Status of the PINGU Detector - TAUP Conference · • PINGU is an integral part of the IceCube-Gen2 observatory to enhance the existing IceCube/ DeepCore programme • PINGU will

Status of the PINGU DetectorStefan Söldner-Rembold, University of Manchester

for the IceCube/PINGU Collaboration

TAUP - International Conference on Topics in Astroparticle and Underground Physics, Torino, Italy, 7-11 September 2015

TAUP 2015 - S Söldner-Rembold 2

TAUP 2015 - S Söldner-Rembold

The IceCube Neutrino Telescope

3

Digital Optical Module


IceCube/DeepCore

4


IceCube

5

• 78 Strings

• 125m string spacing

• 17m DOM spacing

• Add 8 strings


• 7m DOM spacing

• Add 20 strings


• 5m DOM spacing10 TeV 1 EeV1 TeV100 GeV10 GeV1 GeV100 MeV10 MeV

IceCube


IceCube

6

• 78 Strings


• 17m DOM spacing

• Add 8 strings


• 7m DOM spacing

• Add 20 strings



IceCube


IceCube

7

• 78 Strings


• 17m DOM spacing

• Add 8 strings


• 7m DOM spacing

• Add 20 strings



IceCube

125m


IceCube + DeepCore

• 78 Strings


• 17m DOM spacing

• Add 8 strings


• 7m DOM spacing

• Add 20 strings


• 5m DOM spacing

8

10 TeV 1 EeV1 TeV100 GeV10 GeV1 GeV100 MeV10 MeV

DeepCore IceCube

125m

75m


• 78 Strings


• 17m DOM spacing

• Add 8 strings


• 7m DOM spacing

• Add 40 strings


• 3m DOM spacing

IceCube + DeepCore + PINGU

22m

10 TeV 1 EeV1 TeV100 GeV10 GeV1 GeV100 MeV10 MeV

DeepCorePINGU IceCube

75m

125m


Neutrino Mass Hierarchy/Ordering

Knowledge of mass hierarchy has implications for

- Neutrino mass determinations - Neutrinoless double-β decay - CP violation searches


Mass Hierarchy Determination• Exploit the difference in oscillation probability for ν and anti-ν

• Combine with differences in ν and ν cross-section, flux

11

11

22


Neutrino Oscillograms

σ(νN) ≈ 2 σ(νN) Φ(νN) ≈ 1.3 Φ(νN) Patterns are therefore different even after addition.

12

νμ IH

νμ NHνμ NH

νμ IH

+

+

Probabilities


• Sum of νμ and νμ

• Expect after cuts:

- 50k/year for νμ +νμ

- 38k/year for νe +νe

• Reconstruction and particle identification not included here



• Sum of νμ and νμ

• Expect after cuts:

- 50k/year for νμ +νμ

- 38k/year for νe +νe

• Reconstruction and particle identification not included here



Resolutions, Particle ID

CC νμ correctly identified with an efficiency of 80% (E >10 GeV)

15

Muons:

True neutrino Energy (GeV)0 5 10 15 20 25 30

)° Z

enith

(ν

Res

olut

ion

on

0102030405060708090

(Run 215, v15)µνSample:

0

200

400

600

800

1000

1200

1400

1600

1800

2000

2200

Red line is median

(Run 215, v15)µνSample:


Event Signatures

16

Time

Early Late

CC Muon Neutrino νμ + N μ + X

“Track”

NC Neutrino νX + X νX + X

“Cascade”

high-energy eventsreconstruct energies and angles, PID


Mass Hierarchy Determination

• Difference in counts between hierarchies illustrate discrimination power.

• Background rejection criteria not included, but includes reconstruction/PID.

17

Cascade-Like Events Track-Like Events

PRELIMINARY PRELIMINARY


Analysis MethodsCurrently studying two methods: Log Likelihood Ratio (more CPU intensive)

• uses Monte Carlo pseudo-data to construct a distribution of the test statistic

Δχ2 pull method (less CPU intensive) • use error propagation for linear

parameters, scan the non-linear ones • analytically minimize the test statistic

18


• Oscillation Parameters (based on nu-fit values [1])

- dominant uncertainties (no priors): θ23, Δm231

• Detector/Flux/Cross Sections

- normalisation (no prior) - energy scale (10%) - νe/νμ ratio (3%) [2] - ν/anti-ν ratio (10%) [2.3] - atmospheric flux spectral index (3%) [2] - cross section [3] and detailed atmospheric flux uncertainties [2] using fast methods.

[1] M.C Gonzales-Garcia et al., JHEP 1411:052, 2014 [2] G.D. Barr et al., Phys. Rev. D74:094009, 2006 [3] C. Andreopoulos et al., Nucl. Instrum. Meth.A614:87-104, 2010

19

Systematic Uncertainties


The Bottom Line

20

PRELIMINARY


Systematic Effects• Investigate the most

significant systematics • Oscillation parameters

have the largest effect, primarily θ23

• DeepCore serves as ‘prototype’ to validate analysis methods (see talk by J.-P. Athayde Marcondes de André)

21

PRELIMINARY

Type 3-year σ (NMH)

3-year σ (IMH)

Statistical only 4.84 4.82

Flux only 4.55 4.56

Detector only 4.06 3.99

θ23 only 3.52 3.26

Oscillation only

2.96 2.53

All 2.8 2.54


Octant Dependance

Strong dependence of sensitivity on octant.

Current sensitivity close to ‘worst case’.


43

IceCube 2014 [NH]T2K 2014 [NH] - With SystematicsT2K 2014 [NH] - No SystematicsPINGU [NH] 3year - Best FitPINGU [NH] 3 year - Maximal Mixing3.0

3.5

2.5

0.302.0

0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70

sin2(θ23)

|∆m

2 31|[10

−3eV

2]

PRELIMINARY

IceCube 2014

Normal mass ordering assumed, 90% CL contours

PINGU 3 year, Fogli 2012 global inputs

PINGU 3 year, NuFit 2014 global inputs

PINGU 3 year, maximal mixing

IceCube 2015 (3-year DeepCore - projected*)

*does not yet include full systematic uncertainties

Other Analyses

23

PRELIMINARY

PRELIMINARY

Dark Matter

Mixing

Tau-neutrinoAppearance

+ Earth Tomography


Outlook• PINGU is an integral part of the IceCube-Gen2

observatory to enhance the existing IceCube/DeepCore programme

• PINGU will be the first deployed of the new strings • Data taking could start 4-5 years following approval • Revised LoI available soon (currently at arXiv:

1412.5106)

24


Conclusion

• IceCube and DeepCore have successfully demonstrated that particle physics is possible in ice.

• PINGU will provide insight into the nature of the NMH and measure oscillation parameters.

25


BACK UP

26


Events per Year

27

PRELIMINARY PRELIMINARY


Future of the NMH Measurement• MANY caveats

• median outcome shown

• width indicates effect of main uncertainty (δCP, θ23)

• dates are also bound to change as time goes on



29

IceCube

DeepCore

PINGU

Skiway

South Pole Station


Atmospheric Neutrinos

• Source of neutrinos is the interaction of particles in the atmosphere

• These interactions produce neutrinos with an understood flux and flavour content

30



31

IceCube

DeepCore

Skiway

South Pole Station

Documents

Status of the PINGU Detector - TAUP Conference · • PINGU is an integral part of the IceCube-Gen2 observatory to enhance the existing IceCube/ DeepCore programme • PINGU will