PINGU and JUNO synergy for mass ordering determination · PINGU and JUNO synergy for mass ordering...

Outline Introduction Synergy effects PINGU+JUNO Summary and conclusions

PINGU and JUNO synergy for mass orderingdetermination

Mattias [email protected]

August 21, 2013, NuFact 13, Beijing, ChinaBased on arXiv:1306.3988, MB and T. Schwetz

Mattias Blennow KTH Theoretical Physics

PINGU and JUNO synergy for mass ordering determination

mailto:[email protected]


http://theophys.kth.se//


1 Introduction

2 Synergy effects

3 PINGU+JUNO

4 Summary and conclusions







Neutrino status

Current parameter knowledge

The oscillation parameter statussin2 θ12 = 0.302 +0.013

−0.012

sin2 θ13 = 0.0227 +0.0023−0.0024

sin2 θ23 = 0.413 +0.037−0.025 / 0.594 +0.021

−0.022

∆m2

21/10−5 = 7.50 +0.18−0.19 eV

2

∆m231/10−3 = 2.473 +0.070

−0.067 eV2 (NH)

∆m232/10−3 = −2.427 +0.042

−0.065 eV2 (IH)

Gonzalez-Garcia, Maltoni, Salvado, Schwetz, arXiv:1209.3023

We will use (unless stated otherwise):

|∆m231| = 2.4 · 10−3 eV2 , ∆m2

21 = 7.59 · 10−5 eV2 ,

sin2 2θ13 = 0.09 , sin2 2θ23 = 1 , sin2 θ12 = 0.302 , δ = 0 .







Neutrino status

What is left?

The sign of ∆m231 (neutrino mass ordering)

The value of δ (CP violation)

The octant of θ23 (for non-maximal mixing)

I will concentrate on the first of these in this talk







How to measure the ordering (with oscillations)

Atmospherics

Several proposals exist

Indian NeutrinoObservatory (INO)

Hyper-Kamiokande

PINGU

Far detector forLBNE/LBNO

P(νµ → νµ) NO

cos(Θν)

log(

E/1

GeV

)

00.20.40.60.810

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

MB, Smirnov, arXiv:1306.2903








Atmospherics

Several proposals exist

Indian NeutrinoObservatory (INO)

Hyper-Kamiokande

PINGU

Far detector forLBNE/LBNO

P(ν̄µ → ν̄µ) NO

cos(Θν)

log(

E/1

GeV

)

00.20.40.60.810

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1









Long baseline experiments

295 km

109

1010

0

0.01

0.02

0.03

0.04

0.05

0.06

P µ e

109

1010

0

0.02

0.04

0.06

0.08

0.1

0.12

Eν [eV]

1010

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35


Must be long to givelarge matter effect

Compare withCP-violation, whichprefers shorter baseline

LBNE / LBNO

T2HK too short









810 km

109

1010

0

0.01

0.02

0.03

0.04

0.05

0.06

P µ e

109

1010

0

0.02

0.04

0.06

0.08

0.1

0.12

Eν [eV]

1010

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35




LBNE / LBNO

T2HK too short









7500 km

109

1010

0

0.01

0.02

0.03

0.04

0.05

0.06

P µ e

109

1010

0

0.02

0.04

0.06

0.08

0.1

0.12

Eν [eV]

1010

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35




LBNE / LBNO

T2HK too short








Reactors

Have been verysuccessful in determiningθ13

Proposals have longerbaseline

Aim to detect wiggles inhigh frequencyoscillations

JUNO (Daya Bay II)

RENO50

2 3 4 5 6 7 8

EΝ HMeVL

10

20

30

40

50

60

70

NΝHarb.unitsL

Petcov, Piai, hep-ph/0112074v2

WARNING: Huge ∆m221








What about synergy effects?

Experiments are studying different channels/energies/baselines

Sensitivity in different parts of parameter space

Will exclude different regions for the same true values

It may happen that only the combined fit excludes a specificordering







1 Introduction

2 Synergy effects

3 PINGU+JUNO








Fixed baselines

Two flavor approximations

Pαβ = sin2(2θαβ) sin2

(∆m2

αβL

4E

), Pαα = 1− sin2(2θαα) sin2

(∆m2

ααL4E

)What ∆m2

αβ should be inserted in the two-flavorapproximations?

Typically, we see ∆m2αβ ' ∆m2

31 ' ∆m232

What happens when we test the two-flavor formula in anexperiment with better resolution?







Fixed baselines

Looking at different channels

Based on the oscillation maximum:Nunokawa, Parke, Funchal, hep-ph/0503283

∆m2ee = c2

12∆m231 + s2

12∆m232

∆m2µµ = s2

12∆m231 + c2

12∆m232 + cδs13 sin(2θ12) tan(θ23)∆m2

21

∆m2ττ = s2

12∆m231 + c2

12∆m232 − cδs13 sin(2θ12) cot(θ23)∆m2

21

Atmospherics are trickier

Full spectrum of baselines and energiesCombination of channels







Fixed baselines

Reactors vs Long baselines

Idea has been around fora while

The effect is at the %level

Both experiments mustmeasure ∆m2

31 with highprecision

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04 0.045 0.05

sin2θ

13

∆eµ

%

NORMAL

INVERTED

Excl

ud

ed b

y C

HO

OZ

cosδ= 0

cosδ= 0

cosδ = -1

cosδ = 1

cosδ = -1

cosδ = 1

Nunokawa, Parke, Funchal, hep-ph/0503283







Fixed baselines

Reactors vs Long baselines

Idea has been around fora while

The effect is at the %level

Both experiments mustmeasure ∆m2

31 with highprecision 0

0.25

0.5

0.75

1

1.25

1.5

1.75

2

2.25

2.5

1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3

Confidence Level in σ

Pre

cisi

on

Req

uir

ed (

%)

sin2θ

13 = 0.04

sin2θ

13 = 0.005

σee

= σµµ

90

% C

L

95

% C

L

Nunokawa, Parke, Funchal, hep-ph/0503283







Fixed baselines

Atmospherics

2.3 2.35 2.4 2.45 2.5

x 10−3

0

5

10

15

20

25

|∆m2| [eV

2]

∆χ

2

MB, Schwetz, arXiv:1306.3988

More complicateddependence

BaselineEnergyResolutions

∆m221 = 0, still a

difference

Simulated|∆m2| = 2.4 · 10−3 eV2

← inverted, → normaltrue ordering







1 Introduction

2 Synergy effects

3 PINGU+JUNO








Assumptions

PINGU

Muon reconstruction:

Assume no knowledge onthe hadronic part

Just reconstruct the muonenergy and direction

See also Franco et al,arXiv:1301.4332

Neutrino reconstruction:

Assume hadronic shower canhelp neutrino reconstruction

Do the analysis in thereconstructed neutrinoparameters

σEµ σθµ σEν σθνLow 0.15Eµ 10◦ 2 GeV

√1 GeV/Eν

High 0 0 0.2Eν 0.5√

1 GeV/Eν







Assumptions

PINGU results (muon parameters)

0 2 4 6 8 100

10

20

30

40

50

Running time [years]

χ2

True NH

Perfect, Incl syst

Perfect, No syst

0.15Eµ, 10

o, Incl syst

0.15Eµ, 10

o, No syst








Assumptions

JUNO

Assumptions:

Point-like source at 58 km

Different assumptions onenergy resolution

Normalized to 105 events for6 years running(4320 kt GW year)

0 1000 2000 3000 4000 5000Exposure [kt GW yr]

0

10

20

30

40

50

∆χ

2

2%

2.6%

3%

3.5%








Results

PINGU dependence on assumptions (ν reconstruction)

2.3 2.35 2.4 2.45 2.5

x 10−3

0

5

10

15

20

25

|∆m2| [eV

2]

∆χ

2


Thin: High, Thick: Low

Red: w syst, Black: w/osyst

Solid: fixed, Dash: free

← inverted, → normaltrue ordering

Shape mainly dependent on resolutions







Results

Synergy results

PINGU: 1 year (High ν, no syst), JUNO: 1000 kt GW year

-0.0025 -0.0024 -0.0023 -0.0022 -0.0021

∆m2

31 [eV

2]

0

10

20

30

40

50

∆χ

2

PIN

GU

Day

a Bay

II

com

bin

ed

T2K

0.0022 0.0023 0.0024 0.0025 0.0026

∆m2

31 [eV

2]

0

10

20

30

40

50

∆χ

2

PING

U

Day

a Bay

II

com

bin

ed

T2K








Results

Mass squared precision

PINGU: 1 year (no syst), JUNO: 1000 kt GW year

0

2

4

6

8

∆χ

2

1 2 3 4PINGU angular resolution [rad]

2.2

2.25

2.3

2.35

2.4

|∆m

2 31|

[1

0-3

eV

2]

0.03 0.04 0.05 0.06

Daya Bay II energy resolution

2.2

2.25

2.3

2.35

2.4

|∆m

2 31|

[1

0-3

eV

2]

Daya Bay II

PINGU

Daya Bay II

PINGU

0

2

4

6

8

∆χ

2

20 30 40 50 60PINGU energy resolution [%]

2.2

2.25

2.3

2.35

2.4

|∆m

2 31|

[1

0-3

eV

2]

0.03 0.04 0.05 0.06

Daya Bay II energy resolution

2.2

2.25

2.3

2.35

2.4

|∆m

2 31|

[1

0-3

eV

2]

Daya Bay II

PINGU

Daya Bay II

PINGU








1 Introduction

2 Synergy effects

3 PINGU+JUNO








Summary and conclusions

The neutrino mass ordering is one of the remaining unknownsin neutrino oscillations

Synergies in different types of experiments may significantlyincrease global sensitivity

Atmospherics and reactors provide the most separatedbest-fits in the wrong ordering

Crucially dependent on resolution for ∆m2






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