PINGU: a vision for neutrino and particle physics at the South Pole

Abstract

The Precision IceCube Next Generation Upgrade (PINGU) is a proposed low-energy in-fill extension to the IceCube Neutrino Observatory. With detection technology modeled closely on the successful IceCube example, PINGU will provide a 6 Mton effective mass for neutrino detection with an energy threshold of a few GeV. With an unprecedented sample of over 60 000 atmospheric neutrinos per year in this energy range, PINGU will make highly competitive measurements of neutrino oscillation parameters in an energy range over an order of magnitude higher than long-baseline neutrino beam experiments. PINGU will measure the mixing parameters and , including the octant of for a wide range of values, and determine the neutrino mass ordering at median significance within five years of operation. PINGU’s high precision measurement of the rate of appearance will provide essential tests of the unitarity of the 3 × 3 PMNS neutrino mixing matrix. PINGU will also improve the sensitivity of searches for low mass dark matter in the Sun, use neutrino tomography to directly probe the composition of the Earth’s core, and improve IceCube’s sensitivity to neutrinos from Galactic supernovae. Reoptimization of the PINGU design has permitted substantial reduction in both cost and logistical requirements while delivering performance nearly identical to configurations previously studied.

Probing particle physics with IceCube

“…Proposed future extensions of IceCube will enhance the sensitivity of these searches [369]. A low-energy in-fill, such as PINGU [370], would provide highly competitive measurements of the atmospheric neutrino oscillation parameters, the neutrino mass ordering, or the rate of tau neutrino appearance. It would also be more sensitive to indirect signals of lowmass dark matter.…”

WIMP dark matter candidates and searches—current status and future prospects

“…Experiments and anomalies Neutrino telescopes (for review see, e.g., [412]) can be divided into two main categories: muon counters (BAKSAN [413]) and water Cherenkov detectors (ANTARES, IceCube, SuperK). 14 The latter technology will also be used in planned neutrino telescopes, e.g., BAIKAL-GVD [416], IceCube-PINGU [417], HyperK [418] and KM3Net [419]. The most important background in searches for DM-induced neutrinos originates from neutrinos produced in scatterings off cosmic rays in the Earth's atmosphere [420].…”

Current unknowns in the three-neutrino framework

“…The renewed interest in these issues is testified by recent dedicated atmospheric ν workshops [180,181], in addition to traditional series with broader scope [182,183]. Such topics will become even more crucial in the future, to make the best possible use of high-statistics data coming from new-generation projects [184] such as PINGU [185,186], KM3NeT-ORCA [187], Hyper-Kamiokande [188] and INO [189].…”

“…A wise attitude is to wait for further data from all the running experiments which, in the the next few years, can reveal if these two hints at ∼ 2σ level will fluctuate down, or will consistently grow and confirm the preference for NO at a cumulative level > 3σ. On a longer time frame, discovery-level tests of the mass spectrum ordering will be provided by next-generation projects [41], not only with large-volume atmospheric neutrinos [186,187,188,189] but also with medium-baseline reactors such as JUNO [190] and new long-baseline accelerator facilities such as T2HK [191], DUNE [192] and ESSnuSB [193]. Finally, for discrete hypotheses like NO versus IO, the statistical interpretation of ∆χ 2 in terms of N σ remains effectively applicable, but must be taken with a grain of salt [194].…”