Studies on PINGU’s Sensitivity to the Neutrino mass Hierarchy P. Berghaus, H.P. Bretz, A. Groß, A. Kappes, J. Leute, S. Odrowski, E. Resconi, R. Shanidze

Studies on PINGU’s Sensitivity to the Neutrino mass Hierarchy

P. Berghaus, H.P. Bretz, A. Groß, A. Kappes, J. Leute,S. Odrowski, E. Resconi, R. Shanidze

DPG-FrühjahrstagungDresden, March 7, 2013

2Alexander Kappes | DPG-Frühjahrstagung, Dresden | 07.03.2013 |

The IceCube neutrino observatory

Completed since Dec. 2010

‣IceTopAir shower detector

‣IceCube86 strings (5160 PMTs)Instrumented volume: 1 km3

‣Deep Coredensely instrumentedcentral region (8 strings)

-1450 m

-2450 m


DeepCore experience

Veto atmospheric muons

‣Containment cuts → reduction by 103‑4

(signal efficiency 10‑20%)

‣Further improvements can be expected

Reconstruct low-energy events (direction, energy)

‣Measurement of Δm2 and sin2(2θ)

‣Energy information not used yet

‣Significant improvements expected(systematics crucial)

cut level

Example: IC79 DeepCore study


From IceCube via DeepCore to PINGU

IceCube (1 GTon)

DeepCore O(10-100)

MTon

PINGU O(1-10) MTon

E. Resconi

IceCubeInstrumented volume: 1 Gt

Average DOM density: 5×10‑6 m‑3

Target energy: 100 GeV≳

DeepCoreInstrumented volume: 10‑100 Mt

Average DOM density: 20×10‑6 m‑3

Target energy: 10 GeV ‑ 100 GeV

PINGUInstrumented volume: 1‑10 Mt

Average DOM density: > 200×10‑6 m‑3

Target energy: 1 GeV ‑ 20 GeV

PINGU talks at DPG:Mo T109.7 OM developmentMi T89.8,T89.9 Oscillations / matter effectsDo T104.5 Reconstruction


PINGU

What is PINGU?

‣Precision IceCube Next Generation Upgrade

‣20+ additional strings with 60-100 DOMs each in lower detector center

Preliminary timeline

2013 2014 2015 2017 2018 2019 20202016

Proposal tofunding agencies

design, manufacture and test hardware

drill preparations

first deployment

finish deployment(20 strings)

first set of cables/DOMsshipped to Pole

start data taking

Height 300 m


PINGU: Hardware

Minimize cost and risk

‣Reduce (50%) power consumption for each single PINGU-DOM

‣Parts kept: sphere, penetrator, PMT, collar, gel, harness, HV generator and base, quad cable technology

‣Parts under new development: digitizer (ADC), mother board, flasher (LED), FPGA logic, power supply

‣Upgrade: DAQ, down-hole cable, surface electronics

Cost reduction ~30% compared to IceCube

also other ideas for future detectors under development → T109.7 (Mo.) L. Classen


PINGU: Hardware

charg

e r

ati

o

scattering coefficient [1/m]

H.P. Bretzpreliminary

0.015 m-1


PINGU: Physics topics

‣Precision measurement of oscillation parameters (sin θ23, Δm232)

(→ T89.8 Wed. K. Frings)

‣Neutrino mass hierarchy → this talk

‣Low-mass WIMPs

‣MeV neutrinos from Galactic supernovae


Neutrino Oscillations: The MSW effect

‣Electron neutrinos: Modification of oscillation parameters while traveling through matter

‣For two neutrino mixing:

atomic shell

e‑

e‑

W

νe

νe e‑ e‑

W‑

νeνe

Neutrino Anti-Neutrino

electrondensity

sign ≙ mass hierarchy


PINGU: Mass hierarchy

Note: only neutrinos here

NH

IH


PINGU: Mass hierarchy

Note: neutrino telescopes inherently insensitive to ν ↔ ν

Perfect resolutionΔN(IH‑NH) / √N(NH) [PINGU 1 yr]

Akhmedov et al., arXiv:1205.7071


PINGU: Sensitivity to mass hierarchy

Significance crucially depends on ‣selection efficiency‣zenith / energy resolution (→ talk R. Shanidze)‣systematic uncertainties

Akhmedov et al., arXiv:1205.7071


PINGU: Mass hierarchy ‑ systematic uncertainties

ExternalExternal PINGU specificPINGU specific

Primary CR flux(AMS, BESS, …)

M. Sajjad Athar, M. Honda et al., http://arxiv.org/abs/1210.5154

DOM efficiencyimproved in-situ

calibrations

Geomagnetic field, interaction model


Ice optical propertiesdrill water purification,

improved in-situ calibration

Atmospheric neutrinos zenith, energy,

composition


Background contamination

improved reconstruction

Earth Profile (PREM, …) under study(→ T 89.9 (Wed) S. Coenders)

Neutrino Interaction cross section

starting with GENIEunder study

Mixing parameters degeneracies


Summary

‣DeepCore has demonstrated IceCube’s low-energy (10th GeV range) capabilities

‣PINGU aims at lowering the energy threshold to ~1 GeV → prime target: neutrino mass hierarchy

‣Working hard on overcoming challenges: reconstruction, systematic uncertainties, degeneracies with other oscillation parameters

‣Availability of full sensitivity / feasibility study planned for this Summer

Documents

Studies on PINGU’s Sensitivity to the Neutrino mass Hierarchy P. Berghaus, H.P. Bretz, A. Groß, A. Kappes, J. Leute, S. Odrowski, E. Resconi, R. Shanidze