure (kton year) Partial Lifetime (years)

p→eπ0 sensitivity (90%, 3σ CL)

SK-I limit 92ktyr 5.4 x 1033 yrs (90%CL)

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→eπ0 sensitivity (90%, 3σ CL)

SK-I limit 92ktyr 5.4 x 1033 yrs (90%CL)

10 Mty 100 Mty

can start with 5Mt or less can start with 5Mt or less

SLIDE 13

Sensitivity for p Sensitivity for pνΚ νΚ+

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→νK+ sensitivity (90% CL)

SK-I limit 92ktyr 2.3 x 1033 yrs (90%CL) combined sensitivity prompt γ π+π0 µ spectrum

K+ i i i (90% CL)

Once you find the proton decay by e

0 mode then

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→νK+ sensitivity (90% CL)

SK-I limit 92ktyr 2.3 x 1033 yrs (90%CL) combined sensitivity prompt γ π+π0 µ spectrum

5Mt detector 10 yrs p νK+ sensitivity (90% CL)

decay by eπ0 mode, then νK will constrain models.

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→νK+ sensitivity (90% CL)

SK-I limit 92ktyr 2.3 x 1033 yrs (90%CL) combined sensitivity prompt γ π+π0 µ spectrum

HK, UNO 10 years SK 2020

7x10 7x1034

34 yrs

yrs

5 Mt detector 5 Mt detector 10 yrs operation 10 yrs operation

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→νK+ sensitivity (90% CL)

SK-I limit 92ktyr 2.3 x 1033 yrs (90%CL) combined sensitivity prompt γ π+π0 µ spectrum

92 ktyr 2.3x1033yr (90%C.L.)

2020

∼2x10 2x1034

34 yrs

yrs

33

33

∼7x10 7x1034

34 yrs

yrs

0.5 Mt 0.5 Mt 10yrs 10yrs opereration

pereration

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→νK+ sensitivity (90% CL)

SK-I limit 92ktyr 2.3 x 1033 yrs (90%CL) combined sensitivity prompt γ π+π0 µ spectrum

~4x10 4x1033

33 yrs

yrs

SK (22.5 SK (22.5 kt kt) ) 25 yrs operation (2020) 25 yrs operation (2020)

10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→νK+ sensitivity (90% CL)

SK-I limit 92ktyr 2.3 x 1033 yrs (90%CL) combined sensitivity prompt γ π+π0 µ spectrum

combined sensitivity y p ( ) y p ( )

If the detector is expandable, If the detector is expandable, you can continue to study the you can continue to study the

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10 32 10 33 10 34 10 35 10 36 10 37 10

2

10

3

10

4

10

5

10

6

Exposure (kton year) Partial Lifetime (years)

p→νK+ sensitivity (90% CL)

SK-I limit 92ktyr 2.3 x 1033 yrs (90%CL) combined sensitivity prompt γ π+π0 µ spectrum

13 y y y y sensitive regions. sensitive regions.

Y. Suzuki @NEUTRINO2008, Christchurch, New Zealand

SLIDE 14

Bread and Butter

Do you have a bread and butter science for

Do you have a bread and butter science for 5Mt detector.

– Obviously Atmospheric ν – Obviously Atmospheric ν

A.Smirnov said ‘Oscillograms’
Do you have other than Atm ν?
Do you have other than Atm ν?

Answer: Yes! We can detect neutrino bursts from supernovae from 5Mpc distance p p gives you one SN neutrino burst detected gives you one SN neutrino burst detected every year !!! every year !!! every year !!! every year !!!

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SLIDE 15

Supernova Rate p

Galactic SN rate

Galactic SN rate

# of galaxies excluding elliptic ones

~23 ~23 ~45 ~45

– Every 30 Every 30 ∼50 years in our 50 years in our Galaxy Galaxy

SN rate external Gal.,

G l ti

26Al b

d

45 45 By 理科年表

Galactic 26Al abundance, Historical Gal. SN, ……..,

Number of Galaxies

Number of Galaxies

2 3 8 9

– 23 within 5 23 within 5 Mpc Mpc – 45 within 10 45 within 10 Mpc Mpc 1 SN every 1∼2 years (5∼10Mpc)

1 2 3 4 5 6 7 8 9 1 0

Mpc Mpc

1 SN every 1 2 years (5 10Mpc)

There are Galaxies beyond

2 Mpc where SNe have freq entl happened

NGC6946

NGC6946 (5.9 (5.9 Mpc Mpc) ) 10 in 90yr 10 in 90yr

1917A, 1939C, 1948B, 1968D, 1969P, 1980K, 2002hh, 2004et

frequently happened

1 SN every year (within 1 SN every year (within

M83

M83 (4.3Mpc) (4.3Mpc) 6 in 60yr 6 in 60yr

1923A, 1945B, 1950B, 1957D, 1968L, 1983N

NGC2403

NGC2403 ( (3.3Mpc) 3.3Mpc) 3 in 50yr 3 in 50yr

y y ( y y ( 5 5 Mpc Mpc) is not bad estimate ) is not bad estimate

1954J, 2002kg, 2004dj

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Zealand

SLIDE 16

Is it possible to detect SN neutrinos from the distance of 5Mpc

Yes!
SN1987A(50kpc): Extrapolation to 5Mpc & 5Mt

SN1987A(50kpc): Extrapolation to 5Mpc & 5Mt

Kamiokande: 2.7 events IMB 6 0 IMB: 6.0 events

Typical Simulation

5.2 events

Expect Expect 5 events for 5Mt and 5Mpc distance 5 events for 5Mt and 5Mpc distance Expect Expect ∼5 events for 5Mt and 5Mpc distance 5 events for 5Mt and 5Mpc distance

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SLIDE 17

Trigger sensitivity to distant Trigger sensitivity to distant SNe SNe

Background Background

N: N: required multiplicity required multiplicity

Background: Background:

Most BG from single spallation ev. accidental coincidence

5Mt twin=10s

Distance(Mpc) Detection Efficiency

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 2 4 6 8 10 12 14 16 18 20

90% 90%

N: N: required multiplicity required multiplicity

f the events in 10sec
f the events in 10sec

acc de ta co c de ce Select Eth > 18 MeV to remove spallation events

5Mt twin=10s

Distance(Mpc) Detection Efficiency

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 2 4 6 8 10 12 14 16 18 20

15 15 N=3 N=3 5 7

ciency ciency

N=3 5Mpc N=5 4Mpc

BG free measurement BG free measurement

6000 7000

ents/MeV ν

– e

Time= 1-18 sec 122491 events

signal loss:

5Mt twin=10s

Distance(Mpc) Detection Efficiency

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 2 4 6 8 10 12 14 16 18 20

50% 50% 20 20

15 15 10 10 7

ion Effi ion Effi

N=3 7Mpc N=6 5Mpc

2000 3000 4000 5000

Even 122491 events

signal loss: ∼20% at most

5Mt twin=10s

Distance(Mpc) Detection Efficiency

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 2 4 6 8 10 12 14 16 18 20

Detecti Detecti No significance influence No significance influence

1000 10 20 30 40 50 60

Energy (MeV)

5Mt twin=10s

Distance(Mpc) Detection Efficiency

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 2 4 6 8 10 12 14 16 18 20

Distance Distance

5Mpc 5Mpc 10Mpc 10Mpc No significance influence No significance influence

Could detect SN almost every year Could detect SN almost every year

G l ti SN (10k ) G l ti SN (10k ) 1 3M t 1 3M t

sta ce sta ce

p p Galactic SN (10kpc) Galactic SN (10kpc) 1.3M events 1.3M events Neutronization Neutronization B 2500 events B 2500 events

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SLIDE 18

How does the 5Mt detector look like? How does the 5Mt detector look like?

Requirements for the detector

1) Scalability: May start with 5 Mt (or maybe 1Mt) 1) Scalability: May start with 5 Mt (or maybe 1Mt) 2) Better to place > 700m depth (w.e.) 3) L t 3) Low cost 4) Short construction time

Underground?

– OK Up to some level

Expansion may become difficult

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SLIDE 19

Deep Deep‐TITAND TITAND (under water) (under water)

Tension Leg Platform (TLP)

Laboratory, Office, Café, Power station,

Autonomous Underwater Autonomous Underwater

Water purification sys., Dormitory etc.

85m 85m

Autonomous Underwater Autonomous Underwater Vehicle (AOV) Vehicle (AOV)

105m 105m 85m 85m

Depth Depth 1000 m 1000 m

105m 105m

85mx85mx105m=0.76Mt 85mx85mx105m=0.76Mt

Distance Distance 600 m 600 m

76x76x96m 76x76x96m3=0.554Mt (fiducial)

=0.554Mt (fiducial) Inner surface: 44800 m Inner surface: 44800 m2

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9 units 9 units 5.0 Mt (fid.) 5.0 Mt (fid.) Placed at the depth of ~1000m Placed at the depth of ~1000m 20

Y. Suzuki @NEUTRINO2008, Christchurch, New Zealand

SLIDE 20

5 Mt Neutrino Oscillation Detector 5 Mt Neutrino Oscillation Detector

Proton decay search

Proton decay search ∼10 1036

36yr

yr

SN neutrino detection:

SN neutrino detection: ∼1 every year 1 every year

– Reaches 5Mpc w/ Reaches 5Mpc w/ ∼ ∼ 5 events 5 events

PD and SN really add the value to the experiment PD and SN really add the value to the experiment P i t h i t i t P i t h i t i t

Precise atmospheric neutrino measurements

Precise atmospheric neutrino measurements

Flexible location of the detector for a long baseline

Flexible location of the detector for a long baseline neutrino oscillation experiment neutrino oscillation experiment neutrino oscillation experiment neutrino oscillation experiment

Effective investment: accelerator or detector

Effective investment: accelerator or detector

– More on detector More on detector

possibility to find unexpected possibility to find unexpected

Many technical challenges

Many technical challenges

Many technical challenges

Many technical challenges Need to start R&D now for a detector Need to start R&D now for a detector of more

f more

than 20 year from now than 20 year from now than 20 year from now than 20 year from now

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SLIDE 21

Double Beta Decay (DB) Experiments

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SLIDE 22

The next ‘Standard’ neutrino The next ‘Standard’ neutrino‐less less double beta decay experiments double beta decay experiments

D bl b t d i h i t t th

Double beta decay is much important than

Proton Decay (T. Yanagida)

Aim to search for 30meV～50meV

– Cover the region for inverted mass hierarchy – Cover the region for inverted mass hierarchy

‘Next’ DB experiments

Nucl‐ex/0708.1033 Avignone, Elliott, Enge

Experi‐ Nucle Det.mass Sensitivity start p ments us (kg) y (meV) (yr) GERDA

76Ge

15~100 780~30 2008~

SuperNEMO 82S

100 130~40 2012~

SuperNEMO 82Se

100 130~40 2012~

150Nd

100 70 2012~ CUORE 130Te 220 120~20 2012~

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EXO‐200

136Xe

160 550~90 2007~

thers

SLIDE 23

An ‘ultimate’ experiment b d th t

Cover substantial region predicted for the normal mass

beyond the next

Nucl‐ex/0708 1033 Avignone Elliott Enge

Cover substantial region predicted for the normal mass hierarchy sensitivity < a few meV ∼ a few x 1029 yr

Nucl ex/0708.1033 Avignone, Elliott, Enge

a few x 10 yr

–4 orders of magnitudes 4 orders of magnitudes improvement !!! improvement !!! f h i f h i from the next gen. experiments from the next gen. experiments

Larger mass (> x100):

100kg >10 ton >10 ton

Lower BG (< x1/100)

– Gerda, NEMO, Cuore : 10‐3/kg/keV/yr (3x10‐6 /kg/keV/day (dru))

<10

<10‐5/kg/ /kg/keV keV/yr /yr (10

(10‐9∼10 10‐

‐8 8 /kg/

/kg/keV keV/day ( /day (dru dru)) ))

/ g/ / g/ /y /y (

/ g/ / g/ / y ( / y ( )) ))

internal BG: U/ internal BG: U/Th Th < 10 < 10‐16

16g/g

g/g 2008/5/30

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SLIDE 24

Is it possible to achieve 10‐9∼10‐8 dru ?

V SK 1258day 22.5kt ALL (Preliminary)

3

10 4

After 1st reduction After spallation cut After 2nd reduction After gamma cut

/22.5kt/0.5MeV

SK

10 2 10 3

After gamma cut

f events/day/22

~ 10 ~ 10-8 ev ev /day/ /day/keV keV/kg /kg ( ( 5 5 MeV MeV)

D

1 10 Number of e

( )

Remove Rn (214Bi tail) ~ 10 ~ 10-9

9 dru

dru

10

1

1 6 8 10 12 14

SSM(BP98) * 0.4 (efficiencies are considered)

D

~ 10 ~ 10-11

11 ev

ev /day/ /day/keV keV/kg /kg ( 14 ( 14 M V M V)

6 8 10 12 14 Energy (MeV)

( 14 ( 14 MeV MeV)

10 10‐9: : remaining BG remaining BG spallation spallation(CG), High energy gamma. (CG), High energy gamma. This is This is W.Ch W.Ch. (w/poor resolution) and not DB experiment . (w/poor resolution) and not DB experiment

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Y. Suzuki @NEUTRINO2008, Christchurch, New Zealand

25 This is This is W.Ch W.Ch. (w/poor resolution) and not DB experiment . (w/poor resolution) and not DB experiment but tell you that but tell you that 10 10‐8∼10 10‐9

9 dru

dru is not completely crazy!! is not completely crazy!!

SLIDE 25

Ultimate BG Ultimate BG

ν+e +e ν+e +e

10 10‐4 10 10‐5 g 1) 8B solar neutrinos: 1) 8B solar neutrinos: a few x10 a few x10‐10

10 dru

dru

ν+e +e ν+e +e

10 10 10 10‐6 10 10 7 /keV keV/kg /kg (@ a few (@ a few MeV MeV region) region)

pp pp

10 10‐7 10 10‐8 s /day/ s /day/ 2) 8B solar neutrinos are 2) 8B solar neutrinos are the ultimate BG. and you the ultimate BG. and you need to separate need to separate single single 10 10‐9 10 10‐10

10

Event Event need to separate need to separate single single and double electron events and double electron events if you go beyond this point. if you go beyond this point.

8B

10 10‐11

11

y g y p y g y p 3) 3) Enrichment is MUST Enrichment is MUST to to

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Y. Suzuki @NEUTRINO2008, Christchurch, New Zealand

26 enhance the signal enhance the signal

SLIDE 26

In addition to those requirements, In addition to those requirements, the ‘ultimate’ the ‘ultimate’ experiment (as my definition) experiment (as my definition) must include other subjects must include other subjects j

+ Dark Matter Possible discovery or precise study + Low Energy Solar Neutrinos (as a bread and butter subject)

Many people have thought about this

combination and partly done for the past years though the sensitivity was not high.

– Good DB experiments have given results on DM p g

This time: It is MUST, or you never get funded!

This time: It is MUST, or you never get funded!

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Y. Suzuki @NEUTRINO2008, Christchurch, New Zealand

SLIDE 27

Low energy is easier than DB region i th f ll i in the following sense

Self Shielding effect (for liq Xe)

4 5 6 10 10−1 1

Self‐Shielding effect (for liq. Xe) 2.6 2.6 MeV MeV

2 3 4 10 10−1 10 10−2

2

10 10−3

3

600 600 keV keV

Double beta decay region Double beta decay region

1 20 40 60 10 10−4

4

10 10−5

5

100 100 keV keV

Double beta decay region Double beta decay region

nly 2 orders reduction
nly 2 orders reduction

w/ 40cm depth w/ 40cm depth

20 40 60

Depth (cm) Depth (cm)

w/ 40cm depth w/ 40cm depth

Low energy region ( Low energy region (DM+pp DM+pp) )

>5 orders reduction >5 orders reduction >5 orders reduction >5 orders reduction possible possible

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28

SLIDE 28

Signals Signals

10 10‐4

pp

pp‐solar neutrinos: solar neutrinos:

ν+e +e ν+e +e

Next gen. Next gen. DM DM

10 10‐5 10 10‐6 V/kg /kg ∼10 10‐5 dru dru @ <100keV @ <100keV T i T i

pp pp

10 10 6 10 10‐7 day/ day/keV keV To see pp neutrinos To see pp neutrinos BG should be lower than BG should be lower than < 10 < 10‐5 dru dru level level 10 10‐8 10 10‐9 vents /d vents /d < 10 < 10 dru dru level level

We

We will be in <10 will be in <10‐4 dru dru

8B

10 10‐10

10

10 10‐11

11

Ev Ev region region for the next DM for the next DM experiments: experiments: 10 10 4 d

10

10 45

45 2 SI

SI

8B

10 10 10 10‐4 dru dru 10 10‐45

45cm

cm2 SI SI

We will be seeing solar pp We will be seeing solar pp‐neutrinos relatively soon !! neutrinos relatively soon !!

2008/5/30

Y. Suzuki @NEUTRINO2008, Christchurch, New Zealand

29 We will be seeing solar pp We will be seeing solar pp‐neutrinos relatively soon !! neutrinos relatively soon !!

SLIDE 29

Coherent scattering of 8B solar t i (J M ) neutrinos (J. Monroe)

10 10‐2‐> (dru dru) )

1) Integrated histogram

10 10‐3‐> keV keV/kg ( /kg (

1) Integrated histogram 2) high A sharp in lowe

ex. Xe <2keV @10‐4 dru

G 3k V

10 10‐4‐>

5

/day/ /day/k

Next gen.DM (10 Next gen.DM (10‐

‐45 45cm)

cm)

Ge <3keV Ar <5keV ○ high A may be OK

10 10‐5‐> 10 10 6 Events Events

pp ν : νeνe

? Resolution ?? ○ Careful for gas chamber using ‘C’ or ‘F’

10 10‐6‐> E

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30

SLIDE 30

BG in low energy gy

Requirement for BG is modest Requirement for BG is modest

External External self self‐shields work, water for neutron shields work, water for neutron Internal Internal 10 10‐16

16g/g (U/

g/g (U/Th Th) (same as DB requirements) ) (same as DB requirements) Watch: Cosmo Watch: Cosmo‐genic genic, neutron BG , neutron BG from Detector, and so on. from Detector, and so on.

l b i h i l l b i h i l But, mutual obstructive among the signals: But, mutual obstructive among the signals: 1) DM 1) DM pp neutrinos ( pp neutrinos (νeνe) )

Electron/NR separation

Electron/NR separation

Electron/NR separation

Electron/NR separation

[watch coherent scattering of 8B neutrinos: irreducible] [watch coherent scattering of 8B neutrinos: irreducible]

2) pp neutrinos 2) pp neutrinos 2νDB DB 2) pp neutrinos 2) pp neutrinos 2νDB DB if 2 if 2νDB is shorter than some level, DB is shorter than some level,

Single and double electron discrimination

Single and double electron discrimination g

depletion of DB isotope

depletion of DB isotope

two different detector configurations two different detector configurations may be a choice(DB & DM/pp) may be a choice(DB & DM/pp)

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31

SLIDE 31

‘In Reality’ ‘In Reality’

Low BG Low BG PMT development PMT development

We have achieved two order of magnitude

two order of magnitude improvement for the last 5 years 5 years:

Low BG Low BG PMT development PMT development

improvement for the last 5 years 5 years:

(Primarily for DM search (Lq.Xenon)) U 180mBq Th 69mBq – U=180mBq, Th=69mBq

∼1mBq (including the base) 1mBq (including the base)

With 30 cm self‐shield (70% photo‐coverage) 10 10‐5∼10 10‐4 dru dru @2. @2. 47 47 MeV MeV 10 10 5 d @ 100k V @ 100k V <10 <10‐5 dru dru @ < 100keV @ < 100keV [close to : pp [close to : pp‐ν rquirement rquirement (10 (10‐

‐6 dru

dru)] )] But P But PMT cannot be used as a major device as it is But P But PMT cannot be used as a major device as it is for ‘Ultimte’ DB experiments (10‐8 dru) (Typical next DB: 100kg 10‐6∼10‐5)

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32

Further improvement is very challenging ! Further improvement is very challenging !

SLIDE 32

Choice of material and technology

tracking SSD Bolometer

136 136Xe

Xe

76 76Ge

Ge

48 48Ca

Ca

82 82Se

Se

100 100Mo

Mo Scintillator Doped Scintillator R i

Xe Xe

48 48Ca

Ca

96 96Zr

Zr

130 130Te

Te

150 150Nd

Nd

116 116Cd

Cd

Doped‐Scintillator Requirements:

Good energy resolution, Enrichment, Reduce BG (U/Th, γ, neutrons), Particle Id (e, 2e, γ, α,

10ton 10ton 10 10−9

9∼−8 8 dru

dru @ a few @ a few MeV MeV

NR), Reduce Cosmogenic BG, Good Vertex Reconstruction, Material purification, less PMTs, Inexpensive, Availability

First, I thought I would say my preference, but

What is your choice?

@ a few @ a few MeV MeV

+

I have decided not to mention that.

10 10‐6 dru dru @ <500keV @ <500keV

Many Many Many Many technical challenges ! technical challenges !

2008/5/30

Y. Suzuki @NEUTRINO2008, Christchurch, New Zealand

33 @ <500keV @ <500keV

y y g Get R&D started now Get R&D started now

SLIDE 33

Summary: Situation and What to do Summary: Situation and What to do

‘Ultimate Detectors’ (Multi

‘Ultimate Detectors’ (Multi‐Mt and DB) beyond the Mt and DB) beyond the next generation detectors will be next generation detectors will be the ‘only one’ the ‘only one’ experiment experiment in the world, and must have various in the world, and must have various

ther opportunities for including bread and butter
ther opportunities for including bread and butter

subjects subjects subjects subjects

Size of the detector

Size of the detector

Many technical challenges

Many technical challenges y g y g

Problems of the world economy

Problems of the world economy

– Increasing material price Increasing material price – sub sub‐prime problem prime problem sub sub prime problem prime problem

Head wind

Head wind

– Public Society wants innovation, not basic science Public Society wants innovation, not basic science

It t b t d b i l t It t b t d b i l t It cannot be supported by a single country It cannot be supported by a single country

MUST MUST be an International Collaboration be an International Collaboration S R&D i h S R&D i h Start R&D right away Start R&D right away

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Y. Suzuki @NEUTRINO2008, Christchurch, New Zealand

SLIDE 34

How we can establish the world wide ff f h ‘ l ’ efforts for the ‘only one’ experiment

Please do not make a political framework first Start R&D from bottom up 1) Exchange of information 2) Exchange of technology 2) Exchange of technology 3) Exchange of people (ex Exchange Program: Kamioka SNO) (ex. Exchange Program: Kamioka‐SNO) trust each other

ll f

l k can naturally form an international working group

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Y. Suzuki @NEUTRINO2008, Christchurch, New Zealand

35

SLIDE 35

Dream is power of progress Dream is power of progress Prepare for the future Prepare for the future

Thank you for your attention

2008/5/30

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Y. Suzuki @NEUTRINO2008, Christchurch, New Zealand