Marek Kowalsky: the PINGU Experiment
The concept of Pingu is to try and study low-energy spectrum of neutrinos
by moving closer together the strings of IceCube. The threshold one could
achieve in neutrino events is of 1 GeV. DeepCore is already being built,
with 6 strings added to the IceCube array, with a threshold of 10 GeV,
and O(10^5) atmospheric neutrino triggers per year. Pingu can use
the surrounding detector layers as an active veto.
The science potential of Pingu spans the study of the neutrino mass hierarchy, a precise measurement of oscillation parameters in the 2-3 sector, and an earth density profile measurement. The experiment can also do indirect WIMP searches, and neutrino astrophysics, such as searches for Gamma-Ray Bursts, and core-collapse supernovae.
The data sample collected by DeepCore in 2010-2011 has energies of few tens of GeV, and they can extract oscillation parameters in the low-energy sample. They measure a 90% cl region in the sin^2(2 theta) vs dm^2 plane which is just a bit wider than others, but this is based only on one year of data.
The Pingu geometry is still being adjusted to optimize it to the many goals they want to reach. Adding 20 strings with tighter spacing to IceCube and DeepCore strings they can reach to lower energy for neutrino events.
They have been studying the angular and energy resolution, and the flavour ID capabilities of the detector. The speaker showed a sensitivity plot where there is good reach to discriminate the mass hierarchy.
As for WIMPS, there has been considerable interest in the last few years on the low-energy part of the mass spectrum. The limits on the spin-dependent cross sections with Pingu will exceed those of PICASSO and COUPP, going more than one order of magnitude lower in cross sections in a wide range of WIMP masses.