[Paper Review] Letter of Intent: The Precision IceCube Next Generation Upgrade (PINGU)

M. G. Aartsen, N. van Eijndhoven+303 more|arXiv (Cornell University)|Jan 9, 2014

Astrophysics and Cosmic Phenomena164 references119 citations

TL;DR

PINGU proposes a low-energy in-fill array for IceCube to enhance sensitivity to neutrino oscillation physics at a few GeV energies. With increased module density, it will achieve 3σ sensitivity to neutrino mass ordering in under 4 years, enable precise PMNS matrix unitarity tests, and probe Earth's core composition via neutrino tomography.

ABSTRACT

The Precision IceCube Next Generation Upgrade (PINGU) is a proposed low-energy in-fill array of the IceCube Neutrino Observatory. Leveraging technology proven with IceCube, PINGU will feature the world's largest effective volume for neutrinos at an energy threshold of a few GeV, improving the sensitivity to several aspects of neutrino oscillation physics at modest cost. With its unprecedented statistical sample of low-energy atmospheric neutrinos, PINGU will have highly competitive sensitivity to $ u_{\mu}$ disappearance, the $ heta_{23}$ octant, and maximal mixing, will make the world's best $ u_{ au}$ appearance measurement, allowing a unique probe of the unitarity of the PMNS mixing matrix, and will be able to distinguish the neutrino mass ordering at $3\sigma$ significance with less than 4 years of data. PINGU can also extend the indirect search for solar WIMP dark matter complimentary to the on-going and planned direct dark matter experiments. At the lower end of the energy range, PINGU may use neutrino tomography to directly probe the composition of the Earth's core. With its increased module density, PINGU will improve IceCube's sensitivity to galactic supernova neutrino bursts and enable it to extract the neutrino energy spectral shape.

Motivation & Objective

• Address the need for improved sensitivity to low-energy atmospheric neutrinos to study neutrino oscillation parameters.
• Determine the neutrino mass ordering with high significance using a compact, cost-effective upgrade.
• Enable precise measurements of PMNS matrix unitarity and the $\theta_{23}$ octant.
• Extend indirect searches for solar WIMP dark matter complementary to direct detection experiments.
• Use neutrino tomography to probe the composition of Earth's core at low energies.

Proposed method

• Deploy a dense array of low-energy neutrino detection modules within the existing IceCube detector volume.
• Leverage proven IceCube technology to ensure reliability and reduce development costs.
• Utilize the large effective volume for low-energy neutrinos (a few GeV) to enhance statistical power.
• Apply advanced reconstruction techniques to extract energy spectral shapes from galactic supernova neutrino bursts.
• Use directional and energy-dependent neutrino absorption to infer Earth's core composition via neutrino tomography.
• Implement long-term data collection to achieve 3σ significance in distinguishing neutrino mass ordering.

Experimental results

Research questions

• RQ1 Can PINGU achieve 3σ sensitivity to the neutrino mass ordering with less than 4 years of data?
• RQ2 What is the precision of PINGU's measurement of $\theta_{23}$ octant and maximal mixing?
• RQ3 How accurately can PINGU probe the unitarity of the PMNS mixing matrix via $\nu_\tau$ appearance?
• RQ4 To what extent can PINGU extend the indirect search for solar WIMP dark matter?
• RQ5 Can neutrino tomography using PINGU reveal the composition of Earth's core?

Key findings

• PINGU will achieve 3σ significance in distinguishing the neutrino mass ordering with less than 4 years of data.
• The experiment will provide the world's best measurement of $\nu_\tau$ appearance, enabling a unique test of PMNS matrix unitarity.
• PINGU will have highly competitive sensitivity to $\nu_\mu$ disappearance and $\theta_{23}$ octant determination.
• The increased module density will significantly improve sensitivity to galactic supernova neutrino bursts and allow extraction of the neutrino energy spectral shape.
• At low energies, PINGU can use neutrino tomography to directly probe the composition of Earth's core.
• The upgrade will extend the indirect search for solar WIMP dark matter, complementing ongoing and planned direct detection experiments.